The effect of Ramadan fasting on serum osmolarity, some electrolytes and hematological parameters

During the month of Ramadan, 400 million adult Muslims all over the world fast during daylight hours. The effect of Ramadan fasting has been studied in various investigations conducted on normal healthy individuals world wide, but the changes of serum osmolarity and hematological parameters during Ramadan fasting are not known well. This cohort study was performed during Ramadan on 80 medical students (41 male and 39 female). We evaluated weight, Body Mass Index (BMI), serum osmolarity, sodium and potassium, haemoglobin(Hgb), hematocrit (Hct), platelets, red and white blood cell count (RBC and WBC) and Hgb Index before and after Ramadan. The mean age of subjects was 22.7 years. Weight decreased significantly in both genders, and BMI decreased in female subjects after ramadan. While serum osmalarity and sodium increased and glucose decreased in both genders after ramadan, potassium decreased in males. RBC count increased in both genders, but WBC count and platelet count increased significantly in females. Hgb, Htc decreased after Ramadan Fasting in male subjects. We found no significant changes in levels of urea and creatinin in serum. This study indicated that Ramadan fasting leads to increased serum osmolarity, RBC count and some Hgb indices in both genders, but these changes remain within normal range. However, more investigations are suggested of patients with hematological and nephrological disorders.