Association between body composition and pulmonary function in elderly people: the Korean Longitudinal Study on Health and Aging.

The age-related increase in body fat and decrease in muscle mass are associated with increased morbidity in elderly populations. Pulmonary function also decreases with age, but no study has investigated whether regional body composition is associated with pulmonary function in an older population. The Korean Longitudinal Study on Health and Aging is a community-based cohort study of people aged > 65 years selected by random stratified sampling. Anthropometrics, biochemical factors, and lung function by spirometry were evaluated in 439 men (mean age of 75.9 ± 8.6 years) and 561 women (mean age of 76.0 ± 8.8 years). Dual-energy X-ray absorptiometry (DXA) was performed to assess the whole and regional body composition. Computed tomography (CT) was also used to measure fat or muscle distribution at the abdominal and mid-thigh levels. Although pulmonary function and muscle mass were inversely related to age, fat mass was not. After adjusting for age, height, BMI, smoking and exercise status, and high sensitivity C-reactive protein (hsCRP), fat mass in trunk or central area was inversely associated with lung function in both sexes (P < 0.01). Men with more muscle in trunk and mid-thigh level had better lung function (P < 0.01). The results of this community-based study show that regional body composition is significantly associated with lung function. Augmentation of muscle in the trunk and low extremity in men, and reduction of fat in the trunk and upper body in men and women may be helpful in maintaining lung function in the elderly population.