Abstract: 【Abstract】Objective To investigate clinical characteristics and prognosis in maintenance hemodialysis (MHD) patients with low baseline intact parathyroid hormone (iPTH). Methods A total of 224 MHD patients treated in Ningbo First Hospital were recruited and retrospectively studied. They were divided into two groups according to serum iPTH level, low iPTH group (iPTH<150pg/ml, n=74) and high iPTH group (iPTH≥150pg/ml, n=150). Clinical indicators were compared between the two groups. Kaplan-Meier survival curve was used to analyze the survival time between the two groups. Results Compared with the high iPTH group, patients in the low iPTH group had older age (t=2.943, P=0.004), higher hemoglobin (t=2.210, P=0.028), lower serum albumin (t=-2.297, P=0.023), lower creatinine (t=-3.171, P=0.002), lower total cholesterol (t=-2.136, P=0.034), higher blood calcium (t=5.679, P<0.001) and, lower blood phosphorus (t=- 4.592, P<0.001). The mean survival time was 58.3±6.7 (95% CI: 45.2～71.5) months in the low iPTH group, and was 82.6±4.6 (95% CI: 73.6～91.6) months in the high iPTH group, indicating the shorter survival time in the low iPTH group (χ2=9.313, P=0.002). When the patients in the two group were divided into several subgroups based on the iPTH change during follow- up period, we found that the subgroup with persistently low iPTH had the
shortest survival time (χ2=31.059, P<0.001). Conclusions MHD patients with low baseline iPTH had the characteristics of older age, subnormal nutritional status, mild anemia, relatively higher serum calcium and lower serum phosphorus, shorter survival time and unfavorable prognosis, especially those with persistently low iPTH.

Key words: Intact parathyroid hormone, Hemodialysis, Clinical characteristics, Prognosis