by Martha Kerr

Last Updated: 2008-06-12 16:01:31 -0400 (Reuters Health)

SAN FRANCISCO (Reuters Health) – Researchers at the Joslin Diabetes Center report that a 12-week weight-loss program they devised for patients with type 2 diabetes continues to have a positive, long-lasting effect on weight loss a year later, long after patients are off on their own.

The findings of a 1-year follow-up of the 12-week "Why WAIT" weight-loss program were presented here this week at the 68th Annual Scientific Sessions of the American Diabetes Association by principal investigator Dr. Osama Hamdy.

The study involved 85 patients with type 2 diabetes, mean age 54 years and disease duration of approximately 10 years. Average weight was 235 pounds, mean body mass index (BMI) was 38.4, mean hemoglobin A1C was 7.5%, and mean waist circumference was 46.7 inches.

Patients completed the 12-week diet and exercise program and were followed for another year without structured intervention.

Twelve weeks of the intervention resulted in an average weight loss of 24.6 pounds — more than a 10% reduction — a waist circumference reduction of 3.6 inches, and a mean drop of 0.9% in A1C to 6.6%.

After one year of follow-up, weight remained lower than baseline by more than 18 pounds — a long-term loss of 7.6%. However, A1C levels increased to approximately 7.4%.

Overall, 55% of participants continued to lose weight on their own, Dr. Hamdy said. The other 45% gained back approximately 5 pounds, but their final weight remained lower than baseline by 2.0%.

Systolic and diastolic blood pressures were significantly lower at both 12 weeks and 1 year, he added. Lipid profile improved significantly at 12 weeks, but had returned to baseline levels at 1 year, except for HDL, which remained significantly higher.

Dr. Hamdy said there was evidence that kidney function improved as well, with a small decrease in microalbuminuria.

"The clinical implications are enormous," Dr. Hamdy told Reuters Health. "We’ve been glucose-focused for a long time. We need to be weight-focused. We need to focus on the cause of the problem and not the result of the problem."

The mainstays of the "Why WAIT?" program are a low carb diet and tailored exercise. "We use significant calorie reduction and reduce carbohydrates to 40% of calories and increase protein to 30-40% of calories — this is key for patients to maintain muscle," Dr. Hamdy said. "In addition, we teach patients how to exercise, especially the type and the amount, and make sure it is age-appropriate. This is very important."

He added, "The main reason that patients regain weight is that they decrease their protein intake and don’t exercise as much. The weight they gain is mostly fat, and visceral fat."

There is also an economic benefit. "Weight reduction leads to a reduction in need for medications. We saw a 65% reduction in medical costs, or about $560 per year per patient — and patients feel better," Dr. Hamdy reported.

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