Elevated triglyceride-glucose-body mass index associated with lower probability of future regression to normoglycemia in Chinese adults with prediabetes: a 5-year cohort study

Abstract

Objective: Despite the clear association of TyG-BMI with prediabetes and the progression of diabetes, no study to date has examined the relationship between TyG-BMI and the reversal of prediabetes to normoglycemia.

Methods: 25,279 participants with prediabetes who had physical examinations between 2010 and 2016 were enrolled in this retrospective cohort study. The relationship between baseline TyG-BMI and regression to normoglycemia from prediabetes was examined using the Cox proportional hazards regression model in this study. Additionally, the nonlinear association between TyG-BMI and the likelihood of regression to normoglycemia was investigated using the Cox proportional hazards regression with cubic spline function. Competing risk multivariate Cox regression analysis was conducted, with progression to diabetes as a competing risk for prediabetes reversal to normoglycemia. Furthermore, subgroup analyses and a series of sensitivity analyses were performed.

Results: After adjusting for covariates, the results showed that TyG-BMI was negatively associated with the probability of returning to normoglycemia (per 10 units, HR=0.970, 95% CI: 0.965, 0.976). They were also nonlinearly related, with an inflection point for TyG-BMI of 196.46. The effect size (HR) for TyG-BMI to the right of the inflection point (TyG-BMI ≥ 196.46) and the probability of return of normoglycemia was 0.962 (95% CI: 0.954, 0.970, per 10 units). In addition, the competing risks model found a negative correlation between TyG-BMI and return to normoglycemia (SHR=0.97, 95% CI: 0.96-0.98). Sensitivity analyses demonstrated the robustness of our results.

Conclusion: This study demonstrated a negative and nonlinear relationship between TyG-BMI and return to normoglycemia in Chinese adults with prediabetes. Through active intervention, the combined reduction of BMI and TG levels to bring TyG-BMI down to 196.46 could significantly increase the probability of returning to normoglycemia.

Keywords: TyG-BMI; competitive risk model; conversion to normoglycemia; nonlinear; prediabetes.

Figure 1

Flowchart illustrating the composition of study participants.

Figure 2

Distribution of TyG-BMI. It has a mean of 219.47 and a normal distribution with values between 116.94 and 334.08.

Figure 3

The rate of return to normoglycemia from prediabetes according to the quartiles of TyG-BMI. Participants with the highest TyG-BMI(Q4) had a lower regression rate to normoglycemia than those with the lowest TyG-BMI(Q1) (p<0.001 for trend).

Figure 4

showed the Kaplan-Meier curves for the likelihood of transitioning from prediabetes to normoglycemia. Displayed the Kaplan-Meier curves illustrating the probability of regression from Pre-DM to normoglycemia based on TyG-BMI quartiles. There was a significant difference in the probability of returning to normoglycemia in the different TyG-BMI quartile groups (log-rank test, P<0.001). Compared with participants in the lowest TyG-BMI quartile group (Q1), participants in the higher TyG-BMI quartile groups (Q2 to Q4) had a lower probability of reversing to normoglycemia during the follow-up period.

Figure 5

The nonlinear relationship between TyG-BMI and the probability of reversion to normoglycemia from Pre-DM. The result showed that the relationship between TyG-BMI and regression to normoglycemia from Pre-DM was nonlinear, with the inflection point of TyG-BMI being 196.46.