Functional deterioration and selenium-vitamin E treatment in myotonic dystrophy. A placebo-controlled study

Abstract

Objectives: The aim of the investigations was to study the effect of a combined selenium and vitamin E treatment in patients with myotonic dystrophy.

Design: A double-blind placebo-controlled trial.

Subjects: Twenty-seven patients with myotonic dystrophy divided into an experimental (n = 13) and a control (n = 14) group.

Interventions: The experimental group was given increasing doses for 4 months up to a maximum of 1.6 mg selenium and 800 mg vitamin E daily and the control group a corresponding number of placebo tablets. The total treatment period was 2 years.

Main outcome measures: Muscle strength (knee extension, knee flexion, hand-grip), maximal walking speed for 30 m, function in daily activities (disability), well-being and cognitive functioning.

Results: Before treatment, muscle strength showed moderately or markedly reduced values as did maximal walking speed. Disability was most markedly demonstrated in instrumental ADL-activities. Spatial ability was reduced in the majority of patients. During the 2-year follow-up period, the hand-grip strength and maximal walking speed decreased in both groups (P < 0.01). The reduction was not significantly different according to an 'intention-to-treat-analysis'. However, there was a significantly larger decline (P < 0.01) in the left-hand grip strength in the control group when all the patients with complete treatment compliance were included.

Conclusions: A useful set of measurements has been developed for following functional deterioration in myotonic dystrophy. No conclusive evidence of beneficial effects of selenium and vitamin E treatment has been produced.