The efficacy and safety of short-acting testosterone ointment (Glowmin) for late-onset hypogonadism in accordance with testosterone circadian rhythm

Introduction: It is well known that there is a reduction of circadian rhythm in blood testosterone levels with aging. Our previous report revealed that 3?mg of short-acting testosterone ointment (Glowmin: GL) elevated serum testosterone levels to within the physiological range for 4–6?h. The aim of this study was to clarify the clinical efficacy and safety of GL used topically once every morning, to enhance the circadian rhythm of testosterone, for late-onset hypogonadism (LOH).

Methods: A total of 61 LOH patients received 3?mg of GL topically once a day in the morning on scrotal skin for 24 weeks. The clinical efficacy of GL was evaluated by the aging males symptoms (AMS) scale, and blood sampling tests were measured before and after GL treatment.

Results: Mean patients age was 55.3?±?9.2 years old. Total AMS scores at 4, 12, and 24 weeks after GL treatments significantly decreased. The results of sub-analysis of AMS, including psychological, physical, and sexual factors also significantly improved after GL treatments. No severe adverse reactions or abnormal laboratory data were reported.

Conclusions: This study shows that TRT for LOH with once daily GL treatment supports testosterone circadian rhythm and should be considered to be an effective and safe therapy for LOH.     

A randomized,double-blind,placebo-controlled trial of testosterone gel on body composition and health-related quality-of-life in men with hypogonadal to low-normal levels of serum testosterone and symptoms of androgen deficiency over 6 months with 12 months open-label follow-up

Introduction: The clinical significance of low to low-normal testosterone (T) levels in men remains debated. Aim: To analyze the effects of raising serum T on lean body mass (LBM), fat mass (FM), total body mass, and health-related quality-of-life (HRQoL). Methods: Randomized, double-blind, placebo-controlled study. Men, aged 50–80 years, with serum total T<15 nmol/L and bioavailable T < 6.68 nmol/L, and a Aging Males’ Symptoms (AMS) total score >36, received 6 months treatment with transdermal 1% T gel (5–7.5?mg/day; n =183) or placebo gel (n =179), followed by 12 months open-label with T in all. Results: After 6 months, LBM increased in T- treated patients by 1.28?±?0.15?kg (mean ± SE) and FM decreased by 1.16?±?0.16?kg, with minor changes with placebo (LBM +0.02?±?0.10?kg and FM ?0.14?±?0.12?kg; all p < 0.001, T group vs. placebo). Changes were largely similar across subgroups of age, baseline total testosterone, and baseline BMI. Total HRQoL improved compared with placebo (p < 0.05, T group vs. placebo). Conclusions: Six months 1% T gel improved body composition and HRQoL in symptomatic men with low to low-normal T, with further improvements over the following 12 months.     

The impact of testosterone replacement therapy on glycemic control,vascular function,and components of the metabolic syndrome in obese hypogonadal men with type 2 diabetes

Objective: This study set out to assess effects of testosterone replacement therapy (TRT) on parameters of metabolic syndrome and vascular function in obese hypogonadal males with type 2 diabetes mellitus (DM2).

Study design: Fifty-five obese hypogonadal diabetic males on oral hypoglycemic treatment were enrolled into this one-year, double-blind, randomized, placebo-controlled clinical study. Group T (n?=?28) was treated with testosterone undecanoate (1000?mg i.m. every 10?weeks) while group P (n?=?27) received placebo.

Methods: Anthropometrical and vascular measurements – flow-mediated dilatation (FMD) and intima media thickness (IMT) – biochemical and hormonal blood sample analyses were performed at the start of the study and after one year. Derived parameters (BMI, HOMA-IR, calculated free testosterone (cFT) and bioavailable testosterone (BT)) were calculated.

Results: TRT resulted in reduction of HOMA-IR by 4.64?±?4.25 (p?p?p?=?.005).

Conclusion: TRT normalized serum testosterone levels, improved glycemic control and endothelial function while exerting no ill effects on the study population.     

Decline of serum levels of free testosterone in aging healthy Chinese men

Objective.?To investigate the age-related change of serum androgen levels in healthy men and to define a cut-off value of serum testosterone for the diagnosis of androgen deficiency in the aging male.

