To determine fasting plasma glucose and glycosylated hemoglobin (HbA1c) levels in a group of type two diabetic patients of a costarican rural zone, it was performed a descriptive investigation with 443 diabetic patients of the Chronic Patients Program of the Anexion Hospital, Costa Rica during year 2000. The fasting plasma glucose general average was 158,02 mg/dl, ranges 70-110 mg/dl (24,4%), 141-180 mg/dl (21,7%), >/= 201 mg/dl (23,4%). The less body mass index, the less level of fasting plasmaglucose. HbA1c was measured in 61,1% of those patients and the general average was 8,91%, with ranges of 31,7% (HbA1c 4%-7%), 34,3% (HbA1c 7,1%-9,9%) and 34% (10% or more). The comparison between giycemia and HbA1c was oniy good in the 84% patients with HbA1c (5.9% or less), 18% with HbA1c (6%), 8,3% with (HbA1c 7%),9% with (HbA1c 8%), 10.7% with HbA1c (9%), none with HbA1c (10% and 12% or more), The 18.4% of the diabetics with 0-4 years of diagnosis of DM have less that 7% of HbA1c and the 20.3% of diabetics with 10 or more years of DM diagnosis have 9% or more of HbA1c. This is the first study that measure fasting plasma glucose and HbA1c in Costa Rica, so we cannot make comparativa analysis. HbA1c report is preferable to monitor the metabolic control of the diabetic population, because the confiability of glycemic reports are influence by many factors that jeopardice the compliance of the diabetics.

diabetes mellitus ; HbA1c; Body mass index