The decreasing phase angles of the entire body and trunk during bioelectrical impedance analysis are related to locomotive syndrome.

BACKGROUND

The phase angle (measured via bioelectrical impedance analysis [BIA]) is an indicator of cell membrane function and used for prognostic evaluation of diseases. Locomotive syndrome (LS) has been advocated in the evaluation of physical ability. This study aimed to determine the relationship between LS and the phase angle as well as muscle mass, muscular strength, and motor function.

METHODS

In this prospective cohort study, 541 patients undergoing a health checkup participated. All participants were assessed using a 25-question geriatric locomotive function scale for the diagnosis of LS, phase angle, and muscle mass measurements via BIA. Grip strength, back muscle strength, and 3-m timed-up-and-go (TUG) test measurements were used as physical performance tests. Patients were divided into non-LS and LS groups, and their characteristics were compared. We assessed whether the phase angle was related to LS, whether it could be a risk factor in multivariate analysis, and the most important part of the phase angle.

RESULTS

Age, the whole body phase angle, grip strength, back muscle strength, and TUG test result were significantly different between the two groups. Logistic regression analysis revealed that the whole body phase angle and TUG test result were risk factors of LS. Based on the subanalysis targeting specific phase angles, the trunk phase angle was a significant important factor for LS.

CONCLUSION

The phase angle was significantly related to LS, and the decreased phase angle was a significant risk factor of LS together with the TUG test result. Furthermore, in subgroup analysis, the phase angle of the trunk was a significant important factor of LS. BIA can be performed conveniently, and it has been widely used for health checkups and in clinical practice. Focusing on the phase angle in BIA may be additionally helpful for the early detection and early intervention of LS.