Phase Angle and Its 5-Year Change Linked to Mortality in Older Japanese Adults

Phase angle measured by bioimpedance is considered to reflect muscle quality and nutritional status. This study investigated the associations of phase angle and its 5-year change with all-cause mortality among community-dwelling older Japanese adults. A total of 1,291 Japanese adults aged ≥65 years with phase angle measured in 2012 were followed-up for a median of 10.3 years. Participants were divided into age-and sex-specific quartiles of phase angle and into quartiles of 5-year change in phase angle beyond standard age-related decline, defined as the difference between actually measured and estimated values from the linear regression line between phase angle values measured in 2007 and 2012. Hazard ratios (HRs) for all-cause mortality were estimated using Cox proportional hazards models. During follow-up, 347 participants died. The lowest quartile of phase angle showed a higher risk of all-cause mortality compared with the highest quartile after multivariable adjustment (HR 1.49, 95% CI 1.10–2.02). A similar trend was observed for 5-year change in phase angle beyond age-related decline (HR 1.42, 95% CI 1.03–1.97). Lower phase angle and greater decline beyond age-related expectations were associated with increased mortality risk. Phase angle may provide a simple, noninvasive measure of mortality risk in older adults. Rights and permissions Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Reprints and permissions