Purpose: To examine the relationship of retinopathy in persons without diabetes mellitus to the 15-year cumulative incidence of diabetes mellitus and hypertension.
Methods: A total of 3,402 persons 43 to 86 years of age without diabetes mellitus (1,879 without diabetes or hypertension) at the time of a baseline examination in 1988-1990 had follow-up examinations in 1993-1995, 1998-2000, and/or 2003-2005. Diabetes mellitus was defined by a combination of history, serum glucose levels, and glycosylated hemoglobin levels, and hypertension was defined as systolic blood pressure >/=140 mm Hg or diastolic blood pressure >/=90 mm Hg and/or use of antihypertensive medications. Retinopathy at baseline was determined by masked gradings of stereoscopic fundus photographs using standardized protocols.
Results: Retinopathy was present in 7.3% of the nondiabetic persons in the cohort and 5.4% of the nondiabetic, nonhypertensive cohort at baseline. The 15-year cumulative incidence of diabetes was 12.5% and of hypertension 54.1%. While controlling for age, persons with retinopathy were more likely to develop diabetes mellitus (odds ratio, 95% confidence interval, P value: 1.70, 1.17-2.48, P = .005) and hypertension (1.62, 1.18-2.23, P = .003) than persons without retinopathy. While controlling for other risk factors (eg, blood pressure, glucose level, cardiovascular disease history), the associations of retinopathy with incident diabetes mellitus (1.35, 0.90-2.03, P = .15) and hypertension (1.48, 1.05-2.07, P = .02) became attenuated but remained statistically significant for hypertension. In stratified analyses, retinopathy was associated with incident diabetes in persons younger than 65 years (1.80, 1.12-2.89, P = .02)
Conclusions: While controlling for other risk factors, retinopathy in nondiabetic individuals is associated with the incidence of hypertension and, in younger persons, with the incidence of diabetes mellitus.