Long-Acting Natriuretic Peptide Is Inversely Related to Bone Mineral Density in Peritoneal Dialysis Patients

BACKGROUND: Natriuretic peptides had an inhibitory effect on the rennin-angiotensin system and are a potent lipolytic agent that acts in adipose tissue which influenced bone mineral density (BMD). The aim of this study was to investigate the relationships of fasting serum long-acting natriuretic peptide (LANP) levels and BMD among peritoneal dialysis (PD) patients. METHODS: Fasting blood samples were obtained from 48 PD patients. BMD was measured by dual energy X-ray absorptiometry in lumbar vertebrae (L2 ～ L4). Serum LANP levels were measured using a commercial enzyme immunoassay kit. RESULTS: Among the PD patients, 8 patients (16.7%) had osteoporosis and 22 patients (45.8%) had osteopenia, while 18 patients had normal BMD. Increased serum LANP (P = 0.007), age (P = 0.017), while decreased BMI (P = 0.018), body height (P = 0.004), body weight (P = 0.007), and body fat mass (P = 0.025) was associated with lower lumbar T-scores. Different gender, menopause, different modalities of PD model, and having the history of diabetes mellitus or hypertension did not show significantly differences of lumbar BMD levels. Multivariate forward stepwise linear regression analysis of the significant variables showed that LANP (adjusted R^2 = 0.260; P = 0.002) was independent predictors of lumbar BMD among the PD patients. CONCLUSIONS: Fasting LANP level was inversely associated with lumbar BMD among PD patients.