Publications by authors named "Renee Miciek"

13 Publications

  • Page 1 of 1

Long-Term Testosterone Supplementation in Older Men Attenuates Age-Related Decline in Aerobic Capacity.

J Clin Endocrinol Metab 2018 08;103(8):2861-2869

Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.

Context: Testosterone increases skeletal muscle mass and strength, but long-term effects of testosterone supplementation on aerobic capacity, or peak oxygen uptake (V̇O2peak), in healthy older men with low testosterone have not been evaluated.

Objective: To determine the effects of testosterone supplementation on V̇O2peak during incremental cycle ergometry.

Design: A double-blind, randomized, placebo-controlled, parallel-group trial (Testosterone's Effects on Atherosclerosis Progression in Aging Men).

Setting: Exercise physiology laboratory.

Participants: Healthy men aged ≥ 60 years with total testosterone levels of 100 to 400 ng/dL (3.5 to 13.9 nmol/L) or free testosterone levels < 50 pg/mL (174 pmol/L).

Interventions: Randomization to 1% transdermal testosterone gel adjusted to achieve serum levels of 500 to 950 ng/dL or placebo applied daily for 3 years.

Main Outcome Measures: Change in V̇O2peak.

Results: Mean (±SD) baseline V̇O2peak was 24.2 ± 5.2 and 23.6 ± 5.6 mL/kg/min for testosterone and placebo, respectively. V̇O2peak did not change in men treated with testosterone but fell significantly in men receiving placebo (average 3-year decrease, 0.88 mL/kg/min; 95% CI, -1.39 to 0.38 mL/kg/min; P = 0.035); the difference in change in V̇O2peak between groups was significant (average 3-year difference, 0.91 mL/kg/min; 95% CI, 0.010 to 0.122 mL/kg/min; P = 0.008). The 1-g/dL mean increase in hemoglobin (P < 0.001) was significantly associated with changes in V̇O2peak in testosterone-treated men.

Conclusion: The mean 3-year change in V̇O2peak was significantly smaller in men treated with testosterone than in men receiving placebo and was associated with increases in hemoglobin. The difference in V̇O2peak change between groups may indicate attenuation of its expected age-related decline; the clinical meaningfulness of the modest treatment effect remains to be determined.
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http://dx.doi.org/10.1210/jc.2017-01902DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6669813PMC
August 2018

Effects of Testosterone Supplementation for 3 Years on Muscle Performance and Physical Function in Older Men.

J Clin Endocrinol Metab 2017 02;102(2):583-593

Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.

Context: Findings of studies of testosterone's effects on muscle strength and physical function in older men have been inconsistent; its effects on muscle power and fatigability have not been studied.

Objective: To determine the effects of testosterone administration for 3 years in older men on muscle strength, power, fatigability, and physical function.

Design, Setting, And Participants: This was a double-blind, placebo-controlled, randomized trial of healthy men ≥60 years old with total testosterone levels of 100 to 400 ng/dL or free testosterone levels <50 pg/mL.

Interventions: Random assignment to 7.5 g of 1% testosterone or placebo gel daily for 3 years.

Outcome Measures: Loaded and unloaded stair-climbing power, muscle strength, power, and fatigability in leg press and chest press exercises, and lean mass at baseline, 6, 18, and 36 months.

Results: The groups were similar at baseline. Testosterone administration for 3 years was associated with significantly greater performance in unloaded and loaded stair-climbing power than placebo (mean estimated between-group difference, 10.7 W [95% confidence interval (CI), -4.0 to 25.5], P = 0.026; and 22.4 W [95% CI, 4.6 to 40.3], P = 0.027), respectively. Changes in chest-press strength (estimated mean difference, 16.3 N; 95% CI, 5.5 to 27.1; P < 0.001) and power (mean difference 22.5 W; 95% CI, 7.5 to 37.5; P < 0.001), and leg-press power were significantly greater in men randomized to testosterone than in those randomized to placebo. Lean body mass significantly increased more in the testosterone group.

