Elderly women face an increased risk of death if they lose weight or are underweight, according to researchers at the University of Maryland School of Medicine. Elderly women of average weight who lose weight may be at greatest risk.
The six-year study, which appears in the December issue of The Journal of the American Geriatrics Society, involved 648 Baltimore area women between the ages of 65 and 99. The women were interviewed and weighed at their homes once a year for three years, and were followed for another three years.
The risk of death was highest for women with an average body mass index (BMI), who then went on to lose weight. These women were nearly four times more likely to die than women who either maintained their weight or gained a few pounds during the course of the study. A weight change of 4.5 percent or more from one year to the next was recorded as a gain or a loss.
"Our findings run contrary to the popular belief that losing weight always makes you healthier," says Matthew W. Reynolds, M.S., of the School of Medicine's Department of Epidemiology. "We believe doctors should pay close attention to weight change in older women because it could signal potentially serious health problems."
The risk of death was the lowest for elderly women who maintained an average BMI over the six-year study period. Thirteen percent of these women died, compared to the group's overall death rate of 16 percent. The death rate was 22 percent for elderly women who began the study with a lower than average body mass. For the heaviest women, the death rate was 18 percent.
"This work has some very important implications for older women and their health care providers because weight changes are relatively easy to monitor," says Jay S. Magaziner, Ph.D., professor and interim chair, Department of Epidemiology and Preventive Medicine and director of the division of gerontology at the University of Maryland School of Medicine. "Even small changes should be taken seriously."
The study found that weight fluctuation also appears to increase mortality for women over the age of 65. "Fairly minor weight cycling-from five to eight pounds for a five-foot, five-inch woman-is associated with a significantly increased risk of death," says Magaziner.
Regardless of a woman's initial BMI, investigators found that losing weight always increased the risk of dying. "Dieting or trying to return to an "ideal" weight may not be the best recommendation for older women who are not obese," says Reynolds. "It is possible that maintaining body weight may actually help keep you more robust and healthy later in life."
Investigators cautioned that their results do not explain the reasons for the increased death rates. The study took age, income, smoking habits and alcohol use into consideration, but the cause of death for these women is not known. Reynolds says interviewers tried to screen out women with serious pre-existing health problems, but he says some illnesses may have gone undetected, accounting for some of the weight loss.
Journal
Journal of the American Geriatrics Society