Method.?1080 healthy men aged 20 to ?70 years old were enrolled in Beijing, Shanghai, Xian and Chongqing. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (T), calculated free testosterone (cFT), sex hormone binding globulin (SHBG), 17beta-oestradiol (E2), the T/LH ratio, and T/SHBG as a free testosterone index (FTI) were all determined.

Results.?Serum total T did not significantly decline, but the cFT, T/LH and FTI progressively decreased with aging. To determine androgen deficiency, the 10th percentile value of men <40 years was defined as the lower cut-off value for cFT, T/LH or FTI, which were 0.3 nmol/L, 2.8 nmol/IU, and 0.4 nmol/IU respectively. With the median value of cFT of men aged between 20 and 49 years as the criterion, the level of cFT was lower in 2.82% of men from 40 to 49 years, in 19.53% from 50 to 59 years, in 22.57% from 60 to 69 years, and in 33.19% of men ?70 years. Taking the above value of cFT as the cut-off point, the prevalence of androgen deficiency in men 40–49 years was 13.0%, 31.8% in men 50–59 years, 30.1% in men 60 to 69 years, and 46.7% in men >70 years.

Conclusions.?(i). While serum total T values do not decline with aging, the levels of cFT gradually decline with aging; (ii) when using the value of cFT of the 10th percentile of men aged 20 to 39 years as the cut-off point, the prevalence of androgen deficiency was <15% before the age of 50 years, and about 30% thereafter, approaching 45% after the age of 70 years; and (iii) in this study the values of T/LH paralleled those of cFT closely; therefore, T/LH could serve as a surrogate for cFT.     

Free testosterone by direct and calculated measurement versus equilibrium dialysis in a clinical population

Abstract

Introduction: The value of clinically available free testosterone (FT) assays remains controversial. Here, we evaluate the agreement between the radioimmunoassay (RIA) and calculated FT (cFT) versus equilibrium dialysis (EqD), considered the gold standard.

Methods: Fifty-six consecutive men (aged 26–77) had blood samples assessed for FT, including men with treated and untreated testosterone deficiency (TD) and men without TD. Samples were split and tested by the two methodologies at a Quest Diagnostics national reference laboratory. cFT was calculated by the Vermeulen method.

Results: A robust correlation was noted for RIA and EqD (r?=?0.966) and for cFT and EqD (r?=?0.986). Strong correlations were observed for men receiving testosterone therapy and for men in the lowest and highest quartiles for total and FT. The correlation of total testosterone with FT was similar for cFT (r?=?0.843), RIA (r?=?0.806), and EqD (r?=?0.809). Sex-hormone binding globulin (SHBG) was not correlated with any measure of FT. Bland–Altman analysis demonstrated similar bias for both cFT and RIA, although cFT consistently overestimated FT. Numerical values for RIA were approximately one seventh of EqD values.

Conclusions: These results support the clinical use of both RIA and cFT as measures of FT. Due to numerical differences, each test requires its own set of reference values.     

Effects of oral testosterone undecanoate therapy on bone mineral density and body composition in 322 aging men with symptomatic testosterone deficiency: a 1-year,randomized, placebo-controlled,dose-ranging study

Abstract

Objective: We investigated the effects of oral testosterone undecanoate (TU) on bone mineral density (BMD), lean body mass (LBM) and body fat mass (BFM) in aging men with symptomatic testosterone deficiency (TD).

Methods: Three hundred twenty-two men ≥50 years with TD symptoms and calculated free testosterone <0.26?nmol/L participated in a multicenter, double-blind, placebo-controlled trial. Patients were randomized to placebo, oral TU 80?mg/d, oral TU 160?mg/d, or oral TU 240?mg/d, administered as divided doses with normal meals. BMD of the hip and lumbar spine were evaluated by dual energy X-ray absorptiometry (DEXA), and body composition (LBM and BFM) by whole body DEXA.

Results: Oral TU significantly increased BMD at Month 12 at the lumbar spine (240?mg/d), total hip (240?mg/d), and trochanter and intertrochanter (160 and 240?mg/d) compared with placebo. Oral TU significantly increased LBM at Months 6 and 12 for all oral TU groups compared with placebo. BFM significantly decreased at Month 6 (all oral TU groups) and Month 12 (160?mg/d) compared with placebo. The effects on BMD and body composition showed a clear dose response.

Conclusions: Treatment with oral TU led to improvement in BMD, LBM and BFM in aging men with symptomatic TD.     

