Physical fitness and 6.5-year mortality in an 85-year-old community-dwelling population

Although poor physical fitness is known to be associated with increased mortality in adult and elderly populations, this association is not conclusive in very elderly. The purpose of the present study was to evaluate the association for a very old community-dwelling population. The participants (90 males, 117 females) were 85-year-old individuals residing in Fukuoka, Japan. Baseline examinations including muscle strength of the handgrip and leg extension, one-leg standing, leg stepping rate, and walking were performed in 2003 and these subjects were followed for 6.5 years. During the follow-up period, 81 individuals (49 males and 32 females) died. Handgrip strength and leg extension strength at age 85 were stronger in surviving men than in non-survivors. Total mortality adjusted for both gender and serum level of total cholesterol fell 5-6% with a 1-kg increase in the handgrip strength of a single hand or both hands. Total mortality also decreased 2% with a 1 kg increase in the leg extension strength of both legs. With adjustment for gender and total cholesterol, mortality fell by 57% in participants of the walking test and fell by 45% in participants of the stepping-rate test compared to mortality in nonparticipants. No association was found between mortality and participation in the handgrip strength test, leg extension strength test, or one-leg standing time test. In conclusion, not only poor muscle strength in handgrip or leg extension, but also nonparticipation in walking test or leg-stepping test were independent predictors of total mortality in a very elderly population.