Changes in serum leptin concentrations during Ramadan fasting in lean and obese individuals

الملخص EN

Objective : To test the effects of long-term diurnal abstention from food and fluids followed by nocturnal gorging (Ramadan Fasting) on the serum level of leptin.

Setting : Arabian Gulf University, Bahrain, During the holy month of Ramadan.

Subjects and methods : The study was conducted on lean (n = 10, BMI = 24.2 ± 0.8) and obese (n = l 1, BMI = 31.8 ± 1.8) healthy male volunteers.

Seum levels of leptin, insulin and glucose as well as caloric intake and food composition were-estimated at baseline (day 1), as well as in days 14 and 28 of the month of Ramadan.

Results : Baseline serum levels of leptin was significantly higher in obese (9.55 ± 1.30 ng / dl) compared with lean subjects (3.90 ± 0.68 ng / dl) and correlated positively with BMI (r = 0.66, p = 0,004).

Furthermore, serum leptin levels exhibited a significant progressive increase by 47 % and 32 % throughout the month in lean and obese subjects, respectively.

No significant correlation was found between changes in serum leptin levels and changes in the measures of adiposity, or serum insulin and glucose in either lean or obese groups.

Compared with baseline intake, total energy intake increased at day 14 and food composition altered towards consuming more fat in both groups.

Conclusions : Ramada fasting is associated with a significant elevation in serum leptin.

This elevation is unlikely to be mediated by changes in body adiposity or serum levels of insulin or glucose.

However, altered composition of food or increased energy intake could play a role.

The exact mechanism responsible for increased serum level of leptin with Ramadan fasting requires further investigation.