In this study, most participants had continuous 30-day fasting in Ramadan. No episode of hypoglycemia was reported. Every participant was being visited by the research team to adjust their medication dosage and were given counseling about lifestyle changes. Medical consultation before starting to fast has a protective effect against hypoglycemia. Therefore, it was essential to inform the patients about the importance of medical counseling (9, 10). Kalantari evaluated the impact of Islamic fasting on blood sugar level of type ΙΙ diabetic subjects in Gilan province, Iran, 2007. Seventeen patients with type ΙΙ diabetes (5 males, 12 females) who had oral medication or diet enrolled in the study. Their results elucidate that patients taking oral pills did not develop hypoglycemia (11).
Patients’ weight, BMI, waist to hip ratio, and waist circumference reduced after one month of fasting in the current study. These results are consistent with the findings from other studies. In a study conducted by Bravis et al. in 2010, an average weight loss of 0.7 kg occurred in the case group vs 0.6 kg in the control group after Ramadan (p value < 0.001) (12). McEwen’s study also showed a significant decrease in BMI and weight in the intervention group (− 1.1 ± 2.4 kg/m2 vs − 0.2 ± 1.7 kg/m2, p < 0.0001) (10). Another study by Khaled on anthropometric parameters and food consumption in 276 type ΙΙ diabetic obese women in Algeria shows a significant decrease in weight at the end of Ramadan (1).
Evaluating the patients’ lipid profiles in the present study before and after fasting showed a significant increase in the patients’ triglycerides level. However, cholesterol, HDL, and LDL did not change significantly. The study of Zare on the effect of fasting during Ramadan on lipid profile showed a significant decline in TG, Cholesterol, LDL level, and elevation of HDL (13). Nonetheless, in Laajam’s study, cholesterol levels significantly increased, but triglyceride remained unchanged (14). Khaled et al.’s survey on Ramadan fasting showed modifications of certain serum components in 60 obese women with type ΙΙ diabetes, suggesting that fasting reduced HDL and increased cholesterol, triglyceride, and LDL, which is consistent with the results of this study (15, 16). The elevation in blood TG in Ramadan fasting may be the result of increased fat tissues’ lipolytic effect during Ramadan (16). Other possible causes of triglyceride increase in the present study could be due to decreased physical activity or sampling in the evening due to the nature of diurnal triglyceride changes (17).
In our study, a significant reduction in fasting blood sugar was observed during Ramadan. In addition, 2hpp blood sugar level did not show any significant difference between the beginning and the end of the month. Glycosylated hemoglobin (HbA1C) also increased slightly after Ramadan, which was not statistically significant.
In Kalantari et al.’s study, the mean FBS level before and during Ramadan was 152.35 ± 56.25 mg/dl and 140.18 ± 25.29 mg/dl, which showed a slight decrease and was not statistically significant (11). In a study by Katibi on blood sugar control among fasting Muslims with type ΙΙ diabetes mellitus in 33 diabetic patients, there was a significant difference between blood glucose before and after Ramadan, and 76% of patients had better blood sugar levels compared to before Ramadan (18). The differences observed in various studies can be due to differences in study populations, such as participants’ nutritional habits and even different durations of fasting, which may vary from one geographical location to another.
Zainudin conducted a study on diabetes training and modifying medication for self-management during Ramadan fasting with 29 participants (75.9% female and 24.1% male). Patients’ HbA1C and weight at the end of the fasting period revealed a significant decrease (19). In a study by Laajam, none of the patients’ sugar profile indexes changed (14). The study of M'guil focused on the safety of Ramadan fasting and its effect on the clinical and biochemical parameters of type ΙΙ diabetes patients. The results showed that the blood sugar index did not change significantly at the end of the fasting period (20). In a study by Celik on the effects of Ramadan fasting on daily life and metabolic conditions of type ΙΙ diabetic patients, 26 patients did not develop any changes in blood sugar indexes (21).
Another study by Nachvak et al. (20) on the effects of Ramadan on food intake, body composition, glucose homeostasis, and lipid profiles showed a significant decrease in blood glucose, body mass index, and weight at the end of Ramadan. Evaluation of food intake elucidated that the consumption of different food groups, except carbohydrates, decreased during Ramadan. The results from this study are consistent with our findings, but lipid profile was incompatible (22).
Yarahmadi studied anthropometric and biochemical variables of 57 type ΙΙ diabetic patients during Ramadan. Their results indicate that body mass index and waist to hip ratio reduced in men but body mass index increased in women. On the other hand, blood pressure, fasting blood sugar, and serum fructosamine concentrations did not change during the study, whereas total cholesterol, LDL concentrations were significantly increased in all patients (23). Although some of the results from Yarahmadi’s study were consistent with our study, improvement in anthropometric variables was seen in both sexes and there was no significant difference in our study.
In this study, we found significant improvement in systolic and diastolic blood pressure during Ramadan (pvalue < 0.05). According to Azizi, fasting effects blood pressure and may lead to hypotension (24). According to Erdem’s study, intermittent fasting resulted in a significant decrease in office BP values and ABPM (ambulatory blood pressure monitoring) measurements (25). In some studies, no significant changes in systolic and diastolic blood pressure during this month were reported (23, 26). This discrepancy may have occurred due to nutritional consultation in our study.
This study had some limitations, including fewer male participants in the study in addition to the lack of control group. It was not feasible to select a control group due to specific time limitations of Ramadan in a year. Also, most of the diabetic patients did not agree not to fast during Ramadan.