Relation of nutrient intake to microalbuminuria in nondiabetic middle-aged men and women: International Population Study on Macronutrients and Blood Pressure (INTERMAP)

Background: Microalbuminuria (MA) is a risk factor for cardiovascular and renal disease. However, little is known about the relation of nutritional factors to MA, especially in individuals without diabetes. Methods: Data collected by the International Population Study on Macronutrients and Blood Pressure from 1997 to 1999 were used to assess relations of multiple dietary factors (energy intake, macronutrients, and micronutrients) independent of lifestyle-related cardiovascular risk factors to MA (urinary albumin excretion, 30 to <300 mg/24 h). The study population included 4,381 Chinese, Japanese, UK, and US men and women without diabetes aged 40 to 59 years (17 population samples) without macroalbuminuria. Results: MA prevalences ranged from 3.1% to 5.5% for men and 2.6% to 4.6% for women in the 4 countries. With adjustment for age and country, the following nutrients considered singly (of 29) were related in logistic regression analyses to MA prevalence (P < 0.05): for men, inversely, iron, vitamin C and E, estimated total simple sugar, ω-6 fatty acid, polyunsaturated fatty acid, and calcium (all expressed as caloric density) intake; for women, directly, 24-hour urinary sodium excretion and alcohol intake. In multivariate analyses, sugar, iron, polyunsaturated fats, and vitamin C and E intake (in men) and alcohol intake (women only) remained associated with MA (P < 0.05). MA also was related directly to body mass index (P < 0.05), blood pressure (P < 0.001), and smoking (P > 0.05) and inversely to education (P < 0.05 in women). Conclusion: In cross-sectional analyses, several nutrients were related to MA among men. Additional studies are required to confirm these findings.