Body mass index and contralateral ratio predict outcome following unilateral adrenalectomy in primary aldosteronism.

The effect of unilateral adrenalectomy on blood pressure (BP) outcome in primary aldosteronism (PA) is diverse. Therefore, we sought to investigate the preoperative factors contributing to postoperative BP outcome. Data for 96 PA patients who underwent unilateral adrenalectomy at our institution from January 2000 to February 2015 were retrospectively collected. Based on postoperative BP after a 12-month follow-up period, the patients were categorized into two groups: cured (C) (<140/90 mm Hg with no antihypertensive drug) and not cured (NC) (if not normotensive). Patient demographics, blood and urine data, data of loading tests and adrenal vein sampling were evaluated. In all, 46 patients were categorized as C and 50 patients as NC. There were significantly more males in the NC group. Age, body mass index (BMI), number of antihypertensive drugs prescribed, serum uric acid concentration and contralateral ratio (CR) after adrenocorticotropic hormone stimulation were significantly higher in the NC group. In the multivariate model, BMI and CR significantly correlated with resolution outcome. The optimal cutoff values were 23.3 kg m-2 for BMI and 0.5 for CR, and when both parameters were used as predictors, the most optimal cutoff values for BMI and CR were 25.2 kg m-2 and 0.1, respectively. BMI and CR significantly correlated with BP outcome after adrenalectomy. To our knowledge, this is the first report to show that in addition to BMI, CR is a factor in postoperative BP outcome and to determine the optimal cutoff values of BMI and CR and calculate their sensitivities and specificities.