Bone Abstracts

Sarcopenia has been indicated as one of the important markers of frailty among the elderly. This study aims to evaluate mortality risk among Japanese elderly persons with sarcopenia, taking into account lifestyle and physical factors.

From among a population-based community cohort, the Adult Health Study conducted at RERF, 1880 subjects (626 men and 1 254 women) aged 47–95 years old were enrolled in a prospective and longitudinal cohort study in Hiroshima, Japan. These individuals underwent physical examinations including lean body mass using a dual X-ray absorptiometry (DXA) as well as a questionnaire during the period 1994–1995, and were followed for mortality status through 2007. Sarcopenis was defined as having skeletal muscle mass index (SMI) of 6.87 kg/m² or less for men and 5.46 kg/m² or less for women. Mortality risk was estimated using an age-stratified Cox proportional hazards model. In addition, sex, radiation dose, lifestyle and physical factors such as smoking status, alcohol intake, total cholesterol, blood pressure, and diagnosed diseases were included as adjustment factors for analysis of total mortality and mortality from each cause of death.

There were a total of 496 deaths, 42 coronary heart disease deaths, 67 stroke deaths, 116 respiratory disease deaths including 90 pneumonia deaths, and 183 cancer deaths during the follow-up period. Sarcopenia showed a significant association with all-cause mortality among men (HR=1.9, 95% CI 1.3–2.9, P=0.0006), after adjustment was made for atomic-bomb radiation exposure, and lifestyle and physical factors in men. Sarcopenia was also significantly associated with respiratory deaths (HR=2.6, 95% CI 1.2–5.4, P=0.01) in men. There was no significant association between sarcopenia and increased mortality among women.

In conclusion, sarcopenia predicted all-cause deaths and respiratory deaths in men, but not in women.

This study was supported by the research funding for Longevity Sciences from the Ministry of Health and Welfare.