Conclusion: Compared with placebo, testosterone replacement in older men for 3 years was associated with modest but significantly greater improvements in stair-climbing power, muscle mass, and power. Clinical meaningfulness of these treatment effects and their impact on disability in older adults with functional limitations remains to be studied.
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http://dx.doi.org/10.1210/jc.2016-2771DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5413164PMC
February 2017

Testosterone Attenuates Age-Related Fall in Aerobic Function in Mobility Limited Older Men With Low Testosterone.

J Clin Endocrinol Metab 2016 Jun 6;101(6):2562-9. Epub 2016 Apr 6.

Research Program in Men's Health: Aging and Metabolism (T.W.S., S.Bh., T.G.T., K.P., J.M., S.Ba.), Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, and Harvard T.H. Chan School of Public Health (R.M.), Boston, Massachusetts 02115; and Hebrew SeniorLife Institute for Aging Research (T.G.T.), Roslindale, Massachusetts 02131.

Context: Testosterone increases skeletal muscle mass and strength, but the effects of testosterone on aerobic performance in mobility-limited older men have not been evaluated.

Objective: To determine the effects of testosterone supplementation on aerobic performance, assessed as peak oxygen uptake (V̇O2peak) and gas exchange lactate threshold (V̇O2θ), during symptom-limited incremental cycle ergometer exercise.

Design: Subgroup analysis of the Testosterone in Older Men with Mobility Limitations Trial.

Setting: Exercise physiology laboratory in an academic medical center.

Participants: Sixty-four mobility-limited men 65 years or older with low total (100-350 ng/dL) or free (<50 pg/dL) testosterone.

Interventions: Participants were randomized to receive 100-mg testosterone gel or placebo gel daily for 6 months.

Main Outcome Measures: V̇O2peak and V̇O2θ from a symptom-limited cycle exercise test.

Results: Mean (SD) baseline V̇O2peak was 20.5 (4.3) and 19.9 (4.7) mL/kg/min for testosterone and placebo, respectively. V̇O2peak increased by 0.83 (2.4) mL/kg/min in testosterone but decreased by -0.89 (2.5) mL/kg/min in placebo (P = .035); between group difference in change in V̇O2peak was significant (P = .006). This 6-month reduction in placebo was greater than the expected -0.4-mL/kg/min/y rate of decline in the general population. V̇O2θ did not change significantly in testosterone but decreased by 1.1 (1.8) mL/kg/min in placebo, P = .011 for between-group comparisons. Hemoglobin increased by 1.0 ± 3.5 and 0.1 ± 0.8 g/dL in testosterone and placebo groups, respectively.

Conclusion: Testosterone supplementation in mobility-limited older men increased hemoglobin and attenuated the age-related declines in V̇O2peak and V̇O2θ. Long-term intervention studies are needed to determine the durability of this effect.
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http://dx.doi.org/10.1210/jc.2015-4333DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4891791PMC
June 2016

Testosterone dose-response relationships in hysterectomized women with or without oophorectomy: effects on sexual function, body composition, muscle performance and physical function in a randomized trial.

Menopause 2014 Jun;21(6):612-23

From the 1Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine and Boston Medical Center, Boston, MA; 2Department of Biostatistics, Boston University School of Public Health, Boston, MA; 3Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Science, Los Angeles, CA; and 4Division of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, Harbor-UCLA Medical Center, University of California, Los Angeles, CA.

Objective: This study aims to determine the dose-dependent effects of testosterone on sexual function, body composition, muscle performance, and physical function in hysterectomized women with or without oophorectomy.

