Psychological Distress, Glycated Hemoglobin, and Mortality in Adults With and Without Diabetes

Objective: To examine associations between psychological distress, glucose metabolism, and death. There is limited information about the long-term prognosis of diabetic patients with psychological distress. Methods: In a representative cohort of 11,546 adults (6.2% with high-risk/undiagnosed diabetes and 4.8% with physician-diagnosed diabetes), we measured glycated hemoglobin A I C as an indicator of glucose metabolism and psychological distress with the 12-item General Health Questionnaire (GHQ-12). Results: During the mean follow-up of 4.7 years, there were 682 deaths (93 among diabetic, 88 in high-risk/undiagnosed diabetic [A I C >= 6.0% without physician-diagnosed diabetes], and 501 in nondiabetic participants). Psychological distress was apparent in 18.9%, 16.5%, and 13.4% of diabetic, high-risk/undiagnosed diabetic, and nondiabetic participants, respectively. In participants with diabetes, a unit increase in GHQ-12 score was associated with higher risk of death at follow-up (multivariate adjusted hazard ratio, 1.16; 95% confidence interval, 1.09-1.24). Levels of A1C were also higher in diabetic participants with distress (GHQ-12 score of >3) compared with those without (7.86% versus 7.40%; p = .008), although adjustment for A1C did alter the association between distress and mortality. In the whole sample, the coexistence of diabetes and distress was associated with an elevated risk of death, beyond that due to having either diabetes or distress alone (multivariate adjusted hazard ratio, 3.64; 95% confidence interval, 2.21-5.98). Conclusions: Psychological distress is an independent risk factor for death in diabetic patients, although impaired glucose metabolism did not explain the excess risk.