Effect of Caffeinated Coffee Consumption on Renal Function in Health and Diabetes: A Double-Edged Sword

Introduction: Evidently, caffeinated coffee (CCAF) consumption is associated with decreased risk of diabetes mellitus, however, its effect on the kidney in diabetes and health is yet to be thoroughly researched and ascertained. This formed the focus of the present study.

Methods: Sixty (30 male and 30 female) animals were divided into 12 groups (6 pairs) (n=5 per group). Animals in group 1 served as normal control (NCTRL) and were given standard feed and water only. Group 2 animals received standard feed plus CCAF. Group 3 was the diabetic (DIA) alone group while groups 4, 5, and 6 were DIA plus CCAF treatment. After 4 weeks of treatment, the animals were sacrificed and blood obtained and analyzed for the biochemical indices of renal function and carbohydrate metabolism using standard methods.

Results: The consumption of CCAF was not associated with any significant change in serum creatinine (SCr) and electrolyte levels in the CCAF control group compared with the NCTRL group. However, SCr levels increased significantly in DIA alone and DIA plus CCAF groups compared with the NCTRL group. Serum urea increased and decreased significantly in DIA alone and DIA plus CCAF treatment groups respectively. Serum glucose, insulin and HOMA-IR increased and decreased significantly in DIA alone group and DIA plus CCAF treated groups respectively compared with NCTRL and CCAF control groups.

Conclusion: CCAF consumption may not adversely affect renal endpoints in healthy persons; however, those with diabetes mellitus and impaired renal function should avoid CCAF consumption.

Keywords: Caffeine, Coffee, Renal endpoints, insulin, Diabetes.