The present study aims to perform a comprehensive diagnostic assessment, cardio-metabolic evaluation, gut microbiome profiling and early detection of glycemia-related chronic complications in the entire spectrum of early glucose intolerance categories and newly diagnosed diabetes, including gestational diabetes in an adult Bulgarian population. The study is case-control except for the subgroup with gestational diabetes which will be evaluated prospectively for the early postpartum evolution of glucose tolerance and its predictors. The
research goals include:

• Proper timely diagnostic assessment of the different types of diabetes and categories of glucose intolerance, including functional, immunologic and genetic evaluation, if indicated
• Evaluation of the relationship between different glucose homeostasis parameters -Glucose at 0, 60 and 120 min during OGTT (especially the role of 60-min plasma glucose vs. 120-min plasma glucose), glycated albumin, fructosamine, 1,5-anhydroglucitol, HbA1c, TIR, CV%, mean glucose, glucose management indicator (GMI) and insulin sensitivity indices, and cardiovascular risk status and glycemia-related complications, at early stages of glucose intolerance
• Assessment of the presence and severity of chronic diabetes complications at early stages of glucose intolerance
• Assessment of the diagnostic performance of glycated albumin, fructosamine and 1,5-anhydroglucitol for the diagnosis of prediabetes, diabetes and gestational diabetes and development of population specific cut-off values
• Assessment of the performance of glycated albumin, fructosamine and 1,5-
  anhydroglucitol as markers of glycemic control during pregnancy complicated with gestational diabetes and as predictors of pregnancy outcomes in this population
• Assessment of gut microbiome in the different categories of glucose tolerance and newly diagnosed diabetes and its relationship to glycemic and metabolic parameters and chronic complications
• Assessment of a genetic, metabolic and gut microbiome profile associated with the development of gestational diabetes
• Assessment of the prognostic value of some markers (glucose-related, biochemical, genetic and serum biomarkers – fetuin A and B, afamin, FGF 21/23, angiopoetin-like protein 8, pgCD59) for the development and early evolution of gestational diabetes