Impact of Ramadan fasting on a Saudi population with type 2 diabetes mellitus

Background: Diabetes is a metabolic disease that results when either the cells resist insulin or when there is a relative deficiency of insulin production. Kingdom of Saudi Arabia is one of the top ten countries with the highest prevalence of diabetes. Recently, there is a great interest in developing non-pharmacological strategies for preventing, managing, or reversing T2DM. Intermittent fasting is one such strategy that has been shown to be beneficial for individuals with diabetes and in some cases reversal of T2DM has been demonstrated. The month of Ramadan involves a type of religious intermittent fasting, practiced by the majority of Saudi adults, which may offer an excellent opportunity for protecting and improving public health. Aims: This study aimed to investigate the impact of Ramadan on changes in physical, clinical, and biochemical parameters of individuals with T2DM who chose to fast in Ramadan. The role of changes in lifestyle such as physical activity, diet, sleeping patterns, and sun exposure were analysed. The impact of the month of Ramadan on HbA1c levels, an important marker for T2DM, in a Saudi population as a function of monthly ambient temperature was also investigated. Methods: This study investigated Saudi nationals attending hospitals in Riyadh. Ethical approvals were obtained from De Montfort University and relevant Saudi organizations. The methodology of the study is described below in three parts. In study one, a total of 168,614 patients’ records that included age, gender, and HbA1c data for six years were obtained from their medical records. These data were correlated with the ambient monthly temperature, extracted from the General Authority of Meteorology and Environmental Protection in Saudi Arabia. Study two was a prospective, observational, non-interventional study that was conducted on 82 Saudi adults with T2DM in three different phases (pre-, during, and post-Ramadan). In each phase, physical, clinical, and laboratory measurements were obtained from each participant, along with self-administered questionnaires that addressed the demographic variables, dietary patterns, physical activity, sleeping patterns, and sun exposure of the individual. In study three, 36 individuals, randomly selected from the prospective, observational, non-interventional study, were each given a Fitbit Flex 2™ accelerometer along with a questionnaire to assess their physical activity and sleep patterns during two different time points (during, and post-Ramadan). All the obtained data were analysed using univariate and multivariate statistical approaches. Results: For study one, there was a statistically significant positive correlation between ambient temperature and HbA1c levels, where for each 1°C increase in average weekly temperature HbA1c increased by 0.007%. However, this relationship was disrupted by the month of Ramadan, even though this month coincided with a high-temperature period, where the mean of HbA1c declined to the lowest level when compared to the other months. Despite the mean weight, BMI, and waist circumference of the 82 participants were non-significantly higher during Ramadan, study two demonstrated significant reductions in the mean FBG and HbA1c during Ramadan phase (P < 0.05), and improvements in the lipid profile and some other biochemical and clinical measurements compared to pre- and post-Ramadan phases. There were some significant changes in the dietary and sleeping patterns between phases. However, only changes in the frequency of eating rice, fruits, and vegetables had significant medium effect size in the reduction of HbA1c during Ramadan (P = 0.021 and P = 0.043; respectively). Although there were no significant changes in physical activity between the different periods, those with higher physical activity had significantly lower HbA1c levels. In study three, both instruments (Fitbit and questionnaire) revealed a high prevalence of low physical activity among the participants with non-significant changes between phases, and shorter sleeping duration at night-time. The average daily total sleeping hours and average daily night-time sleeping hours significantly increased in the post-Ramadan phase compared to the during Ramadan phase. Conclusion: Overall, the month of Ramadan has a positive impact on the biochemical and clinical parameters related to T2DM. This includes the protective effect against the negative impact of rising ambient temperature on HbA1c levels. Furthermore, dietary changes during Ramadan, especially the reduction in the consumption of rice and increased intake of fruits and vegetables leads to significant reductions in HbA1c. Considering the beneficial changes reported in the current study, it can be concluded that Ramadan fasting has the potential to be used by public health professionals for preventing, managing, or reversing T2DM. However, to obtain the maximal benefits of Ramadan fasting, individuals with T2DM can be advised to follow a healthy diet and achieve the recommended levels of sleep and physical activity. This will help them to better control their diabetes and may even reverse the disease.