Gong Nirong, Xiao Zhiwen, Zhang Fen, Zhong Xiaohong, He Yanfang, Yi Zhixiu, Tang Dan, Yang Cong, Lin Yanhong, Nie Jing, Ai Jun
State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Kidney Dis (Basel). 2020 Nov;6(6):434-443. doi: 10.1159/000507785. Epub 2020 Sep 7.
Serum phosphorus (SP) level is closely associated with overall mortality and cardiovascular events, while the role of SP controlled duration is not fully recognized. Here, we conducted a retrospective cohort study in our department to identify the relationship of SP controlled duration with clinical outcomes in patients undergoing peritoneal dialysis (PD).
PD patients in our center from January 1, 2009, to June 30, 2019, were followed up at 2-month (the first year) or 5-month (the next follow-up period) intervals, and until death, until PD withdrawal, or until June 30, 2019. Data at each follow-up point were collected from their medical records. SP levels, changed degree of SP over baseline, and SP controlled duration were analyzed with overall mortality, PD withdrawal (including death, transferred to hemodialysis, and received renal transplantation), and combined endpoint (including death, acute heart failure, cardiovascular event, and stroke).
A total of 530 patients entered the analysis. Of them, 456 (86.0%) had hyperphosphatemia before dialysis, and the SP levels decreased soon after dialysis. The degree of SP change over baseline was the maximum at the 3rd month after dialysis (-31.0%), and lower degree was associated with higher overall mortality (hazard ratio [HR], 1.012; 95% CI, 1.004-1.020; = 0.003). The median SP controlled duration was 13 (5-28) months, and longer duration was significantly associated with lower overall mortality (HR, 0.968; 95% CI, 0.956-0.981; < 0.001). After categorization, duration more than 12 months greatly improved overall mortality with a HR of 0.197 (0.082-0.458; < 0.001 vs. SP never controlled group) and 0.329 (0.150-0.724; = 0.006 vs. duration <12 months group). Longer SP controlled duration also improved PD withdrawal and combined endpoint.
In summary, both degree and duration of SP control were tightly associated with overall mortality. We should control SP levels as early, as possible, and as long as we could.
血清磷（SP）水平与总死亡率和心血管事件密切相关，而SP控制持续时间的作用尚未得到充分认识。在此，我们在本部门进行了一项回顾性队列研究，以确定SP控制持续时间与腹膜透析（PD）患者临床结局之间的关系。
对2009年1月1日至2019年6月30日在本中心接受PD治疗的患者，在第1年每2个月（后续随访期为每5个月）进行随访，直至死亡、停止PD治疗或至2019年6月30日。每次随访时的数据均从其病历中收集。分析SP水平、SP相对于基线的变化程度以及SP控制持续时间与总死亡率、PD治疗退出（包括死亡、转为血液透析和接受肾移植）以及复合终点（包括死亡、急性心力衰竭、心血管事件和中风）之间的关系。
共有530例患者纳入分析。其中，456例（86.0%）在透析前存在高磷血症，透析后SP水平很快下降。透析后第3个月SP相对于基线的变化程度最大（-31.0%），变化程度较低与较高的总死亡率相关（风险比[HR]，1.012；95%置信区间，1.004-1.020；P = 0.003）。SP控制的中位持续时间为13（5-28）个月，较长的持续时间与较低的总死亡率显著相关（HR，0.968；95%置信区间，0.956-0.981；P < 0.001）。分类后，持续时间超过12个月可显著改善总死亡率，HR为0.197（0.082-0.458；与SP从未得到控制的组相比，P < 0.001）以及0.329（0.150-0.724；与持续时间<12个月的组相比，P = 0.006）。较长的SP控制持续时间也可改善PD治疗退出情况和复合终点。
总之，SP控制的程度和持续时间均与总死亡率密切相关。我们应尽早且尽可能长时间地控制SP水平。
