Biochemical markers of mineral bone disorder in South African patients on maintenance haemodialysis

Abstract

Background and objective: Despite the high mortality and morbidity associated with abnormalities in mineral and bone metabolism in haemodialysis patients, there is limited data on the pattern of mineral bone disorder in African CKD population. Therefore, the purpose of this study was to describe the pattern of mineral bone disease by evaluating biochemical parameters in patients on maintenance haemodialysis (MHD). Methods: We evaluated the serum/plasma intact parathyroid hormone (iPTH), corrected calcium, phosphate, total alkaline phosphatase (TALP) and 25 -OH vitamin D levels of two hundred and seven patients undergoing MHD at two dialysis centers in Johannesburg. Results: The MHD patients (133 men, 74 women) had a mean age of 54.5±15.6 years with a median dialysis vintage of 24 months (IQR, 12-48) and a mean kt/V of 1.45±0.28. The prevalence of hyperparathyroidism (iPTH >150 pg/ml), hyperphosphataemia, hypocalcaemia and 25-OH vitamin D deficiency (<30 ng/ml) was 73.4%, 57.0%, 20.3% and 80.7 % respectively. The combination of markers of bone turnover (iPTH >150pg/ml and TALP> 112 U/L) suggestive of high turnover bone disease, was present in 47.3 % of the study population. In multiple-logistic regression analysis, the odds ratio for developing hyperparathyroidism with hypocalcaemia and hyperphosphataemia were 5.32 (95% CI 1.10 -25.9, P = 0.03) and 3.06(95 % CI 1.15 -8.10, P=0.02) respectively. Ninety eight (47.3%) of the MHD patients had iPTH within the recommended kidney disease improving global outcome (KDIGO) guidelines. Conclusion: Secondary hyperparathyroidism and 25-OH vitamin D deficiency were common in our haemodialysis patients. Hypocalcaemia and hyperphosphataemia were strong predictors for developing secondary hyperparathyroidism.

Is Sevelamer Carbonate Better Than Calcium Acetate in ControllingChroni Kidney Disease-Mineral Bone Disease in Dialysis Patients

“…Many observational and randomized control trials promulgate its relationship with increased morbidity and mortality, but data is still exiguous to suggest a recommendation for the efficacy of one Group of phosphate lowering therapy over the other. High serum phosphorus levels >4.5 mg/dl had been seen in the majority of dialysis patients, and it is likely because of conventional hemodialysis and patient non-compliance with dietary phosphate restriction and phosphate lowering therapy, 11 as 78.1% had hyperphosphatemia >4.5 mg/ml in an Indian study, 12 35.8% of Brazilian study population, 13 and 75% in Nigerian study population. 14 In the present study, the efficacy of Sevelamer with Calcium Acetate was compared by assessing different parameters of CKD-MBD, i.e., serum phosphorus, serum calcium, calcium × phosphorus product, serum alkaline phosphatase and intact parathyroid hormone.…”

“…Normal values for calcium, phosphorus, and iPTH according to KDIGO 2017 Normal values for calcium -8.5-10.5 mg/dl, Phosphate-2.5-4.5 g/dl, Alka-line phosphatase 54-260IU/L, Intact PTH 10-65 pg/ml. 11 All statistical analysis was performed using Statistics Package for Social Sciences version 21.0. Continuous variables were presented as means and standard deviation, while discrete variables as frequency and percentages.…”

25 [OH] Vitamin D and Intact Parathyroid Hormone in Congolese Hemodialysis Patients: Evaluation of KDIGO Targets

“…The similarly high incidence of hypovitaminosis D that we describe is within the range of the results reported in the few studies conducted in SSA in hemodialysis patients. [12][13][14][15] Apart from the risk of bone fragility, this complication exposes patients to decreased muscle tone, the occurrence of tetany and seizures [in relation to hypocalcemia], hypocalcemia, an increased risk of cancer, diabetes, depression and autoimmune diseases. 22 Considering the significant extrarenal production of 1, 25 [OH] D even in advanced CKD, the KDIGO experts recommend supplementing dialysis patients with 25 [OH] D. 17 Since the HD centers in Kinshasa comply with these recommendations, a lower frequency of 25 [OH] D deficiency would be expected, which was not the case.…”

“…A minimal sample size of 245 participants was calculated according to the formula n = Z 2 PQ/d 2 assuming a confidence coefficient (z) of 1.96 for a confidence interval (CI) of 95%, a degree of precision (d) of 5%, Q=1-P and an expected proportion (p) of patients presenting abnormalities in phospho-calcium metabolism is 0.8, referring to the result found by Bala W et al in South Africa. 13 The active queue of patients followed for hemodialysis in these 6 hospitals being 251, we opted for exhaustive sampling.…”

“…10,11 A few rare studies conducted in sub-Saharan Africa [SSA] have reported a frequency of hypovitaminosis D varying between 60 and 80% among chronic hemodialysis patients, often associated with normal or elevated PTH levels. [12][13][14][15] The factors associated with this decrease and the concordance between 25 [OH] D levels and expected iPTH values have not yet been studied in our setting.…”