All Cardiovascular Risk Factors Are Not Consistently Associated With Aortic Stiffness Other Than Hypertension

We read the article “Association of Arterial Stiffness With Obesity in Australian Women: A Pilot Study” by Pal and colleagues1with great interest. They investigated arterial stiffness in overweight/obese Australian women compared with their lean counterparts. They concluded that increased arterial stiffness existed in overweight patients compared with lean patients. In addition, arterial stiffness was positively associated with measurements of body composition, triglycerides and glucose levels, and systolic and diastolic blood pressures. They also concluded that arterial stiffness is associated with obesity, along with other metabolic abnormalities in obese Australian women. We congratulate the authors for this important study. However, we do not share the opinion that aortic stiffness can be affected definitely by cardiovascular risk factors such as smoking, alcohol consumption, and hypercholesterolemia. Previous studies proposed that several cardiovascular risk factors might affect arterial stiffness, such as age, body weight, smoking, alcohol consumption, hypertension, cholesterol and triglyceride concentrations, and glucose levels.2 Recently, Cecelja and colleagues3 published a systematic review which showed that the contribution of cardiovascular risk factors other than age and blood pressure to aortic stiffness measured by carotid-femoral pulse wave velocity is small or insignificant. They demonstrated that age and blood pressure were consistently independently associated with aortic stiffness (91% and 90% of studies, respectively). Diabetes mellitus was associated with aortic stifness in 52% of studies, but the strength of the association was low. The majority of studies found no independent association between aortic stiffness and sex, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, smoking, and body mass index. This systematic review showed that only age and blood pressure were consistently independently associated with aortic stiffness in the majority of studies.3 Arterial stiffness describes the reduced capability of an artery to expand and contract in response to pressure changes and it is an independent predictor of cardiovascular morbidity and all-cause mortality.4 It has been suggested that aortic stiffness occurs as a result of atherosclerosis along the aorta. However, there is little or no association between aortic stiffness and classical risk factors for atherosclerosis, other than age and blood pressure.3 It has also been shown that some antihypertensive drugs like angiotensin-converting enzyme inhibitors, calcium channel blockers and spiranolactone, and statins reduce aortic stiffness.4 Pal and colleagues did not also mention these drugs, which might affect aortic stiffness, and would have been useful if they had provided information about these factors. The results of the study might be specific to this obese Australian women patient group. In other words, there might be an association of cardiovascular risk factors with aortic stiffness in this group. These results cannot be generalized to the general population. Only age and blood pressure were consistently independently associated with aortic stiffness in the majority of previous studies.3