Influence of insulin resistance on total renin level in normotensive women with polycystic ovary syndrome

Angiotensin-converting enzymes play a dominant role in fertility

According to the World Health Organization, infertility, associated with metabolic syndrome, has become a global issue with a 10%-20% incidence worldwide. An accumulating body of evidence has shown that the renin-angiotensin system is involved in the fertility problems observed in some populations. Moreover, alterations in the expression of angiotensin-converting enzyme-1, angiotensin-converting enzyme-2, and angiotensin-converting enzyme-3 might be one of the most important mechanisms underlying both female and male infertility. However, as a pseudogene in humans, further studies are needed to explore whether the abnormal angiotensin-converting enzyme-3 gene could result in the problems of human reproduction. In this review, the relationship between angiotensin-converting enzymes and fertile ability is summarized, and a new procedure for the treatment of infertility is discussed.

Increased total Renin levels but not Angiotensin-converting enzyme activity in obese patients with polycystic ovary syndrome

OBJECTIVE

To investigate the renin-angiotensin-aldosterone system and angiotensin-converting enzyme (ACE) activity in patients with polycystic ovarian syndrome (PCOS).

SUBJECTS AND METHODS

In this case-control study, 41 obese (PCOS) women and 29 healthy controls, matched for age and body mass index, were enrolled. Anthropometric, metabolic, and hormonal patterns, including plasma aldosterone, plasma renin, and ACE activity, were measured in each subject.

RESULTS

Plasma renin levels were significantly higher in PCOS patients (19.7 ± 14.5 µg/ml) compared with controls (12.9 ± 9.0 µg/ml, p < 0.05). ACE activity and aldosterone levels did not significantly differ between both groups (p = 0.15 and p = 0.18, respectively). Analysis of PCOS patients showed a significant correlation of fasting insulin levels with levels of renin (r = 0.305, p < 0.01) and free testosterone (r = 0.384, p = 0.001). Similarly, homeostasis model assessment index was positively correlated with total renin concentrations (r = 0.366, p < 0.01) and free testosterone (r = 0.352, p < 0.01).

CONCLUSION

Obese PCOS women had higher total renin levels, but not ACE activity and aldosterone levels, related to insulin resistance compared with controls.

Angiotensin-converting enzyme gene polymorphism and risk of insulin resistance in PCOS

The aim of this study was to establish the frequency of angiotensin-converting enzyme (ACE) insertion (I) or deletion (D) gene polymorphism in women with polycystic ovary syndrome (PCOS) and to examine the association of this polymorphism with insulin resistance. A total of 32 women with PCOS and 31 healthy, age- and body mass index-matched controls were studied. Serum lipids, fasting glucose, insulin and other hormones concentrations were measured. Homeostasis model assessment was used to estimate insulin resistance (HOMA-IR). DNA was extracted from peripheral blood leukocytes and genotyping of ACE I/D polymorphism was carried out by polymerase chain reaction. ACE genotypes were distributed as follows: DD was present in 16 (50%), ID in 12 (37.5%) and II in four (12.5%) PCOS patients, and DD in seven (22.6%), ID in 20 (64.5%) and II in four (12.9%) of healthy subjects. The frequency of D and I alleles were found in 69% and 31% of the PCOS group and 55% and 45% in the control group, respectively. There were no significant differences regarding the genotypic distribution and allelic frequency between the groups. However the ACE DD genotype was significantly associated with serum insulin concentrations and HOMA-IR measurement (both P=0.005). ACE DD genotype is associated with an increased insulin resistance in women with PCOS.

Effects of metformin and ethinyl estradiol-cyproterone acetate on clinical, endocrine and metabolic factors in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a major endocrine abnormality that affects women of reproductive age. Oral contraceptive pills are usually the first choice of treatment for PCOS when fertility is not desired. Metformin, an insulin-sensitizing drug, has been shown to improve such metabolic abnormality. Aim. To compare the effects of a contraceptive pill in combination with metformin on the clinical, endocrine and metabolic parameters in obese and non-obese patients with PCOS.

