Low self-rated health (SRH) has been found to be associated with increased risk of type 2 diabetes (T2D) and with mortality. We examined the possible interaction between SRH and diabetic state on all-cause mortality in a large cohort of elderly subjects, followed for 14 years.
During the years 2000–2004, survivors of the nationwide longitudinal Israel Study of Glucose Intolerance, Obesity and Hypertension were interviewed and examined for the third follow-up. The 1037 participants (mean age 72.4 ± 7.2 years) were asked to rate their health as: excellent, good, fair, poor, or very poor. Glucose categories were as follows: Normoglycemic, Prediabetes, T2D and Undiagnosed diabetes. Survival time was defined as the time from interview to date of death or date of last vital status follow-up (August 1, 2013). Multivariate Cox proportional hazards models were performed in order to assess whether SRH interacts with glycemic state in the association with mortality.
A better SRH was reported by those with undiagnosed than known diabetes, and best for normoglycemic and prediabetic individuals. While all individuals with fair or poor/very poor SRH were at increased risk of mortality compared to those with excellent/good SRH, in the known diabetic individuals a greater hazard was observed in the excellent/good SRH (HR 3.32, 95 % CI 1.71–6.47) than in those with fair or poor/very poor SRH (HR 2.19, 95 % CI 1.25–3.86), after adjusting for age, sex, ethnic origin, marital status, education, BMI, physical activity, CVD, tumors, and creatinine level (p for interaction = 0.01).
Self-rated health is not a sensitive tool for predicting mortality in elderly men and women with known T2D.