CARDIOVASCULAR JOURNAL OF AFRICA • Volume 35, No 1, January – April 2024 AFRICA 7 Arterial stiffness assessment in obese black South African patients TL Rasakanya, E Osuch Abstract Introduction: 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. Methods: 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). Results: 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. Conclusion: 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. Keywords: arterial elasticity, pulse-wave velocity, augmentation index, blood pressure, body mass index, diabetes Submitted 12/8/21; accepted 23/11/22 Published online 13/2/23 Cardiovasc J Afr 2024; 35: 7–11 www.cvja.co.za DOI: 10.5830/CVJA-2022-064 Arterial stiffening is the ongoing loss and fragmentation of elastin, and an accumulation of stiffer collagen fibres in the arterial wall.1 Arterial stiffness increases with aging and concomitant diseases such as diabetes mellitus, atherosclerosis, hypertension, chronic kidney disease and stroke.2,3 Obesity is linked with a high risk of cardiovascular disease (CVD), particularly when body fat is distributed within the abdominal region. When compared with non-obese subjects, obese subjects have increased arterial stiffness.4,5 Pulse-wave velocity (PWV) and augmentation index (Aix) are gold-standard, non-invasive markers of arterial elasticity and predictors of cardiovascular morbidity and mortality.6 PWV is a direct measure of large-artery stiffness. Aix is a surrogate measure of arterial rigidity that could be influenced by the left ventricular ejection fraction and peripheral haemodynamics, as well as the properties of the large arteries.7 PWV values are calculated from the time interval between the estimated forward and reflected waves and are comparable with invasive measurements. Aix values are calculated as the ratio of the augmentation pressure to the pulse pressure.8 A slow PWV indicates good elasticity and a fast PWV, poor elasticity.9 A 1-m/s increase in aortic PWV has been shown to equate to 39% increase in risk of cardiovascular events.10 PWV is an independent predictor of stroke and coronary heart disease in healthy subjects.11 Aix, a measure of pulse-wave reflection, is a more direct measure of arterial stiffness. It calculates how much of the central pulse pressure is accounted for by the reflected pulse wave.12 ElevatedPWVandAix are associatedwithpoor cardiovascular health.13 Increased PWV and Aix indicate damage to the elastic tissue of the arteries.14 Various studies have reported the effects of obesity on arterial elasticity in different ethnic groups.15,16 The aim of this study was to assess arterial stiffness in obese black South African patients. The objectives of the study were to compare the difference in arterial stiffness and to evaluate the effect of hypertension and diabetes on arterial stiffness in obese and non-obese patients using PWV and Aix analysis. This study is the first to assess the effects of obesity on arterial stiffness in obese black South African patients. Methods The study was approved by the Sefako Makgatho University Research and Ethics Committee (SMUREC/M/112/2016:PG). Informed consent was obtained from the participant before entering the study. Full explanation of the procedure was given with the possibility of withdrawal at any time. The study was conducted in accordance with the principles detailed by the Declaration of Helsinki. A comparative study model was used and 110 participants were recruited from the Sefako Makgatho Health Sciences University community. Body mass index (BMI) groups were Department of Pharmacology and Therapeutics, Sefako Makgatho Health Science University, Pretoria, South Africa TL Rasakanya, MSc Pharmacology, tsakani.rasakanya@smu.ac.za Department of Clinical Pharmacology, School of Medicine, Dr George Mukhari Academic Hospital, Sefako Makgatho Health Sciences University, Pretoria, South Africa E Osuch, MD, PhD, ACCP (SA), FCP (ACCP), MSc (Med) Pharmacology, Dip Fam Med
RkJQdWJsaXNoZXIy NDIzNzc=