T.P.3.03 Long-term, low-dosage, early steroid therapy in Duchenne muscular dystrophy prolongs ambulation and preserves respiratory and cardiac function. 13 years follow-up

Duchenne muscular dystrophy (DMD) is an incurable disease of childhood. In the natural history course of DMD, loss of walking ability at the mean age of 9.5 years (range 6–13) is followed by restrictive respiratory syndrome, cardiomyopathy, and eventually death. The major aim of steroids in the ambulant phase of DMD is to prolong the ability to walk. RCT have shown that steroids improved muscle strength and function for six months to two years, but the overall long-term benefit remains unclear, and has to be weighed against the long-term side effects of steroids. In 1996 we started a prospective long-term open, parallel group, double consent trial of low-dosage prednisone in five early cases of DMD. Prednisone was given 0.75 mg/kg for 2 weeks, then, 1.25 mg/kg on alternate days. Ability to rise from the floor was prolonged comparing with the three controls. Four of the boys on prednisone could be followed up regularly for 13 years. At the last control (mean age 15.8 ± 1.2 years) the four boys could walk independently. One, aged 17 years, lost the ability to rise from the floor at 12 years, and to climb stairs at 16 years. Another one, aged 16.9 years lost the ability to rise from the floor at 15.8 years. Forced vital capacity ranged from 80 to 104 percent of predicted. All had a left ventricular ejection fraction of more than 50% indicating absence of cardiomyopathy. Bone mineral density assessed by dual energy X-ray absorptiometery (DEXA) scans ranged from 0.637 to 0.704 g/cm2. While body mass index was normal (22 ± 2.3), total fat % was 50 ± 6.1 as determined by DEXA total body. Growth failure with short stature was present in all with decline below the third centile from the age of 12 years. Cataracts was not observed.