OBJECTIVE -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.
RESEARCH DESIGN AND METHODS -TheNurses' Health Study is a prospective cohort study. From 1988From -1996,614 female nurses were asked biennially about a physician diagnosis of emphysema, chronic bronchitis, asthma, and diabetes.RESULTS -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.CONCLUSIONS -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.
Diabetes Care 27:2478 -2484, 2004C hronic inflammation has emerged as a new risk factor for the development of type 2 diabetes (1-3). Increasing evidence now points toward a role of proinflammatory cytokines such as C-reactive protein (CRP), interleukin (IL)-6, and tumor necrosis factor (TNF)-␣ in the pathogenesis of insulin resistance and type 2 diabetes (1-4). Due to the upregulation of proinflammatory cytokines in both asthma and chronic obstructive pulmonary disease (COPD) (5,6), one might hypothesize that these chronic inflammatory diseases would increase risk for type 2 diabetes.However, the pattern of inflammation for asthma and COPD differs (7). The cellular infiltrate in asthma contains prominent numbers of eosinophils and type 2 helper (Th2) CD4 T-cells and associated cytokines (IL-4, -5, and -13) (5). By contrast, the cellular infiltrate in COPD is dominated by neutrophils, macrophages, and an increased numbers of lymphocytes thought to be type 1 helper (Th1) or CD8 T-cells (8), and the neutrophilassociated cytokines (TNF-␣, IL-6, and IL-8) predominate (9). A recent report (10) from the Third National Health and Nutrition Examination Survey demonstrated that increasing severity of COPD was associated with increasing levels of CRP. Moreover, systemic inflammation in COPD is associated with increased muscle wasting and a continuous hypoxemic state due to destruction of lung tissue (11). Because of these inflammatory differences, the relationship of COPD or asthma with the development of another condition with an inflammatory component, such as type 2 diabetes, may vary. We therefore evaluated the association between a history of physiciandiagnosed COPD or asthma and incidence of type 2 diabetes among almost 100,000 participants in the Nurses' Health Study. We focused on potential ...