Serum concentration of 1-84 (cyclase-activating) and 7-84 (cyclase-inhibiting) parathormone in elderly women with low mineral density of the trabecular bone.
BACKGROUND
Ageing may cause an increase in parathormone (PTH) secretion and, subsequently, increased bone resorption and osteoporosis. In recent years two subfractions of PTH have been discovered: cyclase-activating (1-84, CAP) and cyclase-inhibiting (7-84, CIP) PTH. It is not known however, whether these may play a role in the pathogenesis of bone loss in elderly subjects.


METHODS
Sixty elderly women were examined, of whom 29 had a T-score of the ultradistal radius < -2.5 (median age 75 [70-80] years, BMI 25 [20.6-33.8] kg/m(2), creatinine clearance 59.9 [39.2-94.9] ml/min/1.73m(2), serum Ca 2.4 [2.2-2.6] mmol/l), while 31 had a T-score > -2.5 (median age 73 [70-86] years, BMI 26.2 [18.8-32.5] kg/m(2), creatinine clearance 54.8 [23-119.2] ml/min/1.73m(2), serum Ca 2.4 [2.2-2.6] mmol/l). Median bone mineral density (BMD) (DXA, Lunar) of the ultradistal radius was 0.263 (0.195-0.449) g/cm(2) and 0.326 (0.236-0.448) g/cm(2) (p < 0.0001), with a median T-score of -3.48 and -1.4, respectively. Each patient with a serum concentration of 1-84 and 7-84 PTH was assessed.


RESULTS
Patients with low BMD did not differ from those with higher BMD with regard to serum iPTH (16 [6-51] vs. 11.5 [7-35] pg/ml, p = 0.066) and CIP (6 [1-14] vs. 4.5 [2-13] pg/ml) concentrations. However, serum CAP concentrations (10.5 [4-41] vs. 6 [4-22] pg/ml, p < 0.05) and CAP/CIP ratios (2.0 [0.71-11] vs. 1.25 [0.5-4.2], p < 0.05) were significantly higher in the low BMD group.


CONCLUSIONS
In elderly women increased serum CAP concentrations and CAP/CIP ratios are associated with low BMD of the trabecular bone.
Franek
Edward
E
Department of Internal Diseases, Endocrinology and Diabetology, Central Clinical Hospital of the Ministry of Internal Affairs, Warszawa. edward.franek@cskmswia.pl
Piwowarska
Iwona
I
Bułanowski
Maciej
M
Kokot
Franciszek
F
Franek
Andrzej Wiecekedward
AW
Piwowarska
Iwona
I
Bułanowski
Maciej
M
Kokot
Franciszek
F
Wiecek
Andrzej
A
D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000097:blood*; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D015999:Multivariate Analysis; D010281:Parathyroid Hormone / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011884:Radius / Q000000981:diagnostic imaging
D015415:Biomarkers; D010281:Parathyroid Hormone; D010446:Peptide Fragments; C414937:parathyroid hormone (7-84)