Sex difference in the effect of obesity on 24-hour mean serum gonadotropin levels

Prevalence of Polycystic Ovarian Syndrome and Its Link to Obesity in Adolescent Girls

Polycystic ovarian syndrome (PCOS), also referred to as Stein-Leventhal syndrome, happens to be one of most common hormonal disorders found in females, causing large-sized ovaries with small cysts of non-ovulated oocytes in the outer medulla part of the ovary. Women suffering from PCOS often exhibit symptoms like oligomenorrhoea, elevated testosterone levels, acne, alopecia, hirsutism, sudden weight gain and many more. It can predispose a woman to developing infertility in future, and thus, difficulties in conceiving; due to the cystic changes in the ovaries, it results in anovulation and amenorrhea. The early symptoms of PCOS are being commonly observed nowadays in young women who are in their early 20s and those who are overweight or obese. The metabolic expression of PCOS increases with obesity. Obesity is a factor that is considered to contribute the most in the occurrence of various long-standing and non-transmissible illnesses apart from PCOS such as atherosclerosis, hypertension, diabetes, high blood cholesterol and even certain types of cancers. In obesity, there is an increase in the size and number of fat cells in the body. Obese and overweight young girls have a heightened likelihood of developing PCOS and its corresponding metabolic and reproductive health complications.

Effects of central obesity on maternal complications in Korean women of reproductive age

BACKGROUND

Considering the obesity-related complications in pregnancy and during delivery, prepregnancy central obesity may also affect pregnancy-related complications. This study aimed to assess the relationship between prepregnancy central obesity and adverse maternal outcomes in Korean women, by using the Korean National Health Insurance Service (NHIS) cohort.

METHODS

In this population-based retrospective cohort study, we used data from the NHIS database, which contains information of health-care utilisation, diagnosis and prescription, and mortality for almost the whole Korean population, together with data from the NHIS health checkup database from 2005 to 2015. The NHIS health checkup data (645-280 days before childbirth) of mothers who had deliveries (total, 783,406 deliveries) from 2006 to 2015 were collected. For maternal adverse outcome data, we searched for diagnoses of maternal complications made during the period of 280 days before each delivery. The odds for maternal complications according to 8 body mass index (BMI) and 10 waist circumference (WC) categories were analysed using logistic regression.

RESULTS

The incidence rates of eclampsia/preeclampsia, caesarean section, multiple gestation, and polycystic ovary syndrome (PCOS) increased according to the increase of BMI and WC. In contrast, the incidence rate of premature rupture of membrane (PROM) was inversely correlated with BMI and WC. In the low BMI (<17.5 and 17.5-19.9 kg/m²) and low WC (<60 and 60.0-64.0 cm) groups, the odds of threatened abortion were elevated.

CONCLUSION

Prepregnancy WC was closely linked to some maternal complications, including eclampsia/preeclampsia, cesarean section, PCOS, and PROM, in a manner similar to prepregnancy BMI.

The Pathogenesis of Polycystic Ovary Syndrome (PCOS): The Hypothesis of PCOS as Functional Ovarian Hyperandrogenism Revisited

