No major month to month variation in free testosterone levels in aging males. Minor impact on the biological diagnosis of 'andropause'

Association of salivary testosterone levels during the post-awakening period with age and symptoms suggestive of late-onset hypogonadism in men

BACKGROUND

The lack of association between serum testosterone levels and symptoms suggestive of hypogonadism is a significant barrier in the determination of late-onset hypogonadism (LOH) in men. This study explored whether testosterone levels increase after morning awakening, likewise the cortisol awakening response (CAR) in the hypothalamic-pituitary-adrenal (HPA) axis, and whether testosterone levels during the post-awakening period are associated with age and symptoms suggestive of late-onset hypogonadism (LOH) in men.

METHODS

Testosterone and cortisol levels were determined in saliva samples collected immediately upon awakening and 30 and 60 min after awakening, and scores of the Aging Males' Symptoms (AMS) questionnaire were obtained from 225 healthy adult men.

RESULTS

A typical CAR (an increase in cortisol level ≥ 2.5 nmol/L above individual baseline) was observed in 155 participants (the subgroup exhibiting typical CAR). In the subgroup exhibiting CAR, testosterone levels sharply increased during the post-awakening period, showing a significant negative correlation with age, total AMS score, and the scores of 11 items on the somatic, psychological, and sexual AMS subscales. Of these items, three sexual items (AMS items #15-17) were correlated with age. Meanwhile, there was no notable increase in testosterone levels and no significant correlation of testosterone levels with age and AMS score in the subgroup exhibiting no typical CAR (n = 70).

CONCLUSIONS

The results indicate that the hypothalamus-pituitary-gonad (HPG) axis responds to morning awakening, and determining testosterone levels during the post-awakening period in men with typical CAR may be useful for assessing HPG axis function and LOH.

Novel reference range values for serum testosterone: a cross-sectional study of 200,000 males

PURPOSE

To better understand the effects of aging, metabolic syndrome, diurnal variation, and seasonal variation on serum testosterone levels in the context of current guideline statements on testosterone deficiency.

METHODS

This cross-sectional study utilized the United Kingdom Biobank. Physical examination, anthropomorphic measurements, and laboratory evaluation were performed at the time of enrollment from 2006 to 2010. The primary outcomes were the effect of age, the presence of metabolic syndrome, the time of day, and the month of the year on serum testosterone levels.

RESULTS

Among 197,883 included men, the 5th, 25th, 50th, 75th and 95th percentile testosterone levels in men without metabolic syndrome were significantly higher than those in men with metabolic syndrome at every decade of life (p < 0.001). The average testosterone level within each group (men without metabolic syndrome vs. men with) was clinically similar across decade of life (12.43 in 40's 12.29 in 50's 12.24 in 60's vs. 10.69 in 40's 10.56 in 50's 10.63 in 60's respectively). Average testosterone levels decreased with blood draws later in the day ranging from 10.91 to 12.74 nmol/L (p < 0.01). Similarly, there was seasonal variation in serum testosterone ranging from 11.86 to 12.18 nmol/L (p < 0.01).

CONCLUSIONS

We found significant variation in serum testosterone according to the presence of metabolic syndrome and time of laboratory draw, but not according to age. These data challenge the prior dogma of age-related hypogonadism and favor an individualized approach towards serum testosterone measurement and interpretation. However, further studies are needed to correlate these population-based data with individuals' hypogonadal symptoms.

SHBG, Free Testosterone, and Type 2 Diabetes Risk in Middle-aged African Men: A Longitudinal Study

Objectives

To investigate longitudinal changes in SHBG and free testosterone (free T) levels among Black middle-aged African men, with and without coexistent HIV, and explore associations with incident dysglycaemia and measures of glucose metabolism.

Design

This longitudinal study enrolled 407 Black South African middle-aged men, comprising primarily 322 men living without HIV (MLWOH) and 85 men living with HIV (MLWH), with normal fasting glucose at enrollment. Follow-up assessments were conducted after 3.1 ± 1.5 years.

