Metabolic and body composition shifts after adrenalectomy in unilateral primary aldosteronism

The primary objective of this prospective cohort study was to assess changes in energy metabolism and body composition following unilateral adrenalectomy in patients with unilateral primary aldosteronism (UPA). Patients with UPA undergoing adrenalectomy were enrolled and underwent standardized evaluations before surgery and at a 3-month postoperative follow-up. 24-h energy metabolism and body composition were measured using whole-room indirect calorimetry and dual-energy X-ray absorptiometry (DXA), respectively. At 3 months after surgery, mean 24-h energy expenditure decreased from 1923.67 ± 378.85 to 1851.71 ± 353.90 kcal/day (P = 0.0063). Carbohydrate oxidation declined from 136.87 ± 29.75 to 122.53 ± 33.37 g/day (P = 0.013), whereas protein oxidation increased from 62.82 ± 17.51 to 70.09 ± 14.55 g/day (P < 0.001). Postoperative body composition showed a reduction in lean mass (44.70 ± 10.31 to 43.54 ± 10.44 kg; P < 0.001), an increase in fat mass (20.45 ± 6.76 to 21.15 ± 6.41 kg; P = 0.026), and a rise in body fat percentage (29.96 ± 5.36% to 31.36 ± 5.04%; P < 0.001). Body weight did not change significantly (p = 0.25). Concurrently, insulin sensitivity indices also changed, with a lower Matsuda index (P = 0.0010) and Quantitative Insulin Sensitivity Check Index (QUICKI) (P = 0.0098), and higher Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (P = 0.015). Unilateral adrenalectomy in patients with UPA is associated with a shift in postoperative metabolic phenotype, characterized by altered energy metabolism, body composition as well as insulin sensitivity. These findings underscore the need for individualized postoperative metabolic monitoring in this population.