Polycystic Ovary Syndrome More Prevalent in Overweight Women
by Crystal Phend
Overweight and obese women may be markedly more likely to suffer from polycystic ovary syndrome (PCOS) than thinner women, according to researchers here.
The syndrome, one of the most common endocrine disorders in premenopausal women, was five times more common in women referred to a clinic for dietary assistance to lose weight than lean women in the same city, said Francisco Álvarez-Blasco, M.D., of the Hospital Universitario Ramón y Cajal, and colleagues.
"Surprisingly, the prevalence of polycystic ovary syndrome in otherwise unselected overweight or obese women is unknown, despite obesity being frequent in patients with [the syndrome]," the authors wrote in the Oct. 23 issue of Archives of Internal Medicine.
They found that prevalence of PCOS was 28.3% (95% confidence interval 20.0% to 36.6%) in the study population of overweight and obese women. By comparison, the prevalence is 5.5% for lean women and 6.5% overall for premenopausal women in the general population of Madrid, according to previous studies.
Though insulin resistance is more common in obese individuals and is thought to contribute to hyperandrogenism, metabolic syndrome did not seem to be responsible for the increased risk of polycystic ovary syndrome. PCOS was equally common in women with the metabolic syndrome as without (27.6% versus 28.6%, P≥0.99).
Screening for PCOS is not usually included in routine clinical evaluation of overweight and obese women, but it should be, the researchers said.
"Physicians treating overweight and obese patients should be aware of the high prevalence of [polycystic ovary syndrome] among these women and that screening for [the syndrome], at least by obtaining a detailed menstrual history and a careful clinical evaluation of hyperandrogenic symptoms, should be conducted routinely," they concluded.
The study included 113 otherwise healthy women referred by their primary physicians to an outpatient endocrinology clinic for dietary treatment. All participants were premenopausal, had a body mass index above 25 and were younger than 50. Women on medications that might interfere with hormone profiles, such as contraceptives or insulin sensitizers, were excluded.
PCOS was diagnosed on the basis of on clinical or biochemical hyperandrogenism or both, infrequent ovulation (oligo-ovulation), and exclusion of secondary causes. The researchers also collected anthropometric measurements, hirsutism scores, and androgen, gonadotropin, metabolic, and lipid profiles. The criteria used for the metabolic syndrome were those of the National Cholesterol Education Program Adult Treatment Panel III.
Endocrinology and nutrition are a single medical specialty in Spain, and most patients interested in dietary intervention because of overweight or obesity are referred directly to endocrinologists by their general physicians, Dr. Álvarez-Blasco said.
"Because our recruitment procedure carefully avoided positive selection biases that might have occurred because of our research interest…we are reasonably convinced that the population studied herein was representative of the general population of Spain," they wrote.
Thirty-two of the 113 unselected patients had PCOS. These participants were more insulin resistant than the 63.7% of the study population that was non-hyperandrogenic. Though the two groups had similar body mass indices (34.8 versus 35.2) and degrees of obesity, women with the syndrome were substantially younger overall (average age 26 versus 32).
Another three women were diagnosed with hyperandrogenemia without oligo-ovulation, two with idiopathic hirsutism, two with isolated chronic oligomenorrhea without clinical or biochemical hyperandrogenism, and two with oligomenorrhea and hyperprolactinemia.
The prevalence was not different by degree of obesity. Metabolic syndrome was as common in women with polycystic ovary syndrome as those without it (25% versus 26%).
"This particular finding suggests that obesity and insulin resistance may be important contributors to the development of [polycystic ovary syndrome] but are not the major etiologic defects leading to this disorder," the investigators said.
The results may not reflect prevalence in the general population of Spain since the study population was women referred for weight loss. Similarly, the findings may not extrapolate to other countries.
The study was supported by the Fondo de Investigacion Sanitaria, Instituto de Salud Carlos III.
