Akasaka H, et al. - Given that adrenal vein sampling (AVS) could identify patients with the unilateral subtype of primary aldosteronism (PA), for which adrenalectomy is an applicable treatment, researchers analyzed patients with PA who underwent AVS from a large database to study sex differences in the impact of age at diagnosis on the subtype and cause of PA. In 2,122 patients, women with the unilateral subtype vs men with the same subtype and women with the bilateral subtype were younger. Younger age was associated with unilateral PA in women and older age was associated with unilateral PA in men. In middle-aged and older patients, but not younger patients, male sex was a predictor of unilateral PA. In addition, obesity, a known factor associated with idiopathic hyperaldosteronism, showed a positive correlation with bilateral PA in younger patients, but not older patients. The combination of sex and age is predictive of the proportion of operable patients with unilateral PA, and that other than obesity, the cause of PA is also linked with the bilateral subtype in older patients.