Background: Sarcopenia and obesity are two common conditions in older adults that may have differing effects on falls and fracture risk. This systematic review and meta-analysis aimed to determine whether older adults with sarcopenic obesity (SO) have increased risk of falls and fractures, or lower areal bone mineral density (aBMD), compared with sarcopenic non-obese (SNO), non-sarcopenic obese (NSO) or non-sarcopenic non-obese counterparts (NSNO).
Methods: An electronic literature search of four databases (MEDLINE, Web of Science, EMBASE and Scopus) was performed using relevant search terms from inception to June 2020. Random-effects meta-analyses determined mean differences (95% confidence intervals) in aBMD, and differences in falls risk (risk ratios; RR) and fracture rates (incidence rate ratios; IRR), between SO, NSO, SNO and NSNO older adults.
Results: Twenty-five cross-sectional and cohort studies (n=36,941) were included in the systematic review and 15 (n=31,189) were included in the meta-analysis. SO older adults had lower femoral neck aBMD compared with NSO and NSNO counterparts, but had higher aBMD compared with SNO counterparts (all P<0.05). SO older adults also had higher aBMD at the total hip and lumbar spine (both P<0.05), but higher non-vertebral fracture rates (IRR: 1.88; CI:1.09, 3.23), compared with SNO individuals. SO older adults had a significantly higher falls risk compared with NSNO (RR: 1.33; CI: 1.08, 1.65) and NSO older adults (RR: 1.17; CI: 1.01, 1.36), but not compared with SNO (RR: 1.07; CI: 0.83, 1.38).
Conclusion: SO older adults have lower femoral neck aBMD and increased falls risk compared with NSO and NSNO counterparts but have increased fracture rates only when compared with SNO counterparts. These data support the need for further investigation of the underlying mechanisms of fracture risk in older adults with sarcopenic obesity, and for interventions to improve bone health and physical function in this population.