Association between pan-immune-inflammation value and bone turnover markers in Chinese patients with osteoporotic fractures: a retrospective cross-sectional study.

BACKGROUND

Systemic inflammation has been linked to impaired bone remodeling and may contribute to the risk of osteoporotic fractures (OPFs). This study examined the relationship between baseline pan-immune-inflammation value (PIV) and bone turnover markers (BTMs) in patients hospitalized for the surgical treatment of OPFs.

METHODS

In this retrospective cross-sectional study, 839 patients aged ≥50 years who were treated for osteoporotic fragility fractures between 2017 and 2024 were analyzed. PIV was calculated as (neutrophils × platelets × monocytes)/lymphocytes. BTMs included serum β-C-terminal telopeptide of type I collagen (β-CTX) and procollagen type I N-terminal propeptide (P1NP). Associations between log₂-transformed PIV and BTMs were assessed using multivariable generalized estimating equations (GEEs), adjusting for demographic, clinical, and biochemical factors. Smoothing spline models and threshold effect analyses were used to explore potential non-linear relationships. Subgroup analyses were conducted to examine effect modification.

RESULTS

The mean age of participants was 69.4 ± 10.9 years, with 70.9% being female. Mean β-CTX and P1NP levels were 0.54 ± 0.29 ng/mL and 58.1 ± 35.3 ng/mL, respectively, and the mean log₂PIV was 8.24 ± 1.28. Higher PIV levels were independently associated with lower BTMs. Specifically, each doubling of PIV was associated with a 4.46 ng/mL reduction in P1NP and a 0.05 ng/mL reduction in β-CTX (both p < 0.001). An inverted J-shaped association was observed, with the relationship plateauing at log₂PIV levels between approximately 8.3 and 10.3. The inverse association was more pronounced in individuals with hypertension or impaired renal function.

CONCLUSION

Elevated PIV is independently and non-linearly associated with suppressed bone turnover, underscoring the role of systemic inflammation in the pathophysiology and management of osteoporosis.