Because of their increased risk of developing impaired glucose tolerance and type 2 diabetes, all women with polycystic ovary syndrome should be screened with a 2-hour oral glucose tolerance test, and that test should be repeated every 2 years, according to a statement from the Androgen Excess Society.
The position statement was developed by an expert multidisciplinary panel from the Medical College of Virginia, Virginia Commonwealth University, Richmond, which conducted a systematic review of the published, peer-reviewed medical literature on the prevalence and risk factors for impaired glucose tolerance in women with polycystic ovary syndrome (J. Clin. Endocrinol. Metab. 2007;92:4546-56).
The recommendation for a full oral glucose tolerance test (OGTT) for all patients with polycystic ovary syndrome (PCOS) goes beyond screening recommendations issued by other professional organizations. Most recommend it only in obese women with PCOS or those with a family history of type 2 diabetes or insulin resistance.
The panel focused on studies indicating that both lean and obese women with PCOS are at increased risk of developing impaired glucose tolerance and diabetes. It also noted that a number of studies show that a finding of impaired fasting glucose is not a useful substitute for an OGTT, because about a third of individuals with type 2 diabetes have normal fasting glucose. Furthermore, impaired glucose tolerance, but not impaired fasting glucose, is a strong predictor of cardiovascular disease and premature mortality.
“The position statement makes a valuable contribution to the health care of women with PCOS by recognizing its strong association with insulin resistance and type 2 diabetes,” Dr. Rhoda H. Cobin said in an interview. Dr. Cobin, a past president of both the American College of Endocrinology and the American Association of Clinical Endocrinologists (AACE), chaired the panel that developed the AACE's 2005 PCOSposition statement (Endocr. Pract. 2005;11:126-34).
However, an oral glucose tolerance test may not be feasible in all clinical settings, which is why “the AACE statement did not make it mandatory but, based on the same evidence, settled for the directive to look for type 2 diabetes, impaired fasting glucose, or impaired glucose tolerance in all PCOS women, using whatever method possible,” Dr. Cobin said. “I [agree] that not only obese women should be tested, but that lean PCOS women may have insulin resistance and diabetes, while obesity exacerbates the situation.”
The position statement from the Androgen Excess Society (AES) notes that several AES board members disagreed with the recommendation to screen all women with PCOS with an OGTT. The minority report says evidence on the risk of impaired glucose tolerance in lean PCOS women is “limited and still emerging.” Those board members recommended an OGTT only in PCOS patients whose body mass index was 30 kg/m
The AES statement makes several recommendations on the prevention, screening, and treatment of impaired glucose tolerance in patients with PCOS. It suggested the OGTT be repeated once every 2 years or even earlier if the patient has additional risk factors. Patients with impaired glucose tolerance should be screened annually for the development of diabetes.
Intensive lifestyle modification and weight loss should be the mainstay of treatment for all patients with PCOS and impaired glucose tolerance. Insulin-sensitizing agents such as metformin and the thiazolidinediones should also be considered.
The panel also recommended that adolescents with PCOS should, like their adult counterparts, be screened with an OGTT every 2 years and should be treated with intensive lifestyle modification, including diet and moderate exercise. Insulin-sensitizing agents should be considered, but should not be mandated until there have been well-designed, randomized controlled trials demonstrating their efficacy.
Dr. Cobin said she saw few arguments against the OGTT recommendations. “The only negatives are inconvenience and [to a small degree] cost [but] the cost factor is far outweighed by the cost of undiagnosed insulin resistance and diabetes.”