METHODS

Sixty PCOS patients (25 obese, 35 non-obese) were enrolled in this prospective clinical study. PCOS was defined according to the Rotterdam criteria. Patients were randomized to oral treatment with Diane35 (35 microg ethinyl estradiol plus 2 mg cyproterone acetate), metformin or a combination of Diane35/metformin for 3 months. Body mass index (BMI), waist-to-hip ratio (WHR), Ferriman-Gallwey (FG) score, leuteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, fasting insulin and glucose/insulin ratio were measured at baseline and at the end of treatment.

RESULTS

Diane35 resulted in a higher reduction of FG score in both obese and non-obese PCOS patients compared with metformin. Menstrual regularity was restored in all PCOS patients treated with Diane35 compared with only 28% of those receiving metformin. Metformin significantly decreased BMI and WHR in obese patients (p < 0.05). Testosterone levels decreased in all three groups. LH levels and LH/FSH ratio decreased with Diane35 and Diane35/metformin in both obese and non-obese patients. Metformin significantly decreased fasting insulin concentrations (p < 0.05 and p < 0.01) and increased the insulin sensitivity (p < 0.05) in both obese and non-obese PCOS patients, while no significant changes were observed in the Diane35 group. In addition, insulin levels also decreased (p < 0.05) in the Diane35/metformin group.

CONCLUSIONS

Our data show that a combination of metformin and contraceptive pill may be more effective in suppressing the hyperandrogenemia of obese and non-obese PCOS patients than metformin alone and may reduce insulin levels more than contraceptive pill alone. Hence, combined treatment may become a more effective therapeutic option for PCOS.

Why does ovarian surgery in PCOS help? Insight into the endocrine implications of ovarian surgery for ovulation induction in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex disorder with heterogeneity of clinical and endocrine features. Ovarian surgery for ovulation induction has been used in the management of clomiphene citrate-resistant anovulatory women with PCOS. Various types of ovarian surgery have been employed (wedge resection, electrocautery, laser vaporization, multiple ovarian biopsies and others) and all procedures result in an altered endocrine profile after surgery. The mechanism behind the reversal of endocrinological dysfunction in PCOS after ovarian surgery remains incompletely understood. This review scans the literature systematically to identify the endocrine changes after ovarian surgery in PCOS, in order to glean some knowledge of the mechanism involved. After ovarian surgery in PCOS, a rapid reduction in serum levels of all ovarian hormones is seen, in combination with increased serum levels of pituitary hormones. Folliculogenesis is then initiated and ovarian hormone production increases, synchronically with a reduction of pituitary hormones. Continuation of follicle growth in subsequent cycles after ovarian surgery occurs in an environment with less androgens and lower LH and FSH levels compared with pretreatment levels. The endocrine changes found after ovarian surgery in PCOS women seem to be governed by the ovaries themselves. Rapid reduced secretion of all ovarian hormones restores feedback to the hypothalamus and pituitary, resulting in appropriate gonadotrophin secretion. Initiation of follicular development seems to be induced by increasing FSH levels following a reduction of the follicle excess and (intra-ovarian) androgen levels. Additionally, anti-Müllerian hormone and gonadotrophin surge attenuating factor probably have a role in the endocrine changes.

Effects of metformin combined with cyproterone acetate on clinical features, endocrine and metabolism of non-obese women with polycystic ovarian syndrome

In order to explore the effects of metformin combined with cyproterone acetate (CPA) on the clinical features, endocrine and metabolism of the patients with polycystic ovarian syndrome (PCOS), 50 cases of non-obese PCOS were randomly subjected to CPA (CPA treatment group, n = 25) and CPA+ metformin (n = 25) treatment for 6 months. Before and after treatment the body mass index (BMI), waist : hip ratio (WHR), ovarian volume, serum gonadotrophin, androgen and sex hormone-binding globulin (SHBG) levels, and fasting lipid, glucose and insulin levels were measured. The results showed that all of the parameters in two groups were similar before treatment. After treatment for 6 months in the CPA+ metformin group, BMI and WHR were significantly decreased, while insulin sensitivity was significantly decreased as Compared with those before treatment. In CPA group, no significant changes were found before and after treatment. Combined use of CPA and metformin could result in the reduction of serum androstenedione and increases of serum SHBG levels as compared with the CPA treatment alone. It was concluded that combined use of CPA and metformin could improve the insulin sensitivity, and further suppress the hyperandrogenism in non-obese women with PCOS.

