Nutritional Risk Factors in Albuminuria and Retinopathy in Patients Newly Diagnosed With Type 2 Diabetes: A Cross-sectional Case Series Study

Abstract

Background/aim: Although nutritional risk factors for developing complications in type 2 diabetes mellitus (T2DM) have been examined, the effect of protein intake on nephropathy is debated, and there is little research on retinopathy. This cross-sectional case-series study aimed to examine the risk factors, including nutritional status, for complications in patients newly diagnosed with T2DM.

Patients and methods: Fifty-four patients were recruited, based on the results of examinations of blood glucose and/or glycated hemoglobin level for T2DM. To evaluate nutritional status, blood and urine examinations were performed and the Food Frequency Questionnaire was administered. Two-way analysis of variance, Fisher's exact test and logistic regression analyses were performed.

Results: The patients were categorized into four groups: 24 without albuminuria and without retinopathy, four without albuminuria with retinopathy, 21 with albuminuria without retinopathy, and five with albuminuria with retinopathy. Logistic analysis of albuminuria revealed that estimated sodium intake was significantly independent as the explanatory factors of age, sex, and body mass index. Patients with retinopathy had significantly higher blood urea nitrogen, and significantly lower plasma total protein levels than patients without retinopathy, suggesting that retinopathy is related to a higher catabolic state. Through a questionnaire on food intake, patients with retinopathy had a significantly lower intake of fat and monounsaturated fatty acids and a significantly higher intake of iodine based on intake of seaweed, corrected for energy intake, than patients without retinopathy.

Conclusion: The present study may lead to planning a large cohort study for examining nutritional risk factors related to complications in patients newly diagnosed with T2DM in Japan.

Keywords: Blood urea nitrogen; food intake questionnaire; iodine intake; retinopathy; sodium intake.