Weight Loss Linked To Better Beta-Cell Function

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Utzschneider KM, Carr DB, Barsness SM, et al.: Diet-induced weight loss is associated with an improvement in b -cell function in older men. J Clin Endocrinol Metab 89:2704-2710, 2004.

What is the problem and what is known about it so far?

Although weight loss in older adults improves insulin sensitivity (a measure of risk for heart disease), its effect on beta-cell function is unknown. Beta cells make insulin and are located in the pancreas.

Why did the researchers do this particular study?

The researchers wanted to know if weight loss has an effect on how beta cells work. They also wanted to know if beta cells have as much effectiveness in slowing the progression of diabetes in older patients as improving insulin sensitivity does.

Who was studied?

Nineteen overweight and obese older men with normal fasting blood glucose were studied for 3 months. Fasting blood glucose is a measure of the amount of glucose people have in their blood before they eat.All the men were nonsmokers, took no medications, hadn't gained or lost any weight recently, and did not exercise. None of the men had impaired glucose tolerance (where blood glucose levels are higher than normal but not high enough to be called diabetes) or diabetes.

How was the study done?

The men met with a dietitian at least once a week and were shown how to follow a 1,200 calorie-per-day diet consisting of 50% carbohydrates, 30% fat and 20% protein. They also took vitamin and mineral supplements. The men were weighed three times per week.

What did the researchers find?

The men in the study lost an average of nine pounds. All the men lost weight, with fat making up 84% of the weight loss. Fasting blood glucose levels were lower after the weight loss. Insulin sensitivity improved, resulting in an improvement in beta-cell function.

How weight loss improves beta-cell function is not known.

What were the limitations of the study?

Only men were included in this study. Researchers believe that the effects of weight loss on beta-cell function would be similar for women, however.

What are the implications of the study?

Weight loss in an older overweight or obese man can improve beta-cell function and insulin sensitivity. This is important because older people are at a higher risk of getting diabetes.