Dynamics of Blood Lipids Before, During, and After Diurnal Fasting in Inactive Men: Quasi-Experimental Study.

Background: There is a lack of investigation into the dynamics of blood lipids before, during, and after diurnal fasting, especially in inactive men.

Objective: This study determined dynamic changes in blood lipids in inactive men before, during, and after they underwent diurnal fasting.

Methods: A total of 44 young men aged a mean 27.6 (SD 5.8) years were recruited to evaluate their habitual physical activity and diet using a questionnaire developed for this study. Body composition was evaluated using a bioelectrical impedance analysis machine (Tanita BC-980). An 8-ml blood sample was collected to evaluate blood lipids and glucose. All measurements were taken 2-3 days before Ramadan, during Ramadan (at week 2 and week 3), and 1 month after Ramadan. A 1-way repeated measures ANOVA was used to compare the measured variables before, during, and after the month of Ramadan. When a significant difference was found, post hoc testing was used. Differences were considered significant at P<.05.

Results: There was a significant reduction in low-density lipoprotein during Ramadan compared to before and after Ramadan (83.49 mg/dl at week 3 vs 93.11 mg/dl before Ramadan [P=.02] and 101.59 mg/dl after Ramadan [P=.007]). There were significant elevations in fasting blood glucose (74.60 mmol/L before Ramadan vs 81.52 mmol/L at week 3 [P=.03] and 86.51 mmol/L after Ramadan [P=.01]) and blood pressure (109 mm Hg before Ramadan vs 114 mm Hg after Ramadan; P=.02) reported during and even after the month of Ramadan, although both fasting blood glucose and blood pressure were within normal levels.

Conclusions: Ramadan fasting could be an independent factor in reducing low-density lipoprotein. Further investigations are encouraged to clarify the impact of diurnal fasting on blood lipids in people with special conditions.