Potential enhanced association between obstructive lung disease and history of depression in patients with diabetes

BACKGROUND: Depression is one of the most common comorbidities of chronic diseases including diabetes and obstructive lung diseases (emphysema, chronic bronchitis, and asthma). Obstructive lung diseases and depression have few symptoms in common. However, they are both common in adults and associated with chronic inflammation. It is not clear if their coappearance in diabetic patients is coincidental or associated beyond that expected by chance. METHODS: A total of 1,003 adults with diabetes in community practice settings were interviewed at home at the time of their enrolment into the Vermont Diabetes Information System, a clinical decision support program. Patients self-reported their personal and clinical characteristics, including any obstructive lung disease. Laboratory data were obtained directly from the clinical laboratory, and current medications were obtained by direct observation of medication containers. We performed a cross-sectional analysis of the interviewed subjects to assess a possible association between the prevalence of obstructive lung disease and depression. RESULTS: In a multivariate logistic regression model, obstructive lung disease was significantly associated with depression even after correcting for gender, obesity (≥30 kg/m(2)), high comorbidities (>2), low annual income (<$30,000/ year), cigarette smoking, alcohol problems, and education level (odds ratio=1.83; 95% confidence interval 1.27, 2.62; P <0.01). CONCLUSION: These data suggest a potential enhanced association between obstructive lung disease and depression in patients with diabetes. Future studies are needed to identify if inflammation is implicated in this association as a common denominator.