The Association Between Osteocalcin and C-Reactive Protein; A Relation of Bone with Inflammation: A Systematic Review and Meta-Analysis

Abstract

A meta-analysis was performed to summarize the evidence from observational studies regarding the association between serum osteocalcin (OC) and C-reactive protein (CRP). A systemic research of the literature databases including PubMed, SCOPUS, and Google Scholar was performed to identify the relevant studies up to March 2018. We used the random-effects model by the method of DerSimonian and Laird to calculate the overall effect size. Q-test and I 2-statistics were used to assess between-study heterogeneity. In addition, we did subgroup analysis to detect possible sources of heterogeneity based on BMI range, gender, type of study population and age. We identified 21studies of association between serum osteocalcin and CRP eligible for the meta-analysis. The overall effect size showed a significant inverse association between OC and CRP (Fisher’s z=–0.127; 95% CI: –0.166, –0.088, p<0.0001). However, the significant chi-squared statistic result, indicates a heterogeneity of effect sizes (I 2=61.6, df=20, p<0.0001). The subgroup analysis found BMI range, type of study population, and age were the potential sources of heterogeneity. In addition, the strongest correlation was observed in the subgroup of obese subjects (Fisher’s z=–0.264, p=0.002), less than 40 years old (Fisher’s z=–0.115, p<0.0001) and healthy subjects (Fisher’s z=–0.115, p<0.0001). These findings suggest that there is a significant inverse association between serum OC and CRP levels in the adult population.

Osteocalcin: A Potential Marker of Peripheral Arterial Stiffness in Hypertensive Patients

“…Given that the kidneys remove circulating OC, OC clearance probably decreases in people with impaired kidney function [28]. A meta-analysis reported a significant inverse association between the levels of serum OC and CRP in the adult population [29]. However, in our study, the serum log-CRP levels were positively correlated with the OC levels in patients with hypertension.…”

“…However, in our study, the serum log-CRP levels were positively correlated with the OC levels in patients with hypertension. Many factors may have affected the consistent and inconsistent findings on OC levels and CRP, including different methods for measuring OC, potential confounders that were not considered, and only observational studies used in the meta-analysis [29]. It will take more investigation to completely comprehend the mechanisms underlying the association between OC and CRP.…”

The Role of Exercise in the Interplay between Myokines, Hepatokines, Osteokines, Adipokines, and Modulation of Inflammation for Energy Substrate Redistribution and Fat Mass Loss: A Review

“…Ocn -/- mice presented increased total body fat and hepatic and AT inflammation, along with decreased insulin sensitivity and total energy expenditure [ 201 ]. Meta-analyses of clinical studies showed inverse correlations between OCN levels and BMI [ 202 ], insulin resistance [ 203 ], the inflammatory marker CRP [ 204 ], body fat mass [ 205 ], and specifically, visceral fat mass, determined with radiologic imaging studies [ 206 , 207 , 208 ]. Importantly, OCN was independently associated with visceral fat area [ 206 ], implying an involvement in the regulation of VAT.…”