Chronic obstructive pulmonary disease, asthma, and risk of type 2 diabetes in women.

Inflammation plays a key role in chronic obstructive pulmonary disease (COPD) and asthma. Increasing evidence points toward a role of inflammation in the pathogenesis of type 2 diabetes. We wanted to determine the relation of COPD and asthma with the development of type 2 diabetes. The Nurses' Health Study is a prospective cohort study. From 1988-1996, 103,614 female nurses were asked biennially about a physician diagnosis of emphysema, chronic bronchitis, asthma, and diabetes. During 8 years of follow-up, we documented a total of 2,959 new cases of type 2 diabetes. The risk of type 2 diabetes was significantly higher for patients with COPD than those without (multivariate relative risk 1.8, 95% CI 1.1-2.8). By contrast, the risk of type 2 diabetes among asthmatic patients was not increased (1.0, 0.8-1.2). The asthma results remained nonsignificant even when we evaluated diabetes risk by duration of asthma exposure. Our findings suggest that COPD may be a risk factor for developing type 2 diabetes. Differences in the inflammation and cytokine profile between COPD and asthma might explain why COPD, but not asthma, is associated with increased risk of type 2 diabetes.