A 49-year-old man comes to the physician for worsening shortness of breath on exertion for the past 6 months. Physical examination shows a lateralized apex beat and S3 heart sound. There is darkening of the skin of the forearms. Serum glucose is 130 mg/dL fasting. BMI is 20. Serum K+ is 4.8 mEq/L. Which of the following is the most likely explanation for these findings?
Adrenal cortical insufficiency
Diminished biliary excretion of cation
Increased intestinal cation absorption
Insensitivity to insertion of GLUT-4
Uroporphyrinogen decarboxylase deficiency
