The relationship between apelin and parathyroid hormone in hemodialysis patients.
Both apelin and parathyroid hormone (PTH) are endogenous ligands for G-protein-coupled receptors. Apelin acts as a mitogenic agent for osteoblasts, and metabolic bone abnormalities are frequently seen in hemodialysis (HD) patients because of hyperparathyroidism. The aim of this study was to analyze plasma apelin levels in HD patients and to determine whether they are related to PTH concentrations. A total of 23 HD patients [15 men and 8 women, with a mean (SD) age of 54.2 (4.4) years and a mean body mass index (BMI) of 25.0 (4.1) kg/m(2)] were studied and compared with 15 healthy subjects [6 men and 9 women, with a mean (SD) age of 51.3 (13.6) years and a BMI of 27.0 (4.3) kg/m(2)]. Plasma apelin-36 was measured using an enzyme immunometric assay method and PTH was measured by ELISA. There was no significant difference in apelin levels between the patients [0.80 (0.6) ng/mL] and the healthy subjects [0.83 (0.23) ng/mL]. There was a positive correlation between apelin and PTH (r = 0.66, p = 0.0001). The patients with PTH >300 pg/mL had significantly higher plasma apelin levels [1.17 (0.7) ng/mL] compared with the patients with PTH <300 pg/mL [0.50 (0.15) ng/mL] (p = 0.003). In conclusion, HD patients with secondary hyperparathyroidism have high plasma apelin levels, which suggest that apelin may protect bone in HD patients by acting as an osteoblastic factor.
Department of Clinical Nutrition, Nutrition Faculty, Fluminense Federal University (UFF), Niterói, Rio de Janeiro, Brazil.
Denise
D
Mafra
Julie C
JC
Lobo
Najla E
NE
Farage
Milena B
MB
Stockler-Pinto
Viviane O
VO
Leal
Antonio
A
Calixto
Bruno
B
Geloneze
D000073861:Apelin; D015519:Bone Density / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood* / Q000209:etiology; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D012016:Reference Values; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy
C115436:APLN protein, human; D000073861:Apelin; D036341:Intercellular Signaling Peptides and Proteins; D010281:Parathyroid Hormone