Baseline comorbidity associated with the short-term effects of exercise intervention on quality of life in the Japanese older population: an observational study.

UNLABELLED: Tamari K. Baseline comorbidity associated with the short-term effects of exercise intervention on quality of life in the Japanese older population: an observational study.

OBJECTIVE: To investigate predictors of responses to a class-based exercise program in terms of health-related quality of life (HRQOL).

DESIGN: A 3-month prospective cohort study.

SETTING: General community.

PARTICIPANTS: A sample of community-dwelling Japanese volunteers (N=137; aged > or =65y) initially was included in the study. More than three fourths (76.6%) completed the follow-up examination.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Eight domains of the Medical Outcomes Study 36-Item Short-Form Health Survey, version 2, were used as main outcome measures. Candidate predictors included demographic variables, medical history of chronic diseases, and results of a set of physical performance tests at the baseline examination. Logistic regression models were used to detect predictors.

RESULTS: Bodily pain, vitality, social functioning, and mental health domains improved after the intervention (P<.01 vs baseline). The absence of diabetes mellitus showed an association with a good response in the identified domains, with an adjusted odds ratio (OR) of 2.88 (confidence interval [CI], .90-9.25). More than 20% of participants had negative changes in the physical functioning, physical role, general health, and emotional role domains at follow-up. The presence of osteoarthritis significantly predicted a poor response in these domains, with an adjusted OR of 6.75 (CI, 1.58-28.83).

CONCLUSIONS: Three months of class-based exercise is effective in alleviating bodily pain and the mental components of HRQOL; however, the effect of exercise on the physical domains of HRQOL may be limited. The presence of osteoarthritis may moderate the effects of exercise on HRQOL physical components.