Methods

At baseline and follow-up, SHBG, albumin, and total testosterone were measured and free T was calculated. An oral glucose tolerance test at follow-up determined dysglycaemia (impaired fasting glucose, impaired glucose tolerance, type 2 diabetes) and glucose metabolism parameters including insulin sensitivity (Matsuda index), insulin resistance (homeostasis model assessment of insulin resistance), and beta(β)-cell function (disposition index). The primary analysis focussed on MLWOH, with a subanalysis on MLWH to explore whether associations in MLWOH differed from MLWH.

Results

The prevalence of dysglycaemia at follow-up was 17% (n = 55) in MLWOH. Higher baseline SHBG was associated with a lower risk of incident dysglycaemia (odds ratio 0.966; 95% confidence interval 0.945-0.987) and positively associated with insulin sensitivity (β = 0.124, P < .001) and β-cell function (β = 0.194, P = .001) at follow-up. Free T did not predict dysglycaemia. In MLWH, dysglycaemia prevalence at follow-up was 12% (n = 10). Neither baseline SHBG nor free T were associated with incident dysglycaemia and glucose metabolism parameters in MLWH.

Conclusion

SHBG levels predict the development of dysglycaemia in middle-aged African men but do not exhibit the same predictive value in MLWH.

Seasonal Variations in Sex Steroids in a Young Male Population and Their Relationship with Plasma Levels of Vitamin D

Purpose

Vitamin D (VD) acts on sperm motility, capacitation and survival but its role in steroidogenesis is less clear. Aims: To analyze seasonal variations in sex steroids and VD in a healthy male population.

Materials and Methods

Twenty-nine healthy males, 34.0±4.8 years were included. Blood collection in winter (W) and summer (S) was performed to measure: 25OHD, total testosterone (TT), free testosterone (FT), estradiol (E2), luteinizing hormone (LH), and sex hormone binding globulin (SHBG). Testosterone/estradiol (T/E2) ratio was calculated.

Results

In W, lower levels of 25OHD: 18.8±7.2 ng/mL vs. 38.8±11.9 ng/mL (p<0.0001) and LH: 3.5±1.2 mU/mL vs. 3.9±1.5 mU/mL (p=0.05), and higher levels of TT: 501.9±157.7 ng/dL vs. 405.0±128.0 ng/dL (p=0.0003), FT: 11.8±4.1 ng/dL vs. 10.2±3.7 ng/dL (p=0.017), SHBG: 28.5±10.9 nmol/L vs. 23.6±7.9 nmol/L (p=0.002) and T/E2 ratio: 30.7±19.7 ng/dL/pg/mL vs. 17.3±3.6 ng/dL/pg/mL (p=0.0015) with no variation in E2 levels were observed. A positive correlation between 25OHD and E2 (r=0.28, p=0.04) and negative correlations between 25OHD and TT (r=−0.27, p=0.049), 25OHD and FT (r=−0.32, p=0.01), and 25OHD and T/E2 (r=−0.44, p=0.0008) were found.

Conclusions

In healthy young male population, seasonal variations were observed in 25OHD and LH levels (higher in S) and in TT, FT, SHBG levels, and T/E2 (higher in W). Lower values of TT and FT in S are accompanied by higher levels of LH, which rules out a central mechanism for lowering testosterone. 25OHD negatively correlated with TT, FT, and T/E2 and positively correlated with E2, suggesting a relationship between VD status and changes in gonadal steroids.

Is vitamin D status reflected by testosterone concentration in elite athletes?

