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Abstract

Background

Hip fractures in older adults are associated with significant morbidity and mortality. Nocturia is a common but under-recognized symptom in this population and may contribute to increased nighttime fall risk. This study aimed to examine the relationship between nocturia severity and nighttime falls among older adults with hip fractures and to evaluate associated clinical and biochemical factors.

Methods

This retrospective observational study included 491 patients aged ≥55 years who underwent surgery for hip fractures between 2019 and 2024. Data were obtained from medical records and a structured questionnaire administered prior to hospital discharge or during follow-up. Patients were categorized into three nocturia groups: none, moderate (1 void/night), and severe (≥2 voids/night). Demographic, clinical, and laboratory parameters (including electrolytes and renal function) were analyzed. Univariate comparisons and multivariate logistic regression were performed to identify independent factors associated with nighttime falls.

Results

Overall, 76.8% of patients reported at least one nocturnal void, and 44.2% had severe nocturia. Nighttime fall incidence increased with nocturia severity (20.4% in the non-nocturia group, 37.3% in moderate, and 40.6% in severe; P < .001). In multivariate analysis, male sex (OR = 1.56, 95% CI: 1.04-2.35), lower serum potassium (OR = 0.58, 95% CI: 0.36-0.94), moderate nocturia (OR = 3.17, 95% CI: 1.70-5.93), severe nocturia (OR = 3.94, 95% CI: 2.21-7.04), and lower serum calcium (OR = 0.65, 95% CI: 0.45-0.93) were independently associated with nighttime falls. Age, renal function, and serum sodium were not significant factors.

Conclusions

Nocturia, particularly at moderate and severe levels, is independently associated with nighttime falls in older adults with hip fractures. Male sex and mild disturbances in potassium and calcium were also associated with the occurrence of nighttime falls. Our results highlight the importance of incorporating nocturia assessment and basic biochemical screening into comprehensive fall-risk evaluation and prevention strategies in geriatric orthopedic care.

Keywords

nocturia nighttime falls hip fracture older adults potassium calcium risk factors

Introduction

Nocturia is one of the most common lower urinary tract symptoms in older adults and has a significant impact on quality of life. Awakening at night to urinate may lead to impaired balance and reduced attention, thereby increasing the risk of falls. The literature demonstrates a significant association between nocturia and falls, particularly hip fractures.^1,2 There is growing evidence that nocturia is not only a urological concern but also a condition with orthopedic consequences.^3,4 Moreover, when evaluated alongside other systemic risk factors in older individuals, nocturia has been shown to contribute to fall-related injuries.^5,6 For these reasons, nocturia should be regarded as a clinically relevant symptom that must not be overlooked in the geriatric population.

However, most studies investigating the relationship between nocturia and hip fractures are based on observational or retrospective designs. While these studies often examine comorbid conditions collectively, they frequently fall short in determining whether nocturia acts as an independent risk factor. Furthermore, existing data are largely derived from Western Europe and North America, highlighting a lack of comprehensive analyses that include cultural, demographic, or socioeconomic variables.⁷ In contrast to Western cohorts, regional differences in nocturia prevalence and fall patterns have been observed in Asian and Middle Eastern populations, suggesting that sociocultural factors such as housing structure, lighting, and nocturnal toileting habits may influence nighttime mobility and safety.⁸ Given these differences, data from Türkiye can provide valuable insights into how lifestyle and environmental characteristics affect fall mechanisms in older adults.⁹ The role of nocturia in fall-related fractures is often underrepresented in broad assessment tools, and its use as a clinical risk marker remains limited in everyday practice. This limitation complicates the development of universally applicable and clinically meaningful conclusions.

This study aims to systematically and specifically analyze the relationship between nocturia and hip fractures in individuals aged 55 and older, in order to determine whether nocturia may serve as a potentially preventable risk factor. Nocturia is often overlooked in older adults; however, when properly addressed, it may represent a modifiable marker that could reduce the risk of falls. If a significant association is established in this study, nocturia could emerge as a clinical warning parameter that should be integrated into both diagnostic algorithms and public health strategies. In this regard, the research not only contributes to academic literature but also holds the potential to enhance the safety and quality of life of older individuals.

Materials and Methods

This retrospective, descriptive observational study was conducted between January 2019 and September 2024 at a tertiary care center. Patients aged 55 years or older who underwent surgery for hip fractures were included in the study. Prior to initiation of the study, ethical approval was obtained from the institutional Clinical Research Ethics Committee. All study procedures were conducted in accordance with the principles outlined in the Declaration of Helsinki.

Following the approval of the ethics committee, patient records were reviewed, and individuals meeting the inclusion criteria were enrolled in the study. Inclusion criteria were as follows: being 55 years of age or older, having undergone surgical treatment for a hip fracture due to low-energy trauma (such as a simple fall), having routine laboratory data available from medical records, and having completed a structured questionnaire without missing data.

