Weight Loss, Not Weight Gain, A Health Risk For Older Adults

A team of researchers led by Dr. Paula Diehr, professor of biostatistics at the University of Washington School of Public Health and Community Medicine, studied a group of 4,317 nonsmoking men and women aged 65 to 100 to examine the relationship between body mass index and mortality rates in seniors. All participants were involved in the Cardiovascular Health Study, a population-based, longitudinal study of older adults designed to identify risk factors for heart disease and stroke. Persons who were wheelchair-bound or receiving hospice treatment, radiation therapy or chemotherapy for cancer were excluded from the study.

"We found no correlation between increased body mass index and mortality among study participants," said Diehr. "Instead, it appears that significant, unintended weight loss should be of primary concern for seniors."

Information on study participants was gathered over a five-year period during home interviews, clinical evaluations and other resources. After controlling for a number of clinical variables including hypertension, diabetes and cardiovascular disease, researchers found that women with a body mass index of 20 or lower had a higher mortality rate than others. (Body mass index is defined by weight in pounds divided by squared height in inches multiplied by 704.5. A BMI of 20 or lower is equivalent to a 5-foot-5 inch woman weighing 120 pounds or less.) Long-term weight change among study participants showed that subjects who lost 10 percent or more of their weight since age 50 had a relatively high death rate -- 15.9 percent for women and 30.3 percent for men over the five-year period studied. Among this group, weight loss averaged 26 pounds for women and 29 pounds for men.

"While research has found a link between high body weight and increased mortality for middle-aged people, this finding doesn't appear to hold true for seniors, " Diehr said. "However, there is a need for more studies that follow older adults for longer than five years, and that examine the effect of weight on people's overall health, as well as on longevity."

Additional investigators include Dr. David Siscovick, University of Washington; Dr. Diane Bild, National Heart, Lung and Blood Institute; Dr. Tamara Harris, National Institute on Aging; Dr. Andrew Duxbury, University of California at Davis School of Medicine; and Dr. Michelle Rossi, University of Pittsburgh.

The study was funded by the National Heart, Lung and Blood Institute.