Relations Between Urinary Albumin Excretion and a Dietary Intake of Fruits in Patients With Type 2 Diabetes

BACKGROUND: It was reported that microalbuminuria and a decline in renal function were associated with cardiovascular disease (CVD) mortality and renal events and prognostic serious complications. Dietary factors and nutrients affecting microalbuminuria in type 2 diabetes remain unclear, and accordingly we conducted a cross-sectional study on the possible relevance of dietary factors to urinary albumin excretion in patients with type 2 diabetes. METHODS: Forty-two patients with type 2 diabetes participated in this study, and these subjects were categorized into patients without microalbuminuria group with urine albumin-to-creatinine ratio (ACR) of less than 30 mg/g Cr (n = 29) and a microalbuminuria group with ACR of 30 - 299 mg/g Cr (n = 13). ACR levels were measured using spot urine samples. At the time of examination, body mass index (BMI) and systolic and diastolic blood pressures were measured and recorded. We performed sampling fasting-blood and spot urine and conducted a food frequency questionnaire based on food groups to examine dietary habits for the past 1 - 2 months. RESULTS: There were no significant differences in sex, age, duration, BMI, blood pressures, biochemical data, and the median of daily intakes of energy and macronutrients between patients without microalbuminuria and microalbuminuria groups. In the intake of 17 food groups per day, fruits were significantly lower in the microalbuminuria group than in patients without microalbuminuria group (the median was 38 g vs. 120 g/day, P < 0.05), but intakes of other food groups were not significantly different between the two groups. Moreover, we examined a model of partial correlation between ACR to the intake of fruits, adjusted by age, sex, glycated hemoglobin and BMI. This partial correlation was insignificantly seen but close to a significant level (partial correlation coefficient: -0.270, P = 0.102). CONCLUSIONS: These results suggest that the intake of fruits may be inversely associated with microalbuminuria in Japanese type 2 diabetic patients. It would be necessary to investigate the exact types and amounts of fruits to be consumed to address microalbuminuria.