Biochemical analyses
At the first visit to the laboratory, 4 mL of whole blood was collected by the vacuum method into EDTA tubes (Plastilab, Brazil) from the antecubital vein after approximately 12 h overnight fasting. Homogenized whole blood was used for preparation and processing of samples.The following analyzes were performed for glucose metabolism: fasting glucose by enzymatic method using commercial kits (Labtest, Brazil), fasting insulin by chemiluminescence and HbA1c by immunoassay. This method is certified by the National Glycohemoglobin Standardization Program (Lipid profile analysis involved total cholesterol by enzymatic system (reaction of the endpoint), HDL by System for direct homogeneous determination of HDL cholesterol in serum, and triglycerides by enzymatic system, by end point reaction, all using commercial kits (Labtest, Brazil).