Depression and advanced complications of diabetes: a prospective cohort study

Abstract

Objective: To prospectively examine the association of depression with risks for advanced macrovascular and microvascular complications among patients with type 2 diabetes.

Research design and methods: A longitudinal cohort of 4,623 primary care patients with type 2 diabetes was enrolled in 2000-2002 and followed through 2005-2007. Advanced microvascular complications included blindness, end-stage renal disease, amputations, and renal failure deaths. Advanced macrovascular complications included myocardial infarction, stroke, cardiovascular procedures, and deaths. Medical record review, ICD-9 diagnostic and procedural codes, and death certificate data were used to ascertain outcomes in the 5-year follow-up. Proportional hazard models analyzed the association between baseline depression and risks of adverse outcomes.

Results: After adjustment for prior complications and demographic, clinical, and diabetes self-care variables, major depression was associated with significantly higher risks of adverse microvascular outcomes (hazard ratio 1.36 [95% CI 1.05-1.75]) and adverse macrovascular outcomes (1.24 [1.0-1.54]).

Conclusions: Among people with type 2 diabetes, major depression is associated with an increased risk of clinically significant microvascular and macrovascular complications over the ensuing 5 years, even after adjusting for diabetes severity and self-care activities. Clinical and public health significance of these findings rises as the incidence of type 2 diabetes soars. Further research is needed to clarify the underlying mechanisms for this association and to test interventions to reduce the risk of diabetes complications among patients with comorbid depression.

Figure 1

Pathways Epidemiologic Follow-Up sample recruitment.