[Clinical study on treating insulin resistance and promoting ovulation in polycystic ovary syndrome]

To investigate the effects of metformin and clomiphene on infertility caused by polycystic ovary syndrome (PCOS) with insulin-resistance (IR) and to observe the effects of metformin on PCOS with pseudoacanthosis nigricans (AN) and IR.

Seventy infertility patients caused by PCOS with IR were randomly divided into three groups : patients in group Aa (n = 20) took metformin 500 mg only, three times daily for 3 months; patients in group Ab (n = 20) took clomiphene 50 mg only, once daily from the 5th day of menstrual cycle or withdrawal bleeding for 5 days and 3 cycles, and patients in group Ac (n = 30) were treated by metformin and clomiphene for 3 cycles, with the same dosages as groups Aa and Ab. Thirty patients who suffered from PCOS with AN and IR were served as group B, They took metformin only, the same as group Aa. The following indexes were measured before and after three months or cycles of treatment in all the patients: body height, weight, waistline, hipline, body mass index (BMI), waist hip ratio (WHR), fasting insulin (FINS), fasting blood-glucose (FBG), total cholesterol (TC), triglyceride (TG), and sex hormones [follicle-stimulating hormone (FSH), luteotropic hormone (LH), prolactin (PRL), estradiol (E(2)), progestin (P), testosterone (T)].

The pregnant rate was 15% (group Aa), 20% (group Ab), and 57% (group Ac) respectively. It was significantly higher in group Ac than in groups Aa and Ab, (P < 0.01), while there was no significant difference between the latter two groups (P > 0.05). In group Ac the pretreatment levels of FINS, BMI, T, TG, and TC were (49.7 +/- 6.4) mU/L, 29.4 +/- 2.2, (6.4 +/- 2.2) nmol/L, (4.1 +/- 1.0) mmol/L, (6.3 +/- 0.5) mmol/L, and posttreatment levels were (27.7 +/- 1.8) mU/L, 23.6 +/- 5.2, (3.8 +/- 2.0) nmol/L, (2.2 +/- 0.7) mmol/L, (4.6 +/- 0.5) mmol/L. In group Aa pretreatment levels of FINS, BMI, T, TG, and TC were (50.0 +/- 8.2) mU/L, 28.7 +/- 1.2, (6.4 +/- 2.0) nmol/L, (4.3 +/- 1.2) mmol/L, (6.6 +/- 0.3) mmol/L, and posttreatment levels were (29.9 +/- 8.2) mU/L, 22.4 +/- 9.3, (4.3 +/- 0.9) nmol/L, (2.3 +/- 0.3) mmol/L, (4.8 +/- 0.6) mmol/L. In group B pretreatment levels of FINS, BMI, T, TG, and TC were (51.0 +/- 8.1) mU/L, 29.8 +/- 3.1, (6.3 +/- 3.5) nmol/L, (4.5 +/- 1.2) mmol/L, (6.8 +/- 0.2) mmol/L, and posttreatment levels were (28.5 +/- 2.8) mU/L, 23.4 +/- 6.1, (3.0 +/- 0.9) nmol/L, (2.3 +/- 0.9) mmol/L, (5.0 +/- 0.6) mmol/L. In groups Ac, Aa and B, the IR condition was obviously improved and posttreatment serum levels of T, TG, TC, FINS and BMI were significantly lower than those of pretreatment (all P < 0.01). In group Ab pretreatment levels of FINS, BMI, T, TG, and TC were (48.8 +/- 7.4) mU/L, 27.3 +/- 2.8, (6.0 +/- 2.0) nmol/L, (3.9 +/- 1.4) mmol/L, (6.4 +/- 0.6) mmol/L, and posttreatment levels were (42.9 +/- 7.0) mU/L, 27.5 +/- 3.1, (4.0 +/- 2.4) nmol/L, (3.9 +/- 0.3) mmol/L, (5.9 +/- 0.3) mmol/L, (all P > 0.05). Among patients in group B, 90% (27/30) menstrual condition and ovulation function were improved and AN was reduced in different degree after three months' treatment.

Metformin can increase the sensitivity of PCOS to clomiphene and improve ovulation function of clomiphene. Metformin plus clomiphene is an effective way of treating infertility caused by PCOS with IR.