Profile of incident chronic kidney disease related-mineral bone disorders in chronic kidney disease Stage 4 and 5: A hospital based cross-sectional survey

Comprehensive evaluation of bone health among kidney transplant recipients - A prospective, single center, observational cohort study from India

BACKGROUND

There is a paucity of studies describing trabecular bone score (TBS) and bone mineral density (BMD) in kidney transplant (KT) recipients from developing countries.

STUDY SETTING

This prospective observational study, from a tertiary teaching hospital in India assessed clinical, biochemical parameters including bone turnover markers and dual-energy X-ray absorptiometry (DXA) for BMD/TBS, hip structural analysis (HSA) and vertebral fracture assessment (VFA) at pre-KT, 3 months and 12 months post-KT.

RESULTS

A total of 53 KT recipients (90.6% living related) were recruited from August 2019 to March 2020 and followed till 1-year post-KT. The mean age was 33.9±10.4 years, 71.7% were males, and 11.5% had a history of pre-KT steroid use. Baseline fractures pre-KT as assessed by VFA were seen in 4 patients (7.5%). Mean BMD at spine and femoral neck and HSA variables at narrow neck and femoral shaft continued to decline till 3 months, but stabilised and reached pre-KT values 12 months post-KT. However, TBS and bone turn over markers continued to decline till 12 months post-KT (p value <0.001). New onset vertebral fractures were seen in 2(3.7%) and 1 patient (2.3%) at 3- and 12-months post-KT respectively. Pre-KT BMD significantly influenced bone health at 12 months post-KT, with patients in each quartile maintaining a similar trajectory over the follow up period (p < 0.001).

CONCLUSION

Despite significant improvement in kidney function following transplant, TBS and BMD of the spine significantly decreased mainly in the early post-KT period suggesting the effect of immunosuppressants on the bone. Strategies to improve bone health in KT patients are warranted.

Profile of chronic kidney disease related-mineral bone disorders in newly diagnosed advanced predialysis diabetic kidney disease patients: A hospital based cross-sectional study

AIM

Chronic kidney disease related-mineral bone disorder (CKD-MBD) has been poorly studied in pre-dialysis Indian CKD population. There are limited data on the pattern of these disturbances in diabetic CKD patients. Therefore, a study was conducted to find out the profile of mineral bone disorders in T2DM patients with pre-dialysis CKD.

METHODS

In this cross-sectional design, diabetic patients with newly-diagnosed stage 4 and 5 CKD were evaluated. Serum levels of calcium, phosphorus, intact parathyroid hormone (iPTH), 25 hydroxy vitamin D and total alkaline phosphatase (ALP) were measured in all patients. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA).

RESULTS

A total of 72 eligible patients participated (44 males, 28 females; age 54.2±11.7). Patients with CKD Stage 5 had a lower level of corrected serum calcium and significantly higher level of inorganic phosphorus, total ALP and iPTH as compared to stage 4 patients. Overall, 38.5% were hypocalcemic, 31.43% were hyperphosphatemic. 24.2% of CKD subjects were vitamin D deficient (<10ng/ml) and 41.4% having vitamin D insufficiency (10-20ng/ml). In stage 4, hyperparathyroidism (iPTH>110pg/ml) was detected in nearly 43% of patients. In stage 5, only 32% patients was found to have hyperparathyroidism (iPTH>300pg/ml). There was a good correlation between iPTH and total ALP (r=0.5, p=0.0001) in this cohort. 25 (OH) vitamin D was inversely correlated with ALP (r=-0.39, P=0.001) and showed negative correlation with urine ACR (r=-0.37, P=0.002). As a group, the osteoporotic CKD subjects exhibited higher iPTH (220.1±153.8 vs. 119±108pg/ml, p<0.05) as compared to those who were osteopenic or had normal bone density. There was significant correlation between BMD and iPTH (adjusted r=-0.436; P=0.001). In the multivariate regression model, we found intact PTH to predict BMD even after adjustment of all the confounders.

CONCLUSION

The current study showed that adynamic bone disease is prevalent even in pre-dialysis CKD population. High bone turnover disease may not be the most prevalent type in diabetic CKD. However, it could contribute to the development of osteoporosis in CKD subjects. Serum total ALP can serve as a biochemical marker to identify pattern of bone turnover where intact PTH is not available.

Acute Kidney Injury Facilitates Hypocalcemia by Exacerbating the Hyperphosphatemic Effect of Muscle Damage in Rhabdomyolysis

BACKGROUND/AIMS

Hypocalcemia is an important complication of rhabdomyolysis for which several pathogenic factors, including acute kidney injury (AKI), have been proposed. To gain insight regarding the hypocalcemic roles of AKI in rhabdomyolysis, we retrospectively examined patients with rhabdomyolysis.

METHODS

Of 28,387 patients admitted to the Department of Internal Medicine, 51 patients met the inclusion criteria for the study. Serum calcium was analyzed based on laboratory data including indicators of AKI, serum creatine kinase (CK) and serum inorganic phosphate (iP).

RESULTS

Twenty-two patients (43%) had hypocalcemia. Compared with patients without hypocalcemia, they had a higher prevalence of AKI (82 vs. 55%; p = 0.046), higher levels of peak CK (39,100 ± 50,600 vs. 9,800 ± 11,900 IU/l; p = 0.003) and higher levels of peak iP (1.77 ± 1.10 vs. 1.10 ± 0.35 mmol/l; p = 0.007). Indicators of AKI were correlated with peak CK and peak iP and were not significant variables in the regression analysis for hypocalcemia. Peak CK and peak iP were not correlated with each other. Impaired phosphate use by muscle contributed to the increased iP.

CONCLUSION

These findings indicate that muscle damage is the primary hypocalcemic factor in rhabdomyolysis. AKI facilitated hypocalcemia by exacerbating the hyperphosphatemic effects of muscle damage. Aggressive hydration, which could increase oxygen supply and subsequently repair phosphate use in muscle, might reduce the incidence of hypocalcemia in rhabdomyolysis.