Bone microarchitecture declines in older men with impaired renal function—the prospective STRAMBO study

Chronic kidney disease (CKD) may be complicated by mineral and bone disorders (CKD-MBD). Data on the association between estimated glomerular filtration rate (eGFR) and bone microarchitecture are limited. We studied the link between eGFR and bone microarchitecture (baseline, changes) assessed by high resolution peripheral quantitative computed tomography (HR-pQCT) in older men followed for 8 years. In 826 men aged ≥60, eGFR was calculated using three equations based on creatinin and cystatin C: CKDEPI-2012, EKFC without race and sex, CKDEPI-2021 without race. Bone microarchitecture was assessed at the distal radius and distal tibia by HR-pQCT at baseline, then after 4 and 8 years. Reaction force and failure load were estimated by microfinite element analysis. Changes in bone measures across the eGFR classes were explored using linear mixed effect models. At baseline, distal radius bone microarchitecture did not differ across the eGFR groups (CKDEPI-2012), whereas distal tibia trabecular measures and failure load were higher in men with decreased eGFR. During the follow-up, lower eGFR was associated with more rapid decrease in total bone mineral density (Tt.BMD), cortical area (Ct.Ar) and BMD (Ct.BMD), trabecular BMD (Tb.BMD), and failure load at the distal radius. Low eGFR was also associated with faster increase in trabecular area (Tb.Ar) and trabecular distribution heterogeneity (Tb.1/N.SD). At the distal tibia, low eGFR was associated with more rapid decrease in Tt.BMD, Ct.Ar, Ct.BMD, Tb.1/N.SD, and failure load as well as with faster increase in Tb.Ar. The patterns were similar for changes expressed as percentages. The patterns were similar for two other equations. Lower eGFR is associated with faster decline in cortical bone microarchitecture and bone strength at the distal radius and tibia in older men. This phenomenon may contribute to the higher fracture risk in older adults with CKD.