Association between involuntary weight loss with low muscle mass and health-related quality of life in community-dwelling older adults: Nationwide surveys (KNHANES 2008-2011).

OBJECTIVES: To investigate the relationship between involuntary weight loss with low muscle mass and health-related quality of life in a large representative sample of older adults.

METHODS: A nationwide cross-sectional study based on data from the Korea National Health and Nutritional Examination Survey, 2008 to 2011. Study participants included 2249 individuals aged ≥70 years. The participants reported an unintentional weight loss >3 kg in the past year. Appendicular lean mass was measured using dual-energy X-ray absorptiometry and calculated with the appendicular lean mass index. Health-related quality of life was measured using the EuroQol-5 dimension (EQ-5D) instrument. Univariate and multivariate survey logistic regression models were used to calculate odds ratios (OR) with 95% confidence intervals (95% CI) for the lowest quintile of the EQ-5D index.

RESULTS: In total, 39.1% of participants were male and 60.9% were female. The weighted mean age was 75.6 years (95% CI; 75.3-75.9). Clinically significant weight loss is typically 5% of one's body weight; average, 2.8 kg (3.1 kg for men; 2.7 kg, women) for our participants. Compared with the normal reference group and after adjusting for potential confounders, the ORs for the lowest quintile of the EQ-5D indices were 1.39 (95% CI, 0.92-2.10), 2.56 (95% CI, 1.56-4.18), and 3.40 (95% CI, 2.05 to 5.63) for the low muscle mass, involuntary weight loss, involuntary weight loss with low muscle mass groups, respectively.

CONCLUSION: Involuntary weight loss combined with low muscle mass was more closely associated with poor quality of life than involuntary weight loss alone in community-dwelling older adults.