The Association Between the Triglyceride-to-High-Density Lipoprotein Cholesterol Ratio and the Risk of Progression to Diabetes From Prediabetes: A 5-year Cohort Study in Chinese Adults

Abstract

Objective: Evidence regarding the relationship between the triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-c) ratio and the risk of progression from prediabetes to diabetes remains limited. The purpose of our study was to investigate the relationship between the TG/HDL-C ratio and incident diabetes in prediabetic patients.

Methods: This retrospective cohort study covered 32 regions and 11 cities in China and consecutively and non-selectively collected data from 15,017 patients with prediabetes who had received a health check from 2010 to 2016. Data were obtained from the DATADRYAD database (www.datadryad.org). The Cox proportional-hazards regression model with cubic spline functions and smooth curve fitting (cubic spline smoothing) was used to explore the non-linear relationship between the baseline TG/HDL-c ratio and the risk of diabetes in patients with prediabetes. In addition, we performed a series of sensitivity and subgroup analyses.

Results: The mean age of the included individuals was 50.95 ± 13.48 years, and 9,745 (64.51%) were men. The median (interquartile range) TG/HDL-c ratio was 1.09 (0.69-1.72). During a median follow-up time of 3.05 years, 1,731 (11.46%) patients had a final diagnosis of diabetes. The analysis after adjusting for covariates showed that the TG/HDL-c ratio was positively related to incident diabetes in patients with prediabetes (HR = 1.111, 95% CI 1.061-1.164). Participants with the highest TG/HDL-c ratio (Q4) had higher diabetes incidence rates than those with the lowest TG/HDL-c ratio (Q1) (P < 0.001 for the trend). There was a non-linear relationship between the TG/HDL-c ratio and the risk of diabetes, and the inflection point of the TG/HDL-c ratio was 1.415. The effect sizes (HR) on the left and right sides of the inflection point were 1.336 (95% CI: 1.134-1.573) and 1.055 (95% CI: 0.988-1.126), respectively. The sensitivity analysis demonstrated the robustness of these results.

Conclusion: This study demonstrates a positive, non-linear relationship between the TG/HDL-c ratio and the risk of diabetes in Chinese patients with prediabetes. Aggressive intervention from a treatment perspective is required to lower the TG/HDL-c ratio below the inflection point (1.415) by lowering TG or increasing HDL-c levels.

Keywords: diabetes; dyslipidemia; nonlinear; prediabetes; smooth curve fitting.

Figure 1

Flowchart of study participants.

Figure 2

Distribution of the TG/HDL-c ratio. It presents a skewed distribution while being in the range from 0.039 to 5.453, with a median of 1.093.

Figure 3

The incidence rate for diabetes(Per 1000 person-year) according to the quartiles of TG/HDL-c ratio. Participants with the highest TG/HDL-c ratio (Q4) had higher diabetes incidence rates than those with the lowest TG/HDL-c ratio (Q1) (P < 0.001 for trend).

Figure 4

The incidence of diabetes (per 1,000 person-years) in prediabetic patients of age stratification by 10 intervals.

Figure 5

Kaplan–Meier event-free survival curve. Kaplan–Meier event-free survival curve. The probability of diabetes-free survival differed significantly between the TG/HDL-c ratio quartiles (log-rank test, P < 0.001). The probability of diabetes-free survival gradually increased with increasing TG/HDL-c ratio, suggesting that the group with the highest TG/HDL-c ratio had the highest risk of diabetes.

Figure 6

The non-linear relationship between TG/HDL-c ratio and the risk of diabetes in prediabetic participants. We used a Cox proportional hazards regression model with cubic spline functions to evaluate the relationship between TG/HDL-c ratio and diabetes risk. The result showed that the relationship between the TG/HDL-c ratio and diabetes risk in prediabetic patients was non-linear, with the inflection point of TG/HDL-c ratio being 1.415.