In our present study, we retrospectively investigated the predictive significance of IR assessed by the TyG index for MA in Chinese children with T1DM. The major findings were listed as follows:(1) The TyG index was significantly correlated with MA levels; (2) An elevated TyG index had a significantly greater risk of MA events independent of DKA, even after adjusting for confounding risk factors; (3) The TyG index was more specific than FPG and HBA1c in predicting MA; (4) Compared to patients with lower TyG index, those with higher TyG index had an apparently higher cumulative incidence of MA in 15 years. To our knowledge, our study is the first to compare the value of FPG, HbA1c, and TyG index to predict the risk of MA events in T1DM children.
Insulin resistance (IR), characterized by a decrease in cell sensitivity to insulin, is one of the leading causes of metabolic abnormalities. Lipidomics studies of young and at-risk patients that progressed to clinical disease revealed that some classes of lipids shown dysregulation in the blood. A few lipid metabolites were found to be associated with T1DM. The prevalence of hypertriglyceridemia and low HDL-C are key metabolic abnormalities in patients with IR and represent diabetic dyslipidemia. Metabolomics techniques have shown that patients who progress to diabetes have different levels of certain lipids when compared with persons who remain non-diabetic. Diabetic patients with dyslipidemia commonly suffer from a higher risk of adverse outcomes.
The TyG index is an advantageous surrogate marker of IR among adolescents, as it is a non-invasive method that uses common components to clinical practice, making it accessible and low cost. Besides, the TyG index has the advantage of being based on FPG levels, which is directly related to the development of IR, β-cell dysfunction, pre-DM, and T2DM in young adults. Thus, the FPG of the TyG index may potentiate it for the prediction of diabetes concerning lipid ratio. IR with higher TG and lower HDL-C concentrations is a clustered pathway of different metabolic disorders. A population-based study explored the associations of lipid parameters with prevalent IR and diabetes. The potential value of using the Non-HDL-C/HDL-C ratio and TG/HDL-C ratio as the dyslipidemia management tool among patients with diabetes should be given more consideration in the clinical approach. A study confirmed that the index provided a good alternative to the gold standard test for recognizing IR in children aged 7–17.IR is an increasingly important issue for the early identification of children at risk, and the TyG index offers the advantage that it not requires insulin measurements and is based on routine laboratory assessments.
The global burden of DN is rising along with an increasing prevalence of diabetes, which is a leading reason of kidney disease. Regular screening to detect DN can prompt early intervention, which can reduce the incidence of ESRD and healthcare costs, and increase ESRD-free survival. Levels of MA are seen as clinically relevant advanced stages of kidney disease because of their strong association with subsequent ESRD.
In our study, the MA patients had higher TG, TC, and LDL-C levels. In contrast, HDL-C was lower in patients with MA. It is clear that dyslipidemia contributes significantly to the excess risk of MA events. In addition, inflammatory protein levels in the serum have been associated with the presence of MA in T1DM patients. High serum concentrations of CRP were correlated with higher urinary albumin-to-creatinine ratio quartiles. However, we have not found the relationship between CRP, PCT, and MA. Several studies supported the clinical significance of the TyG index for the assessment of vascular damage. An elevated TyG index was closely correlated with a higher risk of arterial stiffness and nephric microvascular damage. A study reported that the TyG index demonstrated a positive linear correlation with urinary albumin to creatinine ratio. Zhao et al. found that a higher TyG index was associated with a higher risk of chronic kidney disease and MA. The TyG index could be a predictor of incident DN and play a role in nephric microvascular damage. In the future, more studies are needed to explore the relationship between the TyG index and microvascular damage, such as MA, DN, retinopathy, cardiac microvascular dysfunction, and markers of endothelial injury.
Anyway, recognition of these metabolic alterations may aid in studies of disease progression and may open a time window for MA prevention strategies, it is reasonable to recommend the TyG index as an effective and convenient indicator. The TyG index can identify patients with a higher risk of MA events, which may promote more positive therapies such as exercise, diet management, and even medication treatment to reduce the risk. For T1DM patients, even if they have reached the guideline-guide targets for FPG and HbA1c, the TyG index can identify patients at increased risk and prompt them to consider more aggressive treatments to avoid developing into DN, especially ESRD.
The following limitations of our study should be addressed. Firstly, the findings were restricted to a selected group of Chinese patients from a single center. Hence, results should be interpreted with caution. Secondly, although we did find a significant association between the TyG index and MA, other potential factors were not evaluated in the present study, such as dietary characteristics and other concomitant therapies influencing glucose metabolism and lipid levels. Thirdly, we had a comparatively small sample size of subjects, which had become smaller when dividing into two groups. Therefore, the results and conclusions in our study should be regarded as preliminary. A larger sample size and multicenter trials are necessary to confirm our findings.