Study of association between 24 hours urinary sodium & potassium excretion and blood pressure at a tertiary hospital

Abstract

Background: Hypertension is a very common disorder especially past middle age. It is not a disease in itself, but is an important risk factor for coronary, cerebral, renal and peripheral vascular disease. Present study was aimed to study association between 24 hours urinary sodium & potassium excretion and blood pressure at a tertiary hospital. Material and Methods: Present study was prospective, comparative study, conducted in cases (patients of age between 18 and 75 years, diagnosed with hypertension) & controls (same age and sex, normotensive subjects). Results: We compared 40 cases with 40 age & gender matched controls. There was no statistically significant difference observed in age, gender & BMI (p > 0.05). There was a statistically significant difference noted in serum cholesterol (193 ± 14.768 vs 183.15 ± 13.275, p value 0.0024) & average serum sodium (140.43 ± 4.031 vs 138.28 ± 2.837, p value 0.007) among cases & controls. The mean 24 hour urinary sodium excretion was higher in patients with moderate to severe hypertension (178.689 ± 13.039)  when compared to subjects with mild hypertension (163.636 ± 13.002) which was statistically significant. (p value 0.002) . There was a significant increase in 24 hour urinary sodium excretion in patients with moderate to severe diastolic hypertension (183.33 ± 15.282) as compared to patients with mild diastolic hypertension (169.28 ± 11.433) (P value 0.002). Conclusion: In hypertensive group, there was significantly elevated 24 hour urinary sodium excretion and Na+ / K+ molar ratio whereas there was lower 24 hour urinary potassium excretion.24 hour urinary sodium excretion also correlated with severity of hypertension.