Restricted accessResearch articleFirst published online 2026-3
Improvement of Glycemia Risk Index and Continuous Glucose Monitoring Metrics During Ramadan Fasting in Type 1 Diabetes: A Real-World Observational Study
Managing glycemia during Ramadan is challenging for individuals with type 1 diabetes (T1D) due to prolonged fasting and altered eating patterns. While many are exempt from fasting, some choose to fast, necessitating careful monitoring. The glycemia risk index (GRI) is valuable for assessing glycemic quality and interpreting continuous glucose monitoring (CGM) data to identify individuals needing closer clinical attention. This study investigates the effects of Ramadan fasting on glycemic control in T1D, focusing on GRI and its components for hypoglycemia (CHypo) and hyperglycemia (CHyper).
Method:
An ambispective study involved 186 individuals with T1D using intermittent scanning CGM (isCGM). Data were retrospectively collected for one month before Ramadan and prospectively during and one month after Ramadan. Clinical, metabolic, and glycemic data were collected, with GRI calculated alongside its components.
Results:
During Ramadan, GRI improved by 54.6% (from 56.4 to 25.6), CHypo decreased by 60% (from 6 to 2.4), and CHyper dropped by 40.5% (from 21 to 12.5). However, these benefits were temporary, as glycemic measures increased after Ramadan, reflecting a return to pre-Ramadan patterns once normal routines resumed. No participants were admitted for diabetes emergencies during Ramadan. Adolescents and patients on insulin pumps had more favorable outcomes. GRI and its components significantly correlated with other CGM metrics, with these relationships maintained during and after Ramadan.
Conclusions:
Ramadan fasting significantly improved GRI and its components in individuals with T1D. Incorporating GRI as a novel metric alongside classical CGM metrics could enhance glycemic control, highlighting the need for personalized diabetes management strategies.
SakrAH. Fasting in Islam. J Am Diet Assoc. 1975;67(1):17-21.
2.
PattersonRELaughlinGALaCroixAZ, et al. Intermittent fasting and human metabolic health. J Acad Nutr Diet. 2015;115(8):1203-1212. doi:10.1016/j.jand.2015.02.018.
3.
AbdelrahimDFarisMEHassaneinM, et al. Impact of Ramadan diurnal intermittent fasting on hypoglycemic events in patients with type 2 diabetes: a systematic review of randomized controlled trials and observational studies. Front Endocrinol (Lausanne). 2021;12:624423. doi:10.3389/fendo.2021.624423.
4.
HassaneinMMHanifWMalekR, et al. Changes in fasting patterns during Ramadan, and associated clinical outcomes in adults with type 2 diabetes: a narrative review of epidemiological studies over the last 20 years. Diabetes Res Clin Pract. 2021;172:108584.
5.
HajekPMyersKDhanjiAR, et al. Weight change during and after Ramadan fasting. J Public Health. 2012;34(3):377-381. doi:10.1093/pubmed/fdr087.
6.
FernandoHAZibelliniJHarrisRA, et al. Effect of Ramadan fasting on weight and body composition in healthy non-athlete adults: a systematic review and meta-analysis. Nutrients. 2019;11(2):478. doi:10.3390/nu11020478.
7.
SaltiIBénardEDetournayB, et al. A population-based study of diabetes and its characteristics during the fasting month of Ramadan in 13 countries: results of the epidemiology of diabetes and Ramadan 1422/2001 (EPIDIAR) study. Diabetes Care. 2004;27(10):2306-2311. doi:10.2337/diacare.27.10.2306.
8.
DeebAAl QahtaniNAkleM, et al. Attitude, complications, ability of fasting and glycemic control in fasting Ramadan by children and adolescents with type 1 diabetes mellitus. Diabetes Res Clin Pract. 2017;126:10-15. doi:10.1016/j.diabres.2017.01.015.
9.
Al HayekAARobertAAAl DawishMA. Evaluating the impact of Ramadan fasting on ambulatory glucose profile among patients with type 1 diabetes using Flash Glucose Monitoring System: a comparative study. Diabetes Metab Syndr. 2022;16(4):102472. doi:10.1016/j.dsx.2022.102472.
10.
