AB1228 Sonoelastography of quadriceps is more accuracy than grip strength to predict low muscle mass

Background Reduced muscle mass had associated with higher mortality. So it is mandatory for simple techniques to early detection sof arcopenia. However, some patients with low grip strength had normal muscle mass, especially those with rheumatoid arthritis. Objectives Our objective was to examine the validity of sonoelastography to predict sarcopenia in osteoporotic patients. Methods We conducted an observational study in Kaohsiung Chang Gang Memorial Hospital. Low muscle mass was determined using a dual-energy X-ray absorptiometry. Sonoelastography was performed over mid thigh over quadriceps muscle. We measure grip strength and hardness and elastography ratio of quadriceps over subcutaneous fat tissue. Logistical regression was used to find the factors to predict low muscle mass. While ROC analysis was used to find best cut-off point. Results A total 122 (68 low muscle mass, 54 normal muscle mass) patients were enrolled. The mean age was 79.26±6.77 years in low muscle mass group and 74.7±13.49 in normal muscle mass group(p=0.017). Most patients (86.9%) were women. Sonoelastography showed low muscle mass patients had more soft than normal muscle mass patients, furthermore the elastography ratio of quadriceps over subcutaneous tissue was lower than normal muscle mass patients. Using logistical regression, grip strength, sex and age cannot be used to predict low muscle mass, while the hardness and ratio had statistically significant to predict low muscle mass (p=0.001). When the cut points determined by receiver operating characteristic (ROC) curve analysis were applied, The best cut-point of hardness was 64.79%(sensitivity, 0.741; 1-specificity, 0.147), while the best cut-point of quadriceps over subcutaneous tissue was 0.81 (sensitivity, 0.815; 1-specificity, 0.118). Conclusions Our findings indicate that sonoelastography is more accurate to predict low muscle mass. The measurement include quadriceps over subcutaneous tissue and hardness of the quadriceps. Although, grip strength is less expensive for evaluation of muscular weakness, from this findings, it is not a reliable method for evaluation of low muscle mass. The possible reason is that sarcopenia initial occur at thigh muscle and then spread up to upper limb. So grip strength is not a accurate method to screen sarcopenia. Reference [1] Cruz-Jentoft AJ, Baeyens JP, Bauer JM, Boirie Y, Cederholm T, Landi F, Martin FC, Michel JP, Rolland Y, Schneider SM, et al: Sarcopenia: European consensus on definition and diagnosis: Report of the European Working Group on Sarcopenia in Older People. Age and ageing2010, 39(4):412–423. Acknowledgements This study was supported by Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung grant CMRP Disclosure of Interest None declared