Triglyceride-glucose index predicts hypertension in Singaporeans

Singaporeans with higher triglyceride-glucose index are at higher risk of developing hypertension, as reported in a study.

In the unadjusted Cox proportional hazard model, triglyceride-glucose index was positively associated with the risk of hypertension, and this risk was threefold higher among patients in the highest vs lowest quartile of the index (Q4 vs Q1: hazard ratio [HR], 3.31, 95 percent confidence interval [CI], 2.38–4.60; p<0.001). [J ASEAN Fed Endocr Soc 2023;38:62-67]

The association between higher triglyceride-glucose index quartiles and hypertension risk persisted even after adjusting for demographics and baseline clinical covariates, with the risk increase in Q4 being more than double than that in Q1 (HR, 2.57, 95 percent CI, 1.71–3.87; p<0.001).

A promising surrogate of insulin resistance, triglyceride-glucose index mediated the relationship between body mass index (BMI) and incident hypertension. Higher triglyceride-glucose index accounted for 16.4 percent of the association between increasing BMI and incident hypertension (p<0.001). This suggests that triglyceride-glucose index partially contributes to the detrimental impact of BMI on the risk of hypertension, according to the investigators.

“Interestingly, an earlier study reported an interaction between triglyceride-glucose index and obesity on the risk of hypertension in middle-aged and [older] adults. In our earlier study, triglyceride-glucose index was shown to mediate the association between BMI and the development of diabetes. Thus, it is plausible that triglyceride-glucose index partly accounted for the deleterious effects of BMI on cardiovascular and metabolic risk,” they pointed out. [Clin Exp Hypertens 2017;39:732-739; Diabetes Res Clin Pract 2018;143:43-49]

The analysis included 3,183 individuals identified from a community health screening programme who were free of hypertension at baseline. Hypertension occurred in 363 individuals (11.4 percent) over an average follow-up of 1.7 years.

Individuals with vs without incident hypertension had higher triglyceride-glucose index (8.6 vs 8.2; p<0.001). Furthermore, those in higher triglyceride-glucose index quartiles were more likely to be men and non-Chinese, as well as to smoke and exercise less.

The role of insulin resistance

“There are a few possible explanations for insulin resistance conferring higher risk for the development of hypertension,” the investigators said.

For the most part, insulin resistance may cause thickening of vascular smooth muscle and narrowing of blood vessels. These, according to the investigators, can contribute to an increase in smooth muscle vasculature, which subsequently elevates the blood pressure. [Cardiovasc Diabetolol 2011;10:75; Am J Hypertens 2003;16:223-228; Lipids Health Dis 2017;16:175]

“As triglyceride-glucose index was considered a surrogate of insulin resistance and was also correlated positively with waist circumference (a marker of insulin resistance) in our study (p<0.001), it is then plausible that the above mechanisms accounted for the relationship between triglyceride-glucose index and the development of hypertension,” they said. [Cardiovasc Diabetol 2014;13:146; Prev Med 2016;86:99-105]

Inexpensive measure

Easily available in routine clinical practice, triglyceride-glucose index provides an inexpensive measure to potentially identify individuals at higher risk for hypertension. This is expected to enable healthcare providers to form a stratified approach in hypertension management through more targeted lifestyle interventions and medications.

“The mediating effect of triglyceride-glucose index on the association between BMI and the development of hypertension also highlights the clinical importance of promoting a healthy body weight in an effort to reduce the risk of hypertension,” the investigators said.

“Moving forward, it would be worth returning to this cohort after a longer time period to further explore the development of hypertension and other outcomes such as stroke, heart attack, and mortality. Our methodology is easily repeatable with other large health screening cohorts that can corroborate our observations,” they added.