Association between insulin resistance and lung function change: Analysis from the community-based prospective Ansan-Ansung cohort in Korea

Abstract Background: Diabetes mellitus and hyperglycemia are associated with respiratory dysfunction. Although several studies have reported that insulin resistance is related to decreased lung function, the association between insulin resistance and lung function changes has been rarely studied. This study aimed to investigate the effect of insulin resistance on the annual lung function change using a large-scale prospective cohort.Methods: We analyzed a community-based prospective cohort in Korea comprising 7,536 participants whose serial lung functions were assessed. Exposure was baseline insulin resistance estimated with homeostatic model assessment-insulin resistance (HOMA-IR), and outcomes were annual changes in forced expiratory volume in 1 second (FEV1), functional vital capacity (FVC), and FEV1/FVC ratio.Results: In the multivariate linear regression, the increased in the logarithmic HOMA-IR was associated with a decrease in FEV1 (β: -0.23; 95% CI: -0.32 to -0.13; P < 0.001), and FVC (β: -0.29; 95% CI: -0.39 to -0.19; P < 0.001), but not in FEV1/FVC ratio (β: 0.05; 95% CI: 0.00 to 0.11; P = 0.051). In the generalized additive model plot, L-shaped association between HOMA-IR and changes in FEV1 and FVC were observed with a HOMA-IR threshold of 2.4. Age modulated the effect of HOMA-IR on the change in FEV1, and increased HOMA-IR was associated with decreased annual FEV1 change only in the older population.Conclusions: Insulin resistance was a novel risk factor for the decrease in FEV1 and FVC. The aging process may modulate the effect of insulin resistance on the decline in lung function.