Methods: Seventy-one postmenopausal women who previously underwent hysterectomy with or without oophorectomy and had total testosterone levels less than 31 ng/dL or free testosterone levels less than 3.5 pg/mL received a standardized transdermal estradiol regimen during the 12-week run-in period and were randomized to receive weekly intramuscular injections of placebo or 3, 6.25, 12.5, or 25 mg of testosterone enanthate for 24 weeks. Total and free testosterone levels were measured by liquid chromatography-tandem mass spectrometry and equilibrium dialysis, respectively. The primary outcome was change in sexual function measured by the Brief Index of Sexual Functioning for Women. Secondary outcomes included changes in sexual activity, sexual distress, Derogatis Interview for Sexual Functioning, lean body mass, fat mass, muscle strength and power, and physical function.

Results: Seventy-one women were randomized; five groups were similar at baseline. Sixty-two women with analyzable data for the primary outcome were included in the final analysis. The mean on-treatment total testosterone concentrations were 19, 78, 102, 128, and 210 ng/dL in the placebo, 3-mg, 6.25-mg, 12.5-mg, and 25-mg groups, respectively. Changes in composite Brief Index of Sexual Functioning for Women scores, thoughts/desire, arousal, frequency of sexual activity, lean body mass, chest-press power, and loaded stair-climb power were significantly related to increases in free testosterone concentrations; compared with placebo, changes were significantly greater in women assigned to the 25-mg group, but not in women in the lower-dose groups. Sexual activity increased by 2.7 encounters per week in the 25-mg group. The frequency of androgenic adverse events was low.

Conclusions: Testosterone administration in hysterectomized women with or without oophorectomy for 24 weeks was associated with dose and concentration-dependent gains in several domains of sexual function, lean body mass, chest-press power, and loaded stair-climb power. Long-term trials are needed to weigh improvements in these outcomes against potential long-term adverse effects.
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http://dx.doi.org/10.1097/GME.0000000000000093DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4701202PMC
June 2014

Relationship between poor physical function, inflammatory markers, and comorbidities in HIV-infected women on antiretroviral therapy.

J Womens Health (Larchmt) 2014 Jan 12;23(1):69-76. Epub 2013 Nov 12.

1 Department of Medicine, Division of Infectious Diseases, Drexel University College of Medicine , Philadelphia, Pennsylvania.

Background: HIV-infected individuals may be at increased risk of poor physical function. Chronic inflammation has been associated with decreased physical function in the elderly and may also influence physical function in HIV-infected individuals.

Methods: This cross-sectional study assessed physical function in 65 HIV-infected women aged 40 and older on stable antiretroviral treatment using the Short Physical Performance Battery (SPPB): a standardized test of balance, walking speed, and lower- extremity strength developed for elderly populations. The relationship between low SPPB score, selected demographic and medical characteristics, and high inflammatory biomarker profile was analyzed using Fisher's exact test and Wilcoxon rank sum test.

Results: The median age of subjects was 49 years (interquartile range [IQR] 45-55), and the median CD4 T-cell count was 675 cells/mm(3) (IQR 436-828). Thirteen subjects (20%) had a low SPPB score. Subjects with a low SPPB score were more likely to be cigarette smokers (p=0.03), had more medical comorbidities (p=0.01), and had higher levels of interleukin-6 (IL-6) (p<0.05). They also tended to be older (median age 55 vs. 48, p=0.06), more likely to have diabetes (p=0.07), and have higher levels of soluble tumor necrosis factor-1 (p=0.09).

Conclusions: Twenty percent of women aged 40 and older with well-treated HIV had poor physical-function performance, which was associated with the high burden of comorbidities in this population and with increased IL-6. However, it is unclear from this cross-sectional study whether increased inflammation was related to poor physical function or to other factors, such as age and medical comorbidities.
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http://dx.doi.org/10.1089/jwh.2013.4367DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880911PMC
January 2014

The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral, selective androgen receptor modulator, in healthy young men.

J Gerontol A Biol Sci Med Sci 2013 Jan 28;68(1):87-95. Epub 2012 Mar 28.

Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA 02118, USA.

