Relationship of androgens to body composition, energy and substrate metabolism and aerobic capacity in healthy, young women

Body composition in children and adolescents with non-classic congenital adrenal hyperplasia and the risk for components of metabolic syndrome: An observational study

BACKGROUND

Treated or untreated non-classic congenital adrenal hyperplasia (NCCAH) diagnosed in childhood could pose an increased risk of obesity and metabolic derangements in adolescence and early adulthood. We aimed to explore the interaction between muscle-to-fat ratio (MFR) and components of metabolic syndrome in pediatric subjects with NCCAH.

METHODS

This retrospective observational study was conducted in the Tel Aviv Medical Center from January 2018 to January 2022. The study group comprised 75 subjects (26 males) with NCCAH (61 hydrocortisone-treated [21 males] and 14 untreated [5 males]) and 134 healthy sex- and age-matched subjects (41 males) with normal puberty served as controls. Body composition was measured by bioelectrical impedance analysis (BIA) and muscle-to-fat ratio (MFR) z-scores were calculated. Stepwise linear regression models were applied to evaluate explanatory variables for MFR z-scores, blood pressure percentiles, lipid profiles, and glucose metabolism.

RESULTS

The median age [interquartile range] was 7.5 years [5.3, 8.8] at NCCAH diagnosis and 12.3 years [8.9, 15.4] at BIA. The median cumulative hydrocortisone dose was 7620 mg/m² [2547, 12903]. Subjects with NCCAH had higher mean BMI z-scores and lower median MFR z-scores compared to controls [(0.47 ± 0.97 vs. -0.19 ± 1.04, p<0.001) and (-0.74 [-1.06, -0.14] vs.-0.37 [-0.99, 0.15], p=0.045), respectively]. The linear regression models dependent variables and their explanatory variables were: MFR z-score (R²= 0.253, p<0.001) - socioeconomic position index (β=0.348, p=0.003), birthweight z-score (β=-0.258, p=0.013), and duration of hydrocortisone treatment in years (β=0.048, p=0.023); systolic blood pressure percentile (R² = 0.166, p<0.001) - MFR z-score (β=-9.75, p<0.001); TG/HDL ratio (R² = 0.116, p=0.024) - MFR z-score (β=-0.300, p=0.024). No significant variables were found for glucose.

CONCLUSIONS

Children and adolescents with NCCAH have a body composition characterized by an imbalance between muscle and fat tissues, which may place them at increased risk for early-onset cardiometabolic derangements. It is reassuring that glucocorticoid therapy aimed to alleviate androgen overproduction does not appear to adversely affect their body composition.

Obesity, Body Composition, and Sex Hormones: Implications for Cardiovascular Risk

Cardiovascular disease (CVD) continues to be the leading cause of death in adults, highlighting the need to develop novel strategies to mitigate cardiovascular risk. The advancing obesity epidemic is now threatening the gains in CVD risk reduction brought about by contemporary pharmaceutical and surgical interventions. There are sex differences in the development and outcomes of CVD; premenopausal women have significantly lower CVD risk than men of the same age, but women lose this advantage as they transition to menopause, an observation suggesting potential role of sex hormones in determining CVD risk. Clear differences in obesity and regional fat distribution among men and women also exist. While men have relatively high fat in the abdominal area, women tend to distribute a larger proportion of their fat in the lower body. Considering that regional body fat distribution is an important CVD risk factor, differences in how men and women store their body fat may partly contribute to sex-based alterations in CVD risk as well. This article presents findings related to the role of obesity and sex hormones in determining CVD risk. Evidence for the role of sex hormones in determining body composition in men and women is also presented. Lastly, the clinical potential for using sex hormones to alter body composition and reduce CVD risk is outlined. © 2022 American Physiological Society. Compr Physiol 12:1-45, 2022.

UCP2, SHBG, Leptin, and T3 Levels are Associated with Resting Energy Expenditure in Obese Women

OBJECTIVE

The aim of this study was to investigate the association of Sex Hormone Binding Globulin (SHBG) with leptin, Triidothyronine (T3), and Uncoupling Protein 2 (UCP2) in obese women with low and normal Resting Energy Expenditure (REE) and to determine the role of these factors in the regulation of REE in obese women.

