Information for patients

Categories

You can filter the research news achive by selecting one or multiple categories from the following list.















  Show all news

 

14 July 2014

Effects of testosterone deficiency on body composition, strength and sexual function in men, and the tolerability of long-acting testosterone undecanoate in daily clinical practice

Effects of testosterone deficiency on body composition, strength and sexual function in men, and the tolerability of long-acting testosterone undecanoate in daily clinical practice

Gonadal steroids and body composition, strength, and sexual function in men. Finkelstein JS, Lee H, Burnett-Bowie S-A, et al. N Engl J Med 2013;369:1011−22.

IPASS: A study on the tolerability and effectiveness of injectable testosterone undecanoate for the treatment of male hypogonadism in a worldwide sample of 1,438 men. Zitzmann M, Mattern A, Hanisch J, et al. J Sex Med 2013;10:579−88.

This editorial includes summaries of two studies: the first is an experimental study in men looking at the effects of testosterone deficiency on body composition, strength and sexual function; the second is a post-observational surveillance study (IPASS) investigating the tolerability of long-acting testosterone undecanoate (TU) in men with testosterone deficiency syndrome (hypogonadism) in a clinical practice setting.

The classification of low testosterone levels – at least 2 standard deviations below the mean value for healthy young adults – does not take into account the physiological consequences of various testosterone levels. In particular the implications of the concomitant decline in serum levels of estradiol, a metabolite of testosterone, are generally not considered. This summary describes the results from an experimental study in two cohorts of healthy men, both of whom received goserelin acetate to suppress endogenous testosterone and estradiol (Cohort 1; n=198; Cohort 2; n=202). Participants were randomly assigned to receive placebo, 1.25 g, 2.5 g, 5 g or 10 g of testosterone gel daily for 16 weeks. In order to differentiate between the effects of testosterone and estradiol, participants in Cohort 2 also received anastrozole 1 mg daily, an aromatase inhibitor, to block the conversion of testosterone to estradiol. The primary outcome variables were changes in percentage of body fat and total-body lean mass. Changes in subcutaneous- and intraabdominal-fat areas, thigh-muscle area and leg-press strength, and sexual function were also assessed.

The prospective, observational IPASS was conducted in 23 countries in Europe, Asia, Latin America, and Australia and investigated the safety and efficacy of intramuscular injections of TU in men with hypogonadism in a “real-life setting”.
A total of 1493 men (age 49.2 ± 13.9 years; 72.5% Caucasian) with hypogonadism were enrolled into the study to receive up to five injections of TU over an observation period of 9–12 months. The first and second injections were given at intervals of 6–10 weeks, and subsequent injections at intervals of 12 ± 2 weeks. Patients subjectively assessed the intensity of hypogonadism-related symptoms at each study visit, and at the end of the treatment period gave a rating of overall tolerability. Laboratory measurements, including prostate-specific antigen (PSA), hemoglobin, hematocrit, and lipid profiles, as well as digital rectal examination were also assessed at each study visit. At baseline and the time of the fifth injection a total of 1438 and 1140 men were evaluable, respectively. At baseline, body weight was 86.8 ± 17.6 kg, waist circumference 99.5 ± 15.25 cm and serum testosterone 9.6 ± 7.5 nmol/L.The summary of this study reports the results for the safety, anthropometric and sexual function measurements.



Key Points

  • The randomized controlled study showed that there is considerable variation in the dose of testosterone required to prevent adverse changes in body composition, strength and sexual function

    • Only the highest dose of testosterone (10 g) achieved levels sufficient to reduce body fat
  • In this experimental study, administration of an aromatase inhibitor allowed the effects of testosterone and estrogen to be distinguished

    • Decreases in total-body lean mass, thigh-muscle area and leg-press strength were attributed to testosterone deficiency
    • Estrogen deficiency played a role in the increases in body fat
  • Both testosterone and estradiol are needed for maintenance of normal sexual function
  • Interpretation and treatment of hypogonadism in men should be individualized
  • In IPASS, TU was well tolerated in men with hypogonadism, and ADRs were rare (5.8%)
  • Increases in hematocrit and PSA, and injection site pain were the most common ADRs occurring in <1% of patients
  • Treatment-related ADRs lead to discontinuation in 31 men
  • Marked improvements in overall levels of sexual desire/libido were observed with TU
  • At the fifth injection of TU there was a significant decrease in waist circumference (p≤0.003), and a slight decrease in body weight

14 July 2014

Effects of testosterone deficiency on body composition, strength and sexual function in men

Effects of testosterone deficiency on body composition, strength and sexual function in men
This paper presents the findings from a study that looked at the effects of testosterone on body fat, lean mass, thigh-muscle area and strength, and sexual function in healthy men who had their testosterone levels experimentally reduced. As the majority of estradiol (a form of estrogen) is obtained from testosterone, the concomitant decrease in estradiol was also investigated and the effects differentiated from those of testosterone.

