AD15 Plasma aldosterone-to-potassium ratio as a marker of hypertensive retinopathy in patients with primary aldosteronism
TL;DR
The plasma aldosterone-to-potassium ratio may serve as a practical biochemical marker for identifying hypertensive retinopathy in patients with primary aldosteronism and facilitate early recognition of individuals at increased risk of aldosterone-related retinal microvascular damage.
Abstract
Hypertensive retinopathy (HR) is an important manifestation of hypertension-mediated target-organ damage. In primary aldosteronism (PA), both aldosterone excess and hypokalaemia may contribute to retinal microvascular injury. However, reliable biochemical markers for identifying patients at increased risk remain limited. To evaluate the diagnostic performance of the plasma aldosterone concentration-to-potassium ratio (PAC/K) for identifying hypertensive retinopathy in patients with primary aldosteronism. Patients with confirmed PA were classified according to the presence or absence of HR. Demographic, clinical, and biochemical characteristics were compared between groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of PAC/K and to compare it with the conventional plasma aldosterone concentration-to-plasma renin activity (PAC/PRA) ratio. Eighty-two patients with PA were included, of whom 14 had HR and 68 did not. Age, sex distribution, duration of hypertension, systolic blood pressure, and diastolic blood pressure were comparable between groups. Patients with HR had significantly lower estimated glomerular filtration rate (eGFR) and serum potassium concentrations, while plasma aldosterone concentration and the PAC/PRA ratio were significantly higher. PAC/K demonstrated superior discriminatory performance compared with PAC/PRA for identifying HR. In ROC analysis, PAC/K achieved an area under the curve (AUC) of 0.796 (95% confidence interval [CI] 0.656–0.936; P = 0.001). A cut-off value of 7.98 yielded 85.7% sensitivity and 67.6% specificity. By comparison, the PAC/PRA ratio had an AUC of 0.717 (95% CI 0.541–0.894; P = 0.011), with 71.4% sensitivity and 77.9% specificity at a cut-off value of 130.4. The plasma aldosterone-to-potassium ratio may serve as a practical biochemical marker for identifying hypertensive retinopathy in patients with primary aldosteronism. This parameter may facilitate early recognition of individuals at increased risk of aldosterone-related retinal microvascular damage.