IsmailSAbdul ManafRMahmudA. Comparison of time-restricted feeding and Islamic fasting: a scoping review. East Mediterr Health J. 2019;25(4):239-245. doi:10.26719/emhj.19.011.
11.
MartinezMSantamarinaJPavesiA, et al. Glycemic variability and cardiovascular disease in patients with type 2 diabetes. BMJ Open Diabetes Res Care. 2021;9(1):e002032. doi:10.1136/BMJDRC-2020-002032.
12.
YapanisMJamesSCraigME, et al. Complications of diabetes and metrics of glycemic management derived from continuous glucose monitoring. J Clin Endocrinol Metab. 2022;107(6):e2221-e2236. doi:10.1210/clinem/dgac034.
13.
Al-AroujMBouguerraRBuseJ, et al. Recommendations for management of diabetes during Ramadan. Diabetes Care. 2005;28(9):2305-2311. doi:10.2337/diacare.28.9.2305.
14.
BattelinoTAlexanderCMAmielSA, et al. Continuous glucose monitoring and metrics for clinical trials: an international consensus statement. Lancet Diabetes Endocrinol. 2023;11(1):42-57. doi:10.1016/S2213-8587(22)00319-9.
15.
TianTAaronREYeungAM, et al. Use of continuous glucose monitors in the hospital: the diabetes technology society hospital meeting report 2023. J Diabetes Sci Technol. 2023;17(5):1392-1418. doi:10.1177/19322968231186575.
16.
PionaCMariglianoMRoncaràC, et al. Glycemia risk index as a novel metric to evaluate the safety of glycemic control in children and adolescents with type 1 diabetes: an observational, multicenter, real-life cohort study. Diabetes Technol Ther. 2023;25(7):507-512. doi:10.1089/dia.2023.0040.
17.
KlonoffDCWangJRodbardD, et al. A glycemia risk index (GRI) of hypoglycemia and hyperglycemia for continuous glucose monitoring validated by clinician ratings. J Diabetes Sci Technol. 2023;17(5):1226-1242. doi:10.1177/19322968221085273.
18.
Díaz-SotoGBahíllo-CuriesesMPJimenezR, et al. The relationship between glycosylated hemoglobin, time-in-range and glycemic variability in type 1 diabetes patients under flash glucose monitoring. Endocrinol Diabetes Nutr. 2021;68(7):465-471. doi:10.1016/J.ENDIEN.2021.11.006.
19.
KimJYYooJHKimJH. Comparison of glycemia risk index with time in range for assessing glycemic quality. Diabetes Technol Ther. 2023;25(12):883-892. doi:10.1089/dia.2023.0264.
20.
Pérez-LópezPFérnandez-VelascoPBahillo-CuriesesP, et al. Impact of glucose variability on the assessment of the glycemia risk index (GRI) and classic glycemic metrics. Endocrine. 2023;82(3):560-568. doi:10.1007/s12020-023-03511-7.
21.
RobertAAAl- DawishAMujammamiM, et al. Type 1 diabetes mellitus in Saudi Arabia: a soaring epidemic. Int J Pediatr. 2018;2018:1-9. doi:10.1155/2018/9408370.
22.
NorrisJMJohnsonRKSteneLC. Type 1 diabetes—early life origins and changing epidemiology. Lancet Diabetes Endocrinol. 2020;8(3):226-238. doi:10.1016/S2213-8587(19)30412-7.
23.
AkramZInayatMAkhtarS, et al. Fasting influence on diabetic emergency visits in a tertiary care hospital throughout Ramadan and other lunar months. Pak J Med Health Sci. 2023;17(3):588-590. doi:10.53350/pjmhs2023173588.
24.
TongCVYowHYMohd NoorN, et al. Diabetes emergencies around Ramadan study (DEARS)—a multi-center study of diabetes emergencies admitted before, during and after Ramadan in Malaysia. Diabetes Res Clin Pract. 2021;175:108854. doi:10.1016/j.diabres.2021.108854.
25.
von ElmEAltmanDGEggerM, et al. The strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. Int J Surg. 2014;12:1495-1499. doi:10.1016/j.ijsu.2014.07.013.
26.
