Samenvatting

Introduction: The current daily recommendation of dietary protein for adults is 0.8 g kg BW-1 d-1. Age-related loss of fat-free mass is partly the result of insufficient protein intake in older adults. Recent studies show that a daily intake of 1.2 – 1.5g kg BW-1 of dietary protein may be needed to preserve the muscle tissue in older adults who suffer from acute or chronic diseases. So far, only few studies focused on protein intake and body composition in older adult with obesity and diabetes type 2. Because of reduced insulin functioning, a possible relation between protein intake and fat-free mass can be different in diabetic older adults compared to non-diabetic older adults. The objective of this study was to investigate whether there is a relation between protein intake and body composition in older adults with obesity and diabetes type 2 aged 55-85. Methods: This study included 122 older adults with diabetes type 2 and obesity. PROBE baseline data was used for data analysis. Parameters for body composition were appendicular lean mass, fat free mass and fat mass . Protein intake (g kg BW-1 d-1) was based on 3-day food records. Body composition was measured by dual-energy X-ray absorptiometry. ANOVA compared for significant differences between the protein categorisations (≤0.8 g kg adj BW-1 d-1, 0.8 – 1.2 g kg adj BW-1 d- 1 and ≥1.2 g kg adj BW-1 d-1). Adjusted weight was implemented in the figures to correct for body weight. Regression analysis is executed with body composition as outcome variables and protein intake as main determinant. Body weight was included as confounder. Results: The mean age of the subjects is 66.6 ± 5.0 years, 64.5% men, 35.5% female. Mean protein intake is 1.0 ± 0.34 g kg adj BW-1 d-1. In the study group 9 (20%) of the participating women (n=43) and 22 (28%) of the men (n=78) met the protein recommendations of 1.2 g kg BW-1 d-1 or higher. 1 g kg BW-1 d-1 extra protein associated positive with ALM (bèta is 3.1 kg ± 1.1 SE), P=0.006, 95% CI: 0.9 ; 5.3 kg). 1 g kg BW-1 d-1 extra protein associated positive with FFM (bèta is 6.3 kg ± 2.3 SE, P=0.008, 95% CI: 1.6 ; 10.9). 1 g kg BW-1 d-1 extra protein associated negative with FM (bèta is -6.5 kg ± 2.1 SE, P= 0.002, 95% CI: -10.67 ; -2.351). Conclusion: Adequate protein intake relates positive with appendicular lean mass and fat free mass, while fat mass shows a negative relation. These findings support evidence for a higher protein intake for older adults with obesity and type 2 diabetes to preserve FFM. This study acknowledges protein intake as one of the many factors that influences muscle protein synthesis. Explorative cross- sectional study can’t conclude a causality. Results should always be supported by other (future) studies.