Association of the Global Alignment and Proportion Score with Locomotive Syndrome and Health-Related Quality of Life in Community-Dwelling Middle-Aged and Older Adults: A Retrospective Cross-Sectional Study.

BACKGROUND: The Global Alignment and Proportion score has been validated in surgical cohorts as a predictor of mechanical complications in adult spine deformity, but its significance in the general population is poorly understood. We examined the association of the Global Alignment and Proportion score categories with locomotor syndrome and health-related quality of life in community-dwelling middle-aged and older adults to clarify the role of proportionality of sagittal alignment in musculoskeletal function and quality of life. METHODS: Residents of Hokkaido, Japan, who underwent musculoskeletal health screening in 2019 were included in this retrospective cross-sectional study. Based on their Global Alignment and Proportion score classification, participants were divided into three groups: proportioned, moderately disproportioned (moderate), and severely disproportioned (severe). We compared participants' background, bone mineral density, exercise tests, pain levels, locomotor syndrome stage, and Short Form 36-Item Health Survey score data. RESULTS: The mean age of the 217 participants was 64.0±9.5 years; 127 were female. The mean Global Alignment and Proportion score was 6.1±3.4 points, and the proportioned, moderate, and severe groups comprised 27, 106, and 84 participants, respectively. A statistically significant trend was observed in which the number of participants at high risk for locomotive syndrome increased as the Global Alignment and Proportion risk state worsened. In the Short Form 36 Health Survey domains of bodily pain and physical component summary scores, statistically significant trends toward lower scores were observed across groups with worsening Global Alignment and Proportion risk status. CONCLUSIONS: We identified an association between poorer Global Alignment and Proportion scores and the presence of locomotive syndrome, as well as lower health-related quality of life, among middle-aged and older adults. These findings suggest that the Global Alignment and Proportion score may be a useful indicator for characterizing musculoskeletal alignment in clinical and public health fields.