JAVA. Declaration of Helsinki World Medical Association declaration of Helsinki. Bull World Health Organ. 2013;79(4):373-374. doi:S0042-96862001000400016.
27.
HassaneinMAfandiBYakoob AhmedaniM, et al. Diabetes and Ramadan: practical guidelines. Diabetes Res Clin Pract. 2022;185:109185. doi:10.1016/j.diabres.2021.109185.
28.
HassaneinMAl-AroujMHamdyO, et al. Diabetes and Ramadan: practical guidelines. Diabetes Res Clin Pract. 2017;126:303-316. doi:10.1016/j.diabres.2017.03.003.
29.
BajajHSAbouhassanTAhsanMR, et al. Diabetes Canada position statement for people with types 1 and 2 diabetes who fast during Ramadan. Can J Diabetes. 2019;43(1):3-12. doi:10.1016/j.jcjd.2018.04.007.
30.
ShahVNSakamotoCPyleL. Optimal sampling duration for continuous glucose monitoring for the estimation of glycemia risk index. Diabetes Technol Ther. 2023;25(2):140-142. doi:10.1089/dia.2022.0401.
31.
SinghJASiddiqiMParameshwarP, et al. World Health Organization guidance on ethical considerations in planning and reviewing research studies on sexual and reproductive health in adolescents. J Adolesc Health. 2019;64(4):427-429. doi:10.1016/j.jadohealth.2019.01.008.
32.
IbrahimMAbuAlMagdMAnnabiFA, et al. Recommendations for management of diabetes during Ramadan: update 2015. BMJ Open Diabetes Res Care. 2015;3(1):e000108. doi:10.1136/bmjdrc-2015-000108.
33.
BenerAA Al-HamaqAOAÖztürkM, et al. Effect of Ramadan fasting on glycemic control and other essential variables in diabetic patients. Ann Afr Med. 2018;17(4):196-202. doi:10.4103/aam.aam_63_17.
34.
PanfilKVanderveldenCALockeeB, et al. The glycemia risk index predicts performance of diabetes self-management habits in youth with type 1 diabetes mellitus. J Diabetes Sci Technol. 2024;18(4):779-786. doi:10.1177/19322968241247215.
35.
AfandiBKaplanWAl HassaniN, et al. Correlation between pre-Ramadan glycemic control and subsequent glucose fluctuation during fasting in adolescents with Type 1 diabetes. J Endocrinol Invest. 2017;40(7):741-744. doi:10.1007/s40618-017-0633-y.
36.
BeshyahSAHassaneinMAhmedaniMY, et al. Diabetic hypoglycaemia during Ramadan fasting: a trans-national observational real-world study. Diabetes Res Clin Pract. 2019;150:315-321. doi:10.1016/j.diabres.2019.01.039.
37.
HassaneinMAbdelgadirEBashierA, et al. The role of optimum diabetes care in form of Ramadan focused diabetes education, flash glucose monitoring system and pre-Ramadan dose adjustments in the safety of Ramadan fasting in high risk patients with diabetes. Diabetes Res Clin Pract. 2019;150:288-295. doi:10.1016/j.diabres.2018.12.013.
38.
AlfadhliEM. Higher rate of hyperglycemia than hypoglycemia during Ramadan fasting in patients with uncontrolled type 1 diabetes: insight from continuous glucose monitoring system. Saudi Pharm J. 2018;26(7):965-969. doi:10.1016/j.jsps.2018.05.006.
39.
ElamariSElazizSChadliA, et al. Management of diabetes during Ramadan fasting: applications of international recommendations in clinical practice. Pan Afr Med J. 2020;36:316. doi:10.11604/pamj.2020.36.316.7201.
40.
DeebAAl QahtaniNAttiaS, et al. Does reducing basal insulin during Ramadan fasting by children and adolescents with type 1 diabetes decrease the risk of symptomatic hypoglycemia?Diabetes Technol Ther. 2016;18(9):539-542. doi:10.1089/dia.2016.0197.
41.
OriotPKlipper dit kurzNPonchonM, et al. Benefits and limitations of hypo/hyperglycemic alarms associated with continuous glucose monitoring in individuals with diabetes. Diabet Epidemiol Manag. 2023;9:100125. doi:10.1016/j.deman.2022.100125.