METHOD

A total 49 subjects (25-50 years old) were selected. Anthropometric and body composition parameters and resting energy expenditure were measured. Fasting circulating leptin, T3, SHBG and UCP2 levels were measured. Subjects were divided into three groups: Group І (BMI>30 and low resting energy expenditure, 16 subjects), group II (BMI>30 and normal resting energy expenditure, 17 subjects), and group ІІІ (control group, 16 non-obese subjects).

RESULT

It was found that obese subjects who had higher SHBG and leptin levels were at risk for high levels of UCP2. A significant association was found between T3 and REE. Obese subjects with higher concentrations of UCP2 and SHBG had decreased resting energy expenditure. A significant association was observed between SHBG and leptin in group І (r=0.90, p<0.0001) and group ІІ (r=0.83, p<0.0001). Moreover, a significant association was found between T3 and SHBG in group І (r=-0.69, P=0.003).

CONCLUSION

Changes of the UCP2, leptin, and thyroid hormone (T3) levels may be related to SHBG levels. Thus, lower leptin and T3 levels may decrease SHBG in obese women. Therefore, lower SHBG, leptin, T3 and UCP2 levels may decrease the REE level in obese women.

Metabolic Effects of Testosterone Hormone Therapy in Normal and Orchiectomized Male Rats: From Indirect Calorimetry to Lipolytic Enzymes

BACKGROUND AND AIM

Changes in total energy expenditure (TEE) and substrate metabolism may help explain the metabolic actions of testosterone (T). This study measured respiratory quotient (RQ), TEE, ghrelin, insulin, and key lipolysis enzyme concentrations in relation to body weight (wt) and food intake (FI) in both normal and bilaterally orchiectomized rats with/without T treatment.

METHODS

In total, thirty-two male Wistar rats (300-400 g) were divided into four groups (n = 8/group), including (a) sham-operated and vehicle-injected group (Sham), (b) T-treated sham group (T-Sham) for which sham-operated rats were injected with IM testosterone undecanoate (100 mg/kg, for one week), (c) orchiectomy and vehicle-injected group (Orch), and (d) T-replaced orchiectomy group (T-Orch). After one week, FI and wt were automatically recorded, indirect calorimetry parameters were measured, and blood samples were collected to measure T, ghrelin, insulin, growth hormone (GH), glucose, hormone-sensitive lipase (HSL), adipocyte triglyceride lipase (ATGL), free fatty acids (FFA), and lipid profiles.

RESULTS

Orchiectomy decreased ghrelin, GH, and insulin levels, increased TEE and RQ, and lowered FI and wt. The T-Orch group exhibited increased levels of ghrelin (3-fold), insulin, GH, blood levels of lipolysis products, TEE, and FI in addition to reduced glucose levels (P < 0.05). This group demonstrated no significant changes in wt. In the T-Sham group, T increased ghrelin and insulin levels (P < 0.05) with strong positive correlations (r = 0.663 and 0.644, respectively, P < 0.05), increased ATGL levels, RQ toward carbohydrate utilization ranges, and TEE, and reduced HSL levels (P < 0.05) with insignificant changes in FI or wt.

CONCLUSIONS

T administration in orchiectomized rats significantly increased orexigenic mediators such as ghrelin and insulin without inducing any significant changes in wt. The mechanism for this finding might be the increased TEE and the stimulation of lipolysis through the ATGL enzyme. The associated rise of GH might help in interference with accumulation of lipid in adipose tissue. Apart from the effect on GH, T-Sham showed similar effects of T supplementation.

Increased body fat mass and androgen metabolism - A twin study in healthy young women

OBJECTIVE

Obesity may alter serum steroid concentrations and metabolism. We investigated this in healthy young women with increased body fat and their leaner co-twin sisters.

DESIGN

Age and genetic background both strongly influence serum steroid levels and body composition. This is a cross-sectional study of 13 female monozygotic twin pairs (age, 23-36 years), ten of which were discordant for body mass index (median difference in body weight between the co-twins, 19 kg).

METHODS

We determined body composition by dual energy X-ray absorptiometry and magnetic resonance imaging, serum androgens by liquid chromatography-tandem mass spectrometry, and mRNA expression of genes in subcutaneous adipose tissue and adipocytes.

RESULTS

The heavier women had lower serum dehydroepiandrosterone (DHEA), dihydrotestosterone (DHT), and sex hormone-binding globulin (SHBG) (P < 0.05 for all) compared to their leaner co-twins with no differences in serum testosterone or androstenedione levels. Serum DHEA correlated inversely with %body fat (r = -0.905, P = 0.002), and DHT positively with SHBG (r = 0.842, P = 0.002). In adipose tissue or adipocytes, expressions of STS (steroid sulfatase) and androgen-related genes were significantly higher in the heavier compared to the leaner co-twin, and within pairs, correlated positively with adiposity but were not related to serum androgen levels. None of the serum androgen or SHBG levels correlated with indices of insulin resistance.

