BOSTON — Weight loss can significantly improve menstrual function in overweight adolescent and young adult females with polycystic ovary syndrome, while at the same time reducing some of the risk factors for long-term morbidity associated with the hormonal reproductive problem, said Dr. Rollyn M. Ornstein at the annual meeting of the Society for Adolescent Medicine.
In a 12-week prospective study of 24 females aged 12–22 years with polycystic ovary syndrome (PCOS) and a body mass index above the 85th percentile for their age, half of the subjects were randomized to the calorie-controlled National Cholesterol Education Program Step II Diet and half to a very-low-carbohydrate, high-protein, high-fat diet.
The latter diet was included to determine whether minimizing insulin response would independently impact the signs and symptoms of PCOS, because insulin resistance is thought to play a key role in the pathogenesis of the disorder, said Dr. Ornstein of Schneider Children's Hospital in New Hyde Park, N.Y.
All of the women in the study had fewer than six spontaneous menstrual cycles in the year prior to enrollment, and all underwent laboratory evaluation and assessment at baseline and at the end of the study, including a metabolic panel, fasting lipid profile, hormonal studies, a 2-hour oral glucose tolerance test, blood pressure testing, and waist circumference measuring, which is a marker for insulin resistance. Study participants attended biweekly nutrition and exercise counseling sessions, during which dietary compliance, menstrual history, blood pressure, and weight were recorded. Additionally, lipid profiles were recorded every 6 weeks.
Of the 24 participants, 16 (7 from the low-fat diet group and 9 from the low-carbohydrate group) completed the study. The average overall weight loss in this group was 6.5% and the average waist circumference reduction was 5.7 cm. Of the 16 completers, 12 menstruated during the study period, 8 with regularity.
“Weight loss appeared to play a big role in these results, as women who lost weight were 3.4 times more likely to have improved menstrual function, which is statistically significant,” said Dr. Ornstein.
There were no significant changes in any hormonal variables from baseline, nor were baseline hormone levels predictive of menses improvement or degree of weight loss by multiple regression analysis, reported Dr. Ornstein.
There were no statistically significant differences in outcome between the two diet treatment groups, “nor did the low-carbohydrate diet harm the lipid profile,” she said.
Although limited by the small sample size, the lack of an untreated control group, and the absence of ovulation confirmation, the findings of this study suggest that “weight management might be the preferable first-line treatment for this population compared with the standard use of oral contraceptives and other medications because it addresses menstrual dysfunction and risk factors for type 2 diabetes and cardiovascular disease, both of which have been associated with polycystic ovary syndrome,” said Dr. Ornstein.
Successfully implementing a weight management treatment protocol “requires ongoing nutritional counseling and support,” Dr. Ornstein noted. “It can be challenging, but it is possible,” she said, noting that 8 of the 16 women who completed the initial 12-week study continued to the 6-month follow-up, “losing an average of 10 pounds and, for most of them, continuing their menstrual cycles.””