Association between abdominal obesity indices and risk of cardiovascular events in Chinese populations with type 2 diabetes: a prospective cohort study

Abstract

Background: Waist circumference (WC), visceral adiposity index (VAI), lipid accumulation product (LAP), and Chinese visceral adiposity index (CVAI) are considered surrogate indicators of abdominal fat deposition, but the longitudinal association of these indices with cardiovascular (CV) events in adults with type 2 diabetes (T2D) remains unclear. Our study aimed to examine the associations between abdominal obesity indices and incident CV events among people with T2D and to compare their predictive performance in risk assessment.

Methods: The present study included 2328 individuals with T2D from the Xinjiang Multi-Ethnic Cohort. Multivariable Cox regression analyses were applied to assess the associations between abdominal obesity indices and CV events. Harrell's concordance statistic (C-statistic), net reclassification improvement (NRI) index, and integrated discrimination improvement (IDI) index were utilized to evaluate the predictive performance of each abdominal obesity index.

Results: At a median follow-up period of 59 months, 289 participants experienced CV events. After multivariable adjustment, each 1-SD increase in WC, VAI, LAP, and CVAI was associated with a higher risk of CV events in people with T2D, with adjusted hazard ratios (HRs) being 1.57 [95% CI (confidence interval): 1.39-1.78], 1.11 (95% CI 1.06-1.16), 1.46 (95% CI 1.36-1.57), and 1.78 (95% CI 1.57-2.01), respectively. In subgroup analyses, these positive associations appeared to be stronger among participants with body mass index (BMI) < 25 kg/m² compared to overweight/obese participants. As for the predictive performance, CVAI had the largest C-statistic (0.700, 95% CI 0.672-0.728) compared to VAI, LAP, WC, and BMI (C-statistic: 0.535 to 0.670, all P for comparison < 0.05). When the abdominal obesity index was added to the basic risk model, the CVAI index also showed the greatest incremental risk stratification (C-statistic: 0.751 vs. 0.701, P < 0.001; IDI: 4.3%, P < 0.001; NRI: 26.6%, P < 0.001).

Conclusions: This study provided additional evidence that all abdominal obesity indices were associated with the risk of CV events and highlighted that CVAI might be a valuable abdominal obesity indicator for identifying the high risk of CV events in Chinese populations with T2D. These results suggest that proactive assessment of abdominal obesity could be helpful for the effective clinical management of the diabetic population.

Keywords: Abdominal obesity; Cardiovascular disease; Chinese visceral adiposity index; Lipid accumulation product; Type 2 diabetes; Visceral adiposity index.

Fig.1

Flowchart of the study population

Fig.2

Kaplan–Meier incidence rate of cardiovascular events in people with type 2 diabetes according to quartiles of abdominal obesity indices. A waist circumference (WC), B visceral adiposity index (VAI), C lipid accumulation product (LAP), and D Chinese visceral adiposity index (CVAI)

Fig.3

Association between abdominal obesity indices and cardiovascular events among people with type 2 diabetes in different subgroups. Each subgroup was adjusted for gender, age, ethnicity, education, smoking status, drinking status, low-density lipoprotein cholesterol, total cholesterol, fasting blood glucose, systolic blood pressure, diastolic blood pressure, physical activity, antidiabetic agents, and diabetes duration, except for stratification variables. Hazard ratios are presented as per 1 SD increase in the abdominal obesity indices for cardiovascular events. BMI, body mass index; CI, confidence interval; HR, hazard ratio; WC, waist circumference; VAI, visceral adiposity index; LAP, lipid accumulation product; CVAI, Chinese visceral adiposity index