Undiagnosed diabetes and prediabetes in hypertensive and normotensive adults at the University College Hospital, Ibadan, Nigeria

Abstract

Background: Essential hypertension is associated with an increased incidence of glucose intolerance (prediabetes and type 2 diabetes mellitus) but many persons with glucose intolerance remain undiagnosed for many years. Aims: To determine the frequency of undiagnosed diabetes and prediabetes in a group of hypertensives and normotensives. Methods: Anthropometry, blood pressure and standard oral glucose tolerance test (OGTT) were done in adult participants (hypertensive and normotensive controls) newly presenting to a General Outpatient Clinic of the University College Hospital, Ibadan. Results: Using the OGTT, the frequency of undiagnosed diabetes was 10.4% and 4.3% in hypertensives and normotensives respectively (p=0.031) but was 5.2% and 2.6% in hypertensives and normotensives respectively using fasting plasma glucose (FPG) alone (p=0.308).Using the OGTT, impaired glucose tolerance (IGT) was diagnosed in 32.2% of hypertensives compared to 14.8% of normotensives (p=0.002) while impaired fasting glucose (IFG) was diagnosed in 5.2% of hypertensive and 2.6% of the normotensives (p=0.288). After adjusting for hypertension, age, level of education, body mass index and waist circumference, hypertensives and persons with a higher waist circumference had statistically significantly increased odds of having glucose intolerance: hypertension (OR 2.915; 95% CI 1.5265.556) and waist circumference (OR 1.050; 95%CI 1.010-1.090). Conclusion: Diabetes and prediabetes are commoner in hypertensive persons and such persons require close and frequent monitoring for the development of this disease. Screening with both fasting plasma glucose and post glucose load plasma glucose (OGTT) identifies more persons with glucose intolerance than fasting plasma glucose alone.