Background: Concerns about potential adverse effects of testosterone on prostate have motivated the development of selective androgen receptor modulators that display tissue-selective activation of androgenic signaling. LGD-4033, a novel nonsteroidal, oral selective androgen receptor modulator, binds androgen receptor with high affinity and selectivity. Objectives. To evaluate the safety, tolerability, pharmacokinetics, and effects of ascending doses of LGD-4033 administered daily for 21 days on lean body mass, muscle strength, stair-climbing power, and sex hormones.

Methods: In this placebo-controlled study, 76 healthy men (21-50 years) were randomized to placebo or 0.1, 0.3, or 1.0 mg LGD-4033 daily for 21 days. Blood counts, chemistries, lipids, prostate-specific antigen, electrocardiogram, hormones, lean and fat mass, and muscle strength were measured during and for 5 weeks after intervention.

Results: LGD-4033 was well tolerated. There were no drug-related serious adverse events. Frequency of adverse events was similar between active and placebo groups. Hemoglobin, prostate-specific antigen, aspartate aminotransferase, alanine aminotransferase, or QT intervals did not change significantly at any dose. LGD-4033 had a long elimination half-life and dose-proportional accumulation upon multiple dosing. LGD-4033 administration was associated with dose-dependent suppression of total testosterone, sex hormone-binding globulin, high density lipoprotein cholesterol, and triglyceride levels. follicle-stimulating hormone and free testosterone showed significant suppression at 1.0-mg dose only. Lean body mass increased dose dependently, but fat mass did not change significantly. Hormone levels and lipids returned to baseline after treatment discontinuation.

Conclusions: LGD-4033 was safe, had favorable pharmacokinetic profile, and increased lean body mass even during this short period without change in prostate-specific antigen. Longer randomized trials should evaluate its efficacy in improving physical function and health outcomes in select populations.
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http://dx.doi.org/10.1093/gerona/gls078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111291PMC
January 2013

Effect of testosterone supplementation with and without a dual 5α-reductase inhibitor on fat-free mass in men with suppressed testosterone production: a randomized controlled trial.

JAMA 2012 Mar;307(9):931-9

Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine and Boston Medical Center, 670 Albany St, Boston, MA 02118, USA.

Context: Steroid 5α-reductase inhibitors are used to treat benign prostatic hyperplasia and androgenic alopecia, but the role of 5α-dihydrotestosterone (DHT) in mediating testosterone's effects on muscle, sexual function, erythropoiesis, and other androgen-dependent processes remains poorly understood.

Objective: To determine whether testosterone's effects on muscle mass, strength, sexual function, hematocrit level, prostate volume, sebum production, and lipid levels are attenuated when its conversion to DHT is blocked by dutasteride (an inhibitor of 5α-reductase type 1 and 2).

Design, Setting, And Patients: The 5α-Reductase Trial was a randomized controlled trial of healthy men aged 18 to 50 years comparing placebo plus testosterone enthanate with dutasteride plus testosterone enanthate from May 2005 through June 2010.

Interventions: Eight treatment groups received 50, 125, 300, or 600 mg/wk of testosterone enanthate for 20 weeks plus placebo (4 groups) or 2.5 mg/d of dutasteride (4 groups).

Main Outcome Measures: The primary outcome was change in fat-free mass; secondary outcomes: changes in fat mass, muscle strength, sexual function, prostate volume, sebum production, and hematocrit and lipid levels.

Results: A total of 139 men were randomized; 102 completed the 20-week intervention. Men assigned to dutasteride were similar at baseline to those assigned to placebo. The mean fat-free mass gained by the dutasteride groups was 0.6 kg (95% CI, -0.1 to 1.2 kg) when receiving 50 mg/wk of testosterone enanthate, 2.6 kg (95% CI, 0.9 to 4.3 kg) for 125 mg/wk, 5.8 kg (95% CI, 4.8 to 6.9 kg) for 300 mg/wk, and 7.1 kg (95% CI, 6.0 to 8.2 kg) for 600 mg/wk. The mean fat-free mass gained by the placebo groups was 0.8 kg (95% CI, -0.1 to 1.7 kg) when receiving 50 mg/wk of testosterone enanthate, 3.5 kg (95% CI, 2.1 to 4.8 kg) for 125 mg/wk, 5.7 kg (95% CI, 4.8 to 6.5 kg) for 300 mg/wk, and 8.1 kg (95% CI, 6.7 to 9.5 kg) for 600 mg/wk. The dose-adjusted differences between the dutasteride and placebo groups for fat-free mass were not significant (P = .18). Changes in fat mass, muscle strength, sexual function, prostate volume, sebum production, and hematocrit and lipid levels did not differ between groups.

