Phenotypes of Mineral Bone Disorder in Chronic Kidney Disease in a Dialysis Population

Background

Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) is associated with clinical outcomes. It is necessary to identify the phenotype to make clinical decisions that optimize resources and follow-up.

Objective

To determine the frequency of the CKD-MBD phenotype in dialysis patients and the associated factors.

Methods

Cross-sectional study in 440 patients, evaluated for CKD-MBD. Phenotypes show frequency of high, low or on target levels of PTH, vitamin D and phosphorus. The most common phenotype was used for comparisons.

Results

Age was 37.5 ± 15.8 years, 53% male, 28% were diabetic, 60% on peritoneal dialysis (PD), dialysis vintage was 12.0 months (IQR 3.0–34.3). High PTH was 58%, low vitamin D 82%, high phosphorus 39%, low calcium 50%, and vascular calcification 55%. The combination of high PTH and low vitamin D and high on-target phosphorus was 39%. Those with high PTH and low vitamin D were more likely to use PD (71 vs 51%; p <0.0001), had higher lipids: total cholesterol (159 vs. 152; p = 0.002) and triglycerides (137 vs. 123; p = 0.02), higher potassium (4.7 ± 0.7 vs. 4.9 ± 0.9 mg/dL; p = 0.04), and higher serum creatinine (11.9 ± 4.4 vs. 10.6 ± 3.7 mg/dL; p = 0.01). Predictors of the most common phenotypes were PD use, total cholesterol, and serum creatinine.

Conclusions

More than one third (38%) of our sample of patients had high PTH and low vitamin D with either high or normal phosphorus. Patients with these phenotypes more frequently used PD, had higher lipids and low potassium. PD use, total cholesterol and serum creatinine were significantly associated with these phenotypes.