Sleep disturbance as a clinical sign for severe hypogonadism: efficacy of testosterone replacement therapy on sleep disturbance among hypogonadal men without obstructive sleep apnea

Objective: The present subanalysis of the EARTH study investigates the effects of one year testosterone replacement therapy (TRT) on sleep disturbance among hypogonadal men without obstructive sleep apnea.

Methods: Sleep disturbance was defined as three or more points in question 4 of the aging males symptoms (AMS) questionnaire. All participants completed the AMS scale, International Prostatic Symptoms Score (IPSS), Sexual Health Inventory for Men (SHIM) and Short Form 36 (SF-36) health survey at baseline and after 12?months. Sexual symptoms were also evaluated based on three AMS subscores (Q15, 16 and 17).

Results: We identified 100 patients with sleep disturbance, of whom 48 (24 each in the TRT and control groups) were ultimately included for analysis. All SF-36 categories , AMS scale, IPSS and SHIM score subdomains were significantly worse in patients with sleep disturbance than in those without disturbance. Statistically significant differences in sleep disturbance, erectile symptoms, sexual desire and some domains of the SF-36 were observed between the TRT and control groups after 12?months.

Conclusion: Sleep disturbance may be one of the clinical signs for severe hypogonadism. Moreover, TRT improved sleep conditions, sexual function and quality of life among hypogonadal men with sleep disturbance.     

Interleukin-18 and testosterone levels in men with metabolic syndrome

Objective: Interleukin 18 (IL-18) is an adipokine associated with obesity. Data about the relationship of IL-18 to the metabolic syndrome (MS) are still scarce. Low testosterone (T) levels are common in men with MS, but we did not find data about the levels of IL-18 in men with low T. The aim of this study was to determine the levels of IL-18 in men with MS with or without low T.

Patients and methods: A total of 251 men were included in the study. Of them 218 had MS (IDF 2005) and they were divided according to their morning total testosterone (TT) level (cutoff 10.4?nmol/l) into two groups: MS-low T (N?=?84) and MS-normal T (N?=?134). The control group consisted of 33 men without MS and low T. IL-18 was determined in serum using enzyme-linked immunosorbent assay. A small group of eight men with MS and low T levels received testosterone therapy for three months and physical and laboratory parameters were monitored at the end of that period.

Results: MS men were at mean age (±SD)?=?53.77?±?9.59 years; body mass index (BMI)?=?34.0?±?6.3?kg/m²; and TT?=?12.59?±?5.66?nmol/l. The control group was at age?=?52.12?±?5.2 years (NS); BMI?=?25.6?±?2.4?kg/m² (p?p?p?p?p?p?Conclusions: In this study, higher IL-18 levels were found in the presence of MS compared to healthy men, but they did not differ between men having MS with or without LOH.     

Effects of testosterone replacement therapy on nocturia and quality of life in men with hypogonadism: a subanalysis of a previous prospective randomized controlled study in Japan

Abstract

Objective: We investigated the effects of testosterone replacement therapy (TRT) on nocturia and general health among men with hypogonadism and nocturia.

Methods: From our previous EARTH study population, 64 patients with a clinical diagnosis of nocturia (two or more times per one night) and hypogonadism, comprising the TRT group (n?=?31) and controls (n?=?33), were included in this analysis. The TRT group was administered 250?mg of testosterone enanthate as an intramuscular injection every 4 weeks for 6 months. All patients responded to the following questionnaires: International Prostatic Symptoms Score (IPSS), Aging Male Symptoms (AMS) score and Short Form-36 health survey at baseline and 6-month visit. These categories were compared based on changes from baseline to the 6-month visit between TRT and control groups.

Results: At the 6-month visit, the TRT group had a significant decrease in IPSS question no. 7 and AMS question no. 4, whereas no significant changes were observed in the control group. Additionally, role limitation because of health program, vitality and mental health domains were significantly improved in the TRT group.

Conclusions: Six-month TRT may improve nocturia, sleep conditions and quality of life among men with hypogonadism and nocturia.     

Effects of testosterone replacement therapy on hypogonadal men with osteopenia or osteoporosis: a subanalysis of a prospective randomized controlled study in Japan (EARTH study)

Objective: We investigated the effects of testosterone replacement therapy (TRT) on bone mineral density (BMD) among hypogonadal men with osteopenia/osteoporosis.

