Assessment of bone turnover markers to predict mineral and bone disorder in men with pre-dialysis non-diabetic chronic kidney disease

Current and Emerging Markers and Tools Used in the Diagnosis and Management of Chronic Kidney Disease-Mineral and Bone Disorder in Non-Dialysis Adult Patients

Chronic kidney disease (CKD) is a significant public health concern associated with significant morbidity and has become one of the foremost global causes of death in recent years. A frequent comorbidity of CKD is secondary hyperparathyroidism (SHPT), exemplified by high serum parathyroid hormone (PTH) levels. The mineral metabolism disturbances resulting from CKD and progression to SHPT are currently considered part of the definition of chronic kidney disease-mineral and bone disorder (CKD-MBD). However, CKD-MBD does not only include abnormalities in laboratory-measured parameters; it is a complex condition characterized by dysregulation of bone turnover, mineralization, growth and strength, accompanied by vascular or another soft-tissue calcification. Together, this increases the risk of bone fractures, cardiovascular disease, and overall mortality in CKD-MBD patients. Monitoring serum markers is essential in diagnosing SHPT and CKD-MBD, and there are several recognized indicators for prognosis, optimal clinical management and treatment response in late-stage kidney disease patients receiving dialysis. However, far fewer markers have been established for patients with non-dialysis CKD. This review provides an overview of current and emerging markers and tools used in the diagnosis and management of CKD-MBD in non-dialysis adult patients.

Comparison of Second- and Third-Generation Parathyroid Hormone Test Results in Patients with Chronic Kidney Disease

BACKGROUND In patients with chronic kidney disease (CKD), secondary hyperparathyroidism is assessed by measuring serum parathyroid hormone (PTH) levels. Well-established, recommended, second-generation intact parathyroid hormone (iPTH) tests are typical; rarely are more recent third-generation PTH 1-84 assays used. The agreement between results of the 2 tests in patients with CKD has not been sufficiently defined. MATERIAL AND METHODS This study aimed to compare Roche second- and third-generation PTH assays by establishing a quantitative relationship between the results of assays in patients with CKD and assessing degree of their correlation with kidney function and calcium-phosphate and bone metabolism parameters. In 205 patients with stages 3 to 5D CKD and 30 healthy controls, we measured levels of iPTH and PTH (1-84), creatinine, urea, cystatin C, calcium, inorganic phosphate, magnesium, alkaline phosphatase, bone alkaline phosphatase, osteocalcin, and ß-CrossLaps. RESULTS The third-generation PTH assay results were more than 40% lower than those obtained with the second-generation test in patients undergoing dialysis and approximately 30% lower in patients in the pre-dialysis period. PTH concentrations determined with both assays were almost to the same extent correlated with calcium-phosphate and bone metabolism parameters, and renal function indices. Formulas have been developed enabling 2-way conversion of PTH results determined with both the second- and third-generation PTH assays: For dialyzed patients, PTH (1-84)=0.5181iPTH+18.0595. Serum osteocalcin, ß-CrossLaps, and total calcium were independent predictors of PTH levels. CONCLUSIONS Correcting for the established quantitative differences, the second-and third-generation PTH tests can be used interchangeably, given the almost identical pathophysiological correlations of their results with calcium-phosphate and bone metabolism parameters.

Prevalence of metabolic syndrome among adult population in India: A systematic review and meta-analysis

OBJECTIVE

This review was done to determine the prevalence of metabolic syndrome (MS) among adult general population in India. We also wanted to find the gender, setting, and region-wide distribution of MS in India.

METHODS

We conducted systematic searches in various databases including Medline, ScienceDirect, Cochrane library and Google Scholar from inception until August 2019. We included studies conducted in India reporting the prevalence of MS among adults aged 18 years or more. We used the Newcastle Ottawa scale to assess the quality of included studies. We carried out a meta-analysis with random-effects model and reported pooled prevalence with 95% confidence intervals (CIs). We used the Funnel plot to assess publication biases.

RESULTS

In total, we analysed 113 data from 111 studies with 133,926 participants. Majority of the included studies (76 out of 111) had low risk of bias. We found significant heterogeneity among the included studies (p<0.001). We also found a symmetrical funnel plot indicating an absence of publication bias. The prevalence of MS among adult population in India was 30% (95%CI: 28%-33%). There was a steady increase in the burden across the age groups from 13% (18-29 years group) to 50% (50-59 years). We also found that people living in urban areas (32%; 95%CI: 29%-36%) had higher prevalence when compared to tribal (28%; 95%CI: 21%-36%) or rural adults (22%; 95%CI: 20%-25%). Gender distribution of MS showed that the females had higher prevalence (35%; 95%CI: 31%-38%) when compared to males 26% (95%CI: 22%-29%).

CONCLUSION

Almost one in three adults in India suffer from MS. Females, people living in urban areas and in northeast region had higher prevalence of MS. Development and implementation of policies and protocols for the screening of MS would enable us in early diagnosis and treatment with special focus towards the vulnerable and high-risk groups.

Effects of parathyroidectomy on blood bone markers and heart rate variability in patients with stage 5 chronic kidney disease

PURPOSE

Decreased heart rate variability (HRV) is closely related to abnormal cardiac autonomic nervous function, especially sympathetic hyperactivity, which intensifies the risk of cardiovascular events and sudden death. HRV parameters are lower in chronic kidney disease (CKD) and parathyroidectomy (PTX) can improve these abnormalities in severe secondary hyperparathyroidism (SHPT) patients. However, few studies have evaluated correlations between circulating bone markers and HRV in CKD patients.

METHODS

We conducted a cross-sectional study including 134 stage 5 CKD patients with 100 controls and a prospective study of 29 PTX patients with follow-up. Circulating bone biomarkers included: (1) intact parathyroid hormone (iPTH) as bone remodeling regulator; (2) bone-specific alkaline phosphatase (BAP), representing bone formation; (3) tartrate-resistant acid phosphatase 5b (TRACP-5b), indicating bone resorption; and (4) bone-derived hormone, fibroblast growth factor 23 (FGF23).

RESULTS

Stage 5 CKD patients had higher circulating iPTH, BAP, TRACP-5b, and FGF23 than controls and these bone markers were significantly elevated in SHPT patients. Baseline iPTH, BAP, and lnFGF23 were independently associated with HRV in CKD patients. After PTX with a follow-up (median interval: 6.7 months), high blood iPTH, BAP, TRACP-5b, FGF23, and attenuated HRV were ameliorated. Furthermore, improved HRV indices were associated with reduced iPTH, BAP, TRACP-5b, and FGF23.

CONCLUSIONS

Circulating bone markers are correlated with HRV in CKD 5 patients and PTX can improve decreased HRV, which are associated with corrected bone markers in severe SHPT patients. Thus, we propose that PTH increases sympathetic tone and both high circulating PTH levels and sympathetic hyperactivity increase bone turnover, and that the products of bone turnover influence HRV.