Serum IL-6 and TGF-β1 concentrations as diagnostic biomarkers in elderly male patients with osteoporosis

Purpose

This research is intended to evaluate the correlations of serum IL-6 and TGF-β1 concentrations with bone density and turnover markers as well as their diagnostic value in elderly male patients with osteoporosis (OP).

Methods

A retrospective analysis was conducted on 335 elderly men (≥ 60 years; 90 with normal bone mass, 120 osteopenia cases, and 125 OP cases). Lumbar spine/femoral neck BMD values were measured using dual-energy X-ray absorptiometry. Correlations of serum IL-6 and TGF-β1 concentrations with bone density and bone turnover markers in OP patients were analyzed utilizing Pearson or Spearman correlation coefficients. Independent influencing factors for OP were identified by logistic multivariate regression analysis. The diagnostic value of serum IL-6 and TGF-β1 was assessed with ROC curves and MedCalc software.

Results

Smoking history, drinking history, lumbar spine BMD, femoral neck BMD, PINP, and β-CTX markedly differed among the normal bone mass, osteopenia, and OP groups. Elevated IL-6 and reduced TGF-β1 concentrations were observed in serum samples of OP. Serum IL-6 concentrations was inversely associated with bone density markers but positively lined to bone turnover markers. Conversely, serum TGF-β1 was positively related to bone density markers but negatively associated with bone turnover markers. Smoking history, PINP, and IL-6, were identified as independent risk factors while lumbar spine BMD, femoral neck BMD, and TGF-β1 were independent protective markers for OP. The combined assessment of serum IL-6 and TGF-β1 showed superior diagnostic performance for OP.

Conclusion

Serum IL-6 in combination with TGF-β1 exhibits good diagnostic performance for OP.

Level of evidence

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding

Graphical Abstract