Methods: From our previous EARTH study population, 74 patients with a clinical diagnosis of osteopenia or osteoporosis and hypogonadism were included in this study, as the TRT (n?=?35) and control (n?=?34) groups. The TRT group was administered 250?mg of testosterone enanthate injection every 4 weeks for 12 months. The BMD, waist circumference, body mass index, body fat percentage, and muscle volume were measured at baseline and at 12 months. Blood biochemical data, including total cholesterol, triglycerides, HDL-cholesterol, hemoglobin A1c, and adiponectin values were also evaluated.

Results: At the 12-month visit, BMD significantly increased in both groups. However, comparisons on changes of parameter values from baseline to the 12-month visit between the TRT and control groups were significantly different in BMD (5.0?±?5.0 vs. 3.0?±?3.2; p?=?.0434) and in adiponectin value (?0.90?±?3.33 vs. 0.10?±?2.04; p?=?.0192). There were no significant changes in other parameters.

Conclusions: TRT for 12 months could improve BMD with a decrease in adiponectin levels among hypogonadal men with osteopenia/osteoporosis.     

Effects of testosterone administration on liver structure and function in aging rats

Aging males have a decrease in testosterone levels, by which the testosterone treatment may influence in a negatively fashion the liver.

Aim: This study aimed to analyze the effects of aging with or without testosterone administration on the liver components of animals.

Methods: Wistar rats were divided into three groups: 20 months’ group (G20), 24 months’ group (G24), group treated with testosterone for 16 weeks (GT). All groups were sacrificed at 24 months except for G20 that was sacrificed at 20 months.

Results: Aging and testosterone treatment alters the body weight (BW), liver weight (LW) and relative liver weight. Besides, testosterone increased the mitogen capacity of hepatocytes. Nonetheless, we reinforce the negative effects of testosterone on old animals’ liver as chronic hepatic congestion and/or cholestasis. In addition, we observed that testosterone plays an important role on hepatic glycogen stores.

Conclusions: Our study showed many implications for the knowledge about the effects of aging with or without testosterone administration on old animals’ liver.     

The effect of testosterone therapy on lower urinary tract symptoms/bladder and sexual functions in men with symptomatic late-onset hypogonadism

Objective.?To prospectively investigate the effect of testosterone therapy on lower urinary tract symptoms (LUTS)/bladder and sexual functions in men with symptomatic late-onset hypogonadism (SLOH).

Methods.?The study included 25 men (age range 38 to 73 years) presented with sexual dysfunction, having SLOH, at a single university hospital. All men received testosterone replacement therapy with transdermal testosterone 50–100 mg gel per day for one year. Urodynamic studies with pressure-flow analysis, measurement of prostate volume, prostate specific antigen (PSA) and free PSA level, International Prostate Symptom Score (IPSS), Aging Male Symptom (AMS) scale and International Index of Erectile Function (IIEF-5) score were recorded in all men before and after one year of the treatment.

Results.?The mean AMS score significantly decreased from 40.4 ± 7.3 to 28.8 ± 5.31 (p = 0.001), and mean IIEF-5 score significantly increased from 8.84 ± 3.76 to 14.36 ± 3.62 (p = 0.001). The mean maximal bladder capacity and compliance significantly increased (p = 0.007 and p = 0.032, respectively), and mean detrusor pressure at Qmax significantly decreased from pre-treatment to post-treatment (p = 0.017).

Conclusion.?This study suggests that in addition to improvement in sexual functions, testosterone therapy may also improve LUTS/bladder functions by increasing bladder capacity and compliance and decreasing detrusor pressure at maximal flow in men with SLOH.     

Transversal European survey on testosterone deficiency diagnosis

Background: Despite being one of the relevant public health threats among ageing men, testosterone deficiency syndrome (TDS) is under-recognized and under-diagnosed. Objective: To assess current clinical practices of European physicians regarding diagnosis and management of TDS compared with current guidelines. Methods: Postal survey conducted June–November 2008 in France, Germany, Italy and Spain among urologists, endocrinologists and general practitioners to collect information regarding knowledge of TDS. Results: Among 801 respondents, the majority of endocrinologists and urologists had received training on TDS, either initially or as part of continuous medical education. TDS was recognized by 86.5% of physicians as a true clinical entity, and estimated the prevalence at 10–15% of the male population; 73.5% considered that symptoms and a low level of testosterone were required for diagnosis. Treatment preferences were quarterly intramuscular injections (26.3% of physicians), percutaneous gels (23.9%), matrix patch (21.2%), semi-monthly injections (15.4%) and oral therapy (13.4%). Adverse effects of testosterone replacement therapy, such as benign prostatic hyperplasia and prostate cancer, were a concern for physicians. Conclusions: TDS management appeared to be close to that recommended in international guidelines. Signs and symptoms of testosterone deficiency were fairly well known, but some diagnostic and treatment variations were observed.     

