Nutritional markers, not markers of bone turnover, are related predictors of bone mineral density in chronic peritoneal dialysis patients.

Objective: this study evaluated the factors associated with bone mineral density (BMD) in chronic peritoneal dialysis (CPD) patients.

Methods: in this cross-sectional study in 91 stable CPD patients, BMD was measured using dual-energy X-ray absorptiometry. Markers of bone turnover (iPTH, osteocalcin, bone alkaline phosphatase, serum C-telopeptide), 25-hydroxy (OH) vitamin D3 and nutritional markers (prealbumin, nPNA, BMI) were measured by standard techniques.

Results: of the 91 patients, 48 were female and 22 (24%) had Type 2 diabetes. Mean age of the patients was 52.7, and patients had been on PD for about 44 months. For the lumbar spine (LS) and femoral neck (FN), the mean T-scores were -1.19 ± 1.53 and -1.24 ± 1.01, respectively, and the mean Z-scores were -0.78 ± 1.33 and -0.40 ± 0.92, respectively. Using the WHO-based criteria, osteopenia (-2.5 < T-score < -1.0) at the LS and FN was observed in 37 (41%) and 48 (53%) patients, respectively, and osteoporosis (T-score <= -2.5) at the LS and FN was observed in 15 (17%) and 6 (7%) patients, respectively. LS T-score was positively correlated with BMI (r = 0.40, p < 0.001) and albumin (r = 0.29, p = 0.005), and FN T-score was positively correlated with albumin (r = 0.40, p < 0.001), prealbumin (r = 0.38, p < 0.001), age (r = -0.32, p = 0.002) and BMI (r = 0.29, p < 0.006). Markers of bone turnover were not associated with BMD. In multiple linear regression models, independent predictors of FN T-score were age, BMI, albumin and prealbumin (r(2) = 0.259, F = 6.23, p < 0.001), whereas BMI was the only independent predictor of LS T-score (r(2) = 0.24, F = 6.63, p < 0.001).

Conclusions: nutritional markers, not markers of bone turnover, are correlated predictors of BMD in CPD patients.