Bone mineral density and the risk of kidney disease in patients with type 1 diabetes

Aim: To explore the association between bone disorder and the risk for progression of diabetic kidney disease (DKD) in persons with type 1 diabetes mellitus (T1DM). Methods: In this prospective cohort study the association between bone mineral density (BMD), bone-derived factors (sclerostin, Dickkopf-1, and osteoprotegerin (OPG)), and four outcomes were investigated: 1) progression of albuminuria; 2) decline in estimated glomerular filtration rate (eGFR) ≥30 %; 3) kidney failure (KF); and 4) a composite kidney outcome consisting of at least one of the outcomes. Results: In 318 participants (median follow-up time 5.5 years) patients with osteoporosis (BMD with T-score < −2.5) had increased risk of eGFR decline: hazard ratio (HR) 2.56 (95 % CI 1.06–6.19, p = 0.04), KF: HR 9.92 (95 % CI 1.16–84.95, p = 0.04), and the composite kidney outcome: HR 2.42 (95 % CI 1.18–4.96, p = 0.02). Patients with high OPG had increased risk of eGFR decline, KF, and the composite outcome, compared to patients with low OPG in unadjusted analysis. No bone-derived factor was associated with any outcome in adjusted analyses. Conclusions: In patients with T1DM low BMD was associated with progression of DKD, suggesting an interaction between bone and kidney.