Arterial stiffness assessment in obese black South African patients

Increased arterial stiffness is a determinant of cardiovascular mortality and an independent marker of cardiovascular disease. The objective of this study was to asses arterial elasticity by determination of pulse-wave velocity (PWV) and augmentation index (Aix) in obese black patients.

PWV and Aix were assessed non-invasively using the AtCor SphygmoCor^® system (AtCor Medical, Inc, Sydney, Australia). The study participants were divided into four groups; healthy volunteers (HV) (n = 29), patients with concomitant diseases but normal body mass index (Nd) (n = 23), obese patients without concomitant diseases (OB) (n = 29) and obese patients with concomitant diseases (OBd) ( n = 29).

The difference in the mean levels of PWV was statistically significant in the obese group with and without concomitant disease. The PWV in the OB group (7.9 ± 2.9 m/s) and in the OBd group (9.2 ± 4.4 m/s) was, respectively, 19.7 and 33.3% higher than in the HV group (6.6 ± 2.1 m/s). PWV was directly correlated with age, glycated haemoglobin level, aortic systolic blood pressure and heart rate. The risk of cardiovascular diseases in the obese patient without additional diseases was increased by 50.7%. The presence of concomitant diseases (type 2 diabetes mellitus and hypertension) in addition to obesity increased arterial stiffness by a further 11.4% and therefore also increased the risk of cardiovascular diseases by a further 35.1%. Aix was increased in the OBd and Nd groups by 8.2 and 16.5%, respectively, however the increase was not statistically significant. Aix was directly correlated with age, heart rate and aortic systolic blood pressure.

The obese black patients had a higher PWV, indicating increase in arterial stiffness and therefore a higher risk for cardiovascular disease. In addition, aging, increased blood pressure and type 2 diabetes mellitus contributed further to arterial stiffening in these obese patients.