Exclusion criteria included: being under the age of 55; hip fractures caused by high-energy trauma (eg, motor vehicle accidents, falls from height); isolated fractures of the vertebrae or non-hip bones; pathological fractures secondary to malignancy; active neurological disorders (eg, Parkinson’s disease, epilepsy); a diagnosis of dementia or severe cognitive impairment; a history of active psychiatric illness (eg, schizophrenia, bipolar disorder, major depression); current use of central nervous system–acting medications (eg, anticholinergics, sedatives); recent changes in diuretic dosage; incomplete questionnaire data; or unavailability of biochemical laboratory records.

Data collection was carried out using both patient medical records and structured questionnaires administered prior to hospital discharge, during outpatient follow-up visits, or via telephone interview in cases where in-person data were incomplete or unavailable. The structured questionnaire was adapted from previously published nocturia and fall-risk surveys and was pilot-tested in approximately 10% of the study population to ensure clarity and feasibility. All questionnaire items specifically referred to the pre-fracture period, and patients were asked to report their typical nocturia frequency and sleep patterns before the hip fracture occurred. Nighttime falls were defined as fracture-causing (index) falls that occurred between 10:00 p.m. and 6:00 a.m. Patients were specifically asked whether the fall that resulted in their hip fracture had occurred at night, and those who answered “yes” were classified as having sustained a nighttime fall. Through the questionnaire, structured items were used to assess variables including the presence of nighttime falls (yes/no), presence and frequency of nocturia, morning fatigue, daytime sleepiness, and time required to return to sleep after nighttime awakening. Information on patients’ balance, gait performance, and detailed medication history (eg, sedatives, antihypertensives, or diuretics) was not consistently available in hospital records and therefore was not included in the analysis. Written informed consent was obtained from all participants or their legal guardians prior to data collection, in accordance with the principles of the Declaration of Helsinki.

Nocturia was defined and categorized according to patients’ self-reported frequency of nighttime awakenings to urinate. In accordance with the definitions of the International Continence Society (ICS) and the classification frameworks proposed by Weiss and Van Doorn, nocturia was categorized as follows: “no nocturia” (no nighttime urination), “moderate nocturia” (urination once per night), and “severe nocturia” (urination two or more times per night). This classification was chosen to allow for a more clinically meaningful evaluation of the functional impact of nocturia.^10,11 Although some studies classify ≥3 nightly voids as severe nocturia, we used a ≥2 cutoff to ensure adequate sample size and statistical power across severity groups, consistent with prior geriatric research.^12,13

In addition to questionnaire data, laboratory parameters obtained from patients’ clinical records were analyzed. Preoperative laboratory results obtained at the time of hospital admission, prior to surgical intervention, were reviewed. These parameters included serum sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), creatinine levels, and estimated glomerular filtration rates (eGFR). All laboratory measurements were obtained as part of routine clinical practice and were analyzed in the hospital’s central laboratory. In addition, a history of diuretic use and the presence of comorbid conditions—including hypertension, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and coronary artery disease—were recorded from patient files. For statistical analysis, comorbidities were coded as binary variables (yes/no).

Although it was not within the primary scope of this study, certain subjective parameters related to patients’ quality of life—including morning fatigue, daytime sleepiness, and time to return to sleep—were assessed based on patient self-reports. Morning fatigue and daytime sleepiness were recorded as binary responses (“yes” or “no”), while the time required to return to sleep after nighttime awakening was categorized as 0-10 min, 10-20 min, and 20-30 min. These data were collected through the structured questionnaire administered prior to hospital discharge.

Sample Size and Power Considerations

Because this was a retrospective study, no a priori sample size calculation was performed; all eligible patients during the study period were included (n = 491). A post-hoc sensitivity analysis was conducted to contextualize the detectable differences in nighttime fall incidence across nocturia strata using two-sided tests at α = .05. Based on the observed group sizes (no nocturia ≈23.2% [n ≈ 114], moderate ≈32.6% [n ≈ 160], severe ≈44.2% [n ≈ 217]) and observed nighttime-fall proportions (20.4%, 37.3%, and 40.6%, respectively), the study had approximately 97% power to detect the difference between no nocturia vs severe (20.4% vs 40.6%), ∼87% power for no nocturia vs moderate (20.4% vs 37.3%), but only ∼10% power for moderate vs severe (37.3% vs 40.6%). These figures indicate that the study was well powered to detect contrasts involving the no-nocturia group, while it had limited power to identify small differences between moderate and severe nocturia.

Statistical Analysis

Statistical analyses were performed using SPSS version 25.0 (IBM Corp., Armonk, NY, USA). Continuous variables were expressed as mean ± standard deviation, and categorical variables were presented as counts and percentages (%). The normality of distribution was assessed using the Shapiro–Wilk test. For comparisons between normally distributed variables, the independent samples t-test was used, while the Mann–Whitney U test was applied for non-normally distributed variables. The Chi-square test or Fisher’s exact test (where appropriate) was used to compare categorical variables. Correlations between nocturia and biochemical values or symptom-based parameters were evaluated using Pearson or Spearman correlation analysis, depending on the distribution of the data. A P-value of <.05 was considered statistically significant for all analyses.

Outcome Measures

The primary outcome measure was the occurrence of a nighttime fall (yes/no) leading to hip fracture. Secondary outcomes included nocturia frequency, morning fatigue, and daytime sleepiness.

This study was conducted and reported in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines.

