A 52-year-old man with chronic obstructive pulmonary disease (COPD) exacerbation is prescribed oral prednisolone 40 mg daily for 7 days. He has a past medical history of well-controlled type 2 diabetes mellitus (HbA1c 6.8%) and hypertension. After 5 days of prednisolone therapy, his fasting blood glucose rises to 240 mg/dL and his blood pressure increases to 155/95 mmHg. He also reports new-onset insomnia and mood changes. Which of the following best describes the pharmacologic basis for the glucose elevation in this patient?