SONOGRAPHIC EVALUATION OF CAROTID INTIMA-MEDIA THICKNESS AND BLOOD FLOW VELOCITIES IN TYPE 2 DIABETICS AND NON-DIABETICS IN PORT HARCOURT
Background: Diabetes mellitus (DM), a devastating disease, is one of the major global public health burdens. In Port-Harcourt, the prevalence of type 2 DM is estimated at 7.9%. Diabetic individuals are more prone to advanced atherosclerosis, a known risk factor for stroke. DM has been reported as one of the commonest factors for stroke at the University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt. Carotid intima-media thickness (CIMT) is a marker of the degree of atherosclerosis with resulting carotid haemodynamic changes and these have been found useful in predicting the risk of stroke in type 2 diabetics.
Aims and Objectives: To sonographically evaluate the CIMT and blood flow velocities in type 2 diabetics and to compare the findings to those of non-diabetics.
Materials and Methods: This was a cross-sectional comparative study carried out between February, 2015 and June, 2016. Participants were recruited from UPTH and Braithwaite Memorial Specialist Hospital (BMSH), Port Harcourt. Seven-hundred participants, comprising equal number of type 2 diabetics and non-diabetics aged 18 years and above, had colour Doppler ultrasound scan of the carotid arteries; to measure CIMT and blood flow velocities. The results in the type 2 diabetic group were compared with those of non-diabetic group. Sonographic parameters were correlated with age, gender and BMI. CIMT was also correlated with duration of diabetes. Data was analyzed using statistical package for social sciences (SPSS), version 21 for Windows. P-values ≤ 0.05 (5% level of significance), were considered significant.
Results: There were 174(49.7%) males and 176(50.3%) females among the 350 type 2 diabetic participants, while there were 158(45.1%) males and 192(54.9%) females among the 350 non-diabetic participants. Mean age for type 2 diabetic group was 59.3±10.2 years, while the mean age for the non-diabetic group was 49.6±12.4 years. The cumulative mean
sonographic parameters measured, stated as type 2 diabetic group versus non-diabetic group were as follows, CIMT: 1.09±0.25mm vs 0.94±0.24mm, CCA PSV: 105.43±20.68cm/s vs 112.16±17.07cm/s, CCA EDV: 26.63±11.65cm/s vs 29.65±6.62cm/s, ICA PSV: 90.58±20.29cm/s vs 97.39±14.56cm/s, ICA EDV: 26.79±7.66cm/s vs 30.85±6.88cm/s and ICA/CCA PSV ratio: 1.33±0.29 vs 1.33±0.26.
Conclusion: Type 2 diabetic patients had significantly higher CIMT values than non- diabetics (p = 0.001); CIMT increased with advancing age in both groups. Carotid blood flow velocities in the common carotid and internal carotid arteries were significantly lower in type 2 diabetics compared to non-diabetics. CIMT also increased significantly with duration of DM (r=0.194, p=0.001). There was no significant difference in the prevalence of carotid plaques between type 2 diabetics and non-diabetics (p = 0.32).
Key words: Doppler, Diabetes mellitus, CIMT, Carotid Blood Flow Velocities.