Association between low muscle mass, functional limitations and hospitalisation in heart failure: NHANES 1999-2004

Background/objectives: muscle mass decreases with age, and heart failure (HF) patients may experience greater reductions due to pathophysiological processes associated with this disease. Reduced muscle mass may predispose HF patients to functional limitations and increased morbidity and mortality. This study estimated the associations between HF, low muscle mass (LMM), functional limitations and hospitalisation, as well as the combined effect of HF and LMM on these outcomes in a nationally representative sample. Design: a cross-sectional survey. Setting: the National Health and Nutrition Examination Survey 1999-2004. Subjects: a total of 402 HF (weighted 3,994,205) and 7,061 non-HF participants (weighted 91,058,850), a parts per thousand yen45 years with dual-energy X-ray absorptiometry measurements. Methods: the 20th percentile of the sex-specific distribution of lean appendicular mass residuals from linear regression with height and fat mass as predictors, served as the LMM cut-point. Logistic regression provided adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association of HF and LMM with functional limitations and hospitalisation. Results: there were statistically significant adjusted associations between HF and limitations in household chores, walking one-fourth of a mile and hospitalisation (OR (95% CI): 2.5 (1.7 -3.8), 1.9 (1.2 -3.0) and 1.6 (1.1 -2.4), respectively). LMM was significantly associated with limitations in household chores and walking one-fourth of a mile (OR (95% CI): 1.5 (1.2, 1.9) and 1.4 (1.2, 1.7), respectively). Interaction between HF and LMM was noted for the associations with functional limitations. Conclusions: this hypothesis-generating study found a synergistic interaction between HF and LMM; the presence of LMM increased the negative effects of HF. HF patients may experience increased disease burden due to LMM.