Results

A total of 672 patients who underwent surgery for hip fractures were initially screened. Among the initially screened patients, 181 individuals who did not meet the eligibility criteria were excluded from the study. Specifically, 53 patients were under 55 years of age, 19 had sustained high-energy trauma (eg, motor vehicle accidents), 21 had incomplete clinical records, 68 were unable to complete the structured questionnaire due to cognitive or psychiatric impairment, 15 had active neurological conditions, and 5 had ongoing diuretic adjustments. Following exclusions, a total of 491 patients with hip fractures were included in the final analysis. Among the included participants, 293 were female (59.7%) and 198 were male (40.3%). The overall mean age was 74.5 years. There was no statistically significant difference in age distribution between sexes (P > .05). Among the 491 patients with hip fractures included in the study, 217 (44.2%) had severe nocturia (≥2 nighttime voids), 161 (32.8%) had moderate nocturia (1 nighttime void), and 113 (23.0%) reported no nocturia (Table 1).

Table 1.

Demographic Characteristics and Nocturia Distribution by Gender

	Female (%)	Male (%)	Total	P-value
Patient number	293 (59.7)	198 (40.3)	491
Age	73.4 ± 7.7	74.7 ± 7.9	73.9 ± 7.8	.056^a
Nocturia absent	57 (19.3)	56 (28.3)	113 (23.0)	.071^b
Moderate	102 (34.8)	59 (29.8)	161 (32.8)	.341^b
Severe	134 (45.7)	83 (41.9)	217 (44.2)	.533^b

Descriptive statistics were shown as * mean ± SD or ** median (min-max); where appropriate.

^aStudent’s t-test.

^bChi-square test.

The incidence of nighttime falls, morning fatigue, and daytime sleepiness significantly differed across nocturia severity groups (P < .001 for all; Table 2). Nighttime falls occurred in 20.4% of patients with no nocturia, 37.3% of those with moderate nocturia, and 40.6% of those with severe nocturia. Compared to the Nocturia Absent group, the incidence of nighttime falls was significantly higher in both the Moderate (P < .001) and Severe (P < .001) groups; no significant difference was observed between the Moderate and Severe groups (P = 1.000).

Table 2.

Incidence of Nighttime Falls, Morning Fatigue, and Daytime Sleepiness According to Nocturia Severity

Nocturia severity (n)	Nighttime falls (%)	Morning fatigue (%)	Daytime sleepiness (%)
Nocturia absent (113)	20.4%	57.5%	40.7%
Moderate nocturia (161)	37.3%	58.4%	57.1%
Severe nocturia (217)	40.6%	78.3%	72.8%
P-value	<.001^a	<.001^a	<.001^a

^aChi-square test.

Morning fatigue was reported by 57.5% of the Nocturia Absent group, 58.4% of the Moderate group, and 78.3% of the Severe group. The incidence of morning fatigue was significantly higher in the Severe Nocturia group compared to both the Nocturia Absent (P < .001) and Moderate (P < .001) groups, while no significant difference was found between the Nocturia Absent and Moderate groups (P = 1.000).

Daytime sleepiness was present in 40.7%, 57.1%, and 72.8% of patients in the Nocturia Absent, Moderate, and Severe groups, respectively. The incidence of daytime sleepiness was significantly higher in both the Moderate (P < .001) and Severe (P < .001) groups compared to the Nocturia Absent group, and also significantly higher in the Severe group compared to the Moderate group (P = .024).

According to multivariate logistic regression analysis, male sex (OR = 1.56; 95% CI: 1.04-2.35; P = .031), lower serum potassium levels (OR = 0.58; 95% CI: 0.36-0.94; P = .028), moderate nocturia (OR = 3.17; 95% CI: 1.70-5.93; P < .001), and severe nocturia (OR = 3.94; 95% CI: 2.21-7.04; P < .001) were independently associated with an increased risk of nighttime falls. This sex effect may be related to hormonal or prostatic factors influencing nocturia frequency, although further studies are required to clarify these mechanisms. Other variables, including age, serum sodium, serum calcium, creatinine, GFR, diuretic use, morning fatigue, and daytime sleepiness, were not significant predictors in the multivariate analysis (Table 3). The multivariate model demonstrated moderate discrimination for nighttime falls (AUC = 0.668; Figure 1), indicating limited predictive accuracy. Internal validation indicated stable model performance and acceptable calibration, supporting the robustness of these associations.

Table 3.

Multivariate Logistic Regression for Nighttime Falls

Variable	Odds ratio (OR)	95% CI	P-value
Age	0.98	0.96-1.01	.144
Gender (male)	1.56	1.04-2.35	.031
Severe nocturia	3.94	2.21-7.04	<.001
Moderate nocturia	3.17	1.70-5.93	<.001
Morning fatigue	0.96	0.62-1.49	.858
Daytime sleepiness	0.86	0.56-1.33	.511
Serum sodium (Na)	1.00	0.95-1.05	.978
Serum potassium (K)	0.58	0.36-0.94	.028
Serum calcium (Ca)	0.65	0.45-0.93	.020
Creatinine (mg/dL)	1.33	0.80-2.20	.266
eGFR (mL/min)	1.00	0.99-1.01	.936
Diuretic use	1.23	0.83-1.83	.307

Figure 1.