Polycystic ovary syndrome (PCOS) was hypothesized to result from functional ovarian hyperandrogenism (FOH) due to dysregulation of androgen secretion in 1989-1995. Subsequent studies have supported and amplified this hypothesis. When defined as otherwise unexplained hyperandrogenic oligoanovulation, two-thirds of PCOS cases have functionally typical FOH, characterized by 17-hydroxyprogesterone hyperresponsiveness to gonadotropin stimulation. Two-thirds of the remaining PCOS have FOH detectable by testosterone elevation after suppression of adrenal androgen production. About 3% of PCOS have a related isolated functional adrenal hyperandrogenism. The remaining PCOS cases are mild and lack evidence of steroid secretory abnormalities; most of these are obese, which we postulate to account for their atypical PCOS. Approximately half of normal women with polycystic ovarian morphology (PCOM) have subclinical FOH-related steroidogenic defects. Theca cells from polycystic ovaries of classic PCOS patients in long-term culture have an intrinsic steroidogenic dysregulation that can account for the steroidogenic abnormalities typical of FOH. These cells overexpress most steroidogenic enzymes, particularly cytochrome P450c17. Overexpression of a protein identified by genome-wide association screening, differentially expressed in normal and neoplastic development 1A.V2, in normal theca cells has reproduced this PCOS phenotype in vitro. A metabolic syndrome of obesity-related and/or intrinsic insulin resistance occurs in about half of PCOS patients, and the compensatory hyperinsulinism has tissue-selective effects, which include aggravation of hyperandrogenism. PCOS seems to arise as a complex trait that results from the interaction of diverse genetic and environmental factors. Heritable factors include PCOM, hyperandrogenemia, insulin resistance, and insulin secretory defects. Environmental factors include prenatal androgen exposure and poor fetal growth, whereas acquired obesity is a major postnatal factor. The variety of pathways involved and lack of a common thread attests to the multifactorial nature and heterogeneity of the syndrome. Further research into the fundamental basis of the disorder will be necessary to optimally correct androgen levels, ovulation, and metabolic homeostasis.

Sexual functioning and sex hormones in men who underwent bariatric surgery

BACKGROUND

The relationship between obesity and impairments in male sexual functioning is well documented. Relatively few studies have investigated changes in sexual functioning and sex hormones in men who achieve significant weight loss with bariatric surgery. The objective of this study was to assess changes in sexual functioning, sex hormones, and relevant psychosocial constructs in men who underwent bariatric surgery.

METHODS

A prospective cohort study of 32 men from the Longitudinal Assessment of Bariatric Surgery-2 (LABS) investigation who underwent a Roux-en-Y gastric bypass (median body mass index [25th percentile, 75th percentile] 45.1 [42.0, 52.2]) and completed assessments between 2006 and 2012. Bariatric surgery was performed by a LABS-certified surgeon. Sexual functioning was assessed by the International Index of Erectile Functioning (IIEF). Hormones were assessed by blood assay. Quality of life (QoL), body image, depressive symptoms and marital adjustment were assessed by questionnaire.

RESULTS

Men lost, on average, (95% confidence interval) 33.3% (36.1%, 30.5%) of initial weight at postoperative year 1, 33.6% (36.8%, 30.5%) at year 2, 31.0% (34.1%, 27.9%) at year 3, and 29.4% (32.7%, 26.2%) at year 4. Participants experienced significant increases in total testosterone (P<.001) and sex hormone binding globulin (SHBG) (P<.001) through postoperative year 4. Although men reported improvements in sexual functioning after surgery, these changes did not significantly differ from baseline, with the exception of overall satisfaction at postoperative year 3 (P = .008). Participants reported significant improvements in physical domains of health-related quality of life (HRQoL), all domains of weight-related QOL, and body image, but not in the mental health domains of HRQoL or relationship satisfaction.

CONCLUSIONS

Men who lost approximately one third of their weight after Roux-en-Y gastric bypass experienced significant increases in total testosterone and SHBG. They did not, however, report significant improvements in sexual functioning, relationship satisfaction, or mental health domains of HRQoL. This pattern of results differs from that of women who have undergone bariatric surgery, who reported almost uniform improvements in sexual functioning and psychosocial status.

Effects of hyperandrogenemia and increased adiposity on reproductive and metabolic parameters in young adult female monkeys

