BRIEF REPORT BRIEF REPORT BRIEF REPORT BRIEF REPORT BRIEF REPORT EFFECT OF RAMADAN FASTING ON CLINICAL AND BIOCHEMICAL PARAMETERS IN HEALTHY ADULTS H. Fakhrzadeh, MD, B. Larijani, MD, M. Sanjari, MD, R. Baradar-Jalili, MD, M.R. Amini, MD From the Department of Endocrinology & Metabolism Research Centre, Tehran University of Medical Sciences. Correspondence to: Dr. H. Fakhrzadeh Fifth Floor Doctor Shariati Hospital North Kargar Ave., Tehran 14114 Iran Accepted for publication: January 2003 C oronary heart disease (CHD) is primarily a disease of occidental culture, being more prevalent in populations that have adopted a high-fat, high- cholesterol diet, who smoke and do not engage in sufficient physical activity. 1 The Islamic religion prescribes fasting during Ramadan for all healthy Muslims for ostensibly moral and spiritual reasons. It may, however, be viewed as an effective model for CHD risk profile modulation. The effect of Ramadan fasting on cardiovascular risk factors is still a matter of debate. Energy intake decreases during Ramadan, 2-5 as do weight 2-5 and body fat percentage. 3,5 The effect of Ramadan fasting on serum lipid profile is not so clear, however. Numerous studies report improvements in serum lipoproteins, while a few report a deterioration in the LDL:HDL cholesterol ratio during Ramadan. 4 There seems to be a reduction in the number of hospitalizations for acute coronary events during the month of Ramadan, 6 although this cannot be entirely or necessarily attributed to the physical restrictions, which the faithful endure during this month. This study was performed to evaluate alterations in CHD risk profile during the holy month of Ramadan. Materials and Methods Ninety-one healthy volunteers aged 20.8±3.1 years from two seminary schools in Rey, south of Tehran, took part in this study during Ramadan 2000 (1442 in the lunar calendar). The sample consisted of 50 men (age 19.9±1.8 years) and 41 women (age 21.9±3.9 years). All participants had the same diet and level of physical activity. Participants fasted from sunrise to sunset for at least 25 days during Ramadan. Dietary intake was recorded using a semi-quantitative food frequency questionnaire on days zero and 14 of fasting. None of the students smoked or was taking any medication at the time of the study. Blood samples were collected twice: first, one week before Ramadan after a 12-hour overnight fast (baseline) and then on the 28 th day of Ramadan, just before sunset. Anthropometric measures were performed at the same time as blood sampling. 223 • Annals of Saudi Medicine • 2003 May-July, Volume 23 www.kfshrc.edu.sa/annals Biochemical measurements took place at the laboratory of the Endocrine and Metabolism Research Centre, affiliated to the Tehran University of Medical Sciences. Blood samples were centrifuged and the supernatant plasma stored at -25°C. All blood samples were analyzed in a single batch to avoid day-to-day laboratory variation. Glucose, total cholesterol (T-C) and triglyceride (TG) levels were measured by auto-analyser (Hitachi 911, Böhringer Mannheim, Germany) with standard reagents supplied by the company. High-density lipoprotein cholesterol (HDL-C) was measured enzymatically from the supernatant obtained after precipitation of apolipoprotein B-containing lipoproteins (very low-density lipoprotein [VLDL] and LDL) by dextran sulphate and Mg ++ (HDL-Cholesterol kit, Sigma Diagnostics, USA). The intra-assay and inter-assay variation coefficients were less than 1%. Low-density lipoprotein (LDL-C) levels were then calculated using the Friedwald formula (all participants had TG values <400 mg/dl). Statistical analysis was carried out using the SPSSv10 software package. Results were expressed as mean±standard deviation (SD). Data from before and at the end of Ramadan were compared using the paired t-test. Relationships between variables were evaluated using the Pearson rank correlation test. The level of statistical significance was P<0.05. Results Fasting caused a significant reduction in weight and BMI in men, and in waist circumference in women (Table 1). Neither systolic nor diastolic blood pressure was affected by Ramadan fasting. Fasting plasma glucose decreased significantly in both men ( P<0.0001) and women (P<0.0001). None of the participants reported symptoms of hypoglycaemia during fasting. There was a significant correlation in women between fasting serum glucose and total calorie intake (P=0.001). We detected improvements in the lipid profile of both men and women. Serum T-C, TG and LDL-C decreased and HDL-C increased significantly with Ramadan fasting. There was a significant correlation between reduced calorie intake and increased HDL-C in women (P<0.03). Reduction of calorie intake also correlated with a decrease in LDL-C in men (P=0.08). A significant reduction in total daily calorie intake occurred during Ramadan in both women and men (Table 2). The average duration of the daily fast was 11.5±0.5 hours.