Vitamin D is a nutrient whose active form affects tissues as a hormone and possibly enhances performance. One plausible mechanism is by increasing testosterone concentration, which is established as an important factor for athletic performance. Therefore the aim of the study was to examine the relationship between plasma concentration of 25(OH)D and testosterone in Polish elite track and field athletes depending on vitamin D status, season, training period, body composition, sex, type of training, sun exposure and vitamin D supplementation. Plasma concentrations of 25(OH)D and testosterone were measured in all seasons within two years in athletes (70 females, 79 males) who represent strength (n = 103) and endurance (n = 46) kinds of sports, in the preparatorycompetitive season and transition period. There were no differences in 25(OH)D concentration between male and female athletes, insufficiency [25(OH)D < 30 ng/ml] was observed in 32.9%, whereas deficiency [25(OH)D < 20 ng/ ml] in 3.2%. Circannual rhythm was noted for vitamin D but not for testosterone concentration; no correlations between them were found either in strength or endurance athletes or between 25(OH)D and body composition. Testosterone concentration was higher in the transition period than in the preparatory-competition period only in male athletes. Higher 25(OH)D was observed in athletes who trained during winter in Africa (higher sun exposure) or used oral supplementation, whereas the respective testosterone levels were unchanged. In athletes, testosterone concentration did not reflect vitamin D status. The widespread of inadequate vitamin D status among athletes, makes it vital to recommend them the regular monitoring of 25(OH)D concentration and use of reasonable supplementation.

Seasonal Variations and Correlations between Vitamin D and Total Testosterone Levels

Background

Some studies have provided evidence for a possible association between vitamin D and testosterone levels; however, the evidence from studies in Koreans is inconsistent. In addition, insufficient evidence is available to support an association between seasonal variations in vitamin D and testosterone levels in Koreans. Therefore, we aimed to investigate the association between vitamin D and testosterone levels, and between seasonal variations in these levels in Korean men.

Methods

This cross-sectional study included 1,559 men, aged 25–86 years, who underwent a medical examination. We measured serum 25-hydroxyvitamin D (25[OH]D) and total testosterone levels, and compared other laboratory test results and patient lifestyle characteristics. On the basis of sample collection time, we categorized patients into four seasons, and analyzed seasonal variability in 25(OH)D and total testosterone levels.

Results

The average participant age (±standard deviation) was 53.3±8.8 years, and the average serum 25(OH)D and total testosterone levels were 15.9±7.0 ng/mL and 5.1±1.6 ng/mL, respectively. In the analysis of variance (ANOVA) model, no significant association was found between 25(OH)D and testosterone levels (P=0.51). ANOVA of the average 25(OH)D levels in season-based groups revealed significant seasonal variations in 25(OH)D levels (P-value for trend <0.001). No significant association was found between seasonal variations in total testosterone levels (P=0.06). However, after adjustment for confounding variables, total testosterone and 25(OH)D showed significant seasonal variability (P=0.007 and P<0.001, respectively).

Conclusion

We found no significant correlation between serum 25(OH)D and total testosterone levels in Korean men. Moreover, serum 25(OH)D and total testosterone levels showed significant seasonal variations.

Longitudinal Changes Over 10 Years in Free Testosterone Among HIV-Infected and HIV-Uninfected Men

BACKGROUND

Aging in males is associated with lower testosterone levels and a decrease in diurnal variation of testosterone secretion. Cross-sectional studies have shown lower than expected testosterone levels among HIV-infected men, but whether age-related changes in serum testosterone differ by HIV serostatus are not known.

METHODS

HIV-infected men from the Multicenter AIDS Cohort Study (MACS), age ≥ 45 years at highly active antiretroviral therapy initiation, who had ≥ 2 samples from the subsequent 10 years, were matched to HIV-uninfected men by age, race, MACS site, and calendar time of samples. Linear mixed-effects regression models were used to determine whether free testosterone (FT) and its rate of change differed by HIV serostatus.

RESULTS

One hundred eighty-two HIV-infected and 267 HIV-uninfected men were included, median age: 48.8 years (interquartile range: 45.8-53.4), median numbers of FT measurements per participant 4 (interquartile range: 3-5), 65% were drawn in the adjusted morning (AM). Mean-adjusted FT levels were lower among HIV-infected than HIV-uninfected men in AM samples {-6.1 ng/dL [95% confidence interval (CI): -9.8 to -2.4], P = 0.001}, but not in afternoon samples [-1.7 ng/dL (-6.0 to 2.6), P = 0.441]. The rate of FT decline with age did not differ by HIV serostatus: 9.2 ng/dL (95% CI: -13.4 to -5.0) per 10 years for HIV-infected vs. 7.9 ng/dL (95% CI: -10.2 to -5.5) for HIV-uninfected men, P = 0.578.

