Effects of Age and Other Risk Factors on Vascular Stiffness in the Elderly participants

Abstract

Background: Cardiovascular diseases are the leading cause of death in our country, with atherosclerosis being the primary factor in pathogenesis. Determination of the cardio-ankle vascular index, an indicator of vascular stiffness, enables the diagnosis of atherosclerosis before clinical symptoms manifest. Assessing vascular stiffness and studying risk factors is important to prevent cardiovascular disease and complications. Aim: To determine the changes in vascular stiffness among study participants over a 12-years period and identify contributing factors. Materials and Methods: This prospective cohort study was conducted at the Department of Pathophysiology, School of Biomedicine, and MNUMS. Among the 393 participants from Ulaanbaatar who took part in the study “Study of factors affecting on the aging of the Population,” funded by The Mongolian Foundation for Science and Technology from 2011 to 2015, 89 participants aged 67 to 105 years were selected for reassessment between February and April 2024 based on the exclusion criteria. According to the 2023 data from the Ministry of medicine, 102 elderly individuals have passed away and were excluded from the study. Data collection included a questionnaire with 48 questions across 7 categories, covering socio-economic status, lifestyle, and cardiovascular risk factors. Physical parameters (body weight, height, chest, abdomen, gluteal circumference, and blood pressure) were measured. The Cardio-ankle vascular index (CAVI), indicative of vascular stiffness, was determined on the right and left side using VaSera VS-1000 (FUKUDA DENSHI, JAPAN) instrument. Blood tests were performed to assess total cholesterol, triglycerides, HDL, and LDL. Results: According to the baseline study (2011), CAVI of the participants was 8.67±1.35, but it increased to 9.43±1.62 in the follow-up study (2024) (p<0.05). Over the 12-year period, arterial stiffness (CAVI ≥9) increased from 41.6% (n=37) to 61.8% (n=55) in the follow-up study. On the other hand, the number of individuals in risk groups (CAVI 8-9) decreased from 28.1% (n=25) to 22.5% (n=20), and healthy participants (CAVI≤9) decreased from 30.3% (n=27) to 15.7% (n=14). (p<0.01) In our study 84.6% (n=11) of male participants and 57.9% (n=44) of female participants had arterial stiffness (CAVI ≥9). There is a direct weak correlation (r=0.378, p<0.01) between CAVI and age, and according to linear regression analysis, each unit increase in age resulted in a greater increase in CAVI, with a value of 0.086 (Exp (B) =0.086, p<0.01). Based on the relative risk (RR) calculation from 55 cases of progression to arterial stiffness during the follow-up period, the following associations were found: having diabetes was 1.58 [95%CI 1.21-2.08] times and having hypertension was 2.36 [95%CI 1.11-5.00] times higher risk of arterial stiffness compared to the healthy group. Salt consumption greater than 5g/day increased the risk of arterial stiffness by 1.64 [95%CI 1.24-2.16] times compared to the low consumption group and by 2.08 [95%CI 1.36-3.16] times in the high lamb consumption group compared to the high beef consumption group. Prolonged bed rest has a 1.52[95%CI 1.15-2.02] times increased risk of arterial stiffness compared to other groups. (p<0.05) Conclusions: 1. The vascular stiffness of study participants increased with age, with each one-unit increase in age corresponding to a 0.086-unit increase in vascular stiffness. 2. Diabetes, hypertension, high salt consumption, excessive lamb consumption, and prolonged bed rest are risk factors for arterial stiffness.