Elevated TyG index tied to increased risk of eGFR decline in patients with hypertension

The results indicate that the TyG index could serve as a useful predictor for a decline in renal function among hypertensive patients. Also, the association between the TyG index and renal events suggest that insulin resistance (IR) may be a critical factor in developing hypertensive nephropathy.

Hypertension is a major global health problem affecting about 1.4 billion people worldwide. One of the common complications linked with hypertension is a renal injury that could lead to CKD (chronic kidney disease) and RSRD (end-stage renal disease). Strict BP control has been shown to reduce the risk of renal damage, but it remains uncertain which hypertensive patients are particularly susceptible to this condition, Therefore, identifying novel biomarkers that can predict the development and progression of hypertension-induced renal injury is important.

Insulin resistance has been implicated in kidney damage and progression of nephropathy. Hence IR evaluation may be a valuable tool for assessing the evolution of hypertension-induced renal damage. In this context, the TyG index has emerged as a cost-effective and non-invasive alternative indicator to assess IR. Recent studies have shown that an elevated TyG index is tied to an increased risk of cardiovascular disease, diabetic nephropathy, and arterial stiffness progression. However, there is limited evidence supporting the association between the TyG index and hypertension-induced renal injury.

Thus, there is a need for further need to determine whether the TyG index can serve as a reliable biomarker to evaluate the severity and progression of hypertensive nephropathy. Therefore, Chin-Chou Huang, College of Medicine, National Yang-Ming Chiao Tung University, Taipei, Taiwan, and colleagues aimed to investigate whether the TyG index was correlated with renal function decline in hypertensive patients.

The study included Han Chinese participants with essential hypertension. The TyG index was calculated as ln[fasting triglycerides (mg/dL) * fasting glucose (mg/dL)/2]. The decline in renal function was defined as >25% decline in eGFR. The independent effect of the TyG index on renal events was investigated using the Cox proportional hazard regression model. 548 Han Chinese hypertensive participants with a mean age of 62.1 ± 14.3 years were eligible for enrollment.

The study revealed the following findings:

• During a mean follow-up period of 4.7 ± 3.1 years, 97 patients suffered from >25% decline in eGFR.
• Patients with eGFR decline had higher fasting triglyceride levels, fasting glucose levels, and TyG indexes when compared to those without eGFR decline.
• The Cox proportional hazard regression model revealed that the TyG index (hazard ratio [HR] = 1.490), office systolic blood pressure (HR = 1.013), diabetes mellitus (HR = 1.797), and baseline eGFR (HR = 1.015) were associated with renal events.

The study revealed a significant association between an elevated TyG index and an increased risk of eGFR decline of more than 25%.

"The findings suggest that the TyG index could be a useful tool for evaluating future renal events," the researchers wrote. "While there is a need to further investigate the underlying mechanisms linking the TyG index to renal events, our findings support the clinical significance of this index for risk assessment in hypertension patients."

"Future studies should explore the potential use of the TyG index in clinical practice to improve early detection-making and prevention of renal damage," they concluded.

Reference:

Chen, C., Tsai, H., & Huang, C. Triglyceride glucose index and renal function decline in Han Chinese hypertensive patients. The Journal of Clinical Hypertension. https://doi.org/10.1111/jch.14720