CONCLUSIONS

FT decreased similarly with increasing age regardless of HIV serostatus. The lower AM, but not adjusted afternoon, FT levels among HIV-infected men compared with HIV-uninfected men suggest a loss of diurnal variation in FT levels among HIV-infected men.

Modification Effects of Changes in Job Demands on Associations Between Changes in Testosterone Levels and Andropause Symptoms: 2-Year Follow-up Study in Male Middle-Aged Japanese Workers

PURPOSE

The purpose of this longitudinal study was to ascertain if changes in job demands modify associations between changes in testosterone levels and andropause symptoms in male Japanese workers.

METHOD

A baseline survey including job demands and the Aging Males' Symptoms scale, lifestyle factors, and blood levels of testosterone was conducted in 2007. Among 192 men (mean age ± SD 52.2 ± 7.6 years) who completed all relevant questionnaires and provided blood at baseline, 104 men (50.9 ± 7.2 years) were followed up in 2009. Changes of variables in 2 years were calculated (data of follow-up minus those of baseline).

RESULTS

Testosterone levels were increased significantly, whereas job demands and somatic symptoms were reduced significantly, at follow-up. Changes in testosterone levels were negatively associated with changes in total andropause symptoms, psychological symptoms, and sexual symptoms (standardized β = -0.27, -0.24, and, -0.29, p < 0.05, respectively), after adjustment for confounders. Changes in job demands were positively associated with changes in somatic symptoms (standardized β = 0.21, p < 0.05). Significant interactions of changes in testosterone levels and job demands were noted for changes in psychological symptoms (standardized β = 0.26, p < 0.05). For men with a 1-SD reduction in job demands, negative associations between changes in testosterone levels and psychological symptoms were intensified, but not for men with a 1-SD increase in job demands.

CONCLUSION

Andropause symptoms may be affected by changes in testosterone levels and job demands. Change in job demands may modify associations between changes in testosterone levels and andropause symptoms.

Vitamin D supplementation and testosterone concentrations in male human subjects

OBJECTIVE

A possible association between serum 25-hydroxyvitamin D and testosterone levels has been reported; however, contradictory results have emerged.

DESIGN

To investigate a causal link between vitamin D and testosterone status, we studied the effect of vitamin D supplementation on serum testosterone concentrations in three independent intervention studies including male patients with heart failure (study 1), male nursing home residents (study 2) and male non-Western immigrants in the Netherlands (study 3).

METHODS

In study 1, 92 subjects were randomized to either vitamin D (2000 IU cholecalciferol daily) or control. Blood was drawn at baseline, after 3 and 6 weeks. In study 2, 49 vitamin D deficient subjects received either vitamin D (600 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. In study 3, 43 vitamin D deficient subjects received either vitamin D (1200 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. Serum 25-hydroxyvitamin D levels were measured using LC-MS/MS or radioimmunoassay. Testosterone levels were measured using a 2nd generation immunoassay.

RESULTS

Serum 25-hydroxyvitamin D levels significantly increased in all treatment groups (median increase of 27, 30 and 36 nmol/l in studies 1, 2 3, respectively) but not in the control groups. The documented increase in 25-hydroxyvitamin D levels, however, did not affect mean testosterone concentrations at the end of the study (median increase of 0, 0.5 and 0 nmol/l in studies 1, 2 and 3, respectively).

CONCLUSIONS

In this post hoc analysis of three small clinical trials of limited duration in men with normal baseline testosterone concentrations, vitamin D supplementation was not associated with an increase in circulating testosterone concentrations.

