Increasing Overnight Fluid Intake and Kidney Function During Ramadan Fasting: A Randomized Controlled Trial

Abstract

Background: All healthy Arab individuals are obligated to abstain from eating, drinking, and sexual relations from dawn to sunset during Ramadan, which is one of the 5 pillars of Islam. Fasting effects various body systems, apart from the renal system. Fasting can also increase serum creatinine levels because of dehydration. Our aim was to examine the effects of increased fluid intake during the night on serum creatinine and urea levels.

Methods: This randomized controlled trial included 58 healthy subjects who were randomly divided into 2 groups of 29. The hydrated group drank 2 to 3 L of fluid from sunset to the dawn of the next day. Kidney function was measured before, during, and 1 month after Ramadan.

Results: After adjustment for sociodemographic variables, the control group exhibited higher means of serum concentrations of creatinine and urea and lower estimated glomerular filtration rate than the hydrated group. The Ramadan group exhibited highest means of serum levels of creatinine and urea and the lowest estimated glomerular filtration rate compared with the pre- and post-Ramadan periods. All results were statistically significant at P <.05.

Conclusions: We found that Ramadan fasting was not associated with a permanent increase in serum creatinine or urea. For those groups with a high fluid intake, serum creatinine and urea were significantly lower than the controls suggesting a favorable effect of hydration during the nonfasting hours. This compensated with the dehydration occurring during daylight, as dehydration is responsible for increased concentrations of urea and creatinine. This study adds further evidence that Ramadan fasting does not affect the renal system of healthy subjects; however, fluids should be increased at night, during nonfasting hours.