Background: Chronic malnutrition and cachexia are common in chronic kidney disease (CKD), and importance should be given to these complications because they affect the patient’s quality of life and the prognosis. This sudy analyze the correlation between serum PTH level and nutritional status and body composition of patients with CKD.
Methods: CKD patients were enrolled in Center for Kidney Disease, Second Affiliated Hospital of Nanjing Medical University from December 1, 2016 to November 30, 2020. Bioelectrical impedance technology was applied to examine body composition. The characteristics of the body composition were compared among different stage of CKD patients, then the correlation between PTH and the body composition was analyzed.
Results: 205 CKD patients were enrolled. Twenty-five patients were in stage 1 or 2 CKD, 78 patients were in stage 3 or 4, 31 patients were in stage 5 without dialysis (referred to as CKD stage 5A), and 71 patients were in stage 5 with dialysis (referred to as CKD stage 5B). Body composition analysis showed that the patients had a phase angle (PA) of 5.02 ± 1.07°, a percentage of body fat (PBF) of 27.74 ± 8.8%, and a skeletal muscle mass index (SMI) of 7.4 ± 1.34 kg/m 2. PBF peaked in the CKD stage 3/4 group and gradually decreased with the progression of CKD. PA and SMI differed significantly between the CKD stage 1/2 and stage 5B groups. The proportion of low SMI did not differ significantly between the CKD stage 1/2 and stage 3/4 groups, but it was obviously higher in the CKD stage 5A and 5B groups. PTH was significantly correlated with BMI, hemoglobin, albumin, total cholesterol, triglycerides, and SMI .Binary logistic regression of low SMI showed that the odds ratio for PTH levels greater than the upper limit of the normal range was 11.769 (p = 0.043, 95% confidence interval: 1.078–128.536), and the model predictive power was 0.986 after correction for age, sex, height, weight, hemoglobin, serum calcium, serum phosphorus, serum total cholesterol, serum triglyceride, and basal metabolic rate.
Conclusion: Bioelectrical impedance can effectively assess the nutritional status of CKD patients in terms of fat and muscle parameters. High levels of PTH are an independent risk factor for developing low SMI in CKD patients.