{
  "abstract": "Objective To examine the association of the body roundness index (BRI) with frailty.Design Two nationally representative cohorts and combined analyses.Settings China Health and Retirement Longitudinal Study (CHARLS) and Health and Retirement Study (HRS).Participants A total of 11 417 participants in CHARLS and 7787 participants in HRS were included.Main outcome measures BRI at baseline and during follow-ups, calculated using height and waist circumference, were categorised into five groups. Frailty was assessed using a 34-item frailty index among participants who were non-frail at baseline. Cox proportional-hazards model estimated the association between baseline BRI and frailty, with HR and 95% CI as effect sizes. Receiver operating characteristic (ROC) curves were performed to identify BRI’s predictive ability.Results Higher BRI was linked with an increased frailty risk compared with Q 3 in CHARLS (Q4: HR=1.260, 95% CI 1.099 to 1.443; Q5: HR=1.491, 95% CI 1.306 to 1.702), after full adjustment. In HRS, lower BRI decreased frailty risk (Q1: HR=0.764, 95% CI 0.662 to 0.882; Q2: HR=0.841, 95% CI 0.733 to 0.963) and higher BRI increased frailty risk (Q4: HR=1.134, 95% CI 1.001 to 1.285; Q5: HR=1.597, 95% CI 1.415 to 1.802). A significant association remained for higher BRI in the combined results. Additionally, the ROC curve found BRI’s modestly superior predictive ability for frailty, with cut-off values of 4.604 in CHARLS and 5.727 in HRS.Conclusions Higher BRI is linked to increased frailty risk in Chinese and US populations, with protective effects of lower BRI only seen in the USA. BRI may have potential as a public health tool, warranting further investigation into its role in other conditions and other populations.",
  "authors": [
    {
      "affiliations": [
        "Vanke School of Public Health, Tsinghua University, Beijing, People's Republic of China",
        "Institute for Healthy China, Tsinghua University, Beijing, People's Republic of China",
        "Department of Social Medicine and Behavioral Science, Division of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan",
        "Department of Clinical Epidemiology and Biostatistics, Children' s Hospital of Chongqing Medical University, National Clinical Research Center for Children and Adolescents' Health and Diseases, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, People's Republic of China"
      ],
      "name": "Xiaona Na"
    },
    {
      "affiliations": [
        "Department of Social Medicine and Behavioral Science, Division of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan"
      ],
      "name": "Kokoro Shirai"
    },
    {
      "affiliations": [
        "Department of Social Medicine and Behavioral Science, Division of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan"
      ],
      "name": "Keyang Liu"
    },
    {
      "affiliations": [
        "Vanke School of Public Health, Tsinghua University, Beijing, People's Republic of China",
        "Institute for Healthy China, Tsinghua University, Beijing, People's Republic of China"
      ],
      "name": "Yuefeng Tan"
    },
    {
      "affiliations": [
        "Vanke School of Public Health, Tsinghua University, Beijing, People's Republic of China",
        "Institute for Healthy China, Tsinghua University, Beijing, People's Republic of China"
      ],
      "name": "Ai Zhao"
    }
  ],
  "title": "Body roundness index and frailty: evidence from two prospective studies and combined analyses",
  "uid": "0984f730-56f3-5bf3-bbee-ee9356ceb635"
}