Isolated postprandial hyperglycemia in type 2 diabetic patients in a Nigerian Tertiary Health Center

BACKGROUND: Postprandial hyperglycemia has been shown to be an independent cardiovascular risk factor. Some studies have reported that postprandial hyperglycemia is common and can occur even in patients with normal fasting glucose levels. This has been referred to as isolated postprandial hyperglycemia. OBJECTIVES: This study sets out to estimate the prevalence of isolated postprandial hyperglycemia in a cohort of patients with type 2 diabetes and to identify their clinical characteristics. MATERIALS AND METHODS: Ninety patients being managed for type 2 diabetes were recruited consecutively as they attended the diabetes clinic for follow-up. The patients were assessed with questionnaires, to obtain the demographic data. Their body mass index (BMI) was calculated. Fasting blood samples were collected for analysis of fasting plasma glucose (FPG). Patients were given their usual drugs and then served a standard meal calculated to contain 50 g of carbohydrate, providing 500 kcal. Blood samples were collected two hours after the start of the meal for postprandial glucose levels. RESULTS: The mean age of the patients was 57.7 ± 10.8 years with a male : female ratio of 2 : 3. The mean duration of diabetes was 6.77 ± 6.53 years. The mean BMI was 27.54 ± 6.01 kg / m(2). The mean FPG and two hour postprandial glucose were 7.51 ± 3.39 mmol / l and 11.02 ± 4.03 mmol / L, respectively, and the mean HBA1c was 9.0 ± 2.5%. The prevalence of isolated postprandial hyperglycemia was 24.4%. Elevated postprandial glucose was seen in 41.7% of the patients at target glycated hemoglobin levels. The patients with isolated postprandial hyperglycemia tended to be older and less obese. CONCLUSION: There was poor glycemic control in the patients generally; however, a significant proportion of patients, with apparently good glycemic control, had isolated postprandial hyperglycemia.