Uric Acid Metabolism in a Sample of Egyptian Hypertensive Patients with Normal Kidney Function

Abstract

Background: Hyperuricemia is commonly associated with hypertension. Also, it is well known to coincide with the metabolic syndrome but is still not recognized as a risk factor. So, we aimed to evaluate hyperuricemia among a sample of hypertensive Egyptians with normal renal function. Methods: this study was performed on 303 hypertensive patients aged 30-69 years. Patients were divided into 2 groups according to the level of uric acid: group 1 composed of 168 hypertensive hyperuricemic patient sand group2 composed of 135 hypertensive normouricemic patients. All patients were subjected to complete medical history and detailed clinical examination including body mass index (BMI), complete blood count (CBC), serum creatinine, BUN, FBS, cholesterol, triglycerides, uric acid, sodium, potassium, urinary uric acid, urinary creatinine, urinary uric acid to creatinine ratio and fractional excretion of uric acid(FEUA). Results: The overall prevalence of hyperuricemia was 55.4%. Uric acid correlated significantly with age (p<0.05). BMI was significantly higher in group1 than in group 2(p<0.05), and there was a significant positive correlation between serum uric acid and BMI (p<0.01).Serum triglycerides and cholesterol were significantly higher in group 1than in group 2 (p<0.05for both) denoting risky metabolic effects. Serum uric acid correlated significantly with systolic blood pressure (p<0.05), but not with diastolic blood pressure. No significant difference found between group 1 and group 2 as regards SBP, DBP or blood pressure control(all p values>0.05). Serum uric acid found to correlate significantly (p<0.001) with urinary uric acid, urinary creatinine and negatively with FEUA denoting early tubular defect of the kidney. Also, Urinary uric acid, urinary creatinine and urinary uric acid/creatinine ratio were higher in group 1than in group 2 (p values were<0.001, <0.001 and <0.05 respectively). FEUA was found to be significantly lower in group 1 than in group 2 (p<0.01). We found, also, that serum sodium level was significantly higher in the hyperuricemic group than in the normouricemic group (p<0.001) denoting the role of Na + in the development of hypertension and defective renal excretion of uric acid. Conclusion: We conclude that the incidence hyperuricemia in our sample of Egyptian hypertensive patients was (55.4%). Impaired renal clearance of uric acid occurs before deterioration of GFR. Serum uric acid should be measured in all cases of hypertension together with BMI, total cholesterol, triglycerides and should be treated to avoid consequent metabolic complications. Hypertensive patients with hyperuricemia should be warned strictly of high sodium diet.

Serum uric acid level in Bangladeshi adults with essential hypertension

“…Previous researchers had similar observations. [4][5][6][7][8][9]29 Among the hypertensive subjects of the current study, those with stage II HTN had significantly higher uric acid than those with stage I HTN. The higher uric acid levels with higher stages of HTN were also described by Neki et al, and Meti et al 8,19 Moreover, both the systolic and diastolic BP had significant positive correlations with serum uric acid levels in the hypertensive subjects of this study.…”

“…In Australia, Bauer et al reported 31% of subjects with essential HTN to have hyperuricemia; the frequency was 55.4% in Egypt, 37.4% in Pakistan, 28.8% in Nepal, and two studies from India reported 37% and 46% hypertensive subjects to have hyperuricemia. [4][5][6][7][8][9] In a previous study in Bangladesh, the observed prevalence of hyperuricemia in hypertensive and normotensive subjects were 25.4% and 9.8%, respectively. 29 In the present study, hyperuricemia was observed in 29.7% of hypertensive patients and 6.0% of normotensive controls, which was similar to most of the studies dine in this part of the world.…”

“…3 Some studies have found higher frequencies of hyperuricemia in hypertensive patients in comparison to healthy subjects. [4][5][6][7][8][9] Elevated serum uric acid has been identified as a potential independent risk factor for the development of essential HTN in the Ahammed SKK et al Int J Adv Med. 2020 Jul;7 (7): [1136][1137][1138][1139][1140] International Journal of Advances in Medicine | July 2020 | Vol 7 | Issue 7 Page 1137 general population.…”

Blood glucose and uric acid increases the risk of hypertension in elderly

“…Impaired renal uric acid clearance occurs before a decrease in glomerular filtration rate (GFR), so uric acid must be measured in all cases of hypertension together with BMI, total cholesterol, triglycerides and care must be taken to avoid the occurrence of metabolic complications. 14…”