Influence of diet on microalbuminuria in type 1 diabetic persons: Prospective evaluation over 5 years

The possible influence of dietary components on the progression or regressi on of microalbuminuria (MA) in type 1 diabetic patients was investigated pr ospectively over 5 years. The dietary intake of 47 patients with type 1 dia betes and MA (20-200 mu g/min.), well instructed in diabetes management was observed in bimonthly intervals. Accuracy of 4-day diet protocols was veri fied 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 f rom 37 patients with good compliance over a 5 year period have been used fo r multiple stepwise regression analysis. Taking into consideration Body mas s index (BMI), blood pressure, HbA1c and time, MB was used as dependent var iable, 16 dietary variables with a bivariate significance p < 0.05 as indep endent variables. The regression analysis (R-2=0.589. p=0.0015) showed clea r 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 con sumed mono- and disaccharides (beta = 0.479, p = 0.018). There was no signi ficant association with the amount of protein intake (beta = 0.319, p = 0.1 52). Looking at the fatty acids in particular there were significant associ ations to MA with myristic acid, arachidonic acid and negatively with linol eic acid. Splitting the data in tertiles according to the amount of salt in take (I: < 6 g/d, II: 6- 10 g/d, III: > 10g/d) we could show in addition to the overall effect an intraindividual influence on the amount of MA (MA-me ans+/-SD: I: 45 +/- 56 mu g/min., II: 61 +/- 59, III: 81 +/- 74, p < 0.001 between the groups). There were no significant differences between the grou ps in mean blood pressure, HbA1c and BMI.