No abstract

In a retrospective investigation growth and pubertal development were evaluated in 30 patients with nephropathic cystinosis. Growth was investigated during the stage of chronic renal insufficiency as well as after successful kidney transplantation and growth rates were related to kidney function. Pubertal development was evaluated in 17 patients between 12 and 25 years of age. Prepubertal growth rates were stable in a range between -2 and -3 height velocity SDS as long as glomerular filtration rate was above 20ml/min per 1.73m2. A decrease in glomerular filtration rate below this threshold was followed by further decrease in height velocity. After kidney transplantation a significant catch-up growth was seen if immunosuppression was performed with cyclosporine A and low dose prednisolone. This did not occur if conventional therapy with azathioprine and high-dose prednisolone was used. Onset of puberty was delayed in all patients. Gonadotropin and oestradiol levels in female patients showed normal fluctuations according to ovulatory cycles. In male patients after puberty there was an increase in gonadotropin levels above the normal range for adult men while testosterone levels remained in the low normal range. These results indicate that adult men with nephropathic cystinosis may develop hypergonadotropic hypogonadism.

Physical working capacity and cardiovascular response to graded exercise on a bicycle ergometer were investigated in 70 children and adolescents (33F, 37M) after renal transplantation. Results of static and dynamic lung function tests were within the normal range in all patients. Systolic blood pressure, heart rate, pulmonary ventilation and oxygen uptake increased with workload and returned to pre-exercise levels after 5 m of rest. During exercise, blood pressure values were within the normal range in almost all patients. The increase in heart rate and respiratory frequency was blunted in patients receiving beta blocking agents. Maximum workloads (Wmax) were 2.00 +/- 0.48 W/kg in females and 2.38 +/- 0.54 W/kg in males, which are 78 +/- 18% and 84 +/- 18% of the normal values predicted for age. Maximum oxygen consumption (VO2max) was 23.2 +/- 5.8 ml/min/kg in females and 28.3 +/- 5.8 ml/min/kg in males. Half of the patients had height below the third percentile. For this reason exercise capacity in relation to height is probably a more relevant parameter than age. Using actual height, Wmax was 102 +/- 20% and 102 +/- 29%, and VO2max 74 +/- 14% and 80 +/- 18% of predicted values, respectively. We conclude that the adaption of the cardiovascular and respiratory system to graded exercise was influenced by beta blocking agents. Wmax and VO2max were significantly reduced for age in pediatric patients after renal transplantation. Wmax was normal, but VO2max was still reduced if corrected for height.

Patients with congenital cyanotic heart disease may develop a glomerulopathy with proteinuria and impaired renal function. In order to investigate this problem we conducted a study on 27 patients with uncorrected cyanotic heart disease who were between 1 day and 25 years old. As a consequence of hypoxaemia haematocrit was elevated to 57%. Proteinuria was above 150 mg/day/1.73 m2 body surface in 12 patients. Only one of 9 children under 10 years of age had pathological proteinuria presenting as isolated albuminuria. Seven out of 10 patients between 11 and 20 years had an elevated proteinuria with a glomerular pattern. Creatinine clearance was normal in these patients. All four patients above 20 years of age had a considerable glomerular proteinuria with a mean excretion of 5.7 g/24 h/1.73 m2 body surface. These patients suffered additionally from chronic cardiac failure and creatinine clearance was below the normal range. There was a clear relationship between pathological proteinuria and age of the patients and thus duration of hypoxaemia. Patients with pathological proteinuria had a significant higher erythrocyte count (7.3 +/- 1.3 vs 5.6 +/- 1.4 10(12)/l p less than 0.01) and a lower mean corpuscular haemoglobin. In summary, children with persistent congenital cyanotic heart disease have substantial risk of developing a glomerulopathy if the cyanosis remains unchanged for more than ten years.