The Management of Polycystic Ovary Syndrome

It is well known that subjects with polycystic ovary syndrome (PCOS) show very variable clinical and biochemical aspects. Considering long-term repercussions, two main disturbances, not always strictly related, need to be countered: hyperandrogenism and insulin resistance, with compensatory hyperinsulinemia. The aim of this review is to summarize therapeutic perspectives for PCOS, starting from basic approach, such as weight reduction and changes in lifestyle. The benefits of long-term use of oral contraceptives and the criteria of choice of the estro-progestin combinations are discussed. With severe hyperandrogenism, a pure antiandrogen should be added. The experiences with insulin-sensitizing drugs, especially metformin, are reviewed; while their beneficial role as an adjuvant to treatment of ovulatory infertility has been well established, the effects of a long-term treatment, especially in very young patients, are still under debate. Current studies are testing the results of combinations of different treatments at low dosage; randomized comparative trials on the long-term efficacy of these approaches have yet to be scheduled.

Clinical, endocrine and metabolic effects of metformin added to ethinyl estradiol-cyproterone acetate in non-obese women with polycystic ovarian syndrome: a randomized controlled study

BACKGROUND

Oral contraceptive pills (OC) are usually the first choice of treatment for polycystic ovarian syndrome (PCOS), when fertility is not desired. However, they do not improve, or may even further induce impairment of insulin sensitivity, which is already impaired in women with PCOS. In this prospective, randomized study, we analysed the additional benefits of adding metformin to the OC treatment in non-obese women with PCOS.

METHODS

After a baseline work-up including body mass index (BMI), waist:hip ratio (WHR), Ferriman-Gallwey score, ovarian volume, serum gonadotrophin, androgen and sex hormone-binding globulin (SHBG) levels, and fasting lipid, glucose and insulin levels, 40 non-obese women with PCOS were assigned either to the OC or to the OC + metformin treatment by computer-assisted randomization. At the end of the 4 month follow-up period, subjects were re-evaluated.

RESULTS

The two groups were similar at baseline. After treatment, women in the OC + metformin group had significant decreases in BMI and WHR, and a significant increase in insulin sensitivity, in contrast to those in the OC group, who had insignificant changes in these parameters. Adding metformin also caused significant improvements in serum androstenedione and SHBG levels compared with the OC treatment alone.

CONCLUSIONS

Adding metformin to the OC treatment may improve the insulin sensitivity, and may further suppress the hyperandrogenaemia in non-obese women with PCOS.

Effect of hypertension therapy with the angiotensin-converting enzyme inhibitor lisinopril on hyperandrogenism in women with polycystic ovary syndrome

OBJECTIVE

To investigate the effect of an angiotensin-converting enzyme inhibitor, lisinopril, on serum androgen and sex-hormone-binding globulin (SHBG) levels in hypertensive women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective, observational study.

SETTING

Infertility Clinic of the Sani Konukoglu Hospital, Gaziantep, Turkey.

PATIENT(S)

Ten hypertensive women with PCOS.

INTERVENTION(S)

Lisinopril, 10 mg/day, for 4 weeks. MAIN OUTCOME MEASURE(S)): Serum levels of gonadotropins, DHEAS, total T, free T, 17 alpha-hydroxyprogesterone (17-OHP), androstenedione, E2, SHBG, TSH, and PRL were determined.

RESULT(S)

Hypertension treatment with lisinopril (10 mg/day for 4 weeks) resulted in a statistically significant decrease in serum free T levels. However, there was no difference in the SHBG levels.

CONCLUSION(S)

Use of lisinopril, an angiotensin-converting enzyme inhibitor, results in decreased free T levels independently of SHBG. It may affect the free T levels by affecting the ovarian renin-angiotensin system.

Obesity, polycystic ovary syndrome and anovulation--how are they interrelated?

Polycystic ovary syndrome remains a mystery with respect to its aetiology, consequences and management. There is an increasing emphasis on its familial origins although the genes involved are unknown. There are significant changes in risk profiles for cardiovascular disease but no clear clinical evidence of morbidity or mortality. There is evidence of improvement in insulin resistance or insulin sensitivity drugs but uncertainty about improvement in pregnancy outcomes. This review looks at the latest advances in understanding polycystic ovary syndrome, particularly in obesity.