Testosterone concentrations in young pubertal and post-pubertal obese males

The prevalence and the risk factors of testosterone deficiency in newly diagnosed and previously known type 2 diabetic men

INTRODUCTION

While the epidemiology of testosterone deficiency has been well described in men with previously known type 2 diabetes mellitus (T2DM), it was less reported in those with untreated, newly diagnosed T2DM.

AIM

The aim of this study was to investigate the prevalence and the risk factors of testosterone deficiency of men with newly diagnosed T2DM.

METHODS

The cross-sectional study included 105 men (mean age: 61.2 ± 6.8 years) with previously known T2DM and another 81 (57.8 ± 8.8 years) with newly diagnosed T2DM. All received health checkup and sex hormone measurement at our institute in 2009.

MAIN OUTCOME MEASURES

We calculated the prevalence and explored the risk factors of low total (<300 ng/dL) and free (<6 ng/dL) testosterone in men with newly diagnosed and previously known T2DM.

RESULTS

Men with previously known T2DM were older and had higher diastolic pressure and greater fasting glucose. There was no significant difference in total (358.0 [155.0] ng/dL vs. 363.0 [154.0] ng/dL, P=0.68) and free (7.2 [2.5] ng/dL vs. 7.4 [2.4]ng/dL, P=0.84) testosterone and sex-hormone binding globulin (SHBG) (27.3 [22.3]nmol/L vs. 28.7 [14.9]nmol/L, P=0.46). The prevalence of low total and free testosterone was 28.4% and 21.0%, respectively, in men with newly diagnosed T2DM, and was 26.7% and 19.0% in those with previously known T2DM. In men with previously known T2DM, better glycemic control (HbA1c <7%) was associated with a higher level of total testosterone and a lower risk of low total testosterone. Men with newly diagnosed and previously known T2DM shared similar risk factors of low total testosterone, including high HbA1c (≥ 7%), low SHBG (<20 nmol/L), obesity, hyperuricemia, hypertriglycemia, and metabolic syndrome. Elevated prostate-specific antigen was a protective factor of low total testosterone. However, none of these factors was associated with low free testosterone.

CONCLUSIONS

The prevalence and the risk factors of testosterone deficiency are similar between newly diagnosed and previously known type 2 diabetic men.

Sex steroids in relation to sexual and skeletal maturation in obese male adolescents

BACKGROUND

Childhood obesity is associated with an accelerated skeletal maturation. However, data concerning pubertal development and sex steroid levels in obese adolescents are scarce and contrasting.

OBJECTIVES

To study sex steroids in relation to sexual and skeletal maturation and to serum prostate specific antigen (PSA), as a marker of androgen activity, in obese boys from early to late adolescence.

METHODS

Ninety obese boys (aged 10-19 y) at the start of a residential obesity treatment program and 90 age-matched controls were studied cross-sectionally. Pubertal status was assessed according to the Tanner method. Skeletal age was determined by an x-ray of the left hand. Morning concentrations of total testosterone (TT) and estradiol (E2) were measured by liquid chromatography-tandem mass spectrometry, free T (FT) was measured by equilibrium dialysis, and LH, FSH, SHBG, and PSA were measured by immunoassays.

RESULTS

Genital staging was comparable between the obese and nonobese groups, whereas skeletal bone advancement (mean, 1 y) was present in early and midadolescence in the obese males. Although both median SHBG and TT concentrations were significantly (P < .001) lower in obese subjects during mid and late puberty, median FT, LH, FSH, and PSA levels were comparable to those of controls. In contrast, serum E2 concentrations were significantly (P < .001) higher in the obese group at all pubertal stages.

CONCLUSION

Obese boys have lower circulating SHBG and TT, but similar FT concentrations during mid and late puberty in parallel with a normal pubertal progression and serum PSA levels. Our data indicate that in obese boys, serum FT concentration is a better marker of androgen activity than TT. On the other hand, skeletal maturation and E2 were increased from the beginning of puberty, suggesting a significant contribution of hyperestrogenemia in the advancement of skeletal maturation in obese boys.

Sexual dimorphism in white and brown adipose tissue with obesity and inflammation

This article is part of a Special Issue "Energy Balance". Obesity and its associated comorbidities remain at epidemic levels globally and show no signs of abatement in either adult or child populations. White adipose tissue has long been established as an endocrine signalling organ possessing both metabolic and immune functions. This role can become dysregulated following excess adiposity caused by adipocyte hypertrophy and hyperplasia. In contrast, brown adipose tissue (BAT) is only present in comparatively small amounts in the body but can significantly impact on heat production, and thus could prevent excess white adiposity. Obesity and associated risk factors for adverse metabolic health are not only linked with enlarged fat mass but also are dependent on its anatomical deposition. In addition, numerous studies have revealed a disparity in white adipose tissue deposition prior to and during the development of obesity between the sexes. Females therefore tend to develop a greater abundance of femoral and gluteal subcutaneous fat whereas males exhibit more central adiposity. In females, lower body subcutaneous adipose tissue depots appear to possess a greater capacity for lipid storage, enhanced lipolytic flux and hyperplastic tissue remodelling compared to visceral adipocytes. These differences are acknowledged to contribute to the poorer metabolic and inflammatory profiles observed in males. Importantly, the converse outcomes between sexes disappear after the menopause, suggesting a role for sex hormones within the onset of metabolic complications with obesity. This review further considers how BAT impacts upon on the relationship between excess adiposity, gender, inflammation and endocrine signalling and could thus ultimately be a target to prevent obesity.

The incidence of hypogonadotropic hypogonadism in type 2 diabetic men in Polish population

The aim of this study was to investigate the incidence of hypogonadotropic hypogonadism (HH) in type 2 diabetic men (T2DM) in population of Polish men and examine the possible influence of estradiol levels and glycemic control. We evaluated TT, cfT, estradiol, and glycemic control (HbA1c) in 184 diabetic men and in 149 nondiabetic control group. The mean HbA1c was 8.6 ± 0.2% and 6.1 ± 0.3% and cfT concentration was 0.315 ± 0.08 nmol/L and 0.382 ± 0.07 nmol/L, respectively. T2DM had higher E2 concentration than nonobese control men (29.4 ± 3.7 pg/mL versus 24.5 ± 2.9 pg/mL). Forty-six percent of T2DM were hypogonadal and 93% had HH. We observed inverse relationship between BMI and cfT (r = -0.341, P < 0.01) and positive between BMI and E2 (r = 0.329, P < 0.01). E2 concentration was higher in T2DM with HH versus T2DM with normal TT/cfT concentration (34.5 ± 5.2 versus 27.4 ± 3.4 pg/mL). We observed negative correlation between HbA1c and cfT (r = -0.336, P < 0.005) but positive between HbA1c and E2 levels (r = 0.337, P < 0.002). The prevalence of obesity, hypertension, and CVD was higher in men with hypogonadism. High incidence of hypogonadotropic hypogonadism in type 2 diabetic men in Polish population is associated with poor glycemic control and can be secondary to an increase in estradiol concentrations.