The Study of Uric Acid Levels in Primary Hypertension without End Organ Damage

Background: Hypertension is a major risk factor for cardiovascular events. Serum uric acid has been implicated as a risk factor for development of cardiovascular diseases including hypertension. Previous studies have found association between raised serum uric acid levels and primary hypertension. There was always a debate if uric acid was raised due to complications of hypertension or if uric acid was an independent risk factor for development of hypertension.

Objective: To assess the relationship between serum uric acid and hypertension independent of renal function, obesity, diabetes, stroke and alcoholism. To assess the relationship between serum uric acid and hypertension in whom the target organ damage has not yet appeared.

Methodology: This cross-sectional study was done in Sri Manakula Vinayagar Medical College and Hospital. The study period was of 22 months from November 2012 to August 2014. The total study population was 300 patients, of which 150 were cases and 150 were controls. The patients were included if they satisfied the JNC 7 criteria for hypertension. And only those hypertensives without end organ damage were included. Patients with secondary hypertension and those having other conditions associated with hyperuricemia were excluded from the study.

Results: The study showed that serum uric acid levels were raised in patients with hypertension in comparison to normotensives. The mean serum uric acid levels between patients with hypertension and controls were 4.83 ± 1.72 and 3.92 ± 1.28 mg/dl respectively with p value < .001. The mean serum uric acid levels increased with the increase in the stages of hypertension. The mean serum uric acid levels in prehypertension, stage 1 hypertension and stage 2 hypertension were 3.99± 1.13, 4.57± 1.49, 5.50 ± 1.97 mg/dl respectively.

Conclusion: These results indicate that serum uric acid is independently associated with hypertension without other comorbid conditions. Serum uric acid is elevated in hypertensives even in absence of target organ damage. Thus, in future it may be used as an early biochemical marker to predict the development of hypertension.