A 64-year-old woman comes to her nephrologist for a regular follow-up appointment. The patient's medical problems include diabetes mellitus for 20 years and stage IV chronic kidney disease with a glomerular filtration rate

Question

A 64-year-old woman comes to her nephrologist for a regular follow-up appointment. The patient's medical problems include diabetes mellitus for 20 years and stage IV chronic kidney disease with a glomerular filtration rate <30 mL/min. She takes daily insulin and has made lifestyle modifications. Recently, her blood glucose has been well controlled. The patient's other medical problems include hypertension and dyslipidemia, which are controlled with medication. Her BMI is 27 kg/m². Cardiopulmonary examination is normal. Lower extremity examination shows trace bilateral edema and 2+ pulses. This patient is at greatest risk for which of the following long-term complications of her renal disease?

Quizplus · Accepted Answer

11ec160b_3a2f_9207_9249_a13df693f447_MD0001_00 The abnormal bone pathology seen in chronic kidney disease (CKD) is referred to as renal osteodystrophy. In CKD, failure of glomerular and tubular function results in hyperphosphatemia and hypocalcemia. The parathyroid gland is sensitive to small changes in serum calcium; as a result, the hypocalcemia caused by CKD stimulates parathyroid hormone (PTH) production, leading to secondary hyperparathyroidism (Choice C). PTH mobilizes calcium from bones by activating osteoclastic and osteocytic activity. This high-turnover osteodystrophy increases bone resorption more than bone formation, causing osteopenia and pathologic bone changes similar to those seen in primary hyperparathyroidism (osteitis fibrosa cystica). Patients can also develop PTH resistance, resulting in low-turnover adynamic bone disease and osteomalacia. Deranged signaling between renal cells and bone osteoblasts and osteoclasts (eg, FGF-23, Klotho) also contributes to the skeletal changes that occur in CKD. (Choice A) CKD generally results in hypocalcemia. However, excessive use of calcium-containing phosphate binders or dialysis solutions high in calcium can cause hypercalcemia in some patients. (Choice B) Renal failure results in accumulation of uremic toxins. Uremia has been shown to decrease peripheral tissue conversion of T4 to T3. This could cause functional hypothyroidism (not hyperthyroidism). (Choice E) Patients with diabetic nephropathy should be screened for diabetic retinopathy. Retinopathy is a complication of diabetes, not chronic renal failure or hemodialysis. Educational objective: Patients with chronic kidney disease may develop renal osteodystrophy from secondary hyperparathyroidism (caused by hyperphosphatemia and hypocalcemia). __________ References: Metabolic disorders in patients with chronic kidney failure. (http://www.ncbi.nlm.nih.gov/pubmed/17298212) Treatment of secondary hyperparathyroidism in haemodialysis patients: a randomised clinical trial comparing paricalcitol and alfacalcidol. (http://www.ncbi.nlm.nih.gov/pubmed/19778452) Hyperphosphatemia of chronic kidney disease. (http://www.ncbi.nlm.nih.gov/pubmed/18449174)

A 64-Year-Old Woman Comes to Her Nephrologist for a Regular