ABSTRACT
AIM: Severe hypocalcaemia following parathyroidectomy for secondary or tertiary hyperparathyroidism (SHPT/THPT) is scarcely studied. We aimed to describe and identify risk factors for early and persistent hypocalcaemia after parathyroidectomy. METHODS: Retrospective pair-matched cohort study. We assessed 87 dialysis patients with SHPT (n = 73) or THPT (n = 14) paired with 146 subjects with primary hyperparathyroidism (PHPT) who underwent parathyroidectomy and were followed for 12 months. Early severe hypocalcaemia was defined as a free Ca ≤0.8 mmol/L [3.2 mg/dl] or corrected Ca ≤1.87 mmol/L [7.5 mg/dl] within 48 h. After parathyroidectomy and persistent hypocalcaemia, as an elemental Ca intake >3.0 g/day to achieve corrected Ca >2 mmol/L [8.0 mg/dl]. RESULTS: Early severe hypocalcaemia occurred in 77% (67/87) versus 6.8% (10/146) of subjects with SHPT/THPT and PHPT, respectively (p < .001). In SHPT/THPT cases, persistent hypocalcaemia occurred in 77% (49/64) and 64% (35/54) after 6 and 12 months of parathyroidectomy, respectively. In PHPT cases, persistent hypocalcaemia occurred in 6.8% (10/146) after 4-12 months of parathyroidectomy. Preoperative serum alkaline phosphatase (ALP) was the only risk factor associated to early severe hypocalcaemia (OR 7.3, 95% C.I. 1.7-10.9, p = .006) and persistent hypocalcaemia (OR 7.1, 95% C.I: 2.1-14.2, p = .011). Subjects with persistently low intact parathormone (iPTH) (<5.3 pmol/L [50 ng/ml]), suggestive of adynamic bone disease) showed higher Ca increases and less oral calcium requirements compared to those who progressively increased iPTH after parathyroidectomy. CONCLUSION: Early and persistent hypocalcaemia after parathyroidectomy in severe HPT were a common event associated directly to preoperative ALP levels. Subjects with persistently low postoperative iPTH normalized serum Ca more frequently after 1 year of follow up.
Subject(s)
Hyperparathyroidism/surgery , Hypocalcemia/epidemiology , Parathyroidectomy , Postoperative Complications/epidemiology , Renal Dialysis , Adult , Cohort Studies , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors , Severity of Illness Index , Time FactorsABSTRACT
BACKGROUND: Vitamin D deficiency is common in peritoneal dialysis (PD) patients, so its supplementation has been advocated as potentially beneficial. METHODS: Double-blind, placebo-controlled, randomized clinical trial. Subjects on PD treated with high calcium peritoneal dialysate (Ca 3.5 mEq/l) and serum levels of 25-hydroxi vitamin D (25D) < 20 ng/ml were randomized to receive cholecalciferol (4800 IU/daily) or placebo for 16 weeks. The outcome measures were the effects on the osteogenic biomarkers osteoprotegerin (primary endpoint), intact fibroblast growth factor-23 (iFGF23), osteocalcin, osteopontin, iPTH, 1,25-dyhydroxivitamin D (1,25D), and interleukin-6. RESULTS: Fifty-eight subjects were randomly assigned. Baseline characteristics were similar in both groups. Cholecalciferol supplemented subjects had a significant increase in serum 25D (from 11.4 ± 5.0 to 28.3 ± 10.3 ng/ml), 1,25D and iFGF23 compared with placebo group. iFGF23 levels increased an average of 10,875 pg/ml per month (95% CI 11,778-88,414) in the cholecalciferol group and was unchanged in the placebo group (2829 pg/ml, 95% CI - 2181 to 14,972). Extremely high iFGF23 levels (> 30,000 pg/ml) were observed in 74% of subjects receiving cholecalciferol although iFGF23 returned to baseline values after 32 weeks of withdrawal. The observed changes in iFGF23 correlated with 1,25D levels and were not modified by other variables. No difference was observed between groups in osteoprotegerin or other osteogenic biomarkers levels. CONCLUSIONS: Cholecalciferol supplementation increases serum 25D levels in subjects on PD exposed to high calcium dialysate, yet it induces an exponential increase of iFGF23 in most patients, which disappear after withdrawal of supplementation and may be a major concern for this maneuver.
