Comparison of 24-Hour Urine Sodium Excretion in Controlled and Uncontrolled Essential Hypertensive Patients on Antihypertensive Treatment: A Cross-Sectional Study.

Background: Hypertension is a major risk factor for cardiovascular disease. Despite pharmacologic interventions, a substantial proportion of patients exhibit poor blood pressure (BP) control. High sodium intake is a modifiable contributor to uncontrolled hypertension. This study eva-luates 24-hour urinary sodium excretion as an objective biomarker for sodium intake in controlled versus uncontrolled hypertensive patients. Objectives: To compare 24-hour urinary sodium excretion between hypertensive patients with controlled and uncontrolled BP, and to assess its association with treatment response. Methods: This cross-sectional study was conducted at VMKV Medical College and Hospital, Salem, over 15 months. A total of 100 hypertensive patients aged 45-65 years were recruited and grouped into controlled (n=50) and uncontrolled (n=50) based on JNC VIII BP criteria. Data on demographics, clinical history, and 24-hour urine collections were analyzed. Sodium, potassium, and albumin levels were measured. Independent t-tests and Chi-square tests were used for statistical comparisons. Results: Mean 24-hour urinary sodium was significantly higher in the uncontrolled group (174.5 ± 32.1 mmol/day) compared to the controlled group (142.7 ± 28.3 mmol/day; p < 0.001). No significant differences were noted in urinary potassium levels (p = 0.42) or microalbuminuria prevalence (p = 0.31) between the groups. Conclusion: Higher urinary sodium excretion is significantly associated with poor BP control, underscoring the importance of dietary sodium reduction even in patients under antihypertensive therapy. 24-hour urine sodium measurement can serve as a reliable biomarker in clinical management.