Macronutrient and antioxidant consumption in relation to renal function

Background: It has been postulated that there is some correlation between dietary factors and serum creatinine. Objective: To determine the correlation between the consumption of macronutrients and antioxidants intake with serum creatinine level and GFR . Methods: Out of the 15005 subjects who participated in the Tehran Lipid and Glucose Study (TLGS), 743 ones older than 20 years were randomly selected for nutritional assessment. Excluding under and overreporters, 486 subjects remained in the study whose dietary data was detected by two 24-hour dietary recalls .Serum creatinine was measured by selectra 2 outo analyzer and GFR was detected. Adjusting for the effect of age, sex, weight, height, WHR and serum TG, LDL, HDL and cholesterol ANCOVA was used for statistical analysis. Subjects were categorized into 3 groups: equivalent to and less or more than recommended dietary allowances (RDA). Findings: Mean (±SD) of serum creatinine was 1.04±0.16 mg/dl. In persons who consumed more than 45-56 gr protein per day, serum creatinine level was significantly higher than in subjects whose intake was equvalent to or less than RDA (1.07±0.1 vs 0.90±0.1 and 0.01±0.1 mg/dl respectively, p<0.001). And also in persons with more than 65 gr protein intake per day, GFR was more than two other groups (114 ± 18 vs 99 ± 19 and 91 ± 31 mg/m. P < 0.01 ). Subjects with 0.02-0.1 mg selenium intake per day had the highest level of creatinine (1.07±0.1 mg/dl) in comparison to consumption of more than 0.1 or less than 0.02 (P<0.001). There was no correlation between vitamin A and C intake and the percentage of carbohydrate and fat consumption, and serum creatinine level whether equivalent to, or more and less than RDA. Conclusion: This study showed a correlation between different amounts of protein and selenium intakes and serum creatinine concentration. These correlations need to be taken into account in the future related studies.