IATROGENIC CUSHING SYNDROME IN PATIENTS TAKING INHALATIONAL STEROIDS

Abstract

Objective: To determine the frequency of iatrogenic Cushing syndrome (ICS) in patients taking inhaled corticosteroids and to assess the clinical and biochemical characteristics of affected patients presenting to a tertiary care health facility.

Type of Study: Cross-Sectional Study

Place and Duration of Study: This study was conducted at Department of Internal Medicine and Pulmonology, Combined Military Hospital(CMH), Rawalpindi, from July 2024 to December 2024.

Methodology: This study included a total of 203 patients with chronic respiratory conditions using inhaled corticosteroids for ≥6 months that fulfilled the exclusion and inclusion criteria. Detailed history was taken including duration of respiratory illness, type and dose of inhaled corticosteroids, and presence of cushingoid features. Blood samples were collected for 24-hour urinary free cortisol, late-night salivary cortisol, and morning ACTH levels. DEXA scan was performed to assess bone mineral density. Iatrogenic Cushing syndrome was diagnosed based on clinical features confirmed by biochemical testing. Data was analyzed using SPSS version 28, with Chi-square test used for categorical variables. A p-value ≤0.05 was considered statistically significant.

Results: The overall frequency of iatrogenic Cushing syndrome was found to be 5.9% (12/203 patients). Clinical features included central obesity in 9 patients (75%), moon facies in 8 patients (66.7%), purple striae in 7 patients (58.3%), and proximal muscle weakness in 10 patients (83.3%). Biochemical confirmation showed elevated 24-hour urinary free cortisol (mean 112.4±18.6 μg/24h) and suppressed morning ACTH levels (mean 7.2±2.1 pg/mL) in affected patients. A Chi-square test revealed significant associations between ICS dose, duration of use, and development of Cushing syndrome (p<0.001). High-dose ICS users (>800 mcg/day budesonide equivalent) had 4.2 times higher risk compared to standard-dose users.

Conclusions: In summary, iatrogenic Cushing syndrome represents a clinically significant complication in patients on long-term inhaled corticosteroid therapy, with a frequency of 5.9% in our population. The condition is more prevalent in patients using high-dose formulations and prolonged therapy duration exceeding 12 months. Early recognition through systematic screening and appropriate dose adjustments can prevent serious complications. Clinicians should maintain high clinical suspicion in patients on long-term ICS therapy presenting with cushingoid features, and routine monitoring of HPA axis function should be considered for high-risk patients.