Trends in Cardiovascular Disease Risk Factors in Individuals With and Without Diabetes Mellitus in the Framingham Heart Study

Abstract

Background— Individuals with diabetes mellitus are at 2- to 3-fold increased risk for cardiovascular disease (CVD) relative to those without diabetes. Our objective was to examine CVD risk factor level changes among individuals with and without type 2 diabetes mellitus from 1970 to 2005 in the Framingham Heart Study. Methods and Results— We included 4195 participants (3990 with no diabetes and 205 with diabetes) 50 years of age and 3495 participants (3178 with no diabetes and 317 with diabetes) 60 years of age. Contemporaneous CVD risk factor levels were measured; linear regression models were used to assess the interaction between diabetes status and calendar year on CVD risk factor levels. Among 50-year-olds without diabetes mellitus, there was an increase in body mass index of 0.39 kg/m 2 per 10 years, whereas for those with diabetes, there was an increase of 2.52 kg/m 2 ( P value for the diabetes-by–calendar year interaction [ P for interaction] <0.001). For low-density lipoprotein cholesterol, the mean decrease was −7.43 mg/dL per decade (nondiabetes) and −15.5 mg/dL for diabetes ( P for interaction=0.002). For systolic blood pressure, the mean decrease was −3.35 mm Hg per decade (nondiabetes) and −3.50 mm Hg for diabetes ( P for interaction=0.97). The direction of the trends for those with diabetes relative to those without diabetes was similar for 60-year-olds. Conclusions— Compared with individuals without diabetes mellitus, individuals with diabetes experienced a greater increase in body mass index, a greater decrease in low-density lipoprotein cholesterol, and a similar magnitude of decline in systolic blood pressure. Individuals with diabetes mellitus have not experienced the necessary declines in CVD risk factors to overcome their increased risk of CVD. Further efforts are needed to aggressively control CVD risk factors among individuals with diabetes mellitus.