Unresolved problems concerning optimal therapy of puberty in children withchronic renal diseases

Many children with chronic renal insufficiency (CRI) show growth retardatio n and severely delayed pubertal development. Successful renal transplantati on (RTx) also rarely results in full growth rehabilitation. Pubertal height gain in CRI patients is only 58% and 48% of that observed in late-maturing boys and girls, respectively. Growth retardation in both CRI and RTx patie nts is not the result of abnormal GH secretion or decreased levels of IGF-I , but rather of elevated levels of IGFBPs inhibiting the bioavailability of the IGFs. In RTx patients prednisone may also inhibit growth directly via inhibition of bone matrix formation. Several studies have convincingly show n that GH therapy at a dose of 4 IU/m(2)/day results in a sustained improve ment of growth in prepubertal and pubertal children with CRI and in growth- retarded prepubertal and pubertal post-transplant patients. The following consensus was reached concerning optimal therapy of puberty i n children with chronic renal disease. GH therapy does not lead to an earli er start of puberty. It is safe to give GH to RTx patients if transplant fu nction is stable. GH therapy will not accelerate bone maturation and can im prove the final height of children with CRI and after RTx. Increasing the G H dose above 4 IU/m(2)/day in pubertal RTx patients does not increase heigh t gain or final height and is not advised as it may increase insulin resist ance. GH should best be started before the start of the pubertal growth spu rt but will still be effective in RTx patients with advanced bone age. GH t esting should not be a prerequisite for starting GH therapy. It is importan t to optimise other therapies during puberty. During GH therapy of RTx pati ents use minimum daily, not alternate-day, steroid dosing. Further research is still required on the possible long-term effects of GH therapy in child ren with chronic diseases. Two studies demonstrated improved long-term grow th and final height within the target height range, without significant sid e effects. Renal graft function did not deteriorate more than in matched co ntrols. A GH dose of 4 IU/m(2)/day proved adequate.