The association between dietary micronutrient patterns and odds of diabetic nephropathy: A case-control study

Uncontrolled diabetes can lead to diabetic nephropathy (DN). The aim of the study was to investigate the relationship between different dietary micronutrient patterns and risk of DN in women. This was a case-control study. One hundred and five patients had DN (defined as urinary mg of albumin per gram of creatinine >= 30 mg/g) were chosen as the case and 105 women without DN were chosen as control. Dietary intakes were assessed by a semi-quantitative food frequency questionnaire. Principal component analysis with varimax rotation was used to derive the micronutrient patterns. Patterns were divided into two groups of lower and higher than median. Logistic regression was used to discern and find the odds ratio (ORs) of DN, and its 95% confidence interval (CI) based on the micronutrient patterns in crude and adjusted model. Three patterns which were included, (1) mineral patterns such as chromium, manganese, biotin, vitamin B6, phosphorus, magnesium, selenium, copper, zinc, potassium, and iron, (2) water-soluble vitamin patterns such as vitamin B5, B2, folate, B1, B3, B12, sodium and C, and (3) fat-soluble vitamin patterns such as calcium, vitamin K, beta carotene, alpha tocopherol, alpha carotene, vitamin E, and vitamin A, were extracted. An inverse relationship was found between risk of DN and following mineral patterns and fat-soluble vitamin patterns in adjusted model (ORs = 0.51 [95% CI 0.28-0.95], p = .03) and (ORs = 0.53 [95% CI 0.29-0.98], p = .04), respectively. No relationship was seen between water-soluble vitamin patterns and risk of DN in crude and adjusted model but the significance was decreased in adjusted model. The risk of DN was 47% decreased after high adherence of fat-soluble vitamin patterns. In addition, we saw a 49% decrease of risk of DN in high adherence group of mineral patterns. The findings confirm that renal-protective dietary patterns can reduce risk of DN.