Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
Department of Internal Medicine, Healthcare Research Institute, Healthcare System Gangnam Center, Seoul National University Hospital, Seoul, Korea.
J Cachexia Sarcopenia Muscle. 2023 Jun;14(3):1495-1507. doi: 10.1002/jcsm.13226. Epub 2023 Apr 5.
The prognostic role of increased visceral fat attenuation (VFA) remains underexplored. We investigated the long-term prognostic implications of computed tomography (CT)-derived VFA in a health check-up population.
This study included consecutive individuals who had positron-emission tomography/CT scans for health check-ups between January 2004 and December 2010. The primary outcome was overall survival (OS), and the secondary outcomes were cancer-specific survival (CSS) and non-cancer-specific survival (NCS). Commercially available body composition analysis software was used to obtain abdominal waist VFA, visceral fat volume index (VFI) and skeletal muscle index (SMI) at the L3 level. Sarcopenia was determined using sex-specific SMI references. VFA and VFI were dichotomized using the thresholds for the highest quartiles. The relationship between CT-derived body composition parameters and body mass index (BMI) was evaluated with Pearson correlation coefficients. The prognostic implications of VFA and sarcopenic obesity (SO) defined by VFA were assessed by multivariable Cox regression analysis and Kaplan-Meier plots with log-rank tests.
A total of 2720 individuals (1530 men [56.3%] and 1190 women [43.7%]; median age: 53 years, inter-quartile range: 47-60 years) were included. During the median follow-up of 138 months, 128 individuals (5%) died (cancer mortality: 2%; non-cancer mortality: 3%), with 0.2% (5 of 2720) and 1.1% (30 of 2720) of 1- and 5-year mortality rates. VFA was negatively correlated with BMI (r = -0.62; P < 0.001) and VFI (r = -0.69; P < 0.001). After adjusting for clinical variables, sarcopenia and VFI, high VFA was a negative prognostic factor for OS (hazard ratio [HR]: 1.05 per Hounsfield unit; 95% confidence interval [CI]: 1.02, 1.08; P = 0.001), CSS (HR: 1.07 per Hounsfield unit; 95% CI: 1.02, 1.12; P = 0.006) and NCS (HR: 1.03 per Hounsfield unit; 95% CI: 1.01, 1.06; P = 0.009). Individuals with high VFA had higher high-sensitivity C-reactive protein levels than those with low VFA (0.11 vs. 0.03 mg/dL; P < 0.001). Individuals with SO defined by VFA had worse OS (9% vs. 4%; P < 0.001), CSS (3% vs. 2%; P = 0.02) and NCS (6% vs. 3%; P < 0.001) than those without SO, even in the same BMI (underweight-to-normal BMI, OS: 8% vs. 4%; overweight-to-obese BMI, OS: 38% vs. 4%; P < 0.001 in both) or VFI category (high VFI, OS: 43% vs. 6%; low VFI, OS: 8% vs. 3%; P < 0.001 in both).
High VFA was associated with long-term mortality and low-grade inflammation. VFA can further stratify the current SO by BMI or VFI, and SO defined by VFA can identify individuals who are most vulnerable to long-term mortality.
内脏脂肪衰减程度（VFA）的预后作用仍未得到充分探索。我们研究了健康体检人群中 CT 衍生的 VFA 在长期预后中的意义。
本研究纳入了 2004 年 1 月至 2010 年 12 月期间进行正电子发射断层扫描/CT 健康检查的连续个体。主要结局为总生存（OS），次要结局为癌症特异性生存（CSS）和非癌症特异性生存（NCS）。使用商业体成分分析软件获得 L3 水平的腹部腰围 VFA、内脏脂肪体积指数（VFI）和骨骼肌指数（SMI）。使用性别特异性 SMI 参考值确定肌少症。使用四分位法将 VFA 和 VFI 分为最高四分位数。使用 Pearson 相关系数评估 CT 衍生体成分参数与体重指数（BMI）之间的关系。使用多变量 Cox 回归分析和 Kaplan-Meier 图与对数秩检验评估 VFA 与由 VFA 定义的肌少性肥胖（SO）的预后意义。
共纳入 2720 名个体（男性 1530 名[56.3%]，女性 1190 名[43.7%]；中位年龄：53 岁，四分位间距：47-60 岁）。在中位随访 138 个月期间，128 名个体（5%）死亡（癌症死亡率：2%；非癌症死亡率：3%），1 年和 5 年的死亡率分别为 0.2%（5/2720）和 1.1%（30/2720）。VFA 与 BMI（r=-0.62；P<0.001）和 VFI（r=-0.69；P<0.001）呈负相关。在校正临床变量、肌少症和 VFI 后，高 VFA 是 OS（风险比[HR]：每 Hounsfield 单位 1.05；95%置信区间[CI]：1.02，1.08；P=0.001）、CSS（HR：每 Hounsfield 单位 1.07；95%CI：1.02，1.12；P=0.006）和 NCS（HR：每 Hounsfield 单位 1.03；95%CI：1.01，1.06；P=0.009）的不良预后因素。高 VFA 个体的高敏 C 反应蛋白水平高于低 VFA 个体（0.11 比 0.03mg/dL；P<0.001）。与无 SO 相比，SO 定义为 VFA 的个体 OS（9%比 4%；P<0.001）、CSS（3%比 2%；P=0.02）和 NCS（6%比 3%；P<0.001）更差，即使在相同的 BMI（体重不足至正常 BMI，OS：8%比 4%；超重至肥胖 BMI，OS：38%比 4%；均 P<0.001）或 VFI 类别（高 VFI，OS：43%比 6%；低 VFI，OS：8%比 3%；均 P<0.001）。
高 VFA 与长期死亡率和低度炎症相关。VFA 可以进一步对当前基于 BMI 或 VFI 的 SO 进行分层，而 VFA 定义的 SO 可以识别出最易发生长期死亡率的个体。
