Graduate School, Beijing University of Chinese Medicine, Beijing, China.
Department of Pediatrics, China-Japan Friendship Hospital, Beijing, China.
JAMA Netw Open. 2024 Jun 3;7(6):e2415051. doi: 10.1001/jamanetworkopen.2024.15051.
Obesity, especially visceral obesity, is an established risk factor associated with all-cause mortality. However, the inadequacy of conventional anthropometric measures in assessing fat distribution necessitates a more comprehensive indicator, body roundness index (BRI), to decipher its population-based characteristics and potential association with mortality risk.
To evaluate the temporal trends of BRI among US noninstitutionalized civilian residents and explore its association with all-cause mortality.
DESIGN, SETTING, AND PARTICIPANTS: For this cohort study, information on a nationally representative cohort of 32 995 US adults (age ≥20 years) was extracted from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 and NHANES Linked Mortality File, with mortality ascertained through December 31, 2019. Data were analyzed between April 1 and September 30, 2023.
Biennial weighted percentage changes in BRI were calculated. Restricted cubic spline curve was used to determine optimal cutoff points for BRI.
The survival outcome was all-cause mortality. Mortality data were obtained from the Centers for Disease Control and Prevention website and linked to the NHANES database using the unique subject identifier. Weibull regression model was adopted to quantify the association between BRI and all-cause mortality.
Among 32 995 US adults, the mean (SD) age was 46.74 (16.92) years, and 16 529 (50.10%) were women. Mean BRI increased gradually from 4.80 (95% CI, 4.62-4.97) to 5.62 (95% CI, 5.37-5.86) from 1999 through 2018, with a biennial change of 0.95% (95% CI, 0.80%-1.09%; P < .001), and this increasing trend was more obvious among women, elderly individuals, and individuals who identified as Mexican American. After a median (IQR) follow-up of 9.98 (5.33-14.33) years, 3452 deaths (10.46% of participants) from all causes occurred. There was a U-shaped association between BRI and all-cause mortality, with the risk increased by 25% (hazard ratio, 1.25; 95% CI, 1.05-1.47) for adults with BRI less than 3.4 and by 49% (hazard ratio, 1.49; 95% CI, 1.31-1.70) for those with BRI of 6.9 or greater compared with the middle quintile of BRI of 4.5 to 5.5 after full adjustment.
This national cohort study found an increasing trend of BRI during nearly 20-year period among US adults, and importantly, a U-shaped association between BRI and all-cause mortality. These findings provide evidence for proposing BRI as a noninvasive screening tool for mortality risk estimation, an innovative concept that could be incorporated into public health practice pending consistent validation in other independent cohorts.
肥胖，尤其是内脏肥胖，是与全因死亡率相关的既定风险因素。然而，传统人体测量学指标在评估脂肪分布方面的不足，需要更全面的指标——体圆度指数（BRI），以解析其基于人群的特征及其与死亡风险的潜在关联。
评估美国非住院平民居民的 BRI 随时间的变化趋势，并探讨其与全因死亡率的关系。
设计、地点和参与者：本队列研究从 1999 年至 2018 年，从国家健康和营养检查调查（NHANES）中提取了一个全国代表性的美国成年人队列（年龄≥20 岁）的信息，以及 NHANES 关联死亡率文件，通过 2019 年 12 月 31 日的死亡率确定。数据于 2023 年 4 月 1 日至 9 月 30 日之间进行分析。
计算 BRI 的两年加权百分比变化。使用限制立方样条曲线确定 BRI 的最佳截断点。
生存结局是全因死亡率。通过疾病控制和预防中心网站获取死亡率数据，并使用唯一的主题标识符将其与 NHANES 数据库关联。采用威布尔回归模型来量化 BRI 与全因死亡率之间的关联。
在 32995 名美国成年人中，平均（标准差）年龄为 46.74（16.92）岁，16529 名（50.10%）为女性。BRI 从 1999 年到 2018 年逐渐增加，从 4.80（95%CI，4.62-4.97）增加到 5.62（95%CI，5.37-5.86），每两年变化 0.95%（95%CI，0.80%-1.09%；P<0.001），这种增加趋势在女性、老年人和墨西哥裔美国人中更为明显。在中位数（IQR）随访 9.98（5.33-14.33）年后，共有 3452 人（占参与者的 10.46%）死于各种原因。BRI 与全因死亡率之间存在 U 型关联，BRI 低于 3.4 的成年人的风险增加 25%（风险比，1.25；95%CI，1.05-1.47），BRI 为 6.9 或更高的成年人的风险增加 49%（风险比，1.49；95%CI，1.31-1.70）与 BRI 为 4.5 至 5.5 的中间五分位相比，经充分调整后。
本全国性队列研究发现，美国成年人在近 20 年期间 BRI 呈上升趋势，重要的是，BRI 与全因死亡率之间存在 U 型关联。这些发现为提出 BRI 作为死亡率风险估计的非侵入性筛查工具提供了证据，这是一个创新的概念，可以在其他独立队列中进行一致验证后纳入公共卫生实践。
