A study of association of serum uric acid and hypertension in the patients at tertiary health care center

 

Swapna V S¹, Triveni A Jambale^2*, Mr Anand³

 

Abstract               Background: Uric acid (UA), as the final oxidation product of purine catabolism, has been associated with various clinical conditions such as diabetes mellitus (DM) and atherosclerotic disease. Recent studies suggest that UA is a relevant and independent risk factor particularly in patients with hypertension. Aims and Objectives: To study association of Serum Uric acid and Hypertension in the patients at Tertiary health care center. Methodology: This was a cross-sectional study carried out in the Hypertensive patients at the tertiary health care center during the year January 2016 to January 2017, during one year period total 50 hypertensive patients were studied and corresponding 50 normotensive patients were also included randomly into the study. All the patients were investigated for the serum uric acid level. The patients were categorized into Hyperuricemia if (>7.0 mg/dL) Normal Uric acid level (3.4-7.0 mg/dL). The mean uric acid level of hypertensive and normotensive patients also noted. The statistical analysis done by Chi-square test and unpaired t-test calculated by SPSS-19 version software. Result: Majority of the patients were in the age group of >60 were 38%, followed by 50-60 were 24%, 40-50 were 18%, 30-40 were 14%, 20-30 were 6%. The majority of the patients were Male i.e. 64% and females were 36%. The majority of Hypouricemic patients were in the hypertensive patients i.e. 42 % as compared to 22% in normotensive patients where as the Normal Uric acid level was present in the majority of Normotensive patients i.e. 26% as compared to Hypertensive i.e. 10%. This observed difference was statistically significant (X2 = 5.12, df=1, P<0.05). The Mean Uric acid level (Mean±SD) in Normotensive was 3.28 ± 1.76 and in Hypertensive was 6.12 ± 1.93 this observed difference was statistically significant (P<0.001, t = 5.4217 , df = 48). Conclusion: It can be concluded from our study that the majority with hypertensive patients were significantly associated with raised uric acid level.

Key words: Serum Uric acid, Hypertension, Hyperuricemia, Renal diseases, Cardiovascular diseases.

 

 

INTRODUCTION

Uric acid (UA), as the final oxidation product of purine catabolism, has been associated with various clinical conditions such as diabetes mellitus (DM) and atherosclerotic disease.¹ Recent studies suggest that UA is a relevant and independent risk factor for kidney disease, particularly in patients with hypertension.^1-3 It was shown that hyperuricemia, induced by a uricase inhibitor, triggered hypertension and impaired nitric oxide generation in the macula densa, while both hypertension and renal injury are reduced by inducing nitric oxide.^4-6 The mechanism by which uric acid may cause organ damage is not fully understood; however, there is increasing evidence that endothelial dysfunction is a mechanism whereby this substance may affect kidney function and structure.^7-9

 

METHODOLOGY

This was a cross-sectional study carried out in the Hypertensive patients at the tertiary health care center during the year January 2016 to January 2017, during one year period total 50 hypertensive patients were studied and corresponding 50 normotensive patients were also included randomly into the study. All the patients were investigated for the serum uric acid level. The patients were categorized into Hyperuricemia if (>7.0 mg/dL) Normal Uric acid level (3.4-7.0 mg/dL). The mean uric acid level of hypertensive and normotensive patients also noted. The statistical analysis done by Chi-square test and unpaired t-test calculated by SPSS-19 version software.

RESULT

Table 1: Distribution of the patients as per the age

The majority of the patients were in the age group of >60 were 38%, followed by 50-60 were 24%, 40-50 were 18%, 30-40 were 14%, 20-30 were 6%.

 

Table 2: Distribution of the patients as per the Sex

The majority of the patients were Male i.e. 64% and females were 36%.

 

Table 3: Distribution of the Hypertensive patients as per the Uric acid level

(X² = 5.12, df=1, P<0.05)

From above table it is clear that the majority of Hypouricemic patients were in the hypertensive patients i.e. 42 % as compared to 22% in normotensive patients where as the Normal Uric acid level was present in the majority of Normotensive patients i.e. 26% as compared to Hypertensive i.e. 10%.

This observed difference was statistically significant (X² = 5.12, df=1, P<0.05)

 

Table 4: Distribution of the patients as per the Mean Uric acid level in Normotensive and Hypertensive patients

The Mean Uric acid level (Mean±SD) in Normotensive was 3.28 ± 1.76 and in Hypertensive was 6.12 ± 1.93 this observed difference was statistically significant (P<0.001, t = 5.4217 , df = 48)

DISCUSSION

A number of epidemiological studies have shown that increased uric acid concentrations are associated with increased risk for developing hypertension^10,11. Some observations in cross-sectional analyses and longitudinal studies concluded there was a hyperuricemia-hypertension link^12-13. Although elevated SUA levels have been predictive of hypertension in longitudinal studies, the relationship between uric acid and blood pressure is confounded by numerous factors, so controversy remains. For example, although elevated uric acid levels are often associated with established traditional cardiovascular risk factors, it is not quite clear whether uric acid is the cause or a consequence of hypertension; studies indicating uric acid as an independent risk factor did not sufficiently control for other known risk factors; thus, how uric acid causes hypertension is not fully understood¹⁴. In our study we have seen that the majority of the patients were in the age group of >60 were 38%, followed by 50-60 were 24%, 40-50 were 18%, 30-40 were 14%, 20-30 were 6%. The majority of the patients were Male i.e. 64% and females were 36%. The majority of Hypouricemic patients were in the hypertensive patients i.e. 42 % as compared to 22% in normotensive patients where as the Normal Uric acid level was present in the majority of Normotensive patients i.e. 26% as compared to Hypertensive i.e. 10%. This observed difference was statistically significant (X² = 5.12, df=1, P<0.05). The Mean Uric acid level (Mean±SD) in Normotensive was 3.28±1.76 and in Hypertensive was 6.12 ± 1.93 this observed difference was statistically significant (P<0.001, t = 5.4217, df = 48). These findings are similar to Wei et al¹⁵ they found that the cumulative prevalence of hypertension in their cohort was 20.7 %. The prevalence of hyperuricemia was 17.5 %. Cox regression analysis showed that, compared with the lowest SUA quartile (<4.69 mg/dl), the 4.69–5.58, 5.58–6.52, and ≥6.52 mg/dl quartiles yielded hazard ratios (95 % confidence intervals) for hypertension of 1.652 (1.265–2.156), 2.195 (1.705–2.825), and 3.058 (2.399–3.899), respectively. Cumulative incidence of hypertension was consistently higher among individuals with hyperuricemia than among those with normal SUA levels. A Kaplan–Meier survival analysis showed that hyperuricemia predicted higher incidences of hypertension in a dose-dependent manner: hypertension onset significantly differed across SUA quartiles. SUA levels were significantly and independently associated with incidence of hypertension in their cohort

 

CONCLUSION

It can be concluded from our study that the majority with hypertensive patients were significantly associated with raised uric acid level.

 

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