Conclusion: Changes in fat-free mass in response to graded testosterone doses did not differ in men in whom DHT was suppressed by dutasteride from those treated with placebo, indicating that conversion of testosterone to DHT is not essential for mediating its anabolic effects on muscle.

Trial Registration: clinicaltrials.gov Identifier: NCT00493987.
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http://dx.doi.org/10.1001/jama.2012.227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6035750PMC
March 2012

Muscle function, physical performance and body composition changes in men with prostate cancer undergoing androgen deprivation therapy.

Asian J Androl 2012 Mar 27;14(2):204-21. Epub 2012 Feb 27.

Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA 02118, USA.

Prostate cancer (PCa) is the most common visceral malignancy in men with androgen deprivation therapy (ADT) the preferred therapy to suppress testosterone production and hence tumor growth. Despite its effectiveness in lowering testosterone, ADT is associated with side effects including loss of muscle mass, diminished muscle strength, decrements in physical performance, earlier fatigue and declining quality of life. This review reports a survey of the literature with a focus on changes in muscle strength, physical function and body composition, due to short-term and long-term ADT. Studies in these areas are sparse, especially well-controlled, prospective randomized trials. Cross-sectional and longitudinal data (up to 2 years) for men with PCa treated with ADT as well as patients with PCa not receiving ADT and age-matched healthy men are presented when available. Based on limited longitudinal data, the adverse effects of ADT on muscle function, physical performance and body composition occur shortly after the onset of ADT and tend to persist and worsen over time. Exercise training is a safe and effective intervention for mitigating these changes and initial guidelines for exercise program design for men with PCa have been published by the American College of Sports Medicine. Disparities in study duration, types of studies and other patient-specific variables such as time since diagnosis, cancer stage and comorbidities may all affect an understanding of the influence of ADT on health, physical performance and mortality.
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http://dx.doi.org/10.1038/aja.2011.104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3735097PMC
March 2012

Clinical meaningfulness of the changes in muscle performance and physical function associated with testosterone administration in older men with mobility limitation.

J Gerontol A Biol Sci Med Sci 2011 Oct 22;66(10):1090-9. Epub 2011 Jun 22.

Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine and Boston Medical Center, 670 Albany Street, Boston, MA 02118, USA.

Context: Testosterone in Older Men with Mobility Limitations Trial determined the effects of testosterone on muscle performance and physical function in older men with mobility limitation. Trial's Data and Safety Monitoring Board recommended enrollment cessation due to increased frequency of adverse events in testosterone arm. The changes in muscle performance and physical function were evaluated in relation to participant's perception of change.

Methods: Men aged 65 years and older, with mobility limitation, total testosterone 100-350 ng/dL, or free testosterone less than 50 pg/mL, were randomized to placebo or 10 g testosterone gel daily for 6 months. Primary outcome was leg-press strength. Secondary outcomes included chest-press strength, stair-climb, 40-m walk, muscle mass, physical activity, self-reported function, and fatigue. Proportions of participants exceeding minimally important difference in study arms were compared.

Results: Of 209 randomized participants, 165 had follow-up efficacy measures. Mean (SD) age was 74 (5.4) years and short physical performance battery score 7.7 (1.4). Testosterone arm exhibited greater improvements in leg-press strength, chest-press strength and power, and loaded stair-climb than placebo. Compared with placebo, significantly greater proportion of men receiving testosterone improved their leg-press and chest-press strengths (43% vs 18%, p = .01) and stair-climbing power (28% vs 10%, p = .03) more than minimally important difference. Increases in leg-press strength and stair-climbing power were associated with changes in testosterone levels and muscle mass. Physical activity, walking speed, self-reported function, and fatigue did not change.

