Obesity in middle age increases risk in older age for coronary heart disease, cardiovascular disease, and diabetes even in the absence of hypertension or abnormal lipid profile, according to an article in the January 11 issue of the Journal of the American Medical Association.

Obesity has long been associated with established cardiovascular risk factors, particularly diabetes and elevated blood pressure and serum cholesterol. However, controversies persist as to whether excess weight has additional impact on cardiovascular outcomes beyond its effects on established risk factors.

In clinical settings, patients sometimes ask if they still need to control their weight if their blood pressure and cholesterol levels are normal. Therefore, Lijing L. Yan, PhD, MPH, of Northwestern University, Chicago, and Peking University, China, and colleagues examined the relationship of body mass index earlier in life with illness and death outcomes in older age, 65 years and older, among individuals without and with other major risk factors at baseline.

The study included 17,643 men and women age 31 through 64 years who were free of coronary heart disease, diabetes, or major electrocardiographic abnormalities at baseline (1967-1973). Cardiovascular risk was classified as low with the following: systolic blood pressure 120 or less and diastolic blood pressure 80 mm Hg or less, serum total cholesterol level less than 200 mg/dL, and no current smoking.

In contrast, moderate risk was defined by no smoking and systolic blood pressure 121-139 mm Hg, diastolic blood pressure 81-89 mm Hg, and/or total cholesterol level 200-239 mg/dL; high risk required the presence of 1, 2, or all 3 of the following risk factors: blood pressure 140 or greater/90 mm Hg, total cholesterol level 240 mg/dL or greater, and current cigarette smoking.

Body mass index was classified as normal weight (18.5-24.9), overweight (25.0-29.9), or obese (30 or greater). Average follow-up was 32 years.

In multivariable analyses that included adjustment for systolic blood pressure and total cholesterol, the risk for coronary heart disease death for obese adults compared with normal weight adults in the same risk category was 43 percent higher for the low risk group and nearly 2.1 times higher for the moderate risk group.

Compared with normal weight adults, obese individuals in the low risk group had a 4.2 times higher risk for coronary heart disease-related hospitalization; for the moderate risk obese group, the risk of hospitalization was 2 times as high. Results were similar for other risk groups and for cardiovascular disease, but stronger for diabetes (low risk, 11 times increased risk for death and 7.8 times increased risk for hospitalization).

“In this predominantly white cohort who survived to age 65 years and older, persons who were overweight, and particularly those who were obese earlier in life (aged 31-64 years), had significantly higher risks of hospitalization and mortality in older age compared with persons of normal weight with similar other cardiovascular risk factors at baseline. Elevated risk was present for individuals both with and without other major cardiovascular risk factors (smoking, high blood pressure, and/or serum total cholesterol level) in young adulthood and middle age,” the authors wrote. “In general, relationships were qualitatively consistent for both sexes for both hospitalization for and mortality from coronary heart disease, cardiovascular disease, and diabetes in older age.”

“Convincing evidence from our findings and other studies provides strong support for population-wide, multifaceted, primary prevention starting at young age of all major risk factors, including overweight and obesity, as a key element for the national effort to continue the progress already achieved toward ending the epidemic of coronary heart disease and cardiovascular disease,” the researchers concluded.