Study Background and Disease Burden
Hypertension remains a significant public health challenge, contributing to increased morbidity and mortality worldwide. In Japan, the prevalence of hypertension among adults is notably high, with estimates suggesting that approximately 43% of the adult population lives with high blood pressure. The rising incidence of hypertension is closely linked to lifestyle factors, including diet, physical inactivity, and metabolic disorders such as obesity and diabetes. Given the established role of metabolic disorders in the pathogenesis of hypertension, identifying reliable biomarkers that can predict hypertension risk is crucial for public health interventions and clinical management.
The triglyceride-glucose (TyG) index, a simple composite marker derived from triglyceride and glucose levels, has gained attention in recent years. Studies have suggested that it may serve as a surrogate marker for insulin resistance and cardiovascular risk. This investigation aimed to clarify the relationship between the TyG index and the incidence of hypertension among the Japanese population through a population-based observational study.
Study Design
This study utilized a retrospective cohort design, analyzing annual health checkup data collected from residents of Iki City, Nagasaki Prefecture, Japan. The cohort consisted of 2,600 participants aged 20 years and older who were free of hypertension at baseline. Participants underwent routine health check-ups, which included assessments of fasting triglyceride and glucose levels to calculate the TyG index. The TyG index was stratified into quartiles based on gender-specific cut-off points:
– Men: Quartile 1 (<8.08), Quartile 2 (8.09-8.43), Quartile 3 (8.44-8.84), Quartile 4 (≥8.85)
– Women: Quartile 1 (<7.89), Quartile 2 (7.9-8.22), Quartile 3 (8.23-8.54), Quartile 4 (≥8.55)
The primary endpoint of the analysis was the incidence of hypertension, determined through follow-up health assessments conducted over an average period of 4.96 years. The study adhered to ethical guidelines and maintained participant confidentiality.
Key Findings
Across the 2,600 participants, 789 individuals developed hypertension during the follow-up period. The data indicated a clear trend in the annual incidence of hypertension with increasing TyG index quartiles. Specific findings included:
– In men:
– Quartile 1: 4.79%
– Quartile 2: 6.25%
– Quartile 3: 7.72%
– Quartile 4: 9.31%
– In women:
– Quartile 1: 3.65%
– Quartile 2: 5.36%
– Quartile 3: 5.55%
– Quartile 4: 6.96%
Using the Cox proportional hazards model to adjust for potential confounders, the study reported the following hazard ratios for men:
– Quartile 2: 1.39 (95% CI 0.99-1.93)
– Quartile 3: 1.44 (95% CI 1.03-2.01)
– Quartile 4: 1.79 (95% CI 1.27-2.52) (P = 0.001 for trend)
In contrast, no significant associations were found among women, with hazard ratios as follows:
– Quartile 2: 1.02 (95% CI 0.74-1.40)
– Quartile 3: 1.04 (95% CI 0.75-1.41)
– Quartile 4: 1.02 (95% CI 0.74-1.42) (P = 0.882 for trend)
These results reveal a significant correlation between increased TyG index levels and hypertension development in Japanese men, implicating the TyG index as a potential predictor of cardiovascular risk in this demographic.
Expert Commentary
The findings from Ishida et al. highlight the TyG index’s role in cardiovascular risk assessment, particularly in men. While the association appears robust in the male cohort, the lack of similar findings in women raises questions about biological differences in insulin resistance and hypertension risk between genders. Potential limitations of the study include its observational nature, which limits the ability to draw causal inferences, and the specifics in lifestyle factors or dietary habits that may not have been fully controlled for. Future prospective studies with larger populations are required to validate these findings and explore the underlying mechanisms linking the TyG index and hypertension.
Additionally, given the global obesity epidemic and increasing prevalence of metabolic disorders, clinicians should consider incorporating the TyG index into routine assessments for cardiovascular risk, particularly for populations at higher risk.
Conclusion
This study underscores the significant association between the triglyceride-glucose index and the incidence of hypertension in Japanese men, highlighting its potential as a predictive marker for cardiovascular health. Further research is warranted to explore these relationships across diverse populations and genders to enhance prevention strategies and tailored interventions aimed at reducing hypertension incidence effectively.
References
Ishida S, Shinohara Y, Sakaguchi T, Katsuki S, Kawano K, Ueno T, Maki K, Nohara C, Fujii T, Abe M, Kawazoe M, Maeda T, Yoshimura C, Tada K, Takahashi K, Ito K, Yasuno T, Mukobara S, Masutani K, Arima H. Triglyceride-glucose index and incidence of hypertension, a population-based observational study of the Japanese population. J Hypertens. 2025 Sep 1;43(9):1554-1560. doi: 10.1097/HJH.0000000000004087. Epub 2025 Jun 27. PMID: 40586243.