Serum 25-hydroxyvitamin D levels and testosterone deficiency in middle-aged Korean men: a cross-sectional study

Previous studies have demonstrated that male hypogonadism is associated with a low level of vitamin D. However, no reports have investigated the effects of vitamin D on testosterone levels in Korean men. Our aim was to investigate whether testosterone levels are associated with serum vitamin D levels and whether seasonal variation exists. This cross-sectional study analyzed serum 25-hydroxyvitamin D [25(OH)D], total testosterone (TT), and free testosterone (FT) in 652 Korean men over 40 years of age who had undergone a comprehensive medical examination. The average age of the subjects was 56.7 ± 7.9 years, and the mean serum 25(OH)D, TT and FT levels were 21.23 ± 7.9 ng ml-1 , 4.70 ± 1.6 ng ml-1 , and 8.12 ± 3.3 pg ml-1 , respectively. In the multiple linear regression model, 25(OH)D showed positive association with TT (β =0.137, P< 0.001) and FT (β =0.103, P= 0.008). 25(OH)D and FT showed similar seasonal or monthly variation after adjustment for age. A vitamin D deficiency [25(OH)D < 20 ng ml-1 ] was associated with an increased risk of deficiencies of TT (<2.30 ng ml-1 ) (odds ratio [OR]: 2.65; 95% confidence interval [CI]: 1.21-5.78, P= 0.014) and FT (<6.50 pg ml-1 ) (OR: 1.44; 95% CI: 1.01-2.06 P= 0.048) after adjusting for age, season, body mass index, body composition, chronic disease, smoking, and alcohol use. In conclusion, we demonstrated a positive correlation between 25(OH)D and testosterone, which showed similar seasonal variation in Korean men.

The relation between sex hormone levels, the androgen receptor CAGn-polymorphism and depression and mortality in older men in a community study

BACKGROUND

Sex hormones levels and the androgen receptor CAGn polymorphism have been shown to be involved in depressed mood in aging men. But the few prior studies found inconsistent results on the role of both factors.

METHODS

186 male participants aged ≥65 years from the community based Memory and Morbidity in Augsburg Elderly (MEMO) Study underwent a physical examination, and a medical interview including two scales (Center for Epidemiologic Studies Depression Scale (CES-D); Activities of Daily Living Scale (ADL). Testosterone, SHBG and LH levels were measured and the androgen receptor CAGn polymorphism was genotyped. χ(2), Mann-Whitney U-test, Pearson's correlations and multivariable linear and logistic regression were used in the analysis.

RESULTS

Higher depressive scores were significantly associated with higher SHBG-levels (beta coefficient 0.25, p<0.001). SHBG alone explained 8% of variance of the CES-D depression score. Mortality at 10 years follow-up was predicted by higher SHBG levels, higher ADL-scores, older age, current smoking and the depression score at baseline. This model explained 35% of the variance of mortality. The number of CAG repeats was neither related to depression scores nor to mortality.

CONCLUSIONS

We found positive associations between SHBG levels and old age male depression as well as mortality. Whether SHBG has a testosterone independent effect in this context should be investigated further.

The evidence for seasonal variations of testosterone in men

Ample evidence exists to support the concept of diurnal variations in testosterone levels; however, substantiation for seasonal fluctuations is sparse and inconsistent. Since circadian disparities exist, laboratory screening for hypogonadism has traditionally been conducted using serum testosterone levels obtained in the early morning. Should circannual variability of testosterone be confirmed, it would make the monitoring of testosterone levels more difficult while forcing the development of seasonal reference standards to allow for comparison. Moreover, decisions to begin treatment and adjustment of practice patterns would likely follow. This review thoroughly explores all of the available evidence concerning seasonal variations in testosterone levels. The impacts of melatonin, vitamin D, sleep-wake cycles, light exposure, physical activity, BMI, and waist circumference are also discussed. Current research suggests that while some evidence exists to support the notion of seasonal testosterone variations, the discussed inconsistencies preclude the incorporation of this concept into current clinical standards.

