A patient, aged 34, has been suffering for 7 years from pulmonary tuberculosis. He complains of muscle weakness, weight loss, diarrhea, frequent urination. On examination: hyperpigmentation of skin, gums, and inner sides of the cheeks. BP - 90/58 mm Hg. In blood: RBC - 3,1×1012/l, Hb - 95 g/L, colour index of blood – 0,92; WBC - 9,4×109/l, eosinophils - 7, segmented neutrophils - 45, band neutrophils - 1, lymphocytes - 40, monocytes - 7, Na - 115 mmol/L, К - 7,3 mmol/L. What is the preliminary diagnosis?