Determination of Glycated Haemoglobin (HbA1c) and Fasting Blood Glucose in a Community Diabetes Screening in Osun State

Community-based diabetes screening programmes using combined glycated haemoglobin and fasting glucose measurements can identify undiagnosed cases and prediabetic individuals in high-risk populations, supporting early intervention. This study determines HbA1c and fasting blood glucose levels in a community diabetes screening programme conducted in Osogbo, Osun State, and evaluates their concordance as diagnostic screening tools. Five hundred and forty adults aged thirty years and above attending a free community health fair were recruited. Capillary blood samples were collected after an overnight fast. Fasting blood glucose was measured by glucose oxidase method using a point-of-care glucometer. HbA1c was determined by high-performance liquid chromatography using a dedicated analyser. Participants were classified as normoglycaemic, prediabetic, and diabetic by both measures using current American Diabetes Association diagnostic thresholds. Results show a diabetes prevalence of 9.4 percent by HbA1c criteria and 8.7 percent by fasting glucose criteria, with overall concordance of 82 percent between the two methods. Prediabetes was detected in 21.3 percent by HbA1c and 18.9 percent by fasting glucose. A total of 31 percent of subjects identified as diabetic by HbA1c had no prior diagnosis. Age above fifty, family history of diabetes, obesity, and hypertension were independently associated with elevated HbA1c. HbA1c detected slightly more cases in older adults than fasting glucose, while fasting glucose identified more cases in younger adults. The study supports combined screening approaches in Osun State community diabetes programmes. Keywords: HbA1c, fasting blood glucose, diabetes screening, community health, Osun State.