These are the results of a new study that was published in the February issue of Diabetes Care, of women who participated in the Diabetes Prevention Program (DPP), a clinical study funded by the National Institutes of Health (NIH).
DPP's results announced in 2001 and reported in 2002 revealed that losing 5 to 7 percent of weight through diet as well as a consistent increase in physical activity reduced the onset of type 2 diabetes by 58 percent. In addition treatment with metformin lowered the chances of developing diabetes by 31 percent.
NIH Director Elias A. Zerhouni, M.D said, "To combat the dual epidemics of obesity and type 2 diabetes, Americans need to know about the proven benefits of losing some weight through calorie reduction and increased physical activity."
The DPP randomly assigned 3,234 overweight people with above normal blood glucose levels to one of three approaches to prevent type 2 diabetes: dietary changes and increased physical activity aimed at a 7-percent weight loss; treatment with the oral diabetes drug metformin; or placebo. The last two groups were also given standard medical advice about diet and weight loss. In the study, 660 women were randomly assigned to intensive lifestyle changes, 636 to metformin treatment, and 661 to placebo. Their average age was 50 years old, with an average body mass index of 35 (e.g., a 5' 4" woman weighing 204 pounds).
It was found that women who implemented intensive lifestyle changes and lost 5 to 7 percent of their weight had fewer episodes of weekly incontinence compared to those in the metformin or placebo groups.
Lead author Jeanette S. Brown, M.D., of the University of California, San Francisco said, "Our findings reinforce the DPP's good news about the benefits of modest weight loss. A 200-pound woman who loses 10 to 15 pounds not only lowers the risk of developing type 2 diabetes but also improves bladder control. If you're a woman at risk for type 2 diabetes, preventing or delaying diabetes and improving bladder control are powerful reasons to make these lifestyle changes."
Stress incontinence— leakage of small amounts of urine during physical movement, such as coughing, sneezing, and exercising was also effectively reduced through weight loss. Stress incontinence mostly results from a weakening of the pelvic floor muscles that support the bladder.
However, in the DPP participant loss of weight did not alleviate urge incontinence — leakage of urine at unexpected times. This is because urge incontinence is more closely linked to overactive nerves that control the bladder, causing occasional triggering of inappropriate contractions.
It has been estimated that more than 13 million people in the United States, mostly middle-aged and older women, experience loss of bladder control. Overweight women and those with type 2 diabetes have a 50- to 70-percent increased risk of incontinence. In the National Health and Nutrition Examination Survey 2001-2002 sample, one out of three women with diabetes or prediabetic glucose levels reported weekly or more frequent episodes of UI.
Leroy Nyberg, M.D., Ph.D., of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), which funded the study said, "Urinary incontinence is a costly, socially isolating condition that impairs quality of life and takes a psychological toll on many women. For women at risk for type 2 diabetes, losing a modest amount of weight is likely to alleviate incontinence, especially stress incontinence."
About 40 percent of U.S. adults ages 40 to 74 — 41 million people — have prediabetes, which raises the risk of developing type 2 diabetes and cardiovascular disease.