Conclusions: Testosterone administration in older men with mobility limitation was associated with patient-important improvements in muscle strength and stair-climbing power. Improvements in muscle strength and only some physical function measures should be weighed against the risk of adverse events in this population.
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http://dx.doi.org/10.1093/gerona/glr100DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3202898PMC
October 2011

Habitual physical activity levels are associated with performance in measures of physical function and mobility in older men.

J Am Geriatr Soc 2010 Sep 24;58(9):1727-33. Epub 2010 Aug 24.

Laboratory of Exercise Physiology and Physical Performance, Section of Endocrinology, Diabetes, and Nutrition, School of Medicine, Boston University, Boston, Massachusetts, USA.

Objectives: To determine whether objectively measured physical activity levels are associated with physical function and mobility in older men.

Design: Cross-sectional.

Setting: Academic research center.

Participants: Eighty-two community-dwelling men aged 65 and older with self-reported mobility limitations were divided into a low-activity and a high-activity group based on the median average daily physical activity counts of the whole sample.

Measurements: Physical activity according to triaxial accelerometers; physical function and mobility according to the Short Physical Performance Battery (SPPB), gait speed, stair climb time, and a lift-and-lower task; aerobic capacity according to maximum oxygen consumption (VO(2) max); and leg press and chest press maximal strength and peak power.

Results: Older men with higher physical activity levels had a 1.4-point higher mean SPPB score and a 0.35-m/s faster walking speed than those with lower physical activity levels. They also climbed a standard flight of stairs 1.85 seconds faster and completed 60% more shelves in a lift-and-lower task (all P<.01); muscle strength and power measures were not significantly different between the low- and high-activity groups. Correlation analyses and multiple linear regression models showed that physical activity is positively associated with all physical function and mobility measures, leg press strength, and VO(2) max.

Conclusion: Older men with higher physical activity levels demonstrate better physical function and mobility than their less-active peers. Moreover, physical activity levels are predictive of performance in measures of physical function and mobility in older men. Future work is needed to determine whether modifications in physical activity levels can improve or preserve physical performance in later life.
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http://dx.doi.org/10.1111/j.1532-5415.2010.03012.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2945416PMC
September 2010

Adverse events associated with testosterone administration.

N Engl J Med 2010 Jul 30;363(2):109-22. Epub 2010 Jun 30.

Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts 02118, USA.

Background: Testosterone supplementation has been shown to increase muscle mass and strength in healthy older men. The safety and efficacy of testosterone treatment in older men who have limitations in mobility have not been studied.

Methods: Community-dwelling men, 65 years of age or older, with limitations in mobility and a total serum testosterone level of 100 to 350 ng per deciliter (3.5 to 12.1 nmol per liter) or a free serum testosterone level of less than 50 pg per milliliter (173 pmol per liter) were randomly assigned to receive placebo gel or testosterone gel, to be applied daily for 6 months. Adverse events were categorized with the use of the Medical Dictionary for Regulatory Activities classification. The data and safety monitoring board recommended that the trial be discontinued early because there was a significantly higher rate of adverse cardiovascular events in the testosterone group than in the placebo group.

Results: A total of 209 men (mean age, 74 years) were enrolled at the time the trial was terminated. At baseline, there was a high prevalence of hypertension, diabetes, hyperlipidemia, and obesity among the participants. During the course of the study, the testosterone group had higher rates of cardiac, respiratory, and dermatologic events than did the placebo group. A total of 23 subjects in the testosterone group, as compared with 5 in the placebo group, had cardiovascular-related adverse events. The relative risk of a cardiovascular-related adverse event remained constant throughout the 6-month treatment period. As compared with the placebo group, the testosterone group had significantly greater improvements in leg-press and chest-press strength and in stair climbing while carrying a load.

