Obesity in middle age raises heart disease and diabetes risk

Jan 10 2006

Obesity in middle age - even without established cardiovascular disease risk factors such as high blood pressure or high cholesterol levels - greatly increases risk of hospitalization for and death from heart disease and diabetes in older age, according to a study in the Jan. 11 issue of the JAMA: Journal of the American Medical Association.

Lijing Yan, assistant professor of preventive medicine, and colleagues at Northwestern University Feinberg School of Medicine assessed the relationship of body mass index (BMI) earlier in life with hospitalization for and death from cardiovascular disease and diabetes in older age (65 years and older). BMI is a measure of body fat based on height and weight.

Study participants were classified according to low, moderate, intermediate and high risk, based on blood pressure, treatment for hypertension, total cholesterol level, cigarette smoking and weight.

Of the 17,640 participants who had survived to age 65 and older, those who were overweight, and particularly those who were obese earlier in life, had significantly higher risks of hospitalizations for and death from heart disease and diabetes in older age compared with persons of normal weight with similar other cardiovascular risk factors at the beginning of the study.

Elevated risk was present for individuals both with and without other major cardiovascular risk factors, such as smoking in young adulthood and middle age.

In general, there was a consistent relationship in both men and women for hospitalization for and death from coronary heart disease, cardiovascular disease and diabetes in older age.

Study participants were men and women aged 31 through 64 years from the Chicago Heart Association Detection Project in Industry who were free of coronary heart disease, diabetes or major heart rhythm abnormalities at the beginning of the study in 1967.

The exceptionally long follow-up of the CHA study offered the researchers a rare opportunity to assess the long-term relationship between midlife BMI and health outcomes in older age, for which data are limited.

Results of the study showed that having a normal BMI in young adulthood and middle age confers significant health benefits at all levels of traditional risk factors.

"These outcomes are important to investigate in an era of population aging marked by an unprecedented large number of older adults resulting from aging of the baby boomers and from dramatic improvements in life expectancy for the entire population," said Yan.

"The study findings also strongly support the need for population-wide, multifaceted, primary prevention at young age of all 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 said.