8 March 2012

Link between low testosterone and frailty in elderly men

Image: Senior patient and doctor
This review discussed the relationship between low testosterone levels and frailty in elderly men and evaluated the evidence which shows that testosterone replacement therapy improves the physical functioning and quality of life of elderly frail men with confirmed low testosterone levels.

22 February 2011

Study shows testosterone (T) improves body composition and hip bone mineral density in elderly men with low T

Image: Pelvic x-ray image

Testosterone treatment in elderly men with subnormal testosterone levels improves body composition and BMD in the hip. J Svartberg, I Agledahl, Y Figenschau, T Sildnes, K Waterloo and R Jorde. International Journal of Impotence Research. 2008:20;378–387.

Researchers examined whether lower than normal T levels in elderly men were associated with a reduced quality of life (QoL), as well as physical and mental health, and whether T treatment could improve these conditions.

Unlike earlier testosterone treatment studies that recruited by advertising or direct mailing, researchers contacted elderly men (aged 60–80 years old) surveyed as part of the fifth (2001) Tromsø survey that measured T in 3,447 men. Sixty-nine elderly men with low T (defined as ≤11.0 nmol/l) and 104 men with normal T (>11.0 nmol/l) (control group) took part in a nested case-control study. Of the 69 men with low T, 31were excluded from participation in the one year intervention study due mainly to PSA levels above the reference range (>4.0µg/l) (no.18) or the use of warfarin (no.6). As a result 19 men were included in each of the T and placebo treatment groups (randomized in a double-blind fashion) – one man later withdrew from each group and one man from the T group died from cardiac arrhythmia not considered to be related to T therapy. Treatment was by an intramuscular injection of testosterone undecanoate 1000mg (Nebido®) or an identical looking placebo administered by a nurse (ensuring 100 per cent compliance) at baseline and again at six, 16, 28, and 40 weeks. After 52 weeks the initial examinations and tests were repeated.

Key Points

The nested case-control study showed:

  • No difference in Fat Free Mass (FFM) beween the two groups (low and normal T), but Fat Mass (FM) percentage was significantly higher in the low T group (32.2% vs 25.9%; P<0.001) compared with controls – this group also had higher weight, waist circumference, and total abdominal adipose tissue (TAT)
  • Muscle strength was similar between the groups, but the control group performed significantly better in two of the three functional tests. Bone Mineral Density (BMD) measured in both the lumbar spine and hip showed no significant difference between the groups
  • At the Oral Glucose Tolerance Test men with low T had significantly higher fasting and two hour glucose levels compared with the control group. Likewise, the HbA1c, insulin, C-peptide and triglycerides levels and insulin resistance (HOMA) values were significantly higher in men with subnormal testosterone levels
  • Men in the control group reported better overall and somatic Quality of Life (QoL) scores (AMS) although the scores in the sexual domain were not significantly different. In the Beck Depression Inventory the control group reported a significantly better total and second subscale score
  • There were no differences between groups in the General Health Questionnaire or World Health Organisation quality of life old score (WHOQOL-OLD)

The intervention study showed that:

  • Total and free T increased significantly in the T group. Luteinizing hormone (LH) and follicle stimulating hormone (FSH) decreased in the T group and at the end of the study were significantly lower in the T group compared with placebo
  • FFM increased and FM reduced significantly during T treatment compared to the placebo group at the end of the study (FFM: +4.2 kg in T group, +0.4 kg in placebo; FM: -5.3kg in T group, -0.6 kg in placebo) while weight, BMI and waist circumference did not change significantly
  • BMD in the hip increased significantly in the T group and there was a significant difference between the groups at the end of the study
  • T did not increase strength in knee extension or handgrip strength, but in the placebo group handgrip strength was reduced in both the dominant and non-dominant hand such that at the end of the study there were significant differences between the groups
  • There was no significant difference in QoL, cognitive function or emotional function between the groups at the end of the study
  • Serum PSA, hematocrit and hemoglobin increased in the T group and by the end of the study were significantly higher than in the placebo group; two men in the T group (and one in the placebo group) had PSA levels >4.0µg/l by the end of the study

14 September 2010

Testosterone reduces fat and increases muscle mass in non-obese men aged ≥55 years

Aging is associated with a reduction in testosterone levels in the blood. This reduction causes a number of symptoms, one of which is losing muscle mass.

This small, well-designed 12-month study looked at the effect of the testosterone patch ( the testosterone patch is not available in South Africa) on body composition and hormones in 60 men aged ≥55 years who were healthy and not obese, and who had low-to-normal testosterone levels and typical testosterone deficiency symptoms.
Last updated: 2018
L.ZA.MKT.GM.10.2016.1381