International Journal of Medicine and Data

Sarcopenia is a progressive muscle disorder characterized by progressive and generalized loss of skeletal muscle mass and functions and it is strictly correlated with physical disability and functional decline. When sarcopenia presents itself as the atrophy of tongue muscles which is further manifested by a reduction of tongue thickness, the reduction of suprahyoid muscle strength may result in difficulties in swallowing and increased risks of aspiration, which can be fatal. Common screening approaches at sarcopenia include questionnaires, diagnostic grids, or prediction equations which comprise of “rule-out” tests that identify those who are not at risk of sarcopenia by comparing different parameters. SMM and bodyweight are regarded as the most reliable and common parameters and could be obtained by a bioelectrical impedance analysis (BIA) machine. The Iowa Oral Performance Instrument (IOPI) used as an intervention tool in measuring strength and endurance of tongue in healthy populations or disordered populations. Owing to the adverse impacts of sarcopenia on swallowing, there is a need for using a more cost-effective and universal method to measure tongue thickness for the screening of sarcopenia. This study aimed at measuring the tongue thickness using ultrasound, examining the correlation between sarcopenia and tongue thickness and generalizing the use of ultrasound in the screening of sarcopenia. Objectives The study aimed at comparing the tongue thickness between healthy subjects and older individuals with sarcopenia. Methods A population-based sample of 35 male and female were recruited by convenience sampling. The sample met the selection criteria and was comprised of the sarcopenia group (n=15) who were recruited from the Kowloon Home for the Aged Blind and the healthy subject group (n=25) who were recruited in the community. The tongue thickness of the subjects was examined by the MIRUKO ® Portable Ultrasound (Nippon Sigmax Co. Ltd, Tokyo, Japan). The mean value of the distance between the midpoint of the lower end of the geniohyoid muscle to the tongue dorsum obtained from the three trials was considered to be the tongue thickness. Muscle mass, Skeletal Muscle Mass(SMM) and skeletal muscle index (SMI) were measured by bioelectrical impedance analysis (BIA) using InBody S10 (InBody Co. Ltd, Seoul, Korea). This study adopted the EWGS cut-off thresholds for skeletal muscle index (SMI) hand grip strength was 7.4 kg/m2 and 22 kg for females with sarcopenia. (Bahat G et al., 2016). Results Receiver operating characteristic curve on the tongue thickness revealed that the tongue thickness at 4.145cm displayed the sensitivity and specificity to classify the sarcopenia at 80% and 70% respectively. The area under the curve at 0.737 with p = 0.018. In people with sarcopenia (N= 15), there were significant correlation between tongue thickness, the skeletal muscle mass (r = 0.643, p = 0.01) and skeletal muscle index (r = 0.564, p = 0.028). Regression model on the prediction of the SMM by the tongue thickness showed that the tongue thickness explained 35.7% of the SMM (F = 7.223, df =1, p = 0.019). We incorporated Height, Weight, Tongue thickness, Tongue strength and Lip strength into the regression model, which explained 95.1% of the SMM (F=19.367, df = 7, p<0.001). However, only the coefficient of height and weight were significant in the model. Conclusion and Future Implications Our findings suggested that tongue thickness had a positive and significant correlation with skeletal muscle mass and body weight. The results revealed that tongue thickness might be an indicator of sarcopenia, and hence ultrasound could be used in the screening of sarcopenia. Early screening may help to minimize the health consequences of dysphagia and aspiration that could otherwise be avoided and the economic burden sarcopenia has exerted on the healthcare system. In addition, the use of ultrasound in measuring tongue thickness has the potential to monitor the progress of oral-motor training and rehabilitation process of older individuals with sarcopenia.

Sarcopenia; Dysphagia; Ultrasound