Background: Hypertension is a major modifiable cardiovascular risk factor with an increasing global prevalence. Endothelial dysfunction is an early, subclinical manifestation of vascular disease and plays a central role in the pathogenesis of hypertension-related organ damage. Serum uric acid (SUA) has emerged as a putative biomarker of endothelial dysfunction; however, its utility in newly diagnosed hypertensive patients remains inadequately characterized in the Indian population.

Objectives: To evaluate serum uric acid levels in newly diagnosed hypertensive patients, compare them with normotensive controls, and assess the correlation of SUA with surrogate markers of endothelial dysfunction including serum nitric oxide (NO), high-sensitivity C-reactive protein (hs-CRP), flow-mediated dilatation (FMD), and endothelin-1 (ET-1).

Methods: This prospective observational case-control study was conducted at the Department of Biochemistry, MGM Medical College & LSK Hospital, Kishanganj, Bihar, over a period of ten months (February–December 2025). Fifty newly diagnosed, treatment-naïve hypertensive patients (cases) and an equal number of age- and sex-matched normotensive individuals (controls) were enrolled. Fasting venous blood samples were analyzed for SUA, hs-CRP, serum NO, and ET-1. FMD of the brachial artery was measured by high-resolution ultrasonography. Statistical analysis was performed using SPSS version 25.0; a p-value <0.05 was considered statistically significant.

Results: Mean serum uric acid was significantly elevated in hypertensive cases (6.84 ± 1.42 mg/dL) compared to controls (4.31 ± 0.98 mg/dL; p<0.001). Hyperuricemia (SUA >7 mg/dL in males, >6 mg/dL in females) was present in 46% of cases versus 12% of controls. SUA showed a significant positive correlation with ET-1 (r = 0.61, p<0.001) and hs-CRP (r = 0.54, p<0.001), and a significant negative correlation with NO (r = −0.58, p<0.001) and FMD (r = −0.52, p<0.001). On multivariate logistic regression, SUA was an independent predictor of endothelial dysfunction (OR = 2.84, 95% CI: 1.47–5.49, p = 0.002).

Conclusion: Serum uric acid is significantly elevated in newly diagnosed hypertensive patients and demonstrates a robust correlation with established markers of endothelial dysfunction. SUA may serve as a simple, cost-effective, and readily available biomarker for early identification of vascular risk in hypertensive individuals, particularly in resource-limited settings