Association between frailty and bone health in early-stage chronic kidney disease: a study from the population-based...

Frailty is a clinical syndrome that is particularly prevalent in patients with chronic kidney disease (CKD). We aimed to assess the associations between renal function and the presence of frailty criteria and to assess the association between frailty and bone outcomes.

We have conducted a retrospective study from a population-based cohort, which represents 1% of people aged 40-69 years in a Canadian province, excluding individuals with an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m². Frailty was defined with Fried's criteria. Bone density was estimated with quantitative ultrasound at the calcaneus measuring speed of sound (SOS) and broadband ultrasound attenuation (BUA). Time to first fracture event was assessed and analyses were conducted using logistic regressions, multiple linear regressions and Cox models.

Overall, 19 973 individuals were included: mean ± standard deviation age 54.2 ± 7.8 years, women 51.6%, 47.0% CKD stage G2, 3.9% CKD stage G3, 34.8% with at least one frailty criterion. We observed a U-shaped association between eGFR and the odds ratio (OR) of presenting at least one frailty criterion, with a minimum OR around 77 mL/min/1.73 m² [per a 10 mL/min/1.73 m² increase, respectively, for an eGFR <77 and >77, OR = 0.93, 95% confidence interval (CI) 0.86-1.01 and OR 1.09, 95% CI 1.06-1.13]. After a median follow-up of 5.8 years, there were 837 fracture events. Having at least one frailty criterion was negatively associated with SOS (β = -3.97, P < .0001) and BUA (β = -1.82, P < .0001). Having at least one frailty criterion was associated with a higher fracture risk (hazard ratio 1.23, 95% CI 1.07-1.42).

In conclusion, having at least one frailty criterion was associated with a higher risk of fracture and a lower bone mineral density.