# Cognitive Sarcopenia: Prevalence and the Risk for Mortality and Healthy Aging in the KORA‐Age Study

## TL;DR

This study finds that older adults with both muscle weakness and cognitive issues face higher risks of death and disability, suggesting the need for combined screening and treatment.

## Contribution

The study introduces 'cognitive sarcopenia' as a combined condition and demonstrates its significant impact on mortality and aging outcomes.

## Key findings

- Cognitive probable sarcopenia was present in 8.1% of participants and linked to increased mortality and disability risks.
- Grip strength and gait speed were significantly associated with cognitive impairment, while muscle mass was not.
- Individuals with cognitive sarcopenia had a 1.95 times higher risk of all-cause mortality over 12 years.

## Abstract

Cognitive sarcopenia, defined by this study as the co‐existence of sarcopenia and cognitive impairment, has been frequently reported in older adults, while we hypothesize that the co‐existence increases the risk for adverse outcomes in the older general population.

This study included 1055 participants aged 65–93 years from the population‐based cohort Cooperative Health Research in the Region Augsburg (KORA)‐Age (2008/9). At baseline, probable sarcopenia (i.e., low grip strength) and confirmed sarcopenia (i.e., probable sarcopenia plus low muscle mass) were defined according to the European Working Group on Sarcopenia in Older People (EWGSOP) 2018 consensus. Cognitive impairment was derived from the modified telephone interview for cognitive status or a proxy interview with relatives/caregivers when participants had severe physical/mental impairment. Cognitive probable sarcopenia was defined as having both probable sarcopenia and cognitive impairment; cognitive confirmed sarcopenia as both confirmed sarcopenia and cognitive impairment. Isolated probable sarcopenia and isolated cognitive impairment refer to individuals with only one of the diseases. Mortality was assessed using death certificates over 12 years (553 deaths [52.4%]). Adverse outcomes were assessed in 2012 and 2016 during telephone interviews. Covariate‐adjusted logistic and Cox regression models estimated the associations with adverse outcomes and mortality, respectively.

Almost 50% of older adults with probable sarcopenia had cognitive impairment, whereas among older adults without probable sarcopenia, only 20% had cognitive impairment. A total of 8.1% of the study population had cognitive probable sarcopenia, while 3.3% had cognitive confirmed sarcopenia. Muscle mass was not [OR (95% CI): 0.92 (0.70–1.20)], while grip strength [0.73 (0.57–0.94)], gait speed [0.66 (0.54–0.80)], and Timed Up and Go time [1.51 (1.27–1.82)] were associated with cognitive impairment. Participants with cognitive probable sarcopenia had an increased risk of all‐cause mortality [HR (95% CI): 1.95 (1.41–2.70)], cardiovascular disease mortality [1.64 (1.02–2.64)], and coronary heart disease mortality [2.10 (1.03–4.27)] after 12 years, and activities of daily living disability [OR (95% CI): 6.12 (2.33–16.06)] and requiring nursing care after 3 years [4.77 (1.47–14.63)]. Individuals with isolated probable sarcopenia or isolated cognitive impairment had either lower or no risk for those outcomes.

Since life expectancy and relevant healthcare have not advanced considerably since study baseline, we expect that these results are relevant today. The high prevalence of cognitive impairment in older adults with probable sarcopenia and the increased risk of cognitive sarcopenia on lifespan and independence endorse screening for cognitive impairment in older adults with probable sarcopenia by EWGSOP 2018 and support exploring intervention studies targeting both diseases simultaneously.