Association between papillary thyroid cancer and primary aldosteronism in individuals with hypertension.

BACKGROUND Aldosterone excess chronically induces oxidative stress and cell proliferation. Previously, a single study investigated primary aldosteronism (PA) in patients with papillary thyroid cancer (PTC), albeit without a matched control group. METHODS We conducted a propensity score matched case-control study to investigate the association between PA and PTC in individuals with arterial hypertension (HT). PA was investigated in 137 patients with PTC and HT. The control group included 137 (1:1) age, sex-, and body mass index (BMI)-matched individuals with HT. We conducted a secondary analysis in which the controls were also matched according to HT stage. RESULTS The prevalence of PA was 29.20% (95% confidence interval [CI], 21.91%-37.68%) in the PTC group and 20.44% (95% CI, 14.22%-28.35%) in the controls not matched for HT stage (p = 0.093). Although the PA prevalence was similar in both groups, the frequency of severe HT (stage III or resistant) was significantly lower in the PTC group (23%) compared to the hypertensive controls (73%, p < 0.001). After matching the controls by HT stage, the prevalence of PA in the PTC group was significantly higher compared to the hypertensive controls (9.56%; 95% CI, 5.39%-16.1%, p < 0.0001). In the multivariable analysis, PTC was independently associated with PA in both unmatched hypertensive individuals (odds ratio [OR] 4.74; 95% CI, 2.26-10.55; p< 0.001) and in those matched for HT stage (OR 5.88, 95% CI, 2.79-13.37; p< 0.001). CONCLUSION PTC was an independent variable associated with a diagnosis of PA in hypertensive individuals. Therefore, we propose the association between PTC and HT as a new recommendation for PA screening regardless of HT severity.