Cross-sectional comparison of endothelial function and microvascular reactivity across age groups and cardiovascular health status

Introduction: Aging and factors such as hypertension, obesity, and diabetes increase the risk of cardiovascular diseases. A key precursor of cardiovascular diseases is compromised vascular function. While endothelial function and microvascular reactivity decline with age, few studies have examined how they are further affected by cardiovascular health status. Objective and Hypothesis: This retrospective analysis compares peripheral endothelial function and microvascular reactivity between young, middle-aged and older adults living with or without cardiovascular risk factors. We hypothesized that endothelial function and microvascular reactivity is lower in older adults compared to middle-aged and younger adults and that they are further reduced in the presence of cardiovascular risk factors. Methods: Peripheral endothelial function (brachial artery flow-mediated dilation, FMD) and microvascular reactivity (post occlusive reactive hyperemia) were measured in 241 participants divided into three groups: a) 19 healthy young adults (9 males/10 females, 18–35 years old, BMI: 22.1 ± 2.8 kg/m 2 ); b) 34 healthy middle-aged adults (3 males/ 31 females, 43–57 years old, BMI: 23.4 ± 3.4 kg/m 2 ); c) 64 middle-aged adults living with at least 1 cardiovascular risk factor (42 males/ 22 females, 41–59 years old, BMI: 28.9 ± 5.6 kg/m 2 ); d) 18 healthy older adults (9 males/ 9 females, 60–79 years old, BMI: 25.9 ± 2.5 kg/m 2 ); e) 104 older adults living with at least 1 cardiovascular risk factor (70 males/ 34 females, 60–84 years old, BMI: 29.5 ± 5.6 kg/m 2 ). Healthy participants were free of cardiovascular risk factors. Participants living with cardiovascular risk factors presented with at least one of the following: hypercholesterolemia, hypertension, type 2 diabetes, smoking. Results: Among healthy adults, brachial artery FMD decreased with age (young: 4.10 ± 2.36%, middle-aged: 3.24 ± 3.28%, older: 3.57 ± 1.52%, p=0.01). FMD was further reduced in older adults living with cardiovascular risk factors (2.89 ± 2.09%, p=0.05 vs. healthy older adults). Among healthy adults, microvascular reactivity was lower with middle-age (young: 1.79 ± 0.55 ml/mmHg, middle-age: 1.09 ± 0.47 ml/mmHg, older: 1.99 ± 0.93 ml/mmHg, p<0.01). In the presence of cardiovascular risk factors, microvascular reactivity was greater in middle-aged adults (1.73 ± 0.72 ml/mmHg, p<0.01 vs. healthy middle-aged) but did not differ in older adults (1.53 ± 0.91 ml/mmHg, p=0.07 vs. healthy older). Conclusion: These results suggest that the decline in peripheral endothelial function associated with age is exacerbated by the presence of cardiovascular risk factors. In contrast, microvascular reactivity is not consistently affected by age or cardiovascular health status. Montreal Heart Institute Foundation This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.