The impact of low and high dialysate calcium concentrations on cardiovascular disease and death in patients undergoing maintenance hemodialysis: a systematic review and meta-analysis

• Published in: Clinical and experimental nephrology 2024-06, Vol.28 (6), p.557-570
• Main Authors: Kamei, Keita, Yamada, Shunsuke, Hashimoto, Koji, Konta, Tsuneo, Hamano, Takayuki, Fukagawa, Masafumi
• Format: Article
• Language: English
• Subjects: Calcification; Calcification (ectopic); Calcium - blood; Cardiovascular diseases; Cardiovascular Diseases - mortality; Cardiovascular Diseases - prevention & control; Clinical trials; Coronary artery; Death; Dialysate; Hemodialysis; Hemodialysis Solutions - adverse effects; Hemodialysis Solutions - chemistry; Humans; Medicine; Medicine & Public Health; Meta-analysis; Middle Aged; Nephrology; Original Article; Parathyroid hormone; Parathyroid Hormone - blood; Randomized Controlled Trials as Topic; Renal Dialysis - adverse effects; Structure-function relationships; Systematic review; Treatment Outcome; Urology; Vascular Calcification - diagnostic imaging; Vascular Calcification - prevention & control
• ISSN: 1342-1751; 1437-7799
• DOI: 10.1007/s10157-024-02460-3

Background The optimal dialysate calcium (Ca) concentration for patients undergoing hemodialysis remains inconclusive, particularly concerning cardiovascular protection. Methods We conducted a systematic review of 19 randomized controlled trials (RCTs) and a meta-analysis of eight RCTs to determine the optimal dialysate Ca concentration for cardiovascular protection. We compared outcomes in patients receiving maintenance hemodialysis treated with either a low-Ca dialysate (LCD) (1.125 or 1.25 mmol/L) or a high-Ca dialysate (HCD) (1.5 or 1.75 mmol/L). The outcomes were coronary artery calcification score (CACS), all-cause and cardiovascular death, cardiovascular function and structure, and serum biochemical parameters. Results There was no significant difference between LCD and HCD concerning CACS (standardized mean difference [SMD] = −0.16, 95% confidence interval [CI]: [−0.38, 0.07]), the risk of all-cause death, and cardiovascular death in patients treated with chronic maintenance hemodialysis. Conversely, LCD was associated with a significantly lower intima-media thickness (SMD = −0.49, 95% CI [−0.94, −0.05]) and pulse wave velocity than HCD (SMD = −0.86, 95% CI [−1.21, −0.51]). Furthermore, LCD significantly decreased serum Ca levels (mean difference [MD] = 0.52 mg/dL, 95% CI [0.19, 0.85]) and increased serum parathyroid hormone levels (MD = 44.8 pg/mL, 95% CI [16.2, 73.3]) compared with HCD. Notably, most RCTs examined in our analysis did not include patients receiving calcimimetics. Conclusions Our meta-analysis showed no significant differences in cardiovascular calcification and death between LCD and HCD and revealed a paucity of RCTs on dialysate Ca concentrations, including those involving patients on calcimimetics, indicating the urgent need for further studies.