The impact of androgen receptor CAG repeat polymorphism on andropausal symptoms in different serum testosterone levels

INTRODUCTION

In addition to a depletion of androgen, attenuated action of androgen receptor (AR) might also contribute to andropausal symptoms.

AIM

To evaluate the interaction of AR cytosine adenine guanine (CAG) repeat polymorphism and serum testosterone levels and their effect on andropausal symptoms in aging Taiwanese men.

METHODS

From August 2007 to April 2008, a free health screening for men older than 40 years was conducted by a medical center in Kaohsiung City, Taiwan. All participants received physical examination, answered questionnaires to collect their demographic information and medical histories, completed the Androgen Deficiency in the Aging Male (ADAM) questionnaire, and provided 20-cm(3) whole blood samples for biochemical and genetic evaluation.

MAIN OUTCOME MEASURES

The ADAM questionnaire was used to evaluate andropausal symptoms. Serum albumin, total testosterone (TT), and sex hormone-binding globulin levels were measured. Free testosterone level was calculated. AR gene CAG repeat polymorphism was determined by direct sequencing.

RESULTS

Seven hundred two men with the mean age of 57.2 ± 6.5 years were included. There was no significant association between TT levels and the distribution of AR CAG repeat polymorphism. When TT levels were above 340 ng/dL, subjects with AR CAG repeat lengths ~25 showed significantly higher risk of developing andropausal symptoms, as compared with those with AR CAG repeat lengths ~22 (P = 0.006), but this was not observed when TT levels were 340 ng/dL or below. Age and number of comorbidities were also independent risk factors for andropausal symptoms.

CONCLUSION

In subjects with normal TT concentration, those with longer AR CAG repeat lengths have a higher risk of developing andropausal symptoms. Age and number of comorbidities can also influence the appearance of andropausal symptoms. In clinical practice, a multifactorial approach to evaluate andropausal symptoms and the interactions between those risk factors is suggested.

Aging males' symptoms in relation to the genetically determined androgen receptor CAG polymorphism, sex hormone levels and sample membership

Late-onset hypogonadism describes the co-occurrence of a range of physical, psychological and sexual symptoms in aging men, with the implication that these symptoms are caused by androgen deficiency. Previous investigations examined mostly population samples and did not take into account the testosterone modulating effects of the genetically determined CAG repeat polymorphism (CAGn) of the androgen receptor (AR) gene. This is the first study which investigates aging male symptoms (AMS) in relation to the genetically determined androgen receptor CAG polymorphism, estradiol and testosterone levels in men > or =50 years of age in a healthy population sample (n=100), outpatients of an andrological department (n=76) who presented with sexual and "aging male" symptoms and a psychosomatic/psychiatric sample (n=120) who presented with various psychological and medically unexplained somatic complaints. Although the population sample was significantly older than the two patient groups, they reported significantly fewer AMS and had higher testosterone levels and shorter CAG repeats of the AR. Regression analysis revealed influences of CAGn on the AMS global score and the psychological and somatic subscale only in the two patient samples, while testosterone had some impact on the sexual subscale. Our results suggest that the so-called aging male symptoms show a certain association to androgenicity, but that they are rather unspecific and of multifactorial origin. Other factors contributing to AMS need further clarification.

Partial androgen deficiency, depression and testosterone treatment in aging men

This study provides a critical review of the literature on depressive symptoms of partial androgen deficiency (PADAM) and their treatment with Testosterone (T). PADAM in aging males is responsible for a variety of behavioral symptoms, such as weakness, decreased libido and erectile dysfunction, lower psychological vitality, depressive mood, anxiety, insomnia, difficulty in concentrating, and memory impairment. The psychological and behavioural aspects of PADAM may overlap with signs and symptoms of major depression. Evidence of the relationship between androgen deficiency and male depression comes from studies that have assessed depression in hypogonadal subjects, the association between low T level and male depressive illness, and the antidepressant action of androgen replacement. The etiology of depressive symptoms of PADAM is multifactorial, and results from the interaction of the biological and psychosocial changes that take place during the mid-life transition. Although data derived from androgen treatment trials and androgen replacement do not support T treatment or replacement as more efficacious than placebo for major depressive disorder (MDD), the clinical impression is that, in some sub-threshold depressive syndromes, T may lead to antidepressant benefits.

