Skeletal muscle mass abnormalities are associated with survival rates of institutionalized elderly nursing home residents.

Abstract

Knowledge about the changes in skeletal muscle mass in nursing home residents is very limited. We hypothesized that such patients have different types of skeletal muscle mass abnormalities that may affect mortality rates. Therefore, the objective of this study was to evaluate the prevalence and extent of skeletal muscle mass decline, its different clinical phenotypes (sarcopenia, wasting/atrophy and cachexia) and the mortality rates associated with these abnormalities. A retrospective chart-review study comprising 109 institutionalized nursing home residents. Body mass index, body fat mass, fat free mass, skeletal muscle mass and survival rates were assessed. Skeletal muscle mass abnormalities were found among 73 out of 109 (67.0%) patients and were more prevalent in males compared with females (97.8% and 43.8%, respectively, p<0.001). Most of these patients had muscle wasting/atrophy (51.4%) or sarcopenia (40.3%), and 9.7% suffered from cachexia. One third of the patients with abnorrmal skeletal muscle mass showed a moderate decline of skeletal muscle mass (34.7%) while the remainder (65.3%) had very low levels of skeletal muscle mass. Each group was characterized by typical medical conditions associated with skeletal muscle mass abnormality. A Kaplan-Meier survival plot of mortality showed only lower one-year survival rates in the group with sarcopenia (60%) and muscle atrophy or cachexia (53%), compared with elderly participants with a normal skeletal muscle mass (73%), (p<0.0001). There were no significant differences in 1-year mortality rates between patients with abnormal skeletal muscle mass (whether sarcopenia, cachexia or wasting). About two thirds of nursing home patients show skeletal muscle mass abnormalities, most within the range of very low skeletal muscle mass rather than moderately low skeletal muscle mass, that are associated with shorter survival rates, compared with normal skeletal muscle mass patients.