Conclusions: In this population of older men with limitations in mobility and a high prevalence of chronic disease, the application of a testosterone gel was associated with an increased risk of cardiovascular adverse events. The small size of the trial and the unique population prevent broader inferences from being made about the safety of testosterone therapy. (ClinicalTrials.gov number, NCT00240981.)
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http://dx.doi.org/10.1056/NEJMoa1000485DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440621PMC
July 2010

Effects of testosterone therapy on muscle performance and physical function in older men with mobility limitations (The TOM Trial): design and methods.

Contemp Clin Trials 2009 Mar 29;30(2):133-40. Epub 2008 Oct 29.

Department of Medicine, Boston University Medical Center, Boston, MA 02118, United States.

The TOM study is the first, single-site, placebo-controlled, randomized clinical trial designed to comprehensively determine the effects of testosterone administration on muscle strength and physical function in older men with mobility limitations. A total of 252 community dwelling individuals aged 65 and older with low testosterone levels and self-reported limitations in mobility and short physical performance battery (SPPB) scores between 4 and 9 will be randomized to receive either placebo or testosterone therapy for 6 months. The primary objective is to determine whether testosterone therapy improves maximal voluntary muscle strength as quantified by the one repetition maximum. Secondary outcomes will include measures of physical function (walking, stair climbing and a lifting and lowering task), habitual physical activity and self-reported disability. The effects of testosterone on affect, fatigue and sense of well being will also be assessed. Unique aspects of the TOM Trial include selection of men with self-reported as well as objectively demonstrable functional limitations, community-based screening and recruitment, adjustment of testosterone dose to ensure serum testosterone levels in the target range while maintaining blinding, and inclusion of a range of self-reported and performance-based physical function measures as outcomes. Clinicaltrials.gov identifier: NCT00240981.
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http://dx.doi.org/10.1016/j.cct.2008.10.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3031114PMC
March 2009

Tests of muscle strength and physical function: reliability and discrimination of performance in younger and older men and older men with mobility limitations.

J Am Geriatr Soc 2008 Nov 22;56(11):2118-23. Epub 2008 Sep 22.

Section of Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.

Objectives: To compare the reliability of muscle strength and physical function measures in younger and older men.

Design: Cross-sectional.

Setting: Academic research center.

Participants: Thirty younger men, 31 older men, and 39 older men with mobility limitations.

Measurements: Test-retest measures of one repetition maximum (1 RM), unloaded and loaded 50-m walk and stair climb, and a lift-and-lower task. Reliability was assessed using intraclass correlation (ICC) analysis and the Bland-Altman method.

Results: Leg and chest press 1 RM measures identified significant differences between the groups, exhibited excellent test-retest reliability in younger men, older men, and older men with mobility limitations (ICCs=0.946-0.994) and minimal bias between Trials 1 and 2 (Bland-Altman=improvement of 21.1 and 1.1 N for leg and chest press, respectively). Test-retest measures of the time to walk 50 m and climb 12 steps also demonstrated excellent agreement (ICCs=0.980-0.988 and 0.942-992, respectively) and minimal bias (Bland-Altman=0.755-1.007 and 0.141-0.361 seconds faster, respectively). When a subject repeated these measures carrying a modest load, ICCs remained greater than 0.940, bias was similar, and the tests better discriminated between the groups. The lift-and-lower measure demonstrated excellent agreement (ICCs=0.925-0.947) and minimal bias (1.4-2.9 more shelves) and revealed significant differences between groups.

Conclusion: Measures of muscle strength and physical function can be performed in younger men, older men, and older men with mobility limitations with high reliability. In future clinical trials, more-challenging measures of performance may better discriminate between higher-functioning study participants.
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http://dx.doi.org/10.1111/j.1532-5415.2008.01953.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3031449PMC
November 2008
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