The impact of physical activity in a case of polycystic ovary syndrome

Abstract

Polycystic ovary syndrome (PCOS) affects 5–10% of women of fertile age and most women are diagnosed with the syndrome because of gynecologic symptoms, that is infertility, menstrual disturbances or symptoms of hyperandrogenism such as acne or excess hair growth. Since the report by Burghen et al. (1) in 1980 that PCOS was associated with hyperinsulinemia, it has become clear that women with PCOS are more insulin resistant than weight-matched women without the syndrome (2). PCOS has several features in common with the metabolic syndrome, including dyslipi-demia, abdominal obesity and insulin resistance. In both syndromes, there are also signs of enhanced activity in neuroendocrine stress axes (3, 4), and blood pressure has been found to be higher in PCOS than in controls (5). Metformin, an insulin sensitizing agent, is used for treatment of type 2 diabetes mellitus and also increasingly for PCOS. Other treatments for insulin resistance are physical activity and weight loss (6–8). Motivation is crucial for lifestyle changes (7). Most doctors have experienced that it is difficult to motivate a patient to lose weight and become more physically active and that patient adherence is much easier to achieve to medical treatment than to a change in lifestyle. The following case report illustrates both the effect of physical activity on PCOS and the importance of motivation. A 24-year-old nurse student referred because of oligo-menorrhea and elevated plasma testosterone was enrolled in a double-blind, randomized study of the effect of metformin on PCOS. The study was designed as a crossover study with treatment periods of 6 months separated by a 3-month washout period. Before entering the study, she received general information about PCOS and the importance of being physically active and losing weight was emphasized. Before and after each treatment period, blood pressure and waist-hip (w/h) ratio were measured and body mass index (BMI) calculated. After an overnight fast of 8h, venous plasma levels of glucose (FBG), total cholesterol (chol), triglycerides (TGL), dehydroepiandrostenedione (DHAS), gonadotropins, total testosterone (T) and sex hormone binding globulin (SHBG) were measured. Testosterone index (T index) was calculated as testosterone divided with SHBG. Her periods became regular during the first treatment period and remained so during the remaining study period. She lost weight during the first period, but gained a little again during the second period. Testosterone normalized during both periods. As SHBG rose during the second period, the testosterone index fell. FBG fell continuously during the study (Table 1). An oral glucose tolerance test performed after the study period was normal. When the code was broken, it appeared that she had received metformin during the first treatment period. As the investigator performing the study expressed some surprise over the improving values during the placebo period despite the increasing weight, she explained that she had had a boyfriend for the past 6months. He was a keen sportsman and because of that she had become considerably more physically active. She now took a 1-hour walk each evening, played badminton once a week and went to her job by bike 8 km each day. In the DPP (Diabetes Prevention Program) study (8), physical activity was shown to be more effective than metformin in treating insulin resistance. It is not known how metformin changes insulin sensitivity, but it is thought to increase peripheral glucose uptake in response to insulin, and to reduce hepatic glucose output to some extent. Exercise may enhance insulin sensitivity by affecting the oxidative capacity of skeletal muscle, but it has also been shown that exercise reduces sympathetic nerve activity, which may be exaggerated in insulin resistance (9). The presented case history illustrates that this may also be the case in PCOS, a condition strongly related to insulin resistance. It also shows the importance of social support in changes of lifestyle, and the impact of love as a motivating factor considerably stronger than the advice of doctors.