Endocrine Abstracts

Background: The term ‘Diabesity’ defines the complex relationship between obesity and type 2 diabetes mellitus (T2DM), that involves the convergent role of insulin resistance and chronic inflammation in amplifying the risk of systemic complications. To date, this link has not been fully characterized in terms of markers of tissue damage. The aim of this study was to investigate the association between the newly diagnosed glycemic alterations and the biomarkers of tissue damage through the interaction with the metabolic mileau.

Methods: This observational cohort study consecutively enrolled 656 adult subjects (M/F=277/379, age 50.6±14.9 years; BMI 47.5±7.5 kg/m²) with moderate-to-severe obesity and without a previous diagnosis of T2DM. For each patient, fasting glucose, glycated haemoglobin, and OGTT glucose and insulin levels were assessed. T2DM, impaired fasting glucose (IFG), and impaired glucose tolerance (IGT) were defined according to the ADA criteria, and analyzed in relation to metabolic, body composition and cardiorenal function parameters, intimal media thickness (IMT) and adipokines levels.

Results: The prevalence of screen-detected T2DM was 16.2% and the intermediate conditions of prediabetes, in particular IFG and IGT, were observed in 9.5% and 35.7% of cases, respectively. The waist-to-hip ratio (WHR) was found to be the most accurate anthropometric parameter in predicting the severity of glycaemic alterations (P<0.0001). Among the markers of tissue damage, the most significant variations within the glycemic alteration categories concerned the estimated Glomerular Filtration Rate (eGFR) and microalbuminuria (P<0.01 for both). The 2h post-OGTT glucose level was the glycaemic homeostasis index more strongly correlated with the IMT (r=0.21, P<0.01) and the markers of renal function and damage (eGFR: r=0.09, P<0.05; microalbuminuria: r=0,20, P<0.01), independently from sex and age. At the multivariable logistic regression analysis, age (OR=1.03, 95%CI 1.01-1.05, P=0.001), male sex (OR=1.90, 95%CI 1.12-3.21, P<0.05), C-reactive protein (OR=1.35, 95%CI 1-05-1.74, P<0.05) and adiponectin levels (OR=0.94, 95%CI 0.88-0.99, P<0.05) emerged as the main risk factor of T2DM in our cohort.

Conclusion: Our study identified the 2h post-OGTT glucose level as the most effective tool for the screening of glycemic alterations in the obese population. Moreover, we identified IMT, eGFR and microalbuminuria as the marker of tissue damage more closely associated with glycemic homeostasis in our cohort. Finally, the systemic inflammation index and adiponectin levels represent independent risk factors of screen-detected T2DM together with age and male sex.