202 agement of the CKD-MBD. The etiology of vascular disease in CKD is multifactorial and includes traditional risk factors, such as hyperlipidemia, hypertension, and inflammation, as well as alterations in mineral metabolism specific to CKD; thus, treatment is also multifaceted. Lipid lowering agents are effective in reducing cardiac mortality in adults with CKD [117] and in those with stable renal allografts [118], although no benefit from their use has been established in patients treated with maintenance dialysis [119]. Normalization of mineral metabolism, by the avoidance of PTH over-suppression, avoidance of hyper- calcemia, and the maintenance of normal serum phosphorus and the overall calcium × phosphorus product, is essential in all patients with CKD [18]. The limiting of total calcium intake to less than twice the DRI for age, in conjunction with the routine monitoring of biochemical parameters and adjustment of both phosphate binder and vitamin D sterol therapy, is recommended to prevent progressive vascular disease. Evaluation of vascular calcifications in children may be performed by ultrasound of carotid intimal–medial wall thickness [120]. The methodology for coronary electron beam computed tomography (EBCT) and the value of echocardiogram or abdominal X-rays [121], useful in the adult population, have not been well established in children. Questions (answers appear after the references) A 12-year-old boy has come to a pediatrician’s office for a school physical. He wakes up several times at night to urinate. On examination, he is found to be a pale boy with a height and a weight that are both below the third percentile. He has Tanner 1 pubertal development and normal blood pressure. Serum electrolyte concentrations are: sodium 136 mmol/l, potassium 3.8 mmol/l, chloride 108 mmol/l, total CO2 18 mmol/l, blood urea nitrogen (BUN) 40 mg/dl, creatinine of 1.8 mg/dl (stage 3 CKD), phosphorus 4 mg/dl, calcium 9.9 mg/dl, PTH 170 pg/ml, and a hematocrit of 28%. 1. An appropriate serum PTH level for this child with this degree of renal insufficiency is: a. 10–65 pg/ml b. 65–110 pg/ml c. 200–300 pg/ml d. >400 pg/ml 2. Appropriate management of his secondary hyperpara- thyroidism does not include: a. measurement and repletion of 25(OH) vitamin D b. initiation of a calcium-free phosphate binder c. dietary phosphate restriction d. initiation of calcitriol therapy Pediatr Nephrol (2008) 23:195–207 3. Growth hormone therapy should be initiated: a. immediately, to maximize final height potential b. after correction of acidosis, anemia, and secondary hyperparathyroidism c. after the initiation of dialysis d. after successful renal transplantation e. growth hormone therapy is contraindicated in this child 4. An 8-year-old girl presents with reflux nephropathy and growth failure and has the following serum biochemical determinations: serum creatinine 2.5 mg/dl (CKD stage 4), calcium 8.9 mg/dl, phosphorus 6 mg/dl, and PTH 140 pg/ml. The first step in serum phosphorus management is: a. initiation of a non-calcium-containing phosphate binder b. nutritional assessment and phosphate restriction c. vitamin D sterol therapy d. growth hormone therapy 5. A 14-year-old boy with obstructive uropathy and stage 3 CKD has been treated with growth hormone therapy for the past 2 years. His growth velocity has been decreasing over the past 6 months. An indication to stop therapy would be: a. serum PTH level of 150 pg/ml b. height at 50% for age c. Tanner 2 pubertal development d. increasing alkaline phosphatase activity 6: A 10-year-old boy receiving maintenance hemodialysis is treated with calcium carbonate and thrice-weekly calcitriol to control his renal osteodystrophy. His serum PTH level is 700 pg/ml, phosphorus 5 mg/dl and calcium is 11.5 mg/dl. To ameliorate his hypercalcemia, the next step in his therapy should include: a. dietary calcium restriction b. bone biopsy c. switching to a non-calcium-containing phosphate binder d. increasing the calcitriol therapy 7. An 8-year-old girl with reflux nephropathy has stage 3 CKD and a height SD less than the 3rd percentile. Contraindication to starting GH therapy in this patient is: a. serum PTH level of 900 pg/ml b. bone age of 6 years c. weight SD at the 3rd percentile d. recurrent urinary tract infections