Malnutrition is associated with poor muscle mass and physical performance in community-dwelling older adults: COINS study baseline data

Malnutrition is prevalent in older adults and frequently coexists with sarcopenia(1), a condition characterised by low muscle mass and physical performance(2). Malnutrition and sarcopenia are associated with adverse outcomes in older adults including mortality(3), and thus require early detection. The Mini Nutrition Assessment (MNA) is a validated nutrition screening and assessment tool in older adults(4), but its ability to predict poor muscle mass and physical performance is unclear. This study aimed to determine the association between MNA-determined (risk of) malnutrition and muscle mass and physical performance in community-dwelling older adults. This is a cross-sectional analysis of baseline data from the Capacity of Older Individuals after Nut Supplementation (COINS) study, a randomised controlled trial investigating the effect of peanut butter on functional capacity in older adults. Participants were generally healthy and at risk for falls (simplified fall risk screening score ≥ 2). Participants were screened for malnutrition risk (MNA-Screening score range 0–14; at-risk or malnourished if < 11), followed by assessment (MNA-Assessment score range 0–16) to obtain MNA-Total score (range 0–30; at-risk or malnourished if score < 23.5). Skeletal muscle mass index (SMMI) was derived from bio-impedance analysis. Physical performance including muscle strength, gait speed, balance and power, was objectively measured using multiple standard tests. Linear regression analyses were performed and adjusted for age and sex. A total of 120 participants were included (70% females, age 74.8 ± 4.5 years). MNA-Screening, MNA-Assessment and MNA-Total scores were (median [IQR]) 14 [12–14], 14 [13.5–15] and 27.5 [26.0–28.4] respectively. Malnutrition (or risk) was found in 18 (15.0%) and 8 (6.7%) participants according to MNA-Screening and MNA-Total, respectively. A higher MNA-Screening score was associated with higher knee extension strength [β = 1.36 (Standard Error, SE 0.65) kg, p = 0.039]. A higher MNA-Assessment score was associated with higher gait speed [β = 0.04 (0.01) kg/m2, p = 0.007] and shorter timed up-and-go test time [β = −0.19 (0.09) seconds, p = 0.035]. MNA-Total score was not significantly associated with muscle mass or physical performance. Malnutrition status as determined by MNA-Screening score (but not MNA-Total score) was associated with lower muscle mass (SMMI [β = −0.52 (0.26) kg/m2, p = 0.043]), but not strength and physical performance. In summary, the MNA-Screening score was predictive of muscle mass and strength, whereas the MNA-Assessment score predicted physical performance, particularly gait speed, in community-dwelling older adults at risk of falls. Periodic malnutrition screening by MNA may help early detection of poor muscle mass and function in generally healthy older adults.