Men's Attraction to Women's Bodies Changes Seasonally

Humans exhibit seasonal variation in hormone levels, behaviour, and perception. Here we show that men's assessments of women's attractiveness change also seasonally. In five seasons (from winter 2004 to winter 2005) 114 heterosexual men were asked to assess the attractiveness of the same stimuli: photos of a female with three different waist-to-hip ratios; photos of female breasts, and photos of average-looking faces of young women. For each season, the scores given to the stimuli of the same category (body shape, breast, and face) were combined. Friedman's test revealed significant changes for body shape and breast attractiveness assessments across the seasons, but no changes for face ratings. The highest scores for attractiveness were given in winter and the lowest in summer. We suggest that the observed seasonality is related to the well-known ‘contrast effect’. More frequent exposure to women's bodies in warmer seasons might increase men's attractiveness criteria for women's body shape and breasts.

Lack of seasonal variation in serum sex hormone levels in middle-aged to older men in the Boston area

CONTEXT

Previous studies of seasonal variation of testosterone and other hormones in men have produced mixed results regarding the number and timing of peaks and nadirs and whether hormones vary seasonally at all. Wide variation in study designs, sample sizes, analytical methods, and characteristics of the study populations may account for the heterogeneity of results.

OBJECTIVE

The objective of the study was to determine whether serum total, free, and bioavailable testosterone, dihydrotestosterone, SHBG, LH, dehydroepiandrosterone, dehydroepiandrosterone sulfate, estrone, estradiol, and cortisol vary seasonally in men.

DESIGN

Two blood samples were drawn 1-3 d apart at study entry and again 3 and 6 months later (maximum six samples per subject). Hormone levels 1-3 d apart were averaged to reduce short-term intrasubject variation.

SETTING

The study population consisted of a community-dwelling population (Boston, MA).

STUDY PARTICIPANTS

One hundred thirty-four men 30-79 yr old were randomly selected from the respondents to the Boston Area Community Health Survey. One hundred twenty-one men who completed all six visits were included in the analysis.

MAIN OUTCOME MEASURES

In a repeated-measures analysis, 3-month change in hormone levels, measured twice per subject, and in a sinusoidal nonlinear regression with random subject effects, average hormone level in samples 1-3 d apart were measured.

RESULTS

Aside from cortisol, no evidence of seasonal variation in hormone levels was found. The amplitude of seasonal variation was much smaller than total intraindividual variation for all hormones considered.

CONCLUSIONS

Seasonal variation is likely an unimportant source of variation clinically and in epidemiological studies of hormone levels.

Hypogonadism in HIV-1-Infected Men is common and does not resolve during antiretroviral therapy

Objectives

To assess the prevalence of abnormal testosterone and gonadotropin values in HIV-infected men before and after 2 years of combination antiretroviral therapy (cART).

Design

Multicentre cohort of HIV-infected adults.

Methods

We identified 139 Caucasian antiretroviral-naive male patients who started zidovudine/ lamivudine-based cART that was virologically successful over a 2 year period. Ninety-seven were randomly chosen and plasma hormone determinations of free testosterone (fT) and luteinizing hormone (LH) at baseline and after 2 years of cART were evaluated.

Results

At baseline 68 patients (70%) had subnormal fT levels. In these, LH levels were low in 44%, normal in 47% and high in 9%. There was a trend for an association between lower CD4+ T-cell counts and hypogonadism. Most participants had normal FSH levels. No significant changes of fT, LH and FSH levels were observed after 2 years of cART.

Conclusions

Low fT levels, mainly with normal or low LH levels and thus indicating secondary hypogonadism, are found in the majority of HIV-infected men and do not resolve during 2 years of successful cART.