Brief communication: Respiratory function is closely associated with basal metabolic rate in elderly persons.

To investigate the association between respiratory function and basal metabolic rate (BMR), pulmonary function indices and BMR were measured in 251 elderly persons using a spirometer and a body composition analyzer. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were more strongly correlated with BMR (r = 0.48 and r = 0.43, p < 0.01) than with lean body mass (r = 0.36 and r = 0.35, p < 0.01) and waist-to-hip ratio (r = -0.29 and r = -0.32, p < 0.01) in elderly men. FVC and FEV1 in elderly men with BMR > or = 1390 kcal/day averaged 4.05 +/- 0.56 L and 3.19 +/- 0.45 L, which were significantly above the values (3.54 +/- 0.51 L and 2.80 +/- 0.42 L, p < 0.01) in men with BMR < 1390 kcal/ day. Prevalences of the subjects with elevated FVC or FEV1 were significantly higher in the group of men with BMR > or = 1390 kcal/day than in those with BMR < 1390 kcal/day (66.0% and 68.0% vs 28.3% and 33.9%, p < 0.01). No significant differences were observed between the postmenopausal women with BMR > or = 1135 kcal/day and those with BMR < 1135 kcal/day. In summary, respiratory function is more closely associated with BMR in elderly persons, compared to lean body mass, waist-to-hip ratio, or body fat mass, and these associations are stronger in men than in women.