Dietary Protein Intake Is a Determining Factor for Skeletal Muscle Mass in Japanese Older People with Type 2 Diabetes: A Cross-Sectional Study.

Abstract

Background/Objectives: In this study, we investigated the free-living nutritional intake of older people with type 2 diabetes (T2D) and examined the relationship between nutritional intake and skeletal muscle mass. Methods: Subjects aged 65 years or older with T2D who visited the Kansai Electric Power Hospital between 2015 and 2017 and had not yet received nutritional guidance or intervention at our hospital comprised the study group. Nutritional intake (energy, protein, lipid, and carbohydrate intake) was calculated from a 3-day dietary diary by the participants, and the relationship between nutritional intake and the skeletal muscle index (SMI) was retrospectively investigated. Results: In total, 91 subjects were recruited (53 males and 38 females, aged 70.3 ± 5.5 years). The energy and protein intakes were 28.7 ± 6.1 kcal/kg/day and 1.2 ± 0.3 g/kg/day, respectively. A significant positive correlation was found between the SMI and energy and protein intake (p < 0.001). Multiple regression analysis with the SMI as the dependent variable and age, gender, protein intake, lipid intake, and carbohydrate intake as the independent variables revealed protein intake to be an independent determinant of the SMI. Conclusions: In older people with T2D, the energy and protein intakes are likely to be lower than the recommended levels. Appropriate interventions for protein intake and energy intake are recommended to prevent loss of muscle mass in Japanese older people with type 2 diabetes.