Background
Vascular age is the chronological age of an individual adjusted by their level of atherosclerosis. Vascular age can be used as understandable communication tool towards patients. It has been proposed that carotid intima-media thickness (CIMT) could be used to estimate the vascular age in individuals. The issue on how to best estimate vascular age remains an unanswered question and was evaluated in this study.
Methods
Data were used from the USE-IMT study collaboration, a global individual patient data meta-analysis including 14 population-based cohorts contributing data for 45 828 individuals. We used two methods to define vascular age. First, vascular age was the age at which a participant’s CIMT value would be at the 50th percentile of the age-and sex specific reference values of the healthy USE-IMT subpopulation (VA50). Second, vascular age was the age at which the estimated cardiovascular risk equals the risk of the observed CIMT value (VArisk).
Results
Mean (+/- standard deviation [SD]) chronological age, VA50, and VArisk were 58 (9), 63 (19), and 59 (7) years, respectively. VArisk was 0.24 yrs higher in women and 1.5 yrs higher in men than chronological age whereas VA50 was 4.4 yrs higher in women and 5.8 yrs higher in men than chronological age. After adjustment for traditional cardiovascular risk factors, a SD increase in VA50 and VArisk was associated with a 15% (95% confidence interval [CI]: 1.12; 1.19) and 22% (95% CI: 1.17; 1.28) higher risk of cardiovascular disease. For comparison, a SD increase in mean common CIMT increased the risk of cardiovascular disease with 15% (95% CI: 1.12; 1.19).
Conclusion
We presented two distinct measures a vascular age: VA50, and VArisk. VA50 is a straightforward translation of CIMT and is a measure of the age at which the average person would be expected to have a certain CIMT. In contrast, VArisk incorporates information about expected cardiovascular risk and is the chronological age of a person that conveys the same risk as the CIMT. VA50 and VArisk might provide a convenient transformation of CIMT to a scale that is more easily understood by patients and clinicians.
Assessment of cardiovascular risk and vascular age in overweight/obese adults with primary hypertension