CONCLUSIONS

Serum DHEA levels were best predicted by %body fat, and serum DHT by SHBG. These or other serum androgen concentrations did not reflect differences in androgen-related genes in adipose tissue. General or intra-abdominal adiposity were not associated with increased androgenicity in young women.

Circulating steroid levels as correlates of adipose tissue phenotype in premenopausal women

Background Obesity-related alterations in the circulating steroid hormone profile remain equivocal in women. Our objective was to identify circulating steroid levels that relate to increased adiposity and altered adipose phenotype in premenopausal women. Materials and methods In a sample of 42 premenopausal women [age 46 ± 3 years; body mass index (BMI) 27.1 ± 4.2 kg/m2], 19 plasma steroids were quantified by electrospray ionization-liquid chromatography-tandem mass spectroscopy (ESI-LC-MS/MS). Body composition and fat distribution were assessed by dual-energy X-ray absorptiometry (DXA) and computed tomography (CT), respectively. Markers of adipose tissue function including adipocyte size distributions, radiological attenuation and macrophage infiltration were also analyzed in surgically obtained visceral and subcutaneous fat samples. Results Many negative correlations were observed between adiposity measurements such as BMI, body fat percentage or total abdominal adipose tissue area and plasma levels of androstenedione (Δ4) (r = -0.33 to -0.39, p ≤ 0.04), androsterone (ADT) (r = -0.30 to -0.38, p ≤ 0.05) and steroid precursor pregnenolone (PREG) (r = -0.36 to -0.46, p ≤ 0.02). Visceral adipocyte hypertrophy was observed in patients with low PREG concentrations (p < 0.05). Visceral adipose tissue radiologic attenuation, a potential marker of adipocyte size, was also positively correlated with PREG levels (r = 0.33, p < 0.05). Low levels of PREG were related to increased number of macrophages infiltrating visceral and subcutaneous adipose tissue (p < 0.05). Conclusion Plasma levels of androgens and their precursors are lower in women with increased adiposity and visceral adipocyte hypertrophy. Low circulating PREG concentration may represent a marker of adipose tissue dysfunction.

Circulating 5α-dihydrotestosterone, abdominal obesity and adipocyte characteristics in women

Abstract Background: The association between circulating androgen levels and fat distribution in women has been widely inconsistent among existing studies.

OBJECTIVE

We sought to investigate the relation between plasma adrenal and gonadal androgen levels and body fat distribution, as well as abdominal adipocyte characteristics.

METHODS

Paired omental and subcutaneous adipose tissue samples were surgically obtained from 60 women (age, 47±5 years; body mass index, 26±5 kg/m2) undergoing gynecological surgery. Body composition and fat distribution were measured by dual-energy X-ray absorptiometry and computed tomography, respectively. Adipocyte diameter, basal lipolysis, and heparin-releasable lipoprotein lipase activity were measured. Steroids were quantified using high-performance gas chromatography and mass spectrometry.

RESULTS

Significant negative associations were found between plasma dihydrotestosterone (DHT) levels and total adiposity (body mass index, r=-0.35, p<0.05; fat mass, r=-0.31, p<0.05) as well as computed tomography assessments of abdominal adiposity (r=-0.30, p<0.05 and r=-0.44, p<0.005 for subcutaneous and visceral adipose tissue area, respectively). The association between DHT levels and visceral adipose tissue area was independent of total body fat mass. A significant negative association was also observed between plasma DHT and omental adipocyte diameter (r=-0.27, p<0.05). When expressed as the omental/subcutaneous ratio, heparin-releasable lipoprotein lipase activity was negatively and significantly related to plasma DHT, androstenedione, and dehydroepiandrosterone (DHEA) levels.

CONCLUSION

Abdominally obese women with large, metabolically active omental adipocytes appear to be characterized by reduced endogenous levels of DHT. The assumption that high androgen levels are associated with an android body fat distribution pattern in women should be critically re-examined.

