Frailty, appendicular lean mass, osteoporosis and osteosarcopenia in peritoneal dialysis patients

Abstract

Introduction: The pattern of chronic kidney disease mineral bone disorder (CKD-MBD) is changing with increasing numbers of elderly patients now treated by dialysis. The risk of falls and bone fractures increases with frailty and sarcopenia. As such we wished to review the association between osteoporosis and frailty and loss of appendicular lean mass (ALM). Methods: Dual-energy X-ray absorptiometry (DXA) was used to measure lumbar spine and femoral neck bone mineral density (BMD) and body composition. Osteoporosis and osteopenia were defined according to T scores. ALM was indexed to height (ALMI). Frailty was classified using the clinical frailty scale (CFS). Results: DXA scans from 573 patients, 57.8% male, 36.8% diabetic, mean age 61.0 ± 15.8 years, with a median 6.0 (2–20) months of treatment with PD were reviewed. Forty-two (7.3%) were classified as clinically frail, 115 (20%) osteoporotic, and 198 (34.6%) ALMI meeting sarcopenic criteria, with 43% of osteoporotic patients being osteosarcopenic. In a multivariable model, femoral neck BMD was associated with weight, standardised β (St β) 0.29, p = 0.004, ALM St β 0.11, p = 0.03 and Black vs other ethnicities St β 0.19, p = 0.02, and negatively with age St β −0.24, p < 0.001, and frailty St β −2.1, p = 0.04. Z scores (adjusted for gender and age) were associated with ALMI (r = 0.18, p < 0.001). Discussion: Osteoporosis is increasing with the numbers of elderly dialysis patients. As frailty and sarcopenia increase with age, then the risk of falls and bone fractures increases with osteosarcopenia. Whether interventions with exercise and nutrition can improve bone heath remains to be determined. Graphical abstract: [Figure not available: see fulltext.]