ABSTRACT
BACKGROUND AND OBJECTIVES: Vascular calcification (VC) is common in CKD, but little is known about its prognostic effect on patients with nondialysis CKD. The prevalence of VC and its ability to predict death, time to hospitalization, and renal progression were assessed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Study of Mineral and Bone Disorders in CKD in Spain is a prospective, observational, 3-year follow-up study of 742 patients with nondialysis CKD stages 3-5 from 39 centers in Spain from April to May 2009. VC was assessed using Adragao (AS; x-ray pelvis and hands) and Kauppila (KS; x-ray lateral lumbar spine) scores from 572 and 568 patients, respectively. The primary end point was death. Secondary outcomes were hospital admissions and appearance of a combined renal end point (beginning of dialysis or drop >30% in eGFR). Factors related to VC were assessed by logistic regression analysis. Survival analysis was assessed by Cox proportional models. RESULTS: VC was present in 79% of patients and prominent in 47% (AS≥3 or KS>6). Age (odds ratio [OR], 1.05; 95% confidence interval [95% CI], 1.02 to 1.07; P<0.001), phosphorous (OR, 1.68; 95% CI, 1.28 to 2.20; P<0.001), and diabetes (OR, 2.11; 95% CI, 1.32 to 3.35; P=0.002) were independently related to AS≥3. After a median follow-up of 35 months (interquartile range=17-36), there were 70 deaths (10%). After multivariate adjustment for age, smoking, diabetes, comorbidity, renal function, and level of phosphorous, AS≥3 but not KS>6 was independently associated with all-cause (hazard ratio [HR], 2.07; 95% CI, 1.07 to 4.01; P=0.03) and cardiovascular (HR, 3.46; 95% CI, 1.27 to 9.45; P=0.02) mortality as well as a shorter hospitalization event-free period (HR, 1.14; 95% CI, 1.06 to 1.22; P<0.001). VC did not predict renal progression. CONCLUSIONS: VC is highly prevalent in patients with CKD. VC assessment using AS independently predicts death and time to hospitalization. Therefore, it could be a useful index to identify patients with CKD at high risk of death and morbidity as previously reported in patients on dialysis.
Subject(s)
Renal Insufficiency, Chronic/epidemiology , Vascular Calcification/epidemiology , Aged , Chi-Square Distribution , Disease Progression , Disease-Free Survival , Female , Glomerular Filtration Rate , Hospitalization , Humans , Kaplan-Meier Estimate , Kidney/physiopathology , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Predictive Value of Tests , Prevalence , Proportional Hazards Models , Prospective Studies , Renal Dialysis , Renal Insufficiency, Chronic/diagnosis , Renal Insufficiency, Chronic/mortality , Renal Insufficiency, Chronic/therapy , Risk Assessment , Risk Factors , Spain/epidemiology , Time Factors , Vascular Calcification/diagnosis , Vascular Calcification/mortality , Vascular Calcification/therapyABSTRACT
OSERCE is a multi-centre and cross-sectional study with the aim of analysing the biochemical, clinical, and management characteristics of bone mineral metabolism alterations and the level of compliance with K/DOQI guideline recommendations in patients with chronic kidney disease (CKD) not on dialysis. The study included a total of 634 patients from 32 different Spanish nephrology units, all with CKD, estimated glomerular filtration rates <60 ml/min/1.73 m(2), and not on dialysis (K/DOQI stage: 33% stage 3, 46% stage 4, and 21% stage 5). In 409 of these patients, laboratory parameters were also measured in a centralised laboratory, including creatinine, calcium, phosphorous, intact parathyroid hormone (PTH), 25-OH-vitamin D, and 1,25-OH2-Vitamin D levels. The rates of non-compliance with the K/DOQI objectives for calcium, phosphorous, intact PTH, and calcium x phosphate product among these patients were 45%, 22%, 70%, and 4%, respectively. Of the 70% of patients with intact PTH levels outside of the target range established by the K/DOQI guidelines, 55.5% had values above the upper limit and 14.5% had values below the lower limit. Of the 45% of patients with calcium levels outside of the target range, 40% had values above the upper limit and 5% had values below the lower limit. Of the 22% of patients with phosphorous levels outside of the target range, 19% had values above the upper limit, and 3% had values below the lower limit. Finally, 4% of patients also had values for the calcium x phosphate product that were outside of the recommended range. Only 1.8% of patients complied with all four K/DOQI objectives. The values detected in centralised laboratory analyses were not significantly different from those measured in the laboratories at each institution. In addition, 81.5% of patients had a deficiency of calcidiol (25-OH-D3) (<30 ng/ml); of these, 35% had moderate-severe deficiency (<15 ng/ml) and 47% had mild deficiency (15-30 ng/ml). Calcitriol (1,25-OH2-D3) levels were deficient in 64.7% of patients. Whereas the calcidiol deficiency was not correlated with the CKD stage, calcitriol deficit were more pronounced at more advanced stages of CKD. The results of the OSERCE study confirm the difficulty in reaching the target values recommended by the K/DOQI guidelines in patients with CKD not on dialysis, in particular in the form of poor control of secondary hyperparathyroidism and vitamin D deficiency. With this in mind, we must review strategies for treating bone mineral metabolism alterations in these patients, and perhaps revise the target parameters set by current guidelines.
