Researchers have discovered that pancreatic beta-cells, which are responsible for insulin secretion, play an important role in the existence of polycystic ovary syndrome (PCOS), a hormonal disorder that affects up to 10 percent of reproductive aged women. The findings could lead to better diagnosis and treatment for the condition, which has been linked to diabetes and heart disease.
In order to better understand the role of pancreatic insulin secretion in PCOS, Drs. Mark Goodarzi and Stanley Korenman and researchers at the University of California, Los Angeles School of Medicine tested insulin resistance, pancreatic beta-cell function, obesity and androgen levels in 60 women with PCOS. They compared the data to information collected in the National Health and Nutrition Examination Study (NHANES III, 1988-1994).
The researchers discovered an altered relationship between insulin resistance and pancreatic cells that secrete insulin (beta-cells), in women with PCOS. In women with PCOS, the beta-cell function was more responsive to increases in insulin resistance compared with normal women. This finding was particularly interesting because the two groups of women studied experienced similar mean values of insulin-related traits.
Insulin resistance and bioavailable testosterone (the ability of testosterone to be absorbed and used by the body) were also independent predictors of beta-cell function. At the same time, beta-cell function and obesity were found to be independent predictors of insulin resistance. Most notably, beta-cell function, not insulin resistance, independently predicted bioavailable testosterone.
"Based on our findings, it is clear that beta-cell function plays an important and under-recognized role in PCOS," explained Dr. Korenman. "While previous research has focused on insulin resistance, our findings indicate that beta-cell function may be a much more important indicator of PCOS. This finding may help doctors more effectively diagnose and treat women with PCOS."
Many women with PCOS suffer from intense hunger and large amount of weight gain in a short period of time; insulin may be responsible by lowering blood sugar and stimulating appetite. The new research also indicates that insulin hypersecretion may explain this condition in women with PCOS.
The researchers note that future clinical and cellular research into beta- cell function and PCOS may lead to therapies that directly modulate insulin secretion.