Comprehensive evaluation of androgen replacement therapy in aging Japanese men with late-onset hypogonadism

Abstract

Objective: This study assessed the efficacy and safety of testosterone replacement therapy (TRT) in aging Japanese men with late-onset hypogonadism (LOH).

Methods: This study included 50 (median age: 57.7 years) Japanese men with LOH, who were consecutively enrolled and treated with TRT for at least six months at our institution. We evaluated the following measurements before and after six months of treatment with TRT as follows: blood tests, prostate volume, residual urine volume, self-ratings for International Index of Erectile Function 5 (IIEF-5), International Prostate Symptom Score (IPSS), Self-Rating Depression Scale (SDS), Aging Male Symptom (AMS) and the Medical Outcomes Study 8-item Short-Form health survey (SF-8).

Results: Following six months of TRT, the levels of testosterone, red blood cells, hemoglobin and hematocrit were significantly increased from baseline, while total cholesterol level was significantly decreased from baseline. Furthermore, TRT led to a significant increase in IIEF-5 score and a significant decrease in IPSS score. Of 30 men who were diagnosed with depression at baseline, only 11 men (36.7%) were still suffering from depression after TRT, and SDS scores were significantly decreased from baseline at month six. Treatment with TRT led to a significant decrease in all scores of the AMS scale as well as a significant improvement in all scores of the SF-8 survey, with the exception of the bodily pain score.

Conclusion: These findings suggest that TRT is an effective and safe treatment for aging Japanese men with LOH. TRT improved depressive symptoms as well as health-related quality of life.     

The effects of orchidectomy and supraphysiological testosterone administration on trabecular bone structure and gene expression in rats

Abstract

Objective: This study aimed to determine the effects of orchidectomy and supraphysiological testosterone replacement on trabecular structure and gene expression in the bone.

Methods: Twenty-four 3-month old male rats were randomized into sham (SH), orchidectomized (ORX) and testosterone-treated (TE) groups. Orchidectomy was performed on the ORX and TE group. Weekly testosterone enanthate intramuscular injection at 7?mg/kg body weight was administered to the TE group for 8 weeks while the other groups received peanut oil as vehicle. Blood was collected before and after treatment for serum testosterone analysis. The femora and tibiae were harvested after the treatment period for trabecular structure and gene expression analysis.

Results: The trabecular bone volume decreased significantly and the porosity increased significantly in the ORX group compared to the SH group (p?<?0.05). Testosterone treatment prevented all these changes (p?<?0.05). The expression of osteogenic genes decreased significantly in the ORX group compared to the SH group (p?<?0.05). Testosterone treatment decreased the expressions of RANKL and OPG genes significantly (p?<?0.05).

Conclusion: Orchidectomy-induced degeneration in trabecular structure is caused by a decrease in the expressions of osteogenic genes. Supraphysiological testosterone replacement is able to prevent these degenerative changes in the bone despite the modest changes in gene expression.     

Prevalence of low testosterone in aging men with benign prostatic hyperplasia: data from the Proscar Long-term Efficacy and Safety Study (PLESS)

Abstract

Objectives: We examined the prevalence of low testosterone (LT) in the subset of men in the Proscar Long-term Efficacy and Safety Study (PLESS) who had serum total testosterone (TT) measured at baseline.

Methods: PLESS enrolled 3040 men with benign prostatic hyperplasia (BPH). Of these men, 299 had TT and body mass index (BMI) measurements at baseline. Patients were classified as having LT if their baseline TT was <300?ng/dl.

Results: Of the 299 PLESS patients with baseline TT and BMI measurements, 65 (21.7%) had LT. The prevalence of LT increased with increasing BMI, occurring in 8/78 (10.3%) normal weight patients (baseline BMI <25?kg/m²), 35/160 (21.9%) overweight patients (baseline BMI ≥25–<30?kg/m²), and 22/61 (36.1%) obese patients (baseline BMI ≥30?kg/m²).

