ABSTRACT
Objective:To investigate the predictive value of visceral fat area (VFA) on multiple metabolic risk factors in obese patients undergoing bariatric surgery.Methods:The retrospective case-control study was conducted. The clinical data of 146 obese patients undergoing bariatric surgery in the West China Hospital of Sichuan University from June 2015 to May 2020 were collected. There were 57 males and 89 females, aged (33±9)years, with a range from 15 to 65 years. All patients underwent multi-slice spiral computed tomography (CT) examination, and the total fat area (TFA), VFA and subcutaneous fat area (SFA) were measured. Observation indicators: (1) CT findings of abdominal fat area and patients with multiple metabolic risk factors; (2) receiver operator characteristic(ROC) curve of different clinical indicators for predicting multiple metabolic risk factors; (3) relationship between different VFA and clinicopathological features in patients; (4) analysis of factors influencing multiple metabolic risk factors in patients. Measurement data with normal distribution were expressed as Mean± SD, and comparison between groups was analyzed by independent sample t test. Measurement data with skewed distribution were expressed as M (range) and comparison between groups was analyzed by nonparametric rank sum test. Count data were represented as absolute numbers, and comparison between groups was analyzed using the chi-square test. The ROC curve was used to analyze the predictive value of different clinical indicators for multiple metabolic risk factors in patients. Logistic regression analysis was used for univariate and multivariate analysis. Results:(1) CT findings of abdominal fat area and patients with multiple metabolic risk factors. CT findings of 146 patients showed that VFA was (212±122)cm 2, SFA was (419±147)cm 2, visceral-to-subcutaneous fat ratio (VSR) was 0.60±0.54. The levels of systolic blood pressure (SBP), diastolic blood pressure, fasting blood glucose (FBG), triglyceride and highdensity lipoprotein cholesterol (HDL-C) were (131±16)mmHg(1 mmHg=0.133 kPa), (86±12)mmHg, (6.4±2.5)mmol / L, 4.43 mmol /L(range, 1.23-9.99 mmol/L), (1.5±1.3)mmol/L, respectively. Among the 146 patients, 85 had impaired FBG or diabetes, 82 had hypertension, 139 had high triglyceride, 91 had low serum HDL-C; 128 had multiple metabolic risk factors. (2) ROC curve analysis of different clinical indicators for predicting multiple metabolic risk factors: the ROC curve showed that VFA had better ability to predict or diagnose multiple metabolic risk factors in patients ( hazard ratio=0.617, 95% confidence interval as 0.470-0.764, P<0.05). The cutoff value of VFA was 163.52 cm 2 by calculating Yoden index in ROC curve. (3) Relationship between different VFA and clinicopathological features in patients: according to the cutoff value of 163.52 cm 2 in ROC curve, 146 patients were divided into high VFA group (≥163.52 cm 2) and the low VFA group (<163.52 cm 2), with 49 cases and 97 cases respectively. Cases with hypertension, level of SBP, cases with impaired FBG or diabetes, cases with multiple metabolic risk factors were 64, (134±17)mmHg, 63, 90 for the high VFA group, versus 18, (127±13)mmHg, 22, 38 for the low VFA group; there were significant differences in above indicators between the two groups ( χ2=11.309, t=6.916, χ2=5.380, 6.988, P<0.05). (4) Analysis of factors influencing multiple metabolic risk factors in patients: results of univariate analysis showed that VFA was a related factor for multiple metabolic risk factors in patients ( hazard ratio=3.722, 95% confidence interval as 1.341-10.328, P<0.05). Results of multivariate analysis showed that the VFA≥163.52 cm 2 was an independent rsik factcor or multiple metabolic risk factors in patients ( hazard ratio=5.182, 95% confidence interval as 1.441-18.641, P<0.05). Conclusions:VFA is positively correlated with hypertension, systolic blood pressure, impaired FBG and diabetes. VFA≥163.52 cm 2 is an independent predictor for multiple metabolic risk factors in obese patients undergoing bariatric surgery.