Women live longer, not better, largely because of obesity and arthritis

May 3 2009

Obesity and arthritis that take root during early and middle age significantly contribute to women's decreased quality of life during their senior years, according to researchers at Duke University Medical Center.

In a study that included 5,888 people over 65, women suffered up to two and a half times more disabilities than men of the same age.

Higher rates of obesity and arthritis among these women explained up to 48 percent of the gender gap in disability – above all other common chronic health conditions.

"While women tend to live longer than men, this study shows that they are at greater risk of living with disability and much of the excess disability is attributable to higher rates of obesity and arthritis," said Heather Whitson, M.D., assistant professor of medicine and lead investigator of the study presented today at the Annual Scientific Meeting of the American Geriatrics Society. "This is important because it suggests that women's tendency to pack on extra pounds in their child-bearing and peri-menopausal years translates into loss of independence in their old age."

Researchers said the study is the first to isolate the impact of specific chronic health conditions on the difference in disability rates between older men and women. While many people are studying how chronic conditions affect mortality, the investigators were surprised to see the extent to which these conditions explained the gender difference in disability.

"The reason for this discrepancy in disability has not been well understood but we found that chronic health conditions that women experience in greater numbers than men may explain part of that gap," said Harvey Jay Cohen, M.D., the study's senior author, chair of the Department of Medicine and director of Duke's Center for the Study of Aging and Human Development.

"Women have a natural tendency to gain more weight than men over the lifespan, but may be more motivated to maintain a healthy weight if they realize that those extra pounds make it more likely that they will be disabled in later years – potentially becoming a burden to their children or requiring a nursing home," Whitson said.

The current study is an analysis of the Cardiovascular Health Study which asked participants about their ability to conduct common activities of daily living, such as grooming, eating, getting dressed, managing money and upper and lower body movement, including reaching, grasping, walking and climbing stairs.

The Duke team said the study also draws attention to two concerning health trends that could worsen the average quality of life for women in the future. First, as the rate of obesity continues to rise, the rates of disability in older adults are expected to increase. To the extent that women are more likely than men to develop obesity, the obesity epidemic will have its greatest impact on older women's quality of life.

Second, the investigators note that women are gaining equality with men on cardiovascular disease, stroke and emphysema, which had previously been less common among women. Rates of cardiovascular disease are not improving as quickly among women as they are among men and smoking-related disease is becoming more common in women. If the occurrence of these conditions becomes more comparable between men and women, the result would be an even wider gap in disability rates.

"The findings of our study are more troubling when you consider the increasing rates of obesity among women and the higher rates of other conditions that are currently over-represented among men," Cohen said. "We need to help women make better decisions earlier in life."

In addition to obesity and arthritis, the study found the women were more likely than men to experience fractures, vision problems and bronchitis. Men were more likely to have emphysema, coronary heart disease, congestive heart failure, stroke, diabetes and hearing problems.

Researchers say that the next step is to determine whether older women who have been disabled by obesity or arthritis regain function if they undergo treatment to help them achieve a healthy weight or to control their arthritis pain. If not, then it becomes even more important to focus efforts on preventing obesity and arthritis in younger populations.