Assessment of the health status of vascular endothelial function in middle-aged and older adults in a county in Henan Province using flow-mediated dilation testing

OBJECTIVE: To assess the health status of vascular endothelial function in middle-aged and older adults undergoing health examinations in a county in Henan Province by measuring brachial artery flow-mediated dilation (FMD), and to analyze the effects of age, sex, body fat percentage, and underlying diseases. METHODS: A total of 978 middle-aged and older individuals who underwent FMD testing at Xun County People's Hospital in Henan Province from June 2023 to June 2025 were selected as study participants. Brachial artery FMD was measured using a high-resolution color Doppler ultrasound system, with FMD≥7% defined as normal, and age, sex, body mass index (BMI), body fat percentage, and underlying diseases were recorded. Participants were divided by age into a middle-aged group (40～59 years, 270 individuals) and an older group (≥60 years, 708 individuals); by sex into a male group (487 individuals) and a female group (491 individuals); and by disease into a cerebral infarction group (223 cases), a coronary heart disease group (44 cases), a group with hypertension or diabetes only (585 cases), and a group without underlying diseases (33 cases). Statistical analyses used one-way analysis of variance, the chi-square test, and multivariable Logistic regression analysis. RESULTS: The overall rate of normal FMD (FMD≥7%) was only 14.11% (138/978), with 431 individuals (44.07%) in the abnormal vascular endothelial function group (FMD＜4%) and 409 individuals (41.82%) in the vascular endothelial function risk group (4%～＜7%). The rate of normal FMD in the middle-aged group was 20.00% (54/270), significantly higher than that in the older group (11.86%, 84/708) (P＜0.001). The rate of normal FMD in the female group (21.59%, 106/491) was significantly higher than that in the male group (6.57%, 32/487) (P＜0.001), and this advantage was present in both the middle-aged group (33.85% versus 7.14%) and the older group (17.17% versus 6.34%). Body fat percentage in the normal group, (29.14±2.90)%, was lower than that in the abnormal group, (32.68±7.12)% (P＜0.001), whereas BMI did not differ between groups (P=0.44). Multivariable Logistic regression showed that each 1% increase in body fat percentage increased the risk of abnormal FMD by 8% (OR=1.08, 95%CI:1.03～1.12, P=0.002), independently of age, sex, and underlying diseases. Analysis by disease showed that patients with cerebral infarction had the lowest rate of normal FMD at 10.31% (23/223), compared with 13.64% (6/44) in patients with coronary heart disease, 15.21% (89/585) in patients with hypertension or diabetes only, and 27.27% (9/33) in those without underlying diseases. Among patients with cerebral infarction, the normal rate in the female group (21.95%) was significantly higher than that in the male group (3.55%). Among patients with hypertension or diabetes only, the rate of normal FMD in the middle-aged group (23.16%) was higher than that in the older group (11.76%), and the normal rate in the female group (21.66%) was higher than that in the male group (7.75%). CONCLUSIONS: Vascular endothelial function in middle-aged and older adults in this county was generally poor, with an overall normal rate below 15%. Vascular endothelial function declines with increasing age and is better in women than in men; increased body fat percentage, rather than increased BMI, is an independent risk factor for impaired vascular endothelial function, and endothelial damage is more severe in those who have already experienced cardiovascular or cerebrovascular events.