Associations between FGF21, osteonectin and bone turnover markers in type 2 diabetic patients with albuminuria

We measured the levels of bone turnover markers (BTMs) in patients with early diabetic nephropathy from type 2 diabetes mellitus (T2DM), and investigated the associations of BTMs with adipokines, serum fibroblast growth factor-21 (FGF21) and osteonectin.

We included 159 males and 300 females with T2DM in this cross-sectional study. Clinical characteristics, BTMs and adipokines levels were measured.

One-hundred and ninety-two (41.8%) patients presented with albuminuria. Patients with albuminuria had significantly higher levels of serum osteonectin (P<0.0001) and FGF21 (P=0.0125) than those with normoalbuminuria. Serum levels of P1NP were slightly lower among patients with albuminuria (P=0.031), but the difference disappeared after adjusting for FBG, PBG, and HbA1c. Serum FGF21 levels were independently and negatively related to eGFR (overall β=-0.161, P=0.001; albuminuria group β=-0.240, P=0.001) but not related to uACR. While Osteonectin was independently and positively related to uACR (overall β=0.209, P=0.001; albuminuria group β=0.170, P=0.021). The levels of serum FGF21 were independently inversely related with P1NP (overall β=-0.192, P<0.0001; albuminuria group β=-0.195, P=0.031).

Our results suggest that persistent hyperglycemia may inhibit bone formation. Both osteonectin and FGF21 were associated with early nephropathy in T2DM patients, albeit with different patterns.