Abstract
This study investigates the influence of obesity on the severity of migraine in children. One hundred and twenty-four patients (77 female, 36 with aura; mean age 12.9 ± 2.8 years; age range 4.0–17.0 years) were included. Headache features such as number and duration of attacks, pain severity and associated symptoms were compared between obese, overweight and normal weight patients. The percentage of obesity was 17.7. Although pain severity and duration were not different among groups, obese patients had more frequent attacks than the overweight and normal weight patients (5.3 ± 2.4, 4.4 ± 2.4 and 3.8 ± 2.4 attacks/month, respectively, P = 0.018). There was also a positive correlation between relative body mass index and number of attacks (P = 0.026, r = 0.20). Obesity did not have an influence on migraine-associated symptoms including aura, phono/photophobia, nausea and vomiting. In this study, obesity appeared to be related to the frequency of headache attacks in children and adolescents with migraine.
Keywords
Introduction
Obesity occurs with several chronic pain syndromes. Obesity and migraine are both highly prevalent disorders in the general population, and reports in the literature underscore this association. An increasing number of reports suggest that obesity is a risk factor for migraine progression and headache frequency in adults (1–4). Peres et al. (1) found that lifetime primary headache diagnosis was higher in obese patients than in controls (75% vs. 42%, respectively). The frequency of migraine was 66% and of tension-type headache 9% in obese cases in their studied 74 obese adults. Several inflammatory mediators that are changed in obesity are also important in migraine pathophysiology, including C-reactive protein, tumour necrosis factor-alpha, interleukin-6 and adiponectin (2,3). The negative effects of childhood obesity on quality of life have been shown in some studies (5,6). However, little is known about the influence of weight status on the number of headache attacks and severity of migraine in children. In a recent study, obesity was found to be associated with increased headache frequency and disability in a paediatric headache population (7). Pinhas-Hamiel et al. reported that headache frequency was 14.3% in 273 children and adolescents. They found that overweight girls had fourfold increased risk of headache when compared with normal-weight girls (8). In these latter studies, children with migraine were not specifically evaluated.
In our study, we aimed to assess the impact of obesity on the severity and frequency of migraine attacks. We also discuss the associated clinical features in paediatric migraine patients.
Methods
The medical records of all patients with headache who had been evaluated at the Child Neurology Clinic of Baskent University Hospital in Ankara, Turkey, between March 2000 and September 2006 were reviewed. All patients had been evaluated by the same child neurologist and had undergone a complete physical and neurological examination. A structured interview concerning the characteristics of headache including duration, severity and frequency of headache, any associated symptoms (aura, nausea, vomiting, phonophobia and photophobia), and medications used was obtained for each patient during the initial clinic visit. All children and adolescents fulfilling the criteria of the International Headache Society Classification of Headache Disorders, 2nd edn for migraine were included in the study (9). Subjects having transformed migraine and tension-type headache or another systemic disease or other chronic health problem were excluded. None of them was taking any medication.
Based on the 10-point verbal pain severity scale, headaches were defined as mild (score 1–3), moderate (score 4–7) or severe (score 8–10). Regarding headache severity, patients were categorized into two groups as having mild or moderate/severe headaches. Number of headache attacks within the preceding 3 months was obtained during the interview, and monthly headache frequency was calculated as the mean number during this period. Headache duration was calculated likewise. Anthropometric measurements of height and weight in each patient were obtained during the first visit. Each subject's height was measured with a standard wall-mounted stadiometer. Weight was measured with a calibrated electronic scale. Body mass index (BMI) was calculated as the weight in kg divided by height in m2. Relative BMI (relBMI) was calculated using the following formula: subject's BMI × 100/50th percentile BMI for the subject's age and sex. Children with a relBMI < 110 defined as normal, 110 ≤relBMI < 120, defined as overweight, and rel BMI ≥ 120 defined as obese for age and sex (10).
Data analyses
All statistics were calculated using
Obese, overweight and non-obese patients were compared by sociodemographic properties, clinical features of migraine attacks, frequency and duration of attacks, and severity of pain with Kruskal–Wallis and χ2 tests. The χ2 and Fisher exact tests were used to determine differences of relBMI values between migraine subgroups and the relations between relBMI and severity of headache as well as associated clinical symptoms. Correlations between relBMI and headache duration and frequency were analysed with Pearson correlation. Values for P < 0.05 were considered statistically significant.