Many patients with hyperandrogenemia are overweight or obese, which exacerbates morbidities associated with polycystic ovary syndrome (PCOS). To examine the ability of testosterone (T) to generate PCOS-like symptoms, monkeys received T or cholesterol (control) implants (n = 6/group) beginning prepubertally. As previously reported, T-treated animals had increased neuroendocrine drive to the reproductive axis [increased luteinizing hormone (LH) pulse frequency] at 5 yr, without remarkable changes in ovarian or metabolic features. To examine the combined effects of T and obesity, at 5.5 yr (human equivalent age: 17 yr), monkeys were placed on a high-calorie, high-fat diet typical of Western cultures [Western style diet (WSD)], which increased body fat from <2% (pre-WSD) to 15-19% (14 mo WSD). By 6 mo on WSD, LH pulse frequency in the controls increased to that of T-treated animals, whereas LH pulse amplitude decreased in both groups and remained low. The numbers of antral follicles present during the early follicular phase increased in both groups on the WSD, but maximal follicular size decreased by 50%. During the late follicular phase, T-treated females had greater numbers of small antral follicles than controls. T-treated monkeys also had lower progesterone during the luteal phase of the menstrual cycle. Although fasting insulin did not vary between groups, T-treated animals had decreased insulin sensitivity after 1 yr on WSD. Thus, while WSD consumption alone led to some features characteristic of PCOS, T + WSD caused a more severe phenotype with regard to insulin insensitivity, increased numbers of antral follicles at midcycle, and decreased circulating luteal phase progesterone levels.

Childhood obesity and its impact on the development of adolescent PCOS

Obesity exacerbates the reproductive and metabolic manifestations of polycystic ovary syndrome (PCOS). The symptoms of PCOS often begin in adolescence, and the rising prevalence of peripubertal obesity has prompted concern that the prevalence and severity of adolescent PCOS is increasing in parallel. Recent data have disclosed a high prevalence of hyperandrogenemia among peripubertal adolescents with obesity, suggesting that such girls are indeed at risk for developing PCOS. Obesity may impact the risk of PCOS via insulin resistance and compensatory hyperinsulinemia, which augments ovarian/adrenal androgen production and suppresses sex hormone-binding globulin (SHBG), thereby increasing androgen bioavailability. Altered luteinizing hormone (LH) secretion plays an important role in the pathophysiology of PCOS, and although obesity is generally associated with relative reductions of LH, higher LH appears to be the best predictor of increased free testosterone among peripubertal girls with obesity. Other potential mechanisms of obesity-associated hyperandrogenemia include enhanced androgen production in an expanded fat mass and potential effects of abnormal adipokine/cytokine levels. Adolescents with PCOS are at risk for comorbidities such as metabolic syndrome and impaired glucose tolerance, and concomitant obesity compounds these risks. For all of these reasons, weight loss represents an important therapeutic target in obese adolescents with PCOS.

Determination of the source of androgen excess in functionally atypical polycystic ovary syndrome by a short dexamethasone androgen-suppression test and a low-dose ACTH test

BACKGROUND

Polycystic ovary syndrome (PCOS) patients typically have 17-hydroxyprogesterone (17OHP) hyperresponsiveness to GnRH agonist (GnRHa) (PCOS-T). The objective of this study was to determine the source of androgen excess in the one-third of PCOS patients who atypically lack this type of ovarian dysfunction (PCOS-A).

METHODS

Aged-matched PCOS-T (n= 40), PCOS-A (n= 20) and controls (n= 39) were studied prospectively in a General Clinical Research Center. Short (4 h) and long (4-7 day) dexamethasone androgen-suppression tests (SDAST and LDAST, respectively) were compared in subsets of subjects. Responses to SDAST and low-dose adrenocorticotropic hormone (ACTH) were then evaluated in all.

RESULTS

Testosterone post-SDAST correlated significantly with testosterone post-LDAST and 17OHP post-GnRHa (r = 0.671-0.672), indicating that all detect related aspects of ovarian dysfunction. An elevated dehydroepiandrosterone peak in response to ACTH, which defined functional adrenal hyperandrogenism, was similarly prevalent in PCOS-T (27.5%) and PCOS-A (30%) and correlated significantly with baseline dehydroepiandrosterone sulfate (DHEAS) (r = 0.708). Functional ovarian hyperandrogenism was detected by subnormal testosterone suppression by SDAST in most (92.5%) PCOS-T, but significantly fewer PCOS-A (60%, P< 0.01). Glucose intolerance was absent in PCOS-A, but present in 30% of PCOS-T (P < 0.001). Most of the PCOS-A cases with normal testosterone suppression in response to SDAST (5/8) lacked evidence of adrenal hyperandrogenism and were obese.

