THE EFFECT OF MYOINOSITOL AND METFORMIN ON CARDIOVASCULAR RISK FACTORS IN WOMEN WITH POLYCYSTIC OVARY SYNDROME: A RANDOMIZED CONTROLLED TRIAL

CONTEXT

Cardiovascular risk is increased in women with polycystic ovary syndrome (PCOS). Do insulin sensitizing agents such as metformin (MET) and myoinositol (MI) ameliorate biomarkers of cardiovascular risk?

OBJECTIVE

To compare the effects of MET and MI on blood pressure, lipid profile and high sensitive C-reactive protein (hs-CRP) in women with PCOS in respect to their body mass index (BMI).

DESIGN

Open label, parallel randomized, single center study.

SUBJECTS AND METHODS

Sixty six women with PCOS (33 normal-weight and 33 overweight/obese) were randomized to either MI (4 g/day) or MET (1500 mg/day) for a period of 6 months. Serum concentration of hormones, lipid profile, oxidized LDL (ox-LDL), hs-CRP, blood pressure measurement and clinical assessment of BMI, waist circumference (WC) and Ferriman Gallwey score (FG score) were performed before and after treatment.

RESULTS

Thirty patients in each group completed the trial. Compared with MET, MI significantly decreased diastolic blood pressure (DBP) (p=0.036) and significantly increased serum hs-CRP (p=0.043). No differences between groups in total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, ox-LDL and triglycerides were reported after 6 months. Treatment with MI reduced BMI (p=0.037), WC (p=0.005), DBP (p=0.021) and TC (p=0.008). During MET treatment a significant decrease in BMI (p=0.005), WC (p=0.004), FG score (p=0.001), testosterone (p=0.013) and free androgen index (FAI) (p=0.006) was observed.

CONCLUSIONS

Our study showed an advantage of MI in reduction of DBP and TC thus predicting favorable metabolic and cardiovascular outcomes in PCOS women. MET more effectively decrease indices of hyperandrogenism.

Insulin resistance, androgens, and lipids are gradually improved in an age-dependent manner in lean women with polycystic ovary syndrome: insights from a large Caucasian cohort

PURPOSE

Polycystic ovary syndrome (PCOS), considered a lifelong condition, manifests mainly as a cluster of hyperandrogenic symptoms during the early reproductive years, with the affected woman gradually developing an adverse cardiometabolic profile over the years. However, some data point to the possibility of differences in the evolution of PCOS according to a woman's weight. The aim of the present study was to evaluate the metabolic and hormonal profiles of women with PCOS over time.

METHODS

A total of 763 lean women with PCOS (BMI 20-25 kg/m²) and 376 controls were included. The study group was further divided into three age groups representing women post-adolescence, of reproductive age, and of late reproductive age. All subjects were assessed clinically, biochemically, and hormonally.

RESULTS

Waist circumference, lipids, androgens, and insulin resistance index (homeostasis model assessment of IR index (HOMA-IR)) were significantly higher in the PCOS group compared with controls. Age subgroup analysis showed a progressive decrease of HOMA-IR and waist circumference, and lipid levels were comparable between PCOS and controls in all age groups. Androgens remained significantly higher in PCOS, but they gradually decreased through time. A significant negative association of age with waist circumference, androgens, insulin, and HOMA-IR was revealed. Univariate and multivariate regression analysis disclosed a strong correlation of HOMA-IR with age (p = 0.014, β - 0.19, SE coefficient 0.008) as a single parameter or in combination with total cholesterol (TC) (p < 0.001, age: β - 0.023, SE 0.10; TC: β 0.084, SE 0.027).

CONCLUSION

Insulin resistance, androgens, and lipids are gradually improved in an age-dependent manner in lean PCOS women. We hypothesize that if these women do not gain weight with the passage of time, there is a high probability that their cardiometabolic risk will be attenuated.

Insulin resistance in non-obese women with polycystic ovary syndrome: relation to byproducts of oxidative stress

To get more insight into molecular mechanisms underlying oxidative stress and its link with insulin resistance, oxidative stress parameters, as well as, antioxidant enzyme activities were studied in young, non-obese women with polycystic ovary syndrome (PCOS). Study was performed in 34 PCOS women and 23 age and body mass index (BMI)-matched healthy controls. Plasma nitrotyrosine and malondialdehyde (MDA), representative byproducts of protein and lipid oxidative damage, were determined by enzyme immunoassay. Antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPX) were studied spectrophotometrically. Insulin resistance was calculated using homeostasis assessment model (HOMA-IR). Plasma nitrotyrosine and MDA were increased, but only nitrotyrosine was significantly higher (p < 0.05) in PCOS women compared to controls. Uric acid (surrogate marker of × antine oxidase) was also significantly elevated in PCOS (p < 0.05). Both plasma SOD and GPX activity showed no statistically significant difference between PCOS and controls. Indices of insulin resistance (insulin and HOMAIR) were significantly higher in PCOS group and positively correlated with level of MDA (r = 0.397 and r = 0.523, respectively; p < 0.05) as well as GPX activity (r = 0.531 and r = 0.358, respectively; p < 0.05). Our results indicate that insulin resistance could be responsible for the existence of subtle form of oxidative stress in young, nonobese PCOS women. Hence, presence of insulin resistance, hyperinsulinemia and oxidative damage are likely to accelerate slow development of cardiovascular disease in PCOS.