Association between obesity and asthma in the elderly population: potential roles of abdominal subcutaneous adiposity and sarcopenia

Background Obesity is a significant risk factor for asthma; however, the association of asthma with obesity has rarely been studied in the elderly population. The role of central obesity has been suggested as a link between the 2 entities but has not been comprehensively studied in elderly populations. Objective To investigate the mechanisms of association between obesity and asthma in the elderly population. Methods This cross-sectional analysis included 994 participants (aged ≥65 years) in the Korean Longitudinal Study on Health and Aging. Asthma was defined by using questionnaires. Spirometry and chest radiography were performed to exclude asthma-mimicking conditions. Measurements of abdominal subcutaneous and visceral fat were calculated by computed tomography of the abdomen, and regional body compositions were measured by dual energy X-ray absorptiometry. Biochemical parameters were also measured. Results The prevalence of asthma was 5.4%. The study population had a mean body mass index (BMI) of 24.0. Multivariate logistic regression tests revealed that the risk of asthma increased in proportion to an increase in BMI or abdominal subcutaneous adiposity. However, no association was found with visceral adiposity, serum adiponectin levels, or serum vitamin D levels. The dual energy X-ray absorptiometry–measured appendicular fat-free mass index was inversely related to asthma among patients with a BMI of 25.0 or greater. Conclusion Our findings suggest that the relationships between obesity and asthma in the elderly population may be mediated by factors such as abdominal subcutaneous adiposity and sarcopenia. These associations warrant further investigations to identify their potential roles.