CONCLUSIONS

Functional ovarian hyperandrogenism was not demonstrable by SDAST in 40% of PCOS-A. Most of these cases had no evidence of adrenal hyperandrogenism. Obesity may account for most hyperandrogenemic anovulation that lacks a glandular source of excess androgen, and the SDAST seems useful in making this distinction.

Obesity alters circadian behavior and metabolism in sex dependent manner in the volcano mouse Neotomodon alstoni

The aim of the present study is to evaluate whether circadian locomotor activity, and the daily profile of plasma parameters related to metabolic syndrome (nutrients: glucose and triacylglycerides, and hormones: insulin and leptin), differ between male and female Neotomodon alstoni mice, both lean and obese. Young adult animals were captured in the field and kept at the laboratory animal facility. After 6 to 7 months feeding the animals ad libitum with a regular diet for laboratory rodents, 50-60% of mice became obese. Comparisons between sexes indicated that lean females were more active than males; however obese females reduced their nocturnal activity either in LD or DD, and advanced the phase of their activity-onset with respect to lights off. No differences in food intake between lean and obese mice, either during the day or night, were observed. Daily profiles of metabolic syndrome-related plasma parameters showed differences between sexes, and obesity was associated with increased values, especially leptin (500% in females and 273% in males) and insulin (150% in both females and males), as compared with lean mice. Our results indicate that lean mice display behavioral and endocrine differences between sexes, and obesity affects the parameters tested in a sex-dependent manner. The aforementioned leads us to propose N. alstoni, studied in captivity, could be an interesting model for the study of sex differences in the effects of obesity.

Evidence that obesity and androgens have independent and opposing effects on gonadotropin production from puberty to maturity

Optimal fat mass is necessary for normal gonadotropin levels in adults, and both undernutrition and overnutrition suppress gonadotropins: thus, the gonadotropin response to relative adipose mass is biphasic. Adult obesity is associated with blunted luteinizing hormone (LH) pulse amplitude that is partially attributable to increased LH clearance rate. Testosterone appears to have a biphasic effect on gonadotropin production in females. Moderate elevations of testosterone appear to stimulate LH production at both the hypothalamic and pituitary level, while very high levels of testosterone suppress LH. Thus, obesity per se appears to suppress gonadotropin production, and moderate hyperandrogenemia in women appears to stimulate LH. The ordinary hypergonadotropic hyperandrogenism of obese women appears to be an exception to this model because it is usually due to polycystic ovary syndrome (PCOS), a condition in which intrinsic functional ovarian hyperandrogenism and excess adiposity share a common origin that involves insulin-resistant hyperinsulinemia. LH elevation seems to be secondary to hyperandrogenemia and is absent in the most obese cases. Overweight early pubertal girls have significant blunting of sleep-related LH production, which is the first hormonal change of puberty. The data are compatible with the possibility that excess adiposity may paradoxically subtly suppress hypothalamic-pituitary-gonadal function in early puberty although it is known to contribute to the early onset of puberty.

Androgens and obesity

PURPOSE OF REVIEW

As testosterone levels are frequently reduced in obesity, an understanding of the relationship between serum testosterone and adiposity is necessary in the clinical evaluation of these men, in particular when considering testosterone therapy.

RECENT FINDINGS

Population and interventional data suggest a bi-directional relationship exists between testosterone and obesity in men, with lower total testosterone and sex hormone binding globulin (SHBG) (and to a lesser extent free testosterone) levels than their nonobese peers; obesity having an impact at least as important as ageing. Abnormalities in the hypothalamo-pituitary-testicular axis are seen with increasing obesity. Weight loss in massive obesity increases testosterone levels but its role in mild-moderate obesity is unclear. Testosterone supplementation reduces total body fat in hypogonadal and ageing men although the effects on regional fat distribution are less well described.

SUMMARY

Favourable changes in total body fat and regional fat distribution suggest a potential role for testosterone in obesity. However, lifestyle advice to achieve sustained weight loss should be the mainstay of management. Obese men with confirmed androgen deficiency can be offered treatment, whereas in those with low-normal testosterone levels more research is needed.

