The subjects will receive treatment with recombinant human GH (Genotropin®) or placebo administered by a daily s.c. injection before bedtime. The initial dose of GH will be 0.4 IU per day increased to 0.8 IU after 2 weeks and to 1.2 IU after 4 weeks of treatment. Thus, the target dose is 1.2 IU per day which resembles approximately 0.015 IU/kg/day. The GH dose will be reduced by half in the event of side-effects. Oral and written instructions in terms of administration and dosage will be given.