Androgens, body fat Distribution and Adipogenesis

Androgens are regulators of important adipocyte functions such as adipogenesis, lipid storage, and lipolysis. Through depot-specific impact on the cells of each fat compartment, androgens could modulate body fat distribution patterns in humans. Testosterone and dihydrotestosterone have been shown to inhibit the differentiation of preadipocytes to lipid-storing adipocytes in several models including primary cultures of human adipocytes from both men and women. Androgen effects have also been observed on some markers of lipid metabolism such as LPL activity, fatty acid uptake, and lipolysis. Possible depot-specific and sex-specific effects have been observed in some but not all models. Transformation of androgen precursors to active androgens or their inactivation by enzymes that are expressed and functional in adipose tissue may contribute to modulate the local availability of active hormones. These phenomena, along with putative depot-specific interactions with glucocorticoids may contribute to human body fat distribution patterns.

The visceral adiposity index as a predictor of insulin resistance in young women with polycystic ovary syndrome

OBJECTIVE

Visceral fat accumulation is more strongly related to insulin resistance than to excess total adiposity. The visceral adiposity index (VAI) has recently been suggested as an indicator of the visceral adiposity measured by magnetic resonance imaging. To evaluate whether the VAI could replace visceral computed tomography (CT) scanning and predict insulin resistance in young women with polycystic ovary syndrome (PCOS) was presented.

DESIGN AND METHODS

One hundred and eighty Korean women aged 16-41 years who were diagnosed with PCOS using the Rotterdam criteria were included. The VAI was derived from a formula using body mass index, waist circumference, triglycerides, and high-density lipoprotein cholesterol. Visceral adiposity was defined as a visceral fat area (VFA) measuring > 100 cm(2) by CT scanning. Insulin sensitivity was evaluated by insulin-mediated glucose utilization (M value), which was obtained using a euglycemic hyperinsulinemic clamp.

RESULTS

The VAI positively correlated with VFA, the visceral-to-subcutaneous fat ratio, and systolic and diastolic blood pressure, and negatively correlated with the M value. In a linear regression analysis, the VAI was an independent determinant of the insulin sensitivity after controlling for age, systolic blood pressure, fasting glucose, fasting insulin, and testosterone levels. In a logistic regression analysis, the VAI odds ratio was 3.5 (95% CI 1.2-9.8) for predicting visceral adiposity after controlling for the various metabolic parameters and testosterone.

CONCLUSION

The VAI can replace visceral CT scanning as a marker for visceral adiposity, and it predicts insulin resistance in young women with PCOS.

Seasonal changes in steroid hormone profiles, body weight, semen quality, and the reproductive tract in captive African wild dogs (Lycaon pictus) in South Africa

Characterization of reproductive seasonality in the African wild dog (Lycaon pictus) could assist reintroduction programs. Male wild dogs (n=14) were assessed quarterly (January, mid-summer; April, late summer; August, late winter; November, early summer) for serum testosterone, body weight, testicular and prostatic volume, preputial gland measurement, and ejaculate characteristics. Bi-monthly fecal samples were collected from male (n=11) and female (n=4) wild dogs for analysis of fecal androgens and progestagens. Fecal androgens were higher in early summer (246.4 ± 14.5 ng/g) than in early winter (218.6 ± 13.4 ng/g). Serum testosterone was higher in mid-summer (1.4 ± 0.3 ng/ml) than in late winter (0.7 ± 0.1 ng/ml). Number of spermatozoa per ejaculate was greatest in late summer (301.4 ± 39.3 × 10(6)). Other semen parameters peaked in mid-summer (pH: 7.4; progressive motility: 85.0 ± 0.1%; live spermatozoa: 81.0 ± 16%; normal morphology: 71.5 ± 8.2%). Total testicular and prostatic volume were greater during summer (testicular: 36.7 ± 4.2 cm(3); prostatic: 12.0 ± 1.9 cm(3)) than winter (testicular: 25.2 ± 1.9 cm(3); prostatic: 5.8 ± 0.8 cm(3)). Preputial pendulance also was greater in summer (7.1 ± 0.5 cm; n=9) than winter (5.9 ± 0.2 cm). Baseline fecal progestagen metabolites were 6.2 ± 2.5 μg/g and peak fecal progestagen metabolites were 14.7 ± 2.8 μg/g. Copulations resulting in pregnancies (n=2) occurred in late summer and gestation was 71 days. Female wild dogs were seasonally monoestrous with mating in summer and winter. In conclusion, wild dogs are reproductively seasonal with improvement in male reproductive variables during summer and a bi-phasic seasonal pattern to female receptivity.