Handgrip Strength and Ultrasonographically-measured Lower Arm Muscle Thickness in Hospitalised Older Adults: The SARCopenia and Ultrasound 3rd Pilot Study

Abstract

Objective: The SARCopenia and UltraSound 3rd (SARCUS3) pilot study aims to determine the relationship between ultrasound (US)-based lower arm muscle thickness and handgrip strength in hospitalised older adults. Materials and Methods: SARCUS3 is a single-centre cross-sectional study (Ziekenhuis Netwerk Antwerpen, Campus Middelheim, Antwerp, Belgium). For inclusion, all patients admitted to a geriatric ward were screened. US was used to measure the thickness of the lower arm muscles. On the other hand, a Jamar dynamometer was used to measure handgrip strength. Results: A total of 83 patients were included in the data analysis (48 women, 35 men, mean age 84 years). According to the Shapiro-Wilk test, the lower arm muscle thickness and square root of handgrip strength had a normal distribution. The scatterplot and line of best fit suggested that the two variables had a linear relationship. Pearson’s correlation coefficient was 0.287 (p=0.051) for women and 0.361 (p=0.036) for men for the US-measured muscle thickness of the lower arm and square root of handgrip strength. A linear regression analysis of the data from the participating men revealed that the best estimate for handgrip strength can be calculated using the formula: handgrip strength (kg) = [2.773+0.061 × lower arm muscle thickness (mm2)], with an adjusted R square of 0.103. Conclusion: This pilot study, using US-based muscle measurements, discovered a significant positive relationship for men and a borderline nonsignificant relationship for women between lower arm muscle thickness and handgrip strength. Furthermore, muscle thickness alone can explain up to 10.3% of the measured variability of handgrip strength in men. To our knowledge, this study is the first to show that US-based measurements of the lower arm are related to handgrip strength in a group of hospitalised older people. More research is required to identify other factors that influence lower arm muscle strength in hospitalised older adults.