Comparison of the effects of frequent versus conventional nutritional interventions in patients with type 2 diabetes mellitus: A randomized, controlled trial

Abstract

Aims/introduction: This randomized controlled trial aimed to determine whether frequent nutritional education improves the clinical parameters associated with the onset and progression of diabetic kidney disease in type 2 diabetes mellitus patients.

Materials and methods: A total of 96 patients with type 2 diabetes and diabetic kidney disease were randomly assigned to the intensive intervention group that received nutritional education at every outpatient visit, and the usual intervention group that received nutritional education once a year. The anthropometric parameters, blood pressure, blood chemistry, albuminuria, protein and salt intake, and prescribed medications of 87 patients who completed the 2-year follow up were analyzed.

Results: In the intensive intervention group, body mass index and salt intake significantly decreased over the study period. Hemoglobin A1c levels and body fat percentage were significantly lower in the intensive intervention group than in the usual intervention group. At the end of the 2-year intervention period, the intensive intervention group had significantly lower salt intake (8.1 vs 9.4 g/day) than the usual intervention group. A significant positive correlation was found between salt intake and albuminuria in the overall group and intensive intervention group (r = 0.26, P = 0.02, and r = 0.36, P = 0.02, respectively). The intensive intervention group had a significantly lower insulin use rate than the usual intervention group after the 2-year intervention period (18% vs 42%). No differences were found in estimated glomerular filtration rate and albuminuria.

Conclusion: Intensive nutritional education is useful for alleviating the risk factors associated with the onset and progression of diabetic kidney disease.

Keywords: Body composition; Hemoglobin A1c; Nutritional education.

Figure 1

Process of patient selection in this study. Of the 127 patients who visited the Jichi Medical School Hospital, met the enrollment criteria and were provided with an explanation for obtaining consent, just 102 were able to provide consent. A total of 96 patients were enrolled in the study, excluding five patients who withdrew their consent and one patient who did not meet the selection criteria. The 96 patients were randomly divided into two groups: (i) those who received nutritional education by a dietitian at each outpatient visit; or (ii) those who received nutritional education by a dietitian once a year. After excluding nine patients (five patients who refused nutritional education in the intensive intervention group [INT], and one patient who refused nutritional education, one patient who did not come to the hospital, one patient who was transferred after hospitalization and one patient who did not receive a request for nutritional education from a physician in the control group [CON]), 44 patients in INT and 43 patients in CON who completed 2 years of follow‐up were included in the randomized controlled trial. DKD, diabetic kidney disease.

Figure 2

Changes of clinical, physical and nutritional factors over the 2‐year study period. In the intensive intervention group (INT), both body mass index (BMI) and salt intake decreased significantly over the study period (P = 0.020 and P =0.023, respectively). In addition, hemoglobin A1c (HbA1c) and body fat percentage were significantly lower in the INT group than in the control (CON) group in a comparison that took into account changes over time during the 2‐year study period. (P = 0.047 and P = 0.003, respectively). No differences were observed for the other parameters. Values are presented as the mean ± standard error. The horizontal axis indicates the study period, whereas the vertical axis indicates the HbA1c levels, BMI, body fat percentage and salt intake. Changes in each item were analyzed by repeated measures analysis of variance or the Friedman test, whereas comparisons between the two groups were carried out using the two‐way analysis of variance or mixed‐effects models. *Significant differences in the change over time in each group; ^†significant differences in the change over time between the two groups.