JMIR Publications

ABSTRACT

Background:

Visceral adipose tissue (VAT) plays an active role in the pathogenesis of type 2 diabetes and vascular dysfunction. The lipid accumulation product (LAP), visceral adiposity index (VAI), and Chinese VAI (CVAI) have been proposed as simple and validated surrogate indices for measuring VAT. However, evidence from prospective studies on the associations between these novel indices of visceral obesity and diabetic retinopathy (DR) in type 2 diabetes remains scanty.

Objective:

We aimed to investigate the longitudinal associations of LAP, VAI, and CVAI, with incident DR in patients with type 2 diabetes.

Methods:

This was a prospective cohort study conducted in Guangzhou, southern China. Baseline data was collected between November 2017 and July 2020, while on-site follow-up visits were conducted annually until January 2022. The participants consisted of 1,403 patients with physician-diagnosed type 2 diabetes, referred from primary care, who were free of DR at baseline. The LAP, VAI, and CVAI levels were calculated by sex-specific equations based on anthropometric and biochemical parameters. DR was assessed using 7-field colour stereoscopic fundus photographs and graded according to the modified Airlie House Classification Scheme. Time-dependent Cox proportional hazard models were constructed to estimate the hazard ratios (HR) with 95% confidence intervals (CI). Restricted cubic spline curves were fitted to examine the dose-response relationship between the three indices of visceral obesity and new-onset DR. Subgroup analyses were performed to investigate the potential effect modifiers.

Results:

The mean age of study participants was 64.5 ±7.6 (standard deviation) years and over half (58.2% [816/1,403]) were women. During a median follow-up of 2.13 years, 406 DR events were observed. A one-standard-deviation increment in LAP, VAI, or CVAI was consistently associated with increased risk for new-onset DR, with a multivariable‑adjusted HR of 1.24 (95% CI, 1.09-1.41; P=0.001), 1.22 (95% CI, 1.09-1.36; P<0.001), and 1.48 (95% CI, 1.19-1.85; P=0.001), respectively. Similar patterns were observed across tertiles in LAP (P for trend =0.001), VAI (P for trend <0.001), and CVAI (P for trend =0.009). Patients in the highest tertile of LAP, VAI, and CVAI had an 84%, 86%, and 82% higher hazard of DR, respectively, compared to those in the lowest tertile. A nonlinear dose-response relationship with incident DR was noted for LAP and VAI (both P for nonlinearity <0.05), but not for CVAI (P for nonlinearity =0.508). We did not detect the presence of effect modification by age, sex, duration of diabetes, body mass index, and comorbidity (all P for interaction >0.10).

Conclusions:

Visceral obesity as measured by LAP, VAI, or CVAI, is independently associated with increased risk for new-onset DR in Chinese type 2 diabetic patients. Our findings may suggest the necessity for regular monitoring of visceral obesity indices in clinical practice to enhance population-based prevention for DR.