Performance of the 1 mg dexamethasone suppression test in patients with severe obesity.

OBJECTIVE: To analyze the performance of the 1 mg dexamethasone suppression test (DST) in patients with obesity. Special attention was paid to the influence of interfering medication on DST. METHODS: In this prospective cohort study (Mannheim Obesity Study), patients with obesity were evaluated before bariatric surgery. For evaluation of hypercortisolism, a 1 mg dexamethasone-suppression test (DST) in all subjects was performed. Medication was assessed for possible interference. RESULTS: Two hundred seventy-eight patients with a mean age of 42.3 years (68.8% women) and a mean BMI of 47.9 ± 8.4 kg/m(2) were screened. Insufficient suppression of cortisol after DST was found in 24 patients (8.6%). In two patients hypercortisolism was confirmed. The specificity for DST was calculated at 92.0%. Only CYP3A4 inducers (n = 22, 7.9%) and estrogen therapy (n = 17, 6.1%) were significantly associated with falsely elevated cortisol after DST. Regression analysis excluded any interrelation between DST and anthropometry. CONCLUSIONS: Low prevalence of hypercortisolism (0.7 or <1.8%) was found. Specificity of DST in this cohort typically screened for hypercortisolism was 92.0% (≤ 50 nmol/L). DST should be avoided in patients taking CYP3A4 inducers or estrogen therapy, due to their significant interaction. In summary, the 1 mg DST is an adequate test for screening for hypercortisolism even in patients with extreme obesity.

Adipokines and endothelial dysfunction in obesity WHO°III.

Obesity is closely associated with the metabolic syndrome (MetS) and subsequent low-grade inflammation links to endothelial dysfunction (ED) and cardiovascular disease. The impact of adipokines on retinal ED is not fully understood, in particular not in severe obesity. The aim of the study was to identify the association of the MetS and prespecified adipokines on retinal ED in obesity WHO°III. 92 obese patients (obesity WHO°III) were assessed for the MetS (IDF), neck circumference, adipokines and inflammatory markers (hsCRP, TNFα, Il-6, MCP-1, sICAM, sVCAM, IGF-BP3, RBP 4 and adiponectin). Retinal ED as determined by the arterio-venous-ratio (AVR) and retinal vessel diameters (CRAE, CRVE) was measured using retinal photographs. Obese subjects with MetS (MetS+ group) differed from the MetS- by neck circumference, fasting plasma glucose, insulin, HOMA-IR, triglycerides and HDL-C. Importantly, IL-6, sICAM and adiponectin were significantly different between groups, while measures of retinal ED showed no differences. Univariate linear regression revealed a significant association between neck circumference and ED for patients with MetS, and a significant association between adiponectin and CRAE for patients without MetS. This study shows that ED in obesity WHO°III is independent of MetS or inflammation and that neck circumference has an impact on ED in obesity WHO°III.