A 38-year-old woman with systemic lupus erythematosus (SLE) presents with acute lupus nephritis (Class IV). She is started on high-dose intravenous methylprednisolone 1 g daily for 3 days, followed by oral prednisolone 1 mg/kg/day. After 2 weeks of therapy, she develops severe hypokalemia (K⁺ 2.8 mEq/L), hypertension (160/100 mmHg), and hyperglycemia (fasting glucose 280 mg/dL). Which of the following best explains the mechanism underlying these adverse effects?