Nutritional Intervention in Cushing's Disease: The Ketogenic Diet's Effects on Metabolic Comorbidities and Adrenal Steroids

Background: a very low-calorie ketogenic diet (VLCKD) is associated with improvement of metabolic and cardiovascular disorders. We aimed to evaluate the effects of a VLCKD in patients with Cushing's disease (CD) as adjunctive therapy to treatment for the primary disease. Methods: we evaluated clinical, hormonal and metabolic parameters in 15 patients with CD and 15 controls at baseline after 1 week and 3 weeks of VLCKD and, further, after 2 weeks of a low-carbohydrate ketogenic diet (LCKD). Results: after 5 weeks of diet, a significant decrease in BMI (p = 0.002), waist circumference (WC) (p = 0.024), systolic blood pressure (p = 0.015), diastolic blood pressure (p = 0.005), ACTH (p = 0.026), cortisone (p = 0.025), total cholesterol (p = 0.006), LDL cholesterol (p = 0.017), triglycerides (p = 0.016) and alkaline phosphatase (p = 0.008) and a significant increase in HDL cholesterol (p = 0.017), vitamin D (p = 0.015) and oral disposition index (oDI) (p = 0.004) was observed in the CD patients. A significant decrease in BMI (p = 0.003), WC (p = 0.002), systolic blood pressure (p = 0.025), diastolic (p = 0.007) blood pressure and total cholesterol (p = 0.026) and an increase in HDL cholesterol (p = 0.001) and oDI (p < 0.001) was observed in controls. Conclusions: the current study confirms that a ketogenic diet is effective in improving metabolic disorders in CD and shows that a nutritional approach may be combined with conventional CD therapy in order to improve metabolic and cardiovascular comorbidities.