INTRODUCTION: SCF has been reported to improve calcium absorption. We investigated the long-term effect of SCF and calcium on bone indices of healthy preadolescent children aged 9-11 years old.
METHODS: In a double-blind, randomised, parallel arm study, 243 participants were randomised into four groups: placebo, 12-g SCF, 600-mg calcium lactate gluconate (Ca) and 12-g SCF + 600-mg calcium lactate gluconate (SCF + Ca). Total body bone mineral content (TBBMC) and total body bone mineral density (TBBMD) were measured using dual-energy X-ray absorptiometry at baseline, 6 and 12 months.
RESULTS: At 6 months, SCF + Ca had a significant increase in TBBMC from baseline (27.14 ± 6.10 g, p = 0.001). At 12 months, there was a significant increase in TBBMC from baseline in the SCF + Ca (40.28 ± 9.03 g, p = 0.001) and SCF groups (27.34 ± 7.93 g, p = 0.037). At 6 months, the change in TBBMD in the SCF + Ca (0.019 ± 0.003 g/cm2) and Ca (0.014 ± 0.003 g/cm2) groups was significantly different (p calcium supplementation increased TBBMD at 6 months. Further work is needed to fully understand the mechanism and health benefits of prebiotics in this study population.
CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03864172.
MATERIALS AND METHODS: Retrospective data were obtained for 36 patients with CKD stage 4 and 5 after parathyroid surgery, correlating albumin-corrected serum calcium with the infusion rate of calcium gluconate. Calcium flux was characterised along with excursions out of the target calcium range of 2 to 3 mmol/L. With this data, an improved titration regimen was constructed.
RESULTS: Mean peak efflux rate (PER) from the extracellular calcium pool was 2.97 mmol/h occurring 26.6 hours postoperatively. Peak calcium efflux tended to occur later in cases of severe POH. Eighty-one per cent of patients had excursions outside of the target calcium range of 2 to 3 mmol/L. Mean time of onset for hypocalcaemia was 2 days postoperatively. Hypocalcaemia was transient in 25% and persistent in 11% of patients.
CONCLUSION: A simple titration regimen was constructed in which a 10% calcium gluconate infusion was started at 4.5 mL/h when serum calcium was <2 mmol/L, then increased to 6.5 mL/h and finally to 9.0 mL/h if calcium continued falling. Preoperative oral calcium and calcitriol doses were maintained. Blood testing was done 6-hourly, but when a higher infusion rate was needed, 4-hourly blood testing was preferred. Monitoring was discontinued if no hypocalcaemia developed in the fi rst 4 days after surgery. If hypocalcaemia persisted 6 days after surgery, then the infusion was stopped with further monitoring for 24 hours.
CASE PRESENTATION: We present a case of a 61-year-old Malay female with worsening bilateral limb weakness, paresthesia, and severe carpopedal spasm a week after receiving subcutaneous denosumab for osteoporosis. She had a history of gastric bypass surgery 20 years ago. Post gastric bypass surgery, she was advised and initiated on lifelong calcium, vitamin D, and iron supplementations that she unfortunately stopped taking 5 years after surgery. Her last serum blood tests, prior to initiation on denosumab, were conducted in a different center, and she was told that she had a low calcium level; hence, she was advised to restart her vitamin and mineral supplements. Laboratory workup revealed severe hypocalcemia (adjusted serum calcium of 1.33 mmol/L) and mild hypophosphatemia (0.65 mmol/L), with normal magnesium and renal function. Electrocardiogram showed a prolonged QTc interval. She required four bolus courses of intravenous calcium gluconate, and three courses of continuous infusions due to retractable severe hypocalcemia (total of 29 vials of 10 mL of 10% calcium gluconate intravenously). In view of her low vitamin D level of 33 nmol/L, she was initiated on a loading dose of cholecalciferol of 50,000 IU per week for 8 weeks. However, despite a loading dose of cholecalciferol, multiple bolus courses, and infusions of calcium gluconate, her serum calcium hovered around only 1.8 mmol/L. After 8 days of continuous intravenous infusions of calcium gluconate, high doses of calcitriol 1.5 μg twice daily, and 1 g calcium carbonate three times daily, her serum calcium stabilized at approximately 2.0 mmol/L. She remained on these high doses for over 2 months, before they were gradually titrated down to ensure sustainability of a safe calcium level.
CONCLUSION: This case report highlights the importance of screening for risk factors for iatrogenic hypocalcemia and ensuring normal levels before initiating denosumab. The patient history of bariatric surgery could have worsened the hypocalcemia, resulting in a more severe presentation and protracted response to oral calcium and vitamin D supplementation.
METHODS: Retrospective data on serum calcium and infusion rates was collected from 2011-2015. The relationship between peak calcium efflux (PER) and time was determined using a scatterplot and linear regression. A comparison between regimens was made based on treatment efficacy (hypocalcaemia duration, total infusion amount and time) and calcium excursions (outside target range, peak and trough calcium) using bar charts and an unpaired t-test.
RESULTS: Fifty-one and 34 patients on the original and new regimens respectively were included. Mean PER was lower (2.16 vs 2.56 mmol/h; P = 0.03) and occurred earlier (17.6 vs 23.2 h; P = 0.13) for the new regimen. Both scatterplot and regression showed a large correlation between PER and time (R-square 0.64, SE 1.53, P calcium infusion (67.7 vs 127.2 mmol, P = 0.02) for a shorter duration (57.3 vs 102.9 h, P = 0.001). Calcium excursions, peak and trough calcium were not significantly different between regimens. Early postoperative high excursions occurred when the infusion was started in spite of elevated peri-operative calcium levels.
CONCLUSION: The new infusion regimen was superior to the original in that it required a shorter treatment period and resulted in less hypocalcaemia. We found that early aggressive calcium replacement is unnecessary and raises the risk of rebound hypercalcemia.