Results
Characteristics of normal weight, overweight and obese patients suffering migraine
P < 0.001 for three groups; **P = 0.018 for obese group.
NS, not significant.
Characteristics of migraine subgroups (migraine with and without aura)
For all parameters P > 0.05.
Discussion
Migraine and obesity are important clinical problems in adults and childhood; both significantly affect quality of life, health and individual well-being (5,11). The relations between headache frequency and obesity are complex. Migraine and obesity are independent risk factors for cardiovascular disorders, particularly stroke (12–14). Obesity is a proinflammatory and prothrombotic state, and migraine is also associated with neurovascular inflammation. Dysmodulation of some neuropeptides such as calcitonin gene-related peptide and orexin A and B in obesity also might be associated with increased neurogenic inflammation and consequent migraine attacks (2,3,15). Adipose tissue has also been described as a source of inflammatory cytokines (16,17). Adiponectin is a protein secreted by adipose tissue, which has protective roles against the development of insulin resistance and atherosclerosis. Adiponectin also has anti-inflammatory properties. Its levels are decreased in obesity. It has also been speculated that adiponectin might play a common role in the pathogenesis and generation of obesity, insulin resistance, cardiovascular disorders and migraine (3).
In the light of these findings and speculations, it is not surprising to find a relation between migraine and obesity. Although studies in adults suggest this interaction, there remains some controversy. Few data are given in children.
In studies in adults, obesity has been found to be associated with an increased incidence of chronic daily headaches, as well as the frequency and severity of migraine attacks (15,18,19). Kaplan has shown that obese women with migraine had more frequent and severe attacks (20). Peres and associates (1) observed that migraine is the most frequent diagnosis in obese patients undergoing obesity corrective surgery. Recent studies have also stressed the relationship between headache and obesity in the paediatric population (7,8).
A further relation between obesity and higher headache frequency and headache-related disability has been found in those patients with concomitant depression and anxiety (4). There is growing evidence that there are common brain monoamines and peptides influencing depression, anxiety, migraine and regulation of body weight, which may serve as a neurobiological link (21,22). In contrast, Mattson failed to detect a significant correlation between obesity and migraine in 684 women aged 40–74 years (23). Bigal and associates (24) also did not observe significant differences with regard to refractory migraine after preventive treatment between obese and non-obese migraineur adults. However, the reduction of the number of severe headache days was higher in the obese group, suggesting that obese migraineurs respond better to preventive medication than do normal-weight patients (24).
In our group, obesity did not have any effect on migraine-associated symptoms, such as aura, phono/photophobia, nausea, or vomiting. In Kaplan's study (20), vomiting was more frequent in obese migraineur than in non-obese migraineur women. However, there were no significant differences between obese and non-obese women with regard to aura, prodromal symptoms, or symptoms accompanying pain. In another adult migraine study, BMI was shown to influence some associated symptoms such as phono/photophobia, but not aura (19).
Horev et al. (25) found a high incidence of migraine, especially migraine with aura, among morbidly obese women. It was thought that migraine with aura in women might be associated with high oestrogen levels produced by adipose tissue (26,27).
We hypothesized that obesity might be a risk factor for the frequency and severity of migraine attacks during childhood and adolescence. In our study, although the severity of headache attacks and migraine-associated symptoms was not different between obese and non-obese patients, there was an association between obesity and headache attack frequency in children and adolescents with migraine. Obese patients had headache attacks more frequently than non-obese patients. These results are compatible to previous studies in adult patients (4,19).
In a recent study of Turkish children aged 6–17 years, the prevalence of obesity was found to be 6.1% (28). In our study, in migraineur children within a similar age distribution, the frequency of obesity was higher (17.7%). That finding might suggest an interaction between obesity and migraine in childhood.
In conclusion, obesity seems to occur at greater frequency in children and adolescents with migraine compared with persons in the general population, and obese patients had more frequent migraine attacks than did non-obese patients. Our results underscore the importance of obesity prevention and treatment during childhood.