Relationship between Carotid Intima-Media Thickness and Diabetes Clinical Risk Factors among Normotensive Type 2 Diabetes Mellitus among Native Black African Population

Background: Type 2 diabetes mellitus is frequently associated with atherosclerosis with changes in the thickness of the intima-media of carotid arteries which causes increased risk of cardiovascular diseases. Cardiovascular disease is a major cause of morbidity and mortality in this group of patients. The carotid artery reflects the degree of atherosclerosis in the various vessels especially coronary arteries. Measurement of the carotid artery thickness with real time, relatively cheap and non-invasive ultrasonography method is used in monitoring atherosclerotic disease progression and response to treatment. This study is aimed at ultrasonographic evaluation of the carotid intima-media thickness (CIMT) in adult Type 2 Diabetic patients compared to non-diabetic healthy controls matched for age, gender and body mass index (BMI). And to also determine its association if any with selected clinical factors among a native Black African population. Methodology: This was a prospective case control study involving 54 adult type 2 diabetics and 54 adult non-diabetic controls. CIMT was measured at 3 segments of the extracranial carotid arteries by a 7.5 - 10 MHz linear transducer of a portable Mindray M5 ultrasound machine. Results: Among the native black African population studied, there was significant difference in CIMT of adult type 2 diabetics compared to healthy non-diabetics adults (p value = 0.012 and 0.001 on the right and left respectively). The mean carotid intima-media thickness in diabetics was 0.81 mm and 0.85 mm, while in non-diabetics it was 0.74 mm and 0.75 mm on the right and left respectively. The presence of diabetes showed independent positive correlation with CIMT (beta: 0.24, p value = 0.004). Age (beta: 0.30, p value = 0.001) and plasma cholesterol level (beta: 0.30, p value = 0.013) also had positive correlation with CIMT. Conclusion: There was statistically significant difference in carotid intima-media thickness between adult type 2 diabetics and age, sex matched non-diabetics. DM showed independent correlation with CIMT.