42.
ChehregoshaHKhamsehMEMalekM, et al. A view beyond HbA1c: role of continuous glucose monitoring. Diabetes Ther. 2019;10(3):853-863. doi:10.1007/s13300-019-0619-1.
43.
ReddyNVermaNDunganK. Monitoring technologies—continuous glucose monitoring, mobile technology, biomarkers of glycemic control. In: FeingoldKRAnawaltBBoyceA, et al, eds. Endotext [Internet]. South Dartmouth, MA: MDText.com, Inc; 2020:1-51.
44.
Al-KhawariMAl-RuwayehAAl-DoubK, et al. Adolescents on basal-bolus insulin can fast during Ramadan. Pediatr Diabetes. 2010;11(2):96-100. doi:10.1111/j.1399-5448.2009.00544.x.
45.
MoYLuJZhouJ. Glycemic variability: measurement, target, impact on complications of diabetes and does it really matter?J Diabetes Investig. 2024;15(1):5-14. doi:10.1111/jdi.14112.
46.
SiawMYLChewDEKDalanR, et al. Evaluating the effect of Ramadan fasting on Muslim patients with diabetes in relation to use of medication and lifestyle patterns: a prospective study. Int J Endocrinol. 2014;2014:308546. doi:10.1155/2014/308546.
47.
KaplanWAfandiBAl HassaniN, et al. Comparison of continuous glucose monitoring in adolescents with type 1 diabetes: Ramadan versus non-Ramadan. Diabetes Res Clin Pract. 2017;134:178-182. doi:10.1016/j.diabres.2017.10.010.
48.
Al-SofianiMAlharthiSAlbunyanS, et al. 909-P: predictors of successful fasting and attaining glycemic targets during the month of Ramadan among people with type 1 diabetes. Diabetes. 2023;72(suppl 1):909-p. doi:10.2337/db23-909-p.
49.
AlamoudiRAlsubaieeMAlqarniA, et al. Comparison of insulin pump therapy and multiple daily injections insulin regimen in patients with type 1 diabetes during Ramadan fasting. Diabetes Technol Ther. 2017;19(6):349-354. doi:10.1089/dia.2016.0418.
50.
KhaledMBBelbraouetS. Ramadan fasting diet entailed a lipid metabolic disorder among type 2 diabetic obese women. Am J Appl Sci. 2009;6(3):471-477. doi:10.3844/ajas.2009.471.477.
51.
KhaledBMBelbraouetS. Effect of Ramadan fasting on anthropometric parameters and food consumption in 276 type 2 diabetic obese women. Int J Diabetes Dev Ctries. 2009;29(2):62-68. doi:10.4103/0973-3930.53122.
52.
Mora-RodriguezROrtegaJFRamirez-JimenezM, et al. Insulin sensitivity improvement with exercise training is mediated by body weight loss in subjects with metabolic syndrome. Diabetes Metab. 2020;46(3):210-218. doi:10.1016/j.diabet.2019.05.004.
53.
UusitupaMLindiVLouherantaA, et al. Long-term improvement in insulin sensitivity by changing lifestyles of people with impaired glucose tolerance: 4-year results from the Finnish Diabetes Prevention Study. Diabetes. 2003;52(10):2532-2538. doi:10.2337/diabetes.52.10.2532.
54.
Vazquez ArreolaEKnowlerWCHansonRL. Weight loss, lifestyle intervention, and metformin affect longitudinal relationship of insulin secretion and sensitivity. J Clin Endocrinol Metab. 2022;107(11):3086-3099. doi:10.1210/clinem/dgac509.
55.
LeeMHVogrinSJonesTW, et al. Hybrid closed-loop versus manual insulin delivery in adults with type 1 diabetes: a post hoc analysis using the glycemia risk index. J Diabetes Sci Technol. 2024;18:764-770. doi:10.1177/19322968241231307.
56.
ZhongTHeBLiX, et al. Glycaemia risk index uncovers distinct glycaemic variability patterns associated with remission status in type 1 diabetes. Diabetologia. 2024;67(1):42-51. doi:10.1007/s00125-023-06042-y.
