Steroidal contraceptives: effect on carbohydrate metabolism in women without diabetes mellitus

Increased Insulin following an Oral Glucose Load, Genetic Variation near the Melatonin Receptor MTNR1B, but No Biochemical Evidence of Endothelial Dysfunction in Young Asian Men and Women

Aim

To identify biochemical and genetic variation relating to increased risk of developing type 2 diabetes mellitus and cardiovascular disease in young, lean male and female adults of different ethnicities.

Method

Fasting blood and urine and non-fasting blood following oral glucose intake were analysed in 90 Caucasians, South Asians and South East/East Asians.

Results

There were no differences in age, birthweight, blood pressure, body mass index, percent body fat, total energy, percentage of macronutrient intake, microalbumin, leptin, cortisol, adrenocorticotropic hormone, nitric oxide metabolites, C-reactive protein, homocysteine, tumor necrosis factor-α, interleukin-6, von Willebrand factor, vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, and tissue plasminogen activator. Fasting total cholesterol (P = .000), triglycerides (P = .050), low density lipoprotein (P = .009) and non-fasting blood glucose (15 min) (P = .024) were elevated in South Asians compared with Caucasians, but there was no significant difference in glucose area under curve (AUC). Non-fasting insulin in South Asians (15–120 min), in South East/East Asians (60–120 min), and insulin AUC in South Asians and South East/East Asians, were elevated compared with Caucasians (P≤0.006). The molar ratio of C-peptide AUC/Insulin AUC (P = .045) and adiponectin (P = .037) were lower in South Asians compared with Caucasians. A significant difference in allele frequency distributions in Caucasians and South Asians was found for rs2166706 (P = 0.022) and rs10830963 (P = 0.009), which are both near the melatonin receptor MTNR1B.

Conclusions

Elevated non-fasting insulin exists in young South Asians of normal fasting glucose and insulin. Hepatic clearance of insulin may be reduced in South Asians. No current biochemical evidence exists of endothelial dysfunction at this stage of development. MTNR1B signalling may be a useful therapeutic target in Asian populations in the prevention of type 2 diabetes mellitus.

A new combination of testosterone and nestorone transdermal gels for male hormonal contraception

CONTEXT

Combinations of testosterone (T) and nestorone (NES; a nonandrogenic progestin) transdermal gels may suppress spermatogenesis and prove appealing to men for contraception.

OBJECTIVE

The objective of the study was to determine the effectiveness of T gel alone or combined with NES gel in suppressing spermatogenesis.

DESIGN AND SETTING

This was a randomized, double-blind, comparator clinical trial conducted at two academic medical centers.

PARTICIPANTS

Ninety-nine healthy male volunteers participated in the study.

INTERVENTIONS

Volunteers were randomized to one of three treatment groups applying daily transdermal gels (group 1: T gel 10 g+NES 0 mg/placebo gel; group 2: T gel 10 g+NES gel 8 mg; group 3: T gel 10 g+NES gel 12 mg).

MAIN OUTCOME VARIABLE

The main outcome variable of the study was the percentage of men whose sperm concentration was suppressed to 1 million/ml or less by 20-24 wk of treatment.

RESULTS

Efficacy data analyses were performed on 56 subjects who adhered to the protocol and completed at least 20 wk of treatment. The percentage of men whose sperm concentration was 1 million/ml or less was significantly higher for T+NES 8 mg (89%, P<0.0001) and T+NES 12 mg (88%, P=0.0002) compared with T+NES 0 mg group (23%). The median serum total and free T concentrations in all groups were maintained within the adult male range throughout the treatment period. Adverse effects were minimal in all groups.

CONCLUSION

A combination of daily NES+T gels suppressed sperm concentration to 1 million/ml or less in 88.5% of men, with minimal adverse effects, and may be further studied as a male transdermal hormonal contraceptive.