Receiver operating characteristic (ROC) curve for the multivariate logistic regression model predicting nighttime falls in patients with hip fractures

The age distribution did not significantly differ across nocturia severity groups (P = .765, Kruskal-Wallis test). Pairwise comparisons between nocturia groups revealed no significant differences in age (all Bonferroni-adjusted P > .05) (Figure 2).

Figure 2.

Distribution of age across nocturia severity groups in patients with hip fractures

The relationships between gender, serum sodium, serum potassium, and serum calcium with nocturia severity were evaluated. Univariate analyses demonstrated that only serum sodium levels significantly differed across nocturia severity groups. No significant differences were observed for gender, serum potassium, or serum calcium.

Pairwise comparisons revealed that serum sodium levels were significantly lower in patients with severe nocturia compared to both those with no nocturia and moderate nocturia. No significant pairwise differences were observed between the no and moderate nocturia groups. Additionally, there were no significant pairwise differences in gender distribution, serum potassium, or serum calcium levels between any of the nocturia severity groups (Table 4).

Table 4.

Univariate and Pairwise Comparisons of Gender, Serum Sodium, Serum Potassium, and Serum Calcium Across Nocturia Severity Groups

Variable	P-value	Pairwise comparison	P-value
Gender	.071^a	Nocturia absent vs moderate nocturia	1.000^a,d
		Nocturia absent vs severe nocturia	.273^a,d
		Moderate nocturia vs severe nocturia	.222^a,d
Serum sodium (Na⁺)	<.001^b	Nocturia absent vs moderate nocturia	.945^c,d
		Nocturia absent vs severe nocturia	<.001^c,d
		Moderate nocturia vs severe nocturia	<.001^c,d
Serum potassium (K⁺)	.975^b	Nocturia absent vs moderate nocturia	1.000^c,d
		Nocturia absent vs severe nocturia	1.000^c,d
		Moderate nocturia vs severe nocturia	1.000^c,d
Serum calcium (Ca²⁺)	.516^b	Nocturia absent vs moderate nocturia	1.000^c,d
		Nocturia absent vs severe nocturia	1.000^c,d
		Moderate nocturia vs severe nocturia	1.000^c,d

^aChi-square test.

^bKruskal-Wallis test.

^cMann-Whitney U test.

^dBonferroni-adjusted P-values.

Discussion

Nocturia is increasingly recognized as a significant symptom contributing to fall and fracture risk in older adults, with a growing body of research addressing this issue.¹⁴ However, in much of the existing literature, this association has been examined primarily in conjunction with comorbidities, often overlooking the independent effect of nocturia itself.

In our study, multivariate logistic regression analysis demonstrated that severe nocturia was independently associated with an increased risk of nighttime falls. Specifically, patients with severe nocturia had a nearly 3.94-fold higher risk of experiencing nighttime falls compared to those without nocturia. Similarly, those with moderate nocturia had a 3.17-fold increased risk. These findings support the notion that increasing nocturia severity is significantly associated with a greater risk of nighttime falls, which may contribute to serious outcomes such as hip fractures. It should be noted that, as this was a case-only study including patients already hospitalized for hip fractures, our findings do not indicate an increased overall risk of falls associated with nocturia but rather describe the temporal pattern (nighttime vs daytime) of the fracture-causing events.”

Nocturia is a prevalent and clinically significant symptom among older adults, known not only to impair quality of life but also to compromise physical safety. Recent literature suggests that nocturia is closely linked not merely with advancing age, but also with geriatric syndromes such as frailty and increased risk of falls. In a recent scoping review, Komleva et al reported that the prevalence of nocturia exceeds 60% in older adults, with substantially higher rates observed in individuals with impaired mobility and reduced functional capacity.¹⁵ Similarly, López-Soto et al emphasized that in patients with chronic kidney disease—a population particularly vulnerable to falls—nocturia often coexists with fall-related fractures, further underlining its role in adverse outcomes among the elderly.¹⁶ In our study cohort of 491 elderly patients hospitalized for hip fracture surgery, 76.8% reported at least one nocturnal void per night, and 44.2% met the criteria for severe nocturia (≥2 voids/night). These rates are considerably higher than those reported in general community-dwelling elderly populations. Our findings suggest that nocturia may act not only as a coexisting condition but also as a potential independent risk factor for falls and fall-related injuries, including hip fractures. Given its high prevalence and strong association with adverse events, nocturia should be systematically assessed during clinical evaluations, especially in populations at elevated risk for falls and fragility fractures. Recent geriatric research has demonstrated that urinary symptoms, including nocturia, are closely linked with frailty, sarcopenia, and reduced core muscle strength, supporting the concept that nocturia should be evaluated within a multidimensional geriatric framework.¹⁷

