[Effect of nutrition on microalbuminuria in patients with type 1 diabetes: prospective data evaluation over 5 years]

The possible influence of dietary components on the progression or regression of microalbuminuria (MA) in type 1 diabetic patients was investigated prospectively over 5 years. The dietary intake of 47 patients with type 1 diabetes and MA (20-200 micrograms/min.), well instructed in diabetes management was observed in bimonthly intervals. Accuracy of 4-day diet protocols was verified by comparing the amount of documented protein intake with the measured nitrogen excretion. Non compliance was defined as deviation more than 30% between both values. These patients were eliminated from the study. Data from 37 patients with good compliance over a 5 year period have been used for multiple stepwise regression analysis. Taking into consideration Body mass index (BMI), blood pressure, HbA1c and time, MA was used as dependent variable, 16 dietary variables with a bivariate significance p < 0.05 as independent variables. The regression analysis (R2 = 0.589, p = 0.0015) showed clear associations between MA and the amount of salt intake (beta = 0.683, p < 0.002), saturated fatty acids (beta = 0.342, p = 0.029) and the amount of consumed mono- and disaccharides (beta = 0.479, p = 0.018). There was no significant association with the amount of protein intake (beta = 0.319, p = 0.152). Looking at the fatty acids in particular there were significant associations to MA with myristic acid, arachidonic acid and negatively with linoleic acid. Splitting the data in tertiles according to the amount of salt intake (I: < 6 g/d, II: 6-10 g/d, III: > 10 g/d) we could show in addition to the overall effect an intraindividual influence on the amount of MA (MA-means +/- SD: I: 45 +/- 56 micrograms/min., II: 61 +/- 59, III: 81 +/- 74, p < 0.001 between the groups). There were no significant differences between the groups in mean blood pressure, HbA1c and BMI.