Overview

This is an observational study to define the cut-off value of 24-hour urinary aldosterone for screening primary aldosteronism in hypertensive patients in our center. Plasma aldosterone and renin measurements are subject to significant intra-individual variability, including variation related to posture, time of day and sodium balance. Aldosterone secretion is not constant and may be subject to diurnal variation. As such one-off testing of ARR, does not consider the salt status of the individual necessitating repetition of tests to ensure false negative or false positive test results are ruled out. The value of accumulated aldosterone in a 24-hour sample has the advantage that it does not depend on circadian variation. This study will help establish the positivity rates of 24-hour urine aldosterone, and test the robustness of current standard guidelines for primary aldosteronism screening and case confirmation.

Previous studies reported that primary aldosteronism is associated with a higher risk of CV complications and a higher prevalence of target organ damage. Also, previous studies reported on the association of echocardiographic parameters with circulating or urinary aldosterone. Therefore, we intent to investigate the independent associations of different target organ damage with the urinary excretion of aldosterone.

Eligibility

Inclusion Criteria:

1. Aged 18 years and above.
2. Meets the ACC/AHA hypertension guidelines for a diagnosis of hypertension with an age of onset of hypertension between 18-60 years.
3. Meets the Endocrine Society Clinical Practice Guidelines for a diagnosis of primary aldosteronism with an age of onset of hypertension between 18-60 years.

Exclusion Criteria:

1. Other causes of secondary hypertension, including renal hypertension, renovascular hypertension and adrenal hypertension (i.e., pheochromocytoma and Cushing syndrome).
2. Urine output less than 400ml per day.
3. Severe renal insufficiency with a glomerular filtration rate < 30 mL/min.
4. IgA nephropathy.
5. Alcohol abuse or pregnancy