Obesity and the metabolic syndrome in men are associated with a high prevalence of hypogonadism of up to 50%. Increased fat mass leads to augmented release of adipocytokines and pro-inflammatory cytokines such as IL-1-beta, IL-6 and tumor necrosis factor-alpha which in turn suppress the hypothalamic-pituitary-gonadal (HPG) axis, leading to hypogonadism. This pathophysiological interplay is termed hypogonadal-obesity-adipocytokine hypothesis. TestIL is a prospective, multicenter, randomized, double-blinded, placebo-controlled trial to test the hypothesis that inhibition of IL-1-activity diminishes the inhibitory effects on HPG axis and increases testosterone levels in men with metabolic syndrome.

Obesity and the metabolic syndrome are considered as chronic low-grade inflammatory states. Elevated pro-inflammatory mediators in obesity and metabolic syndrome have an inhibitory effect on the hypothalamic-pituitary-gonadal axis (HPG axis) leading to hypogonadism. Decreased testosterone production in obese men in turn promotes additional fat deposition, contributing to a vicious cycle of fat accumulation. This complex pathophysiological interplay is termed hypogonadal-obesity-adipocytokine hypothesis, describing a bidirectional relationship between low levels of testosterone and the metabolic syndrome.

TestIL is a prospective, multicenter, randomized, double-blinded, placebo-controlled trial to test the hypothesis that inhibition of IL-1-activity diminishes the inhibitory effects on HPG axis and increases testosterone levels in men with metabolic syndrome.

Inclusion Criteria:

1. Informed consent as documented by signature,
2. Men at the age between 18 and 75 years,
3. BMI >30 kg/m2 and at least 1 manifestation of the metabolic syndrome (i.e. prediabetes, diabetes, hypertension, dyslipidemia),
4. Total testosterone level <12 nmol/l.

Exclusion Criteria:

1. Previous or current medication with testosterone,
2. Testosterone deficiency of other cause, i.e. primary hypogonadism caused e.g. by Klinefelters syndrome, cryptorchidism, condition following orchiectomy. Known secondary hypogonadism caused by pituitary adenoma. Patients on antiandrogen medication,
3. Clinical signs of infection in the week before inclusion or history of a severe infection during the last 2 months,
4. Severe immunosuppression (e.g. patients with previously known infection with human immunodeficiency virus and a cluster of differentiation 4 (CD4) count below 350 x 109/L, patients on immunosuppressive therapy after solid organ transplantation and neutropenic patients with neutrophil count < 500 x 109/L and patients under chemotherapy with neutrophils 500-1000 x 109/L with an expected decrease to values < 500 x 109/L),
5. Hematologic disease (leukocyte count < 1.5 x 109/l, hemoglobin < 11 g/dl, platelets <100 x 103/µl),
6. Other clinically significant concomitant disease states (e.g., renal failure [Creatinine-Clearance < 30 ml/min], hepatic dysfunction [transaminases >3x upper normal range], active carcinoma,
7. History of tuberculosis,
8. Known or suspected non-compliance, drug or alcohol abuse,
9. Contraindications to the class of drugs under study, e.g. known hypersensitivity or allergy to anakinra/Kineret®,
10. Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
11. Previous enrolment into the current study.