Randomized controlled trial of testosterone in myotonic dystrophy

Abstract

Because testosterone has an anabolic effect in myotonic dystrophy, we conducted a 12-month, randomized, double-blind therapeutic trial of testosterone enanthate (3 mg/kg/wk) in 40 men with myotonic dystrophy. We evaluated strength by manual muscle tests, quantitative myometry, pulmonary function, and quantitative functional assessment. A sustained, significant elevation of testosterone levels was produced but there was no effect on any measurement of muscle strength. Muscle mass as estimated by creatinine excretion and lean body mass (40K method) increased significantly. We conclude that testosterone does not improve strength in myotonic dystrophy despite increasing muscle mass.

Computerized hand grip myometry reliably measures myotonia and muscle strength in myotonic dystrophy (DM1)

“…The muscles were tested in specific positions including sitting, supine, prone, and side lying and each graded on a modification of the Medical Research Council scale (0 to 5) to construct a composite MMT WholeBody Strength score as previously reported. 5,17 Statistical Analysis. We averaged the three RT measurements and PF measurements for each individual on each day of testing.…”

Effects of Supraphysiologic Doses of Testosterone on Mood and Aggression in Normal Men

“…6,[24][25][26] Experimental treatment studies avoid such limitations but ethically cannot use highly supraphysiologic doses of AAS approaching those used illicitly. Endocrinologic, 27,28 physiological, [29][30][31] and medical [32][33][34] studies have typically used at most 300 mg/wk of testosterone [27][28][29][30][31][32][33][34] or nandrolone 29 and have noted few psychiatric effects. However, 3 recent laboratory studies have used higher doses: 2 reported occasional manic or hypomanic reactions in participants administered methyltestosterone 35 or testosterone, 36 whereas a third study using testosterone did not.…”

Hypogonadism in DM1 and its relationship to erectile dysfunction

“…Testosterone has already been tried in muscular dystrophy and, in particular, in DM1. Experimental trials, in which sexual function was not however tested, have shown that weekly T administration in DM1 increases the muscle protein synthesis rate in DM1 [25] as well as the basal metabolic rate and lean body mass in healthy men and in men with muscular dystrophy (DM1, facioscapulohumeral and limb girdle dystrophy) [26], but has no effect on muscle strength in DM1 [27]. Moreover, the use of T to enhance strength and muscle mass has been considered not only in hypogonadal [28] and aging men [29] but also in glucocorticoid induced myopathy [30,31] and in HIV and cancer-related skeletal muscle loss and wasting [32,33].…”

“…Although T supplementation is, on the basis of the results of a previous randomized trial [27], unlikely to have a therapeutic effect on muscle strength in DM1, it should be considered to treat ED as it may improve the sexual life in such patients. Further studies are warranted to investigate the potential utility of T supplementation in the sexual life of DM1 patients.…”