The association between nocturia severity and nighttime falls in older adults has been increasingly recognized in recent literature. Frequent nocturnal voiding disrupts sleep architecture, impairs postural stability upon awakening, and increases the likelihood of unsupervised ambulation in low-light conditions—each of which are well-established risk factors for nighttime falls. Ancoli-Israel et al emphasized that older adults with nocturia are particularly vulnerable to falls during nocturnal toileting due to impaired balance and sleep inertia.¹⁸ Furthermore, Bliwise et al reported that the risk of falls significantly increases in those with moderate to severe nocturia, highlighting its multifactorial role in reducing nighttime physical safety.¹⁹ In our study, a statistically significant association was observed between nocturia severity and the incidence of nighttime falls (P < .001). While only 20.4% of patients without nocturia experienced nighttime falls, this rate increased to 37.3% in patients with moderate nocturia and further to 40.6% in those with severe nocturia. The difference in fall incidence between the Nocturia Absent group and both nocturia-present groups was significant, although no difference was observed between the Moderate and Severe groups. These findings underscore the potential of nocturia as an independent correlate of nighttime falls, rather than a confirmed risk factor, and suggest that its influence extends beyond sleep quality alone. Preventive strategies aimed at improving nighttime safety in older adults—particularly those with even mild nocturia—may therefore merit consideration as part of a broader geriatric assessment framework, although this study alone does not establish that addressing nocturia directly reduces fall risk. However, it is also possible that both nocturia and nighttime falls reflect shared underlying vulnerabilities, such as frailty, polypharmacy, or impaired mobility, rather than a direct causal relationship. Future studies incorporating objective assessments of physical function and frailty are warranted to clarify these pathways.

From a clinical standpoint, several evidence-based strategies may help mitigate the impact of nocturia in older adults. Behavioral measures such as evening fluid management, limiting caffeine and alcohol intake, timed voiding before sleep, and optimizing bedroom lighting have been shown to reduce nocturnal awakenings. Identifying and treating reversible contributors such as poorly controlled diabetes, heart failure, or sleep disorders may also provide benefit. In selected patients, pharmacologic options—such as desmopressin or antimuscarinic agents—may be considered with careful assessment of comorbidities and electrolyte status. Although our study does not evaluate the effect of these interventions on fall prevention, integrating nocturia management into geriatric care could support broader efforts to enhance nighttime safety.²⁰

Sleep disruption caused by nocturia has been increasingly recognized as a driver of residual morning fatigue in older adults. A recent large-scale population-based study by Nonaka et al further supported these association, reporting that increased nocturnal voiding frequency was significantly associated with sleep disturbances and reduced sleep quality in older adults.²¹ Bower et al described nocturia-induced sleep fragmentation as a central mechanism leading to daytime tiredness, diminished psychomotor alertness, and functional impairment.²² Similarly, Dani et al emphasized that multiple nocturnal voiding episodes interfere with deep sleep phases, thereby reducing sleep efficiency and contributing to early-morning exhaustion and poor quality of life.²³ Consistent with these findings, the current investigation revealed a clear pattern linking nocturia severity with the prevalence of morning fatigue. Specifically, self-reported fatigue was observed in 57.5% of individuals with no nocturia, 58.4% of those with moderate nocturia, and sharply rose to 78.3% among those classified as having severe nocturia. Statistical comparisons confirmed that participants in the Severe group reported significantly higher rates of fatigue compared to both the Nocturia Absent and Moderate groups (P < .001), while the difference between the latter two was not significant (P = 1.000). This threshold-like effect suggests that only more severe nocturia meaningfully disrupts restorative sleep, supporting its potential role as a clinical marker for sleep-related fatigue burden.

Nocturia has been increasingly recognized as a contributor to impaired daytime alertness, particularly in older adults. Repeated nighttime awakenings fragment sleep architecture, reducing restorative deep sleep and leading to excessive daytime sleepiness. Dasari and Nagai reported that patients experiencing two or more nocturnal voids per night exhibited significantly higher levels of daytime drowsiness, attributed to disrupted sleep continuity and insufficient recovery during the night.²⁴ Likewise, Finsterer emphasized that nocturia, even in the absence of neurological disorders, independently contributes to reduced daytime vigilance by altering sleep quality.²⁵ Aligned with these findings, our analysis demonstrated a progressive increase in daytime sleepiness with rising nocturia severity: 40.7% in patients without nocturia, 57.1% in those with moderate nocturia, and 72.8% in the severe group. These differences were statistically significant across all comparisons (P < .001), including between the moderate and severe groups (P = .024). This pattern suggests a dose-dependent relationship, where more frequent nocturnal voiding leads to greater daytime impairment, further reinforcing the importance of identifying and managing nocturia as a clinically relevant sleep-related disorder.

Sex-based differences in fall risk among older adults remain a complex and evolving area of geriatric research. Although women are traditionally considered more vulnerable to falls due to postmenopausal osteoporosis and balance instability, recent studies have identified men as being at particular risk for nocturnal falls, often with more severe or traumatic consequences. Oda et al found that male sex was independently associated with nighttime falls in acute care settings, citing unassisted bed exits and nocturnal toileting as key contributors.²⁶ Similarly, Di Simone et al proposed that sex-specific differences in sleep quality and arousal thresholds may predispose older men to sudden awakenings and destabilization, increasing fall risk during the night.²⁷ In our study, multivariate logistic regression confirmed male sex as an independent risk factor for nighttime falls (OR = 1.56; 95% CI: 1.04-2.35; P = .031). This association aligns with recent literature and suggests that older men may require targeted fall prevention strategies. Clinical attention to behavioral patterns, nighttime mobility habits, and sleep fragmentation in male patients may help mitigate fall-related morbidity in this subgroup.