Conclusions: LT was observed in more than one in five PLESS patients with baseline TT and BMI measurements. The prevalence of LT increased with increasing BMI – more than one in three obese PLESS patients with baseline TT measurements had LT.     

Time for international action on treating testosterone deficiency syndrome

Aim. Testosterone deficiency is having an increasing impact on men's health because of global aging, higher levels of obesity, diabetes and metabolic syndrome and adverse environmental factors such as stress xenoestrogens and anti-androgens. The question addressed is to what extent the large body of evidence on the benefits and safety of testosterone therapy is applied in clinical practice.

Methods. Demographic data for men over the age of 50 from different regions of the world have been compared with the number of men in that age group estimated from sales figures to be receiving testosterone treatment.

Results. On the basis of estimate that 20% of men over 50 in the general population of each region could be expected to have testosterone deficiency symptoms, on average only these men (0.69%) in most European countries were receiving treatment. Proportion was higher in the UK (1.00%) and Germany (1.89%), but lower in France (0.49%), Italy (0.51%) and Russia (0.54%). Interestingly, Australia had higher figures (1.64%), in spite of tight state control measures on androgen use. The USA has the highest treatment rate (7.96%) and this is increasing rapidly.

If the basis for the diagnosis was the more conventional combination of symptoms plus biochemical evidence of low total and free testosterone levels, androgen deficiency would be expected in at least 5% of men over 50, and percentage treatment rates therefore four times higher. However, even on that basis, only in the USA do these exceed 10%.

Conclusions. International action is urgently needed to raise awareness in the medical profession in the various countries of these remarkably low levels of testosterone treatment. Improvement in this requires education and motivation of doctors and those regulating the healthcare systems. A public awareness campaign is needed to educate men about the symptoms of testosterone deficiency and its impact on their health.     

Testosterone supplementation's effects on age-related bladder remodeling – experimental study in rats

Abstract

Objective: This study was designed to evaluate the effect of testosterone replacement on the fibrotic process of the detrusor bladder muscle during the normal aging process.

Methods: 15 Wistar senile rats, aged between 18 and 20 months were divided into two groups: testosterone group – 11 animals submitted to the administration of testosterone undecanoate (50?mg/kg intramuscular), once per month; and, Control group – four animals underwent a sham procedure. At the end of eight weeks, animals from both groups were sacrificed; bladders were removed and subsequently stereologically evaluated to determine the volumetric density of collagen fibers. The success of testosterone administration was confirmed by the measurement of serum testosterone at the beginning and end of the experiment.

Results: In the replacement group, testosterone average was 3.2?ng/ml, whereas in the control group, the mean testosterone at the end of the experiment was 0.64?ng/ml (p?<?0.05). Analysis of stereological collagenous fiber showed higher density in the control group compared to the testosterone group I (56% versus 37.02%, respectively). The difference of volume concentration of collagen between both groups was statistically significant (p?<?0.000).

Conclusion: Bladder wall fibrosis was reduced in senile rats subjected to testosterone replacement.     

The relationship between serum total testosterone and free testosterone levels with serum hemoglobin and hematocrit levels: a study in 1221 men

Objective: To investigate the relationship between serum total testosterone (TT) and free testosterone (FT) levels in men with anemia.

Methods: We reviewed the records of 1221 subjects between March 2009 and December 2014. All the subjects’ blood samples were drawn for TT and FT assays. Their serum hemoglobin (Hb) and serum hematocrit (Hct) levels were measured. The primary objective of our study was to investigate the association between TT and FT levels with Hb and Hct levels.

Results: The mean age was 59.82?±?12.71 years. The mean TT and FT levels were 4.54?±?2.02?ng/mL and 10.63?±?3.69?pg/mL, respectively. The mean Hb and Hct levels were 14.72?±?1.34?g/dL and 43.11?±?3.75%, respectively. Subjects with low TT (<2.35?ng/mL) had low Hb and Hct levels (p?p?Conclusions: Subjects with low TT and FT levels had low Hb and Hct levels. This suggests that TT and FT play a significant role in erythropoiesis. Testosterone replacement therapy may be effective in men with hypogonadism to reduce the incidence of anemia.