Coronary calcification is highly prevalent in pre-dialysis patients and correlates with traditional and non-traditional risk factors for CVD.

Vascular calcification is a strong prognostic marker of mortality in hemodialysis patients and has been associated with bone metabolism disorders in this population. In earlier stages of chronic kidney disease (CKD), vascular calcification also has been documented. This study evaluated the association between coronary artery calcification (CAC) and bone histomorphometric parameters in CKD predialysis patients assessed by multislice coronary tomography and by undecalcified bone biopsy. CAC was detected in 33 (66%) patients, and their median calcium score was 89.7 (0.4-2299.3 AU). The most frequent bone histologic alterations observed included low trabecular bone volume, increased eroded and osteoclast surfaces, and low bone-formation rate (BFR/BS). Multiple logistic regression analysis, adjusted for age, sex, and diabetes, showed that BFR/BS was independently associated with the presence of coronary calcification [p ¼ .009; odd ratio (OR) ¼ 0.15; 95% confidence interval (CI) 0.036-0.619]. This study showed a high prevalence of CAC in asymptomatic predialysis CKD patients. Also, there was an independent association of low bone formation and CAC in this population. In conclusion, our results provide evidence that low bone-formation rate constitutes another nontraditional risk factor for cardiovascular disease in CKD patients. ß

Associação entre indoxil sulfato e histomorfometria óssea em pacientes renais crônicos pré-diálise

SummaryBackground and objectives Low bone mineral density and coronary artery calcification (CAC) are highly prevalent among chronic kidney disease (CKD) patients, and both conditions are strongly associated with higher mortality. The study presented here aimed to investigate whether reduced vertebral bone density (VBD) was associated with the presence of CAC in the earlier stages of CKD.Design, setting, participants, & measurements Seventy-two nondialyzed CKD patients (age 52 Ϯ 11.7 years, 70% male, 42% diabetics, creatinine clearance 40.4 Ϯ 18.2 ml/min per 1.73 m 2 ) were studied. VBD and CAC were quantified by computed tomography.Results CAC Ͼ 10 Agatston units (AU) was observed in 50% of the patients (median 120 AU [interquartile range 32 to 584 AU]), and a calcification score Ն 400 AU was found in 19% (736 [527 to 1012] AU). VBD (190 Ϯ 52 Hounsfield units) correlated inversely with age (r ϭ Ϫ0.41, P Ͻ 0.001) and calcium score (r ϭ Ϫ0.31, P ϭ 0.01), and no correlation was found with gender, creatinine clearance, proteinuria, lipid profile, mineral parameters, body mass index, and diabetes. Patients in the lowest tertile of VBD had expressively increased calcium score in comparison to the middle and highest tertile groups. In the multiple logistic regression analysis adjusting for confounding variables, low VBD was independently associated with the presence of CAC.Conclusions Low VBD was associated with CAC in nondialyzed CKD patients. The authors suggest that low VBD might constitute another nontraditional risk factor for cardiovascular disease in CKD.

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