Association of changes in bone remodeling and coronary calcification in hemodialysis patients: a prospective study.
BACKGROUND
Vascular calcification is common and constitutes a prognostic marker of mortality in the hemodialysis population. Derangements of mineral metabolism may influence its development. The aim of this study is to prospectively evaluate the association between bone remodeling disorders and progression of coronary artery calcification (CAC) in hemodialysis patients.


METHODS
Cohort study nested within a randomized controlled trial.


METHODS
64 stable hemodialysis patients.


METHODS
Bone-related laboratory parameters and bone histomorphometric characteristics at baseline and after 1 year of follow-up.


RESULTS
Progression of CAC assessed by means of coronary multislice tomography at baseline and after 1 year of follow-up. Baseline calcification score of 30 Agatston units or greater was defined as calcification. Change in calcification score of 15% or greater was defined as progression.


RESULTS
Of 64 patients, 38 (60%) of the patients had CAC and 26 (40%) did not [corrected]. Participants without CAC at baseline were younger (P < 0.001), mainly men (P = 0.03) and nonwhite (P = 0.003), and had lower serum osteoprotegerin levels (P = 0.003) and higher trabecular bone volume (P = 0.001). Age (P = 0.003; beta coefficient = 1.107; 95% confidence interval [CI], 1.036 to 1.183) and trabecular bone volume (P = 0.006; beta coefficient = 0.828; 95% CI, 0.723 to 0.948) were predictors for CAC development. Of 38 participants who had calcification at baseline, 26 (68%) had CAC progression in 1 year. Progressors had lower bone-specific alkaline phosphatase (P = 0.03) and deoxypyridinoline levels (P = 0.02) on follow-up, and low turnover was mainly diagnosed at the 12-month bone biopsy (P = 0.04). Low-turnover bone status at the 12-month bone biopsy was the only independent predictor for CAC progression (P = 0.04; beta coefficient = 4.5; 95% CI, 1.04 to 19.39). According to bone histological examination, nonprogressors with initially high turnover (n = 5) subsequently had decreased bone formation rate (P = 0.03), and those initially with low turnover (n = 7) subsequently had increased bone formation rate (P = 0.003) and osteoid volume (P = 0.001).


CONCLUSIONS
Relatively small population, absence of patients with severe hyperparathyroidism, short observational period.


CONCLUSIONS
Lower trabecular bone volume was associated with CAC development, whereas improvement in bone turnover was associated with lower CAC progression in patients with high- and low-turnover bone disorders. Because CAC is implicated in cardiovascular mortality, bone derangements may constitute a modifiable mortality risk factor in hemodialysis patients.
Barreto
Daniela Veit
DV
Department of Internal Medicine, Division of Nephrology, Federal University of São Paulo, São Paulo, Brazil.
Barreto
Fellype de Carvalho
Fde C
Carvalho
Aluízio Barbosa de
AB
Cuppari
Lilian
L
Draibe
Sérgio Antonio
SA
Dalboni
Maria Aparecida
MA
Moyses
Rosa Maria Affonso
RM
Neves
Kátia Rodrigues
KR
Jorgetti
Vanda
V
Miname
Márcio
M
Santos
Raul D
RD
Canziani
Maria Eugênia F
ME
D000085:Acetates / Q000627:therapeutic use; D000328:Adult; D016723:Bone Remodeling / Q000187:drug effects; D002114:Calcinosis / Q000453:epidemiology*; D017610:Calcium Compounds / Q000627:therapeutic use; D003324:Coronary Artery Disease / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011073:Polyamines / Q000627:therapeutic use; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D006435:Renal Dialysis; D000069603:Sevelamer
D000085:Acetates; D017610:Calcium Compounds; D011073:Polyamines; D000069603:Sevelamer; C120662:calcium acetate