Abstract

OBJECTIVE: Insulin resistance (IR) may be a risk factor for lung disease, but objective evidence is limited. We sought to define the relationship of longitudinal IR with radiographic imaging outcomes and examiner-identified incident lung disease in the Framingham Offspring Study. RESEARCH DESIGN AND METHODS: Participants without baseline lung disease underwent repeated measurements of fasting insulin and glucose levels over an average period of 13.6 years, from which time-weighted average HOMA-IR was calculated. Each participant then underwent a cardiac gated whole-lung computed tomography scan, which was analyzed for the presence of emphysema, interstitial lung abnormalities (ILAs), and quantitative airway features. Incident lung disease was determined by a study examiner. The relationship of HOMA-IR to these outcomes was estimated in models adjusted for demographics, BMI, and lifetime smoking. RESULTS: A total of 875 participants with longitudinal IR data and outcomes were identified. Their mean age was 51.5 years, and BMI was 26.7 kg/m2. HOMA-IR was temporally unstable, with a within-person SD approximately two-thirds of the between-person SD. In adjusted models, a 1 SD increase in log(HOMA-IR) z score was associated with higher odds of qualitative emphysema (odds ratio [OR] 1.33; 95% CI 1.04-1.70), ILAs (OR 1.35; 95% CI 1.05-1.74), and modest increases in airway wall thickness and wall area percentage. These radiographic findings were corroborated by a positive association of HOMA-IR with incident lung disease. CONCLUSIONS: IR is associated with radiographic lung abnormalities and incident lung disease. Deeper phenotyping is necessary to define mechanisms of IR-associated lung injury.