Hypokalemia, or reduced serum potassium levels, has been identified as a potential contributor to fall risk in older adults due to its impact on muscle strength, postural control, and neuromuscular conduction. Lin et al reported a case in which recurrent falls in an octogenarian patient were attributed to resistant hypokalemia, with fall episodes resolving after potassium repletion.²⁸ Additionally, Simal et al found that in elderly patients with multimorbidity, even mild potassium deficits—when combined with polypharmacy—were associated with an increased frequency of clinically relevant fall events.²⁹ Consistent with this evidence, our multivariate analysis identified low serum potassium as an independent predictor of nighttime falls (OR = 0.58; 95% CI: 0.36-0.94; P = .028). This association highlights the role of hypokalemia not merely as a secondary comorbidity but as a clinically actionable biochemical risk factor. In older adults, particular attention should be given to identifying and correcting potassium imbalances—whether due to diet, medication, or renal handling—as a key component of fall prevention strategies.

Although age, renal function, and serum creatinine are commonly reported as predictors of fall risk in the elderly, recent evidence highlights their inconsistent role when other factors are considered. In a comprehensive cross-sectional study, Magnuszewski et al found that neither age above 75, GFR, nor creatinine levels were independently associated with past-year falls in multivariate analysis, suggesting that these classical markers may lose predictive power in complex clinical scenarios.³⁰ Similarly, Tap et al, based on data from the European SCOPE study, reported that CKD and reduced eGFR did not predict falls when adjusted for polypharmacy, frailty, and functional impairments.³¹ In our model, age, serum creatinine, GFR, and other traditionally considered clinical predictors such as serum sodium, calcium, and diuretic use were not independently associated with nighttime falls. This finding aligns with recent literature, suggesting that fall risk in older adults may be more strongly driven by functional, behavioral, and symptom-based factors—such as nocturia—rather than by age or renal parameters alone.

Age is often assumed to be a major determinant of lower urinary tract symptoms (LUTS), including nocturia. However, recent evidence suggests that the relationship between age and nocturia severity may be less consistent than traditionally thought. Matsuo et al observed that although nocturia becomes more prevalent with age, its severity does not necessarily intensify in parallel, particularly in patients with comorbid urologic or neurological disorders.³² Similarly, Gao et al demonstrated that, after controlling for metabolic and lifestyle variables, age was not a significant predictor of severe nocturia in older adults.³³ In our cohort, the severity of nocturia showed no significant association with age. Age distribution did not differ across nocturia severity groups (P = .765, Kruskal-Wallis), and all pairwise comparisons were non-significant. These findings reinforce the view that nocturia severity may be better explained by functional or biochemical disruptions rather than chronological aging alone.

Electrolyte levels, particularly serum sodium and potassium, have been investigated in relation to nocturia and fall risk in elderly populations, yet their clinical relevance varies depending on the analytical approach. In a cross-sectional study of elderly men, Gourova et al reported that although certain electrolytes appeared to be associated with nocturia in univariate analyses, these associations often diminished in multivariate models when other confounding factors were considered. Their findings emphasized the importance of distinguishing between statistical correlation and independent predictive value, especially in multifactorial conditions like nocturia.³⁴ In our study, serum sodium levels were significantly lower in patients with severe nocturia compared to those with no or moderate nocturia in univariate analysis. This suggests a potential link between sodium imbalance and nocturia severity. However, serum potassium levels did not significantly differ between nocturia severity groups in the same analysis. Interestingly, in the multivariate logistic regression model for nighttime falls, low serum potassium emerged as an independent predictor, while sodium did not. This contrast highlights that certain biochemical associations may appear relevant when assessed alone but fail to retain significance when adjusted for coexisting clinical variables. Therefore, while serum sodium may reflect underlying conditions or fluid imbalance, serum potassium likely represents a more robust, independent contributor to nocturia-related fall risk in older adults.

This study has certain limitations. Its retrospective design relied on patient self-reports for nocturia and sleep-related variables, which may introduce recall bias and precludes establishing temporal or causal relationships between nocturia and nighttime falls. Although the questionnaire specifically referred to the pre-fracture period, some degree of misreporting may have occurred. Moreover, as this was a case-only study including patients who had already sustained hip fractures, the findings should not be interpreted as demonstrating a general increase in fall risk associated with nocturia. Rather, they describe the temporal distribution (nighttime vs daytime) of fracture-related falls within this specific population. In addition, detailed data on some established fall risk factors—such as frailty, gait speed, balance, and medication use—were not consistently available and therefore could not be included in the analysis. Finally, since the study population consisted of patients already hospitalized for hip fractures, the findings may not be fully generalizable to community-dwelling older adults. Despite these limitations, the study highlights nocturia and mild electrolyte disturbances as independent correlates of nighttime falls in a large orthopedic cohort, providing clinically relevant insights for fall-prevention strategies.