Body mass index in relation to semen quality, sperm DNA integrity, and serum reproductive hormone levels among men attending an infertility clinic

OBJECTIVE

To examine the association between body weight and measures of male reproductive potential.

DESIGN

Cross-sectional study.

SETTING

Fertility clinic in an academic medical center.

PATIENT(S)

Four hundred eighty-three male partners of subfertile couples.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Standard semen analysis, sperm DNA fragmentation, and serum levels of reproductive hormones.

RESULT(S)

As expected, body mass index (BMI) was positively related to estradiol levels and inversely related to total testosterone and sex hormone-binding glogulin (SHBG) levels. There was also a strong inverse relation between BMI and inhibin B levels and a lower testosterone:LH ratio among men with a BMI > or = 35 kg/m(2). Body mass index was unrelated to sperm concentration, motility, or morphology. Ejaculate volume decreased steadily with increasing BMI levels. Further, men with BMI > or = 35 kg/m(2) had a lower total sperm count (concentration x volume) than normal weight men (adjusted difference in the median [95% confidence interval] = -86 x 10(6) sperm [-134, -37]). Sperm with high DNA damage were significantly more numerous in obese men than in normal-weight men.

CONCLUSION(S)

These data suggest that despite major differences in reproductive hormone levels with increasing body weight, only extreme levels of obesity may negatively influence male reproductive potential.

Diminished paternity and gonadal function with increasing obesity in men

OBJECTIVE

To examine the relationship of male obesity and reproductive function.

DESIGN

Observational study.

SETTING

Academic medical center.

PATIENT(S)

Eighty-seven adult men, body mass index (BMI) range from 16.1 to 47.0 kg/m(2) (mean = 29.3 kg/m(2); SD = 6.5 kg/m(2)).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Reproductive history, physical examination, inhibin B, FSH, LH, T, and unbound T levels, and semen analysis.

RESULT(S)

Body mass index was negatively correlated with testosterone (r = -0.38), FSH (r = -0.22), and inhibin B levels (r = -0.21) and was positively correlated with E(2) levels (r = 0.34). Testosterone also negatively correlated with skinfold thickness (r = -0.30). There was no correlation of BMI or skinfold thickness with semen analysis parameters (sperm density, volume, motility, or morphology). Inhibin B level correlated significantly with sperm motility (r = 0.23). Men with paternity had lower BMIs (28.0 kg/m(2) vs. 31.6 kg/m(2)) and lower skinfold thickness (24.7 mm vs. 34.1 mm) than men without.

CONCLUSION(S)

Obesity is an infertility factor in otherwise normal men. Obese men demonstrate a relative hypogonadotropic hypogonadism. Reduced inhibin B levels and diminished paternity suggest compromised reproductive capacity in this population.

Hypogonadism in men with chronic obstructive pulmonary disease: prevalence and quality of life

We recently reported that hypogonadism does not affect respiratory muscle performance and exercise capacity in men with chronic obstructive pulmonary disease (COPD). In COPD, however, the relationship between exercise capacity and quality of life is controversial, making it unreliable to extrapolate about quality of life from exercise data. Accordingly, we determined prevalence and impact of hypogonadism on health-related quality of life in men with COPD. We enrolled 101 stable outpatient men (FEV1 1.34 +/- 0.04 L) older than 54 years; 38 patients were hypogonadal-a prevalence similar to that reported in the general population. The degree of airflow limitation did not predict levels of free testosterone. Quality of life, as quantified by a disease-specific instrument (St. George's Respiratory Questionnaire) and a general-health instrument (Veterans Short Form-36) were equivalent in the hypogonadal and eugonadal groups. Both groups demonstrated large decrements in perceived physical health and smaller decrements in perceived emotional and mental health. No relationship was found between free testosterone level and physical activity, respiratory symptoms, or quality of life. In conclusion, hypogonadism, although common among men older than 54 years with COPD, does not worsen the severity of respiratory symptoms or quality of life.