Background: Myotonic dystrophy type 1 may be associated with low circulating dehydroepiandrosterone (DHEA) levels. This study was aimed at investigating the efficacy and safety of DHEA in myotonic dystrophy type 1 patients.
Methods: This was a prospective, multicenter, randomized, double-blind, placebo-controlled trial conducted from February 2005 to January 2006 at 10 university-affiliated neuromuscular disease centers in France. Seventy-five ambulatory adults with myotonic dystrophy type 1 received an oral replacement dose (100 mg/d) or a pharmacologic dose (400 mg/d) of DHEA, or placebo. The primary endpoint was the relative change in the manual muscle testing (MMT) score from baseline to week 12. Secondary outcome measures included changes from baseline to week 12 in quantitative muscle testing and timed functional testing, respiratory and cardiac function, and quality of life. This study was registered with ClinicalTrials.gov identifier NCT00167609.
Results: The median (1st, 3rd quartile) relative changes in MMT score from baseline to week 12 after randomization were 3.1 (-0.9, 6.7), 1.9 (-2.7, 3.5), and 2.2 (0, 7.9), in the DHEA 100 mg, DHEA 400 mg, and placebo groups, respectively. There were no differences between placebo and combined DHEA groups (p = 0.34), placebo and DHEA 100 mg (p = 0.86), or placebo and DHEA 400 mg (p = 0.15). There were also no evidence for a difference between groups for the changes from baseline to week 12 in any secondary outcome.
Conclusions: There is no evidence that a 12-week treatment with replacement or pharmacologic doses of dehydroepiandrosterone improves muscle strength in ambulatory myotonic dystrophy type 1 patients.