Circulating biochemical markers of bone remodeling in uremic patients

Abstract

Chronic renal failure is often associated with bone disorders, including secondary hyperparathyroidism, aluminum-related low-turnover bone disease, osteomalacia, adynamic osteopathy, osteoporosis, and skeletal beta2-microglobulin amyloid deposits. In spite of the enormous progress made during the last few years in the search of noninvasive methods to assess bone metabolism, the distinction between high- and low-turnover bone diseases in these patients still frequently requires invasive and/or costly procedures such as bone biopsy after double tetracycline labeling, scintigraphic-scan studies, computed tomography, and densitometry. This review is focused on the diagnostic value of several new serum markers of bone metabolism, including bone-specific alkaline phosphatase (bAP), procollagen type I carboxy-terminal extension peptide (PICP), procollagen type I cross-linked carboxy-terminal telopeptide (ICTP), pyridinoline (PYD), osteocalcin, and tartrate-resistant acid phosphatase (TRAP) in patients with chronic renal failure. Most of the observations made by several groups converge to the conclusion that serum bAP is the most sensitive and specific marker to evaluate the degree of bone remodeling in uremic patients. Nonetheless, PYD and osteocalcin, in spite of their retention and accumulation in the serum of renal insufficient patients, are also excellent markers of bone turnover. The future generalized use of these markers, individually or in combination with other methods, will undoubtedly improve the diagnosis and the treatment of the complex renal osteodystrophy.

Indicações de paratireoidectomia no hiperparatireoidismo secundário à insuficiência renal crônica

“…A menor prevalência foi encontrada nos pacientes que mantinham PTH aproximadamente 1 a 3 vezes o limite superior do valor de referência (81). Assim, valores de PTH acima de 3 vezes o normal associado a níveis de fosfatase alcalina elevados são considerados preditores de HPT, enquanto a doença adinâmica do osso é mais comum em pacientes com PTH menores que 2 vezes o limite superior e com valores não elevados de fosfatase alcalina (82,83).…”

Associations of Serum Skeletal Alkaline Phosphatase with Elevated C-Reactive Protein and Mortality

“…Skeletal AP is produced exclusively by osteoblasts and plays an important role in bone mineralization by hydrolysis of pyrophosphate (9). Skeletal and liver AP isoenzymes differ only by post-translational glycosylation (10).…”

The need for a reliable bone biomarker to better assess chronic kidney disease mineral and bone disorder

“…Total AP is a poor marker of bone turnover, since it is comprised of six AP isoenzymes i.e. hepatic, intestinal, skeletal, renal, placental and tumoral (12)(13)(14). Osteocalcin is the most abundant non-collagen protein of the bone matrix and human osteocalcin is produced by osteoblasts and odontoblasts under the control of 1, 25-(OH)2 D. There is a good correlation between osteocalcin and bone turnover in normal individuals, premenopausal women and osteoporotic women, but not in uremic patients since osteocalcin accumulates in the plasma in patients with renal failure (15).…”