The effects of old, new and emerging medicines on metabolic aberrations in PCOS

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age that is associated with significant adverse short- and long-term health consequences. Multiple metabolic aberrations, such as insulin resistance (IR) and hyperinsulinaemia, high incidence of impaired glucose tolerance, visceral obesity, inflammation and endothelial dysfunction, hypertension and dyslipidemia are associated with the syndrome. Assessing the metabolic aberrations and their long term health impact in women with PCOS is challenging and becomes more important as therapeutic interventions currently available for the management of PCOS are not fully able to deal with all these consequences. Current therapeutic management of PCOS has incorporated new treatments resulting from the better understanding of the pathophysiology of the syndrome. The aim of this review is to summarize the effect of old, new and emerging therapies used in the management of PCOS, on the metabolic aberrations of PCOS.

Divergent effects of a combined hormonal oral contraceptive on insulin sensitivity in lean versus obese women

OBJECTIVE

To evaluate the effects of a commonly used combined hormonal oral contraceptive (OC) on carbohydrate metabolism in obese as compared with lean women.

DESIGN

6-month prospective study.

SETTING

Clinical research center at an academic medical center.

PATIENT(S)

Premenopausal nondiabetic women with body mass index <25 kg/m(2) (n = 15) or >30 kg/m(2) (n = 14).

INTERVENTION(S)

Ethinyl estradiol (35 μg) and norgestimate (0.18/0.215/0.25 mg) for 6 cycles.

MAIN OUTCOME MEASURE(S)

Insulin sensitivity by frequent sampling intravenous glucose tolerance test; other indices of insulin sensitivity (homeostatic model assessment of insulin sensitivity index [ISI HOMA], the Matsuda index); fasting lipid panel.

RESULT(S)

Insulin sensitivity changed from 6.62 ± 3.69 min(-1)/mIU/L (baseline) to 8.23 ± 3.30 min(-1)/mIU/L (6 months) in lean women, and from 4.36 ± 2.32 to 3.82 ± 2.32 min(-1)/mIU/L in obese women. Divergent effects on insulin sensitivity were also observed with ISI HOMA and the Matsuda index. Low-density lipoprotein increased by approximately 20 mg/dL in both the lean and obese groups.

CONCLUSION(S)

Lean and obese women exhibit differential changes in insulin sensitivity when given 6 months of a commonly used oral contraceptive. The mechanisms of these differences and whether these divergent effects persist in the long term require further investigation.

Managing women with gestational diabetes mellitus in the postnatal period

Guidelines for management of women with a history of gestational diabetes mellitus (GDM) in the postpregnancy period have lagged behind the recognition that this is an important time for medical intervention. However, in the past decade, the evidence-base for screening algorithms, contraceptive management, diabetes prevention strategies and implications for offspring has expanded. In this review, we discuss current recommendations for managing women with GDM in the postnatal period, with particular attention to postpartum diabetes screening, prevention of future glucose intolerance and family planning.

Metabolic and cardiovascular impact of oral contraceptives in polycystic ovary syndrome

Chronic anovulation, polycystic ovarian morphology and hyperandrogenism are the diagnostic criteria for polycystic ovary syndrome (PCOS). Metabolic disturbances are more common in PCOS women who are prone to develop metabolic syndrome and to present higher levels of some cardiovascular disease risk marker. Oral contraceptives are widely used in PCOS, but conflicting data have been reported regarding their impact on carbohydrate and lipid metabolism on PCOS women. This paper presents a critical evaluation of combined oral contraceptives (COCs) metabolic effect - carbohydrate metabolism and insulin sensitivity, lipid metabolism, haemostasis, body weight, arterial pressure and cardiovascular impact - on PCOS women. Because of the paucity of data on the impact of COCs on cardiovascular and metabolic parameters in PCOS patients, most of there commendations are based on studies involving ovulatory women. The use of low-dose COCs is preferable in PCOS, especially among patients with glucose intolerance, insulin resistance and uncomplicated diabetes mellitus. Although reported as a side effect of COCs, marked weight gain has not been confirmed among users. However, when arterial hypertension or elevated risk for thromboembolism is present, progestogen-only hormonal contraceptives should be used instead of COCs. Regarding dyslipidaemia, COCs reduce low-density lipoprotein and total cholesterol and elevate high-density lipoprotein and triglycerides, and therefore are not recommended for women with high triglycerides levels. The choice of a COC, which alleviates the PCOS-induced hyperandrogenism without significant negative impact on cardiovascular risk, is one of the greatest challenges faced by gynaecologists nowadays.