Conclusion

This study represents one of the most comprehensive investigations to date that integrates clinical, biochemical, and functional parameters in evaluating the association between nocturia severity and nighttime falls among older adults. It highlights the multifactorial nature of nighttime falls, emphasizing the importance of both functional symptoms and biochemical contributors. Nocturia—particularly at moderate and severe levels—showed a strong and independent association with nighttime falls among older adults with hip fractures, even after adjustment for demographic and biochemical variables. Additionally, male sex and lower serum potassium levels were identified as independent predictors of fall risk. These findings suggest that incorporating urinary symptoms and basic electrolyte profiles into geriatric assessments may help identify older adults at higher risk of nighttime falls; however, further prospective studies are needed before routine screening or targeted interventions can be recommended. Future prospective studies should investigate whether targeted interventions addressing nocturia and electrolyte imbalances can effectively reduce fall incidence and improve postoperative outcomes in older adults with hip fractures, thereby informing preventive strategies in orthopedic and geriatric practice.

Supplemental Material

Supplemental Material - Nocturia and Nighttime Falls in Older Adults With Hip Fractures: A Retrospective Observational Study

Supplemental Material for Nocturia and Nighttime Falls in Older Adults With Hip Fractures: A Retrospective Observational Study by Nihat Yiğit, Ali Said Nazligul, Nuri Koray Ulgen, Tahsin Aydin, and Mehmet Orcun Akkurt in Geriatric Orthopaedic Surgery & Rehabilitation.

Supplemental Material

Supplemental Material - Nocturia and Nighttime Falls in Older Adults With Hip Fractures: A Retrospective Observational Study

Footnotes

ORCID iDs

Nihat Yiğit

Nuri Koray Ulgen

Ethical Considerations

The study was approved by the Clinical Research Ethics Committee of Bilkent City Hospital (Approval No: [eklenmeli]). All procedures were conducted in accordance with the Declaration of Helsinki.

Consent to Participate

Informed consent was obtained from all participants.

Authors Contributions

Dr. Nihat and Dr. Koray contributed to the conception and design of the study. Dr. Ali Said was responsible for data collection and statistical analysis. Dr. Tahsin participated in manuscript drafting and critical revision of the content. All authors read and approved the final manuscript.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.*

Supplemental Material

Supplemental material for this article is available online.

References

Szabo

Gooch

Walker

Johnston

Wagg

. The association between overactive bladder and falls and fractures: a systematic review. Adv Ther. 2018;35(11):1831-1841. doi:10.1007/s12325-018-0796-8

Pesonen

Vernooij

RWM

Cartwright

, et al. The impact of nocturia on falls and fractures: a systematic review and meta-analysis. J Urol. 2020;203(4):674-683. doi:10.1097/JU.0000000000000459

Liu

Huang

Ding

. Association of lower urinary tract symptoms and hip fracture in adults aged ≥50 years. PLoS One. 2021;16(3):e0246653. doi:10.1371/journal.pone.0246653

Zusman

McAllister

Chen

, et al. Incontinence and nocturia in older adults after hip fracture: analysis of a secondary outcome for a parallel group, randomized controlled trial. Gerontol Geriatr Med. 2017;3:2333721417709578. doi:10.1177/2333721417709578

Tarazona-Santabalbina

Ojeda-Thies

Figueroa Rodríguez

Cassinello-Ogea

Caeiro

. Orthogeriatric management: improvements in outcomes during hospital admission due to hip fracture. Int J Environ Res Publ Health. 2021;18(6):3049. doi:10.3390/ijerph18063049

Yong

Logan

. Menopausal osteoporosis: screening, prevention and treatment. Singap Med J. 2021;62(4):159-166. doi:10.11622/smedj.2021036

Azarboo

Ghaseminejad-Raeini

Teymoori-Masuleh

, et al. Risk factors of postoperative urinary retention following total hip and knee arthroplasty: a systematic review and meta-analysis. Bone Jt Open. 2024;5(7):601-611. doi:10.1302/2633-1462.57.BJO-2024-0003.R1

Mariappan

Turner

Sothilingam

Rajan

Sundram

Stewart

. Nocturia, nocturia indices and variables from frequency-volume charts are significantly different in Asian and Caucasian men with lower urinary tract symptoms: a prospective comparison study. BJU Int. 2007;100(2):332-336. doi:10.1111/j.1464-410X.2007.06979.x

Dutoglu

Soysal

Smith

, et al. Nocturia and its clinical implications in older women. Arch Gerontol Geriatr. 2019;85:103917. doi:10.1016/j.archger.2019.103917

10.

Weiss

Blaivas

Jones

Wang

Guan

037 Study Group . Age related pathogenesis of nocturia in patients with overactive bladder. J Urol. 2007;178(2):548-551. doi:10.1016/j.juro.2007.03.117

11.

Abrams

Cardozo

Fall

, et al. The standardisation of terminology of lower urinary tract function: report from the standardisation sub-committee of the international continence society. Neurourol Urodyn. 2002;21(2):167-178. doi:10.1002/nau.10052

12.

Bosch

JLHR

Weiss

. The prevalence and causes of nocturia. J Urol. 2010;184(2):440-446. doi:10.1016/j.juro.2010.04.011

13.

