In obese individuals cortisol production and secretion is increased but the underlying mechanism is not known. Obesity leads to a pathological activation of the innate immune system partly driven by tissue production of IL-1β. Furthermore, IL-1β is also known to stimulate the release of adrenocorticotropin hormone (ACTH). Therefore, the investigators hypothesise that in obese individuals tissue inflammation stimulates ACTH via IL-1β, thereby explaining the observed hypercortisolism.

Inclusion Criteria:

• Age 18-80 years
• BMI >30kg/m2 and at least 1 manifestations of the metabolic syndrome (i.e. diabetes/ prediabetes, hypertension, dyslipidemia)
• Willingness to use contraceptive measures adequate to prevent becoming pregnant

Exclusion Criteria:

• Medication with glucocorticosteroids
• Known Cushing Syndrome
• Pregnancy or breast feeding
• Clinical signs of infection in the week before inclusion or history of a severe infection during the last 2 months
• Hematologic disease (leukocyte count < 1.5x109/l, hemoglobin <11 g/dl, platelets <100 x 103/ul)
• Kidney disease (creatinine-clearance < 30ml/min))
• Liver disease (transaminases >4x upper normal range)
• Active carcinoma
• History of tuberculosis
• Alcohol consumption >40g/d for men, >30g/d for women
• Known allergy towards anakinra
• Subject refusing or unable to give written informed consent