Poor trabecular microarchitecture at the distal radius in older men with increased concentration of high-sensitivity C-reactive protein--the STRAMBO study.

Low-grade inflammation, assessed by serum high-sensitivity C-reactive protein (hsCRP) concentration, is associated with higher fracture risk irrespective of areal bone mineral density (aBMD). We assessed the association of hsCRP with bone microarchitecture (measured by high-resolution pQCT) at the distal radius and tibia in 1,149 men, aged 19-87 years. hsCRP concentration increased with age until the age of 72, then remained stable. aBMD was not correlated with hsCRP level. After adjustment for confounders, bone microarchitecture was not associated with hsCRP level in men aged <72. After the age of 72, hsCRP >5 mg/L was associated with lower trabecular density, lower trabecular number, higher trabecular spacing, and more heterogeneous trabecular distribution (p < 0.05-0.005) at the distal radius versus hsCRP ≤ 5 mg/L. Similar differences were found for the fourth hsCRP quartile (>3.69 mg/L) versus the three lower quartiles combined. Cortical parameters of distal radius and microarchitectural parameters of distal tibia did not vary according to hsCRP concentration in men aged ≥ 72. Fracture prevalence increased with increasing hsCRP level. After adjustment for confounders (including aBMD), odds for fracture were higher in men with hsCRP >5 mg/L compared to hsCRP <1 mg/L (OR = 2.22, 95 % CI 1.29-3.82) and did not change after additional adjustment for microarchitectural parameters. The association between hsCRP level and bone microarchitecture was observed only for trabecular parameters at the radius in men aged ≥72. Impaired bone microarchitecture does not seem to explain the association between elevated CRP level and higher risk of fracture.