57.
HoogendoornCJHernandezRSchneiderS, et al. Glycemic risk index profiles and predictors among diverse adults with type 1 diabetes. J Diabetes Sci Technol. 2023;18:1070-1078. doi:10.1177/19322968231164151.
58.
OmarASSalamaAAllamM, et al. Association of time in blood glucose range with outcomes following cardiac surgery. BMC Anesthesiol. 2015;15(1):14. doi:10.1186/1471-2253-15-14.
59.
RajRMishraRJhaN, et al. Time in range, as measured by continuous glucose monitor, as a predictor of microvascular complications in type 2 diabetes: a systematic review. BMJ Open Diabetes Res Care. 2022;10(1):e002573. doi:10.1136/bmjdrc-2021-002573.
60.
LuJMaXZhouJ, et al. Association of time in range, as assessed by continuous glucose monitoring, with diabetic retinopathy in type 2 diabetes. Diabetes Care. 2018;41(11):2370-2376. doi:10.2337/dc18-1131.
61.
BeckRWBergenstalRMRiddlesworthTD, et al. Validation of time in range as an outcome measure for diabetes clinical trials. Diabetes Care. 2019;42(3):400-405. doi:10.2337/dc18-1444.
62.
EkhlaspourLTownMRaghinaruD, et al. Glycemic outcomes in baseline hemoglobin A1C subgroups in the international diabetes closed-loop trial. Diabetes Technol Ther. 2022;24(8):588-591. doi:10.1089/dia.2021.0524.
63.
ZhouLDengMZhaiX, et al. The effects of dietary nutrition intake on glycemic variability in type 1 diabetes mellitus adults. Diabetes Ther. 2021;12(4):1055-1071. doi:10.1007/s13300-021-01028-8.
64.
HerzDHauptSZimmerRT, et al. Efficacy of fasting in type 1 and type 2 diabetes mellitus: a narrative review. Nutrients. 2023;15(16):3525. doi:10.3390/nu15163525.
65.
CristelloAKahkoskaARSmartCE, et al. 223-OR: preliminary evidence that “structured eating” (SE) may be acceptable and promote glycemic control in type 1 diabetes (T1D). Diabetes. 2020;69(suppl 1):2229-2237. doi:10.2337/db20-223-or.
66.
NanselTRLipskyLMLiuA. Greater diet quality is associated with more optimal glycemic control in a longitudinal study of youth with type 1 diabetes. Am J Clin Nutr. 2016;104(1):81-87. doi:10.3945/ajcn.115.126136.
67.
LinYHHuangYYChenHY, et al. Impact of carbohydrate on glucose variability in patients with type 1 diabetes assessed through professional continuous glucose monitoring: a retrospective study. Diabetes Ther. 2019;10(6):2289-2304. doi:10.1007/s13300-019-00707-x.
68.
PeairsADShahASSummerS, et al. Effects of the dietary approaches to stop hypertension (DASH) diet on glucose variability in youth with Type 1 diabetes. Diabetes Manag (Lond). 2017;7(5):383-391.
69.
SeckoldRHowleyPKingBR, et al. Dietary intake and eating patterns of young children with type 1 diabetes achieving glycemic targets. BMJ Open Diabetes Res Care. 2019;7(1):e000663. doi:10.1136/bmjdrc-2019-000663.
70.
AldibbiatAAlqashamiAHussainS. Use of automated insulin delivery systems in people with type 1 diabetes fasting during Ramadan: an observational study. J Diabetes Investig. 2022;13(4):647-651. doi:10.1111/jdi.13720.
71.
AlGhatamGO’KeeffeDTahaH. Effects of alternate insulin pump settings in patients with type 1 diabetes during Ramadan: a randomized pilot study. J Diabetes Sci Technol. 2023;17(2):409-416. doi:10.1177/19322968211059217.
72.
AlawadiFAlsaeedMBachetF, et al. Impact of provision of optimum diabetes care on the safety of fasting in Ramadan in adult and adolescent patients with type 1 diabetes mellitus. Diabetes Res Clin Pract. 2020;169:108466. doi:10.1016/j.diabres.2020.108466.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
