Objective measures of physical function and their association with cognitive impairment in older adults with cancer prior to treatment

Abstract

Introduction: Objective measures of physical function are associated with cognitive function in community-dwelling older adults. Many older adults experience cognitive declines prior to cancer treatment initiation. Thus, it is unclear whether the association between low physical function and cognitive impairment is generalizable to older adults with cancer prior to treatment. Our objective was to examine whether objective measures of physical function were associated with cognitive impairment in geriatric oncology patients prior to treatment.

Materials and methods: We used prospectively collected data from an institutional database within a cancer centre and electronic medical records of older adults who had undergone a geriatric assessment before cancer treatment. Objective measures of physical function included grip strength and the Short Physical Performance Battery (SPPB). Cognitive impairment was assessed via the Mini-Cog. Multivariable logistic regression was used to determine whether grip strength and SPPB were associated with cognitive impairment prior to cancer treatment in all patients, as well as in patients with moderate-to-high comorbidity as part of a sensitivity analysis.

Results: A total of 386 older adults (mean age 80.9 years) were included in the analysis. Most participants (65.3%) had low grip strength and/or low SPPB, whereas 42.2% were cognitively impaired. Neither low grip strength (odds ratio [OR] = 1.55, 95% confidence interval [CI] = 0.92-2.63, p = 0.097) nor low SPPB (OR = 1.29, 95%CI = 0.69-2.42, p = 0.41) alone or combined (OR = 1.05, 95%CI = 0.59-1.88, p = 0.85) were significantly associated with cognitive impairment in multivariable analyses of all patients. However, low SPPB was significantly associated with cognitive impairment in the sensitivity analysis restricted to patients with moderate-to-high comorbidity (OR = 4.05, 95%CI = 1.50-10.95, p = 0.006). Dependence in one or more instrumental activities of daily living [IADLs] was consistently associated with cognitive impairment in the main and sensitivity analyses.

Discussion: Low physical performance and IADL dependence are associated with cognitive impairment in patients with moderate-to-high comorbidity prior to cancer treatment. Scrutiny is advised for these patients to assess for possible cognitive impairment. Larger studies are warranted to confirm our findings.

Keywords: Cognitive function; Geriatric assessment; Muscle strength; Physical function; Physical performance; cancer.