Supplementary Material for: Low hand grip strength is associated with increased risk of cognitive impairment in older men, including men with probable sarcopenic obesity: results from the Northern Ireland PRIME-COG cohort

Background: The relationship between cognitive impairment and a phenotype comprising low muscle strength coupled with excess adiposity, representative of sarcopenic obesity, is not well defined. The present study aimed to elucidate the relationship between low hand grip strength (HGS), representative of ‘probable sarcopenia’, coupled with obesity, thus representing ‘probable sarcopenic obesity’, and cognitive impairment.

Methods: Logistic regression models were implemented between probable sarcopenia and cognitive impairment in older men residing in Northern Ireland within the PRIME-COG cohort, a nested study in the PRIME (Prospective Epidemiological Study of Myocardial Infarction) cohort. In addition, associations across Body Mass Index (BMI) strata were evaluated, including probable sarcopenic obesity (low HGS and BMI ≥ 30 kg/m2). Models were adjusted for demographics, cardiometabolic disease and risk factors, APOE-ε4, and lifestyle behaviours.

Results: Among 792 men (79.1 SD 3.2 yr), low HGS was associated with a significantly increased odds ratio (OR) of cognitive impairment (OR 2.14 (95% confidence intervals (CI) 1.51 – 3.03), p < 0.001). The risk was broadly consistent across BMI strata, including men with probable sarcopenic obesity (OR 2.36 (95% CI 0.85 – 6.35), p = 0.05). The consistent risk across BMI strata was supported by a non-significant interaction between BMI and probable sarcopenia (likelihood ratio test, p = 0.772).

Conclusions: Probable sarcopenia, indicated by low HGS, was associated with an increased risk of cognitive impairment in older men, with risk consistent across BMI strata, including men living with probable sarcopenic obesity. Our findings have clinical relevance, suggesting that phenotypes comprising low muscle strength, in the presence of excess adiposity must not be overlooked and appropriate interventions explored to attenuate physical perturbations which could carry significance towards ameliorating cognitive function in aging.