Tikkinen

KAO

Auvinen

Johnson

, et al. A systematic evaluation of factors associated with nocturia--the population-based FINNO study. Am J Epidemiol. 2009;170(3):361-368. doi:10.1093/aje/kwp133

14.

Homma

. Classification of nocturia in the adult and elderly patient: a review of clinical criteria and selected literature. BJU Int. 2005;96(Suppl 1):8-14. doi:10.1111/j.1464-410X.2005.05655.x

15.

Komleva

Gollasch

König

. Nocturia and frailty in older adults: a scoping review. BMC Geriatr. 2024;24(1):498. doi:10.1186/s12877-024-05049-3

16.

López-Soto

De Giorgi

Senno

, et al. Renal disease and accidental falls: a review of published evidence. BMC Nephrol. 2015;16(1):176. doi:10.1186/s12882-015-0173-7

17.

Sahiner

Mangır

Güner

, et al. The relationship between urinary incontinence and abdominal muscle thickness in community-dwelling older women undergoing comprehensive geriatric assessment. Eur Geriatr Med. 2023;14(6):1319-1325. doi:10.1007/s41999-023-00874-y

18.

Ancoli-Israel

Bliwise

Nørgaard

. The effect of nocturia on sleep. Sleep Med Rev. 2011;15(2):91-97. doi:10.1016/j.smrv.2010.03.002

19.

Bliwise

Wagg

Sand

. Nocturia: a highly prevalent disorder with multifaceted consequences. Urology. 2019;133:3-13. doi:10.1016/j.urology.2019.07.005

20.

Dani

Esdaille

Weiss

. Nocturia: aetiology and treatment in adults. Nat Rev Urol. 2016;13(10):573-583. doi:10.1038/nrurol.2016.134

21.

Nonaka

Suzuki

Negoro

, et al. Association between nocturia and sleep issues, incorporating the impact of lifestyle habits perceived as promoting sleep in an internet survey. Sci Rep. 2025;15(1):17508. doi:10.1038/s41598-025-02587-7

22.

Bower

Whishaw

Khan

. Nocturia as a marker of poor health: causal associations to inform care. Neurourol Urodyn. 2017;36(3):697-705. doi:10.1002/nau.23000

23.

Dani

Esdaille

Weiss

. Nocturia: aetiology and treatment in adults. Nat Rev Urol. 2016;13(10):573-583. doi:10.1038/nrurol.2016.134

24.

Nagai

Dasari

. Nocturia and sleep blood pressure - a key link in a vicious cycle? Hypertens Res. 2025;48(4):1652-1653. doi:10.1038/s41440-025-02136-9

25.

Finstere

. Before attributing sleep deprivation in ALS to depression or muscle weakness, all other factors influencing sleep quality must be excluded. Sarcouncil J Med Series. 2025;4(3):1-2. doi:10.5281/ZENODO.14962851

26.

Oda

Hospital

Takechi

, et al. Association between nocturnal falls and hypnotic drug use in older patients at acute care hospitals. Eur J Clin Pharmacol. 2023;79(6):753-758. doi:10.1007/s00228-023-03485-5

27.

Di Simone

Giannetta

Ragnoli

, et al. Sleep quality and sex-related differences in an older adult population: a web-based cross-sectional study. Nsc Nurs. 2024;4(3):46-68. doi:10.32549/OPI-NSC-112

28.

Sun

Chao

Lin

. Recurrent falls as the presentations of Gitelman syndrome in an octogenarian. Aging. 2025;17(3):872-880. doi:10.18632/aging.206216

29.

Simal

Somers

Amrouch

, et al. A descriptive analysis of drug-drug interactions and corresponding adverse drug reactions in multimorbid older inpatients: findings from the SENATOR trial. Eur Geriatr Med. 2024;15(5):1357-1367. doi:10.1007/s41999-024-01025-7

30.

Magnuszewski

Swietek

Kasiukiewicz

Kuprjanowicz

Baczek

Beata Wojszel

. Health, functional and nutritional determinants of falls experienced in the previous year—a cross-sectional study in a geriatric ward. Int J Environ Res Publ Health. 2020;17(13):4768. doi:10.3390/ijerph17134768

31.

Britting

Artzi-Medvedik

Fabbietti

, et al. Kidney function and other factors and their association with falls: the screening for CKD among older people across Europe (SCOPE) study. BMC Geriatr. 2020;20(S1):320. doi:10.1186/s12877-020-01698-2

32.

Matsuo

Kakita

Honda

, et al. Relationship between tooth loss due to chronic periodontitis and lower urinary tract symptoms. Medicina. 2024;60(11):1829. doi:10.3390/medicina60111829

33.

Gao

Cheng

, et al. Blood cadmium levels and overactive bladder in middle-aged and older adults in the United States: insights from NHANES 2007–2020 data. Environ Pollut. 2024;363:125148. doi:10.1016/j.envpol.2024.125148

34.

Gourova

Van De Beek

Spigt

Nieman

FHM

Van Kerrebroeck

PEVA

. Predictive factors for nocturia in elderly men: a cross‐sectional study in 21 general practices. BJU Int. 2006;97(3):528-532. doi:10.1111/j.1464-410X.2006.06029.x

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