Understanding Vascular Age: Insights from the NHANES Study
Table of Contents
Published on February 20, 2025, by Time.News
Population Overview
the National Health and Nutrition Examination Survey (NHANES),conducted by the US Centers for Disease Control and Prevention (CDC),provides critical insights into the health of the American population. This survey,which obtained informed consent from all participants and received approval from the National Center for Health Statistics Ethics Review Board,included a cross-sectional analysis of 2,788 individuals aged 30 and older. Notably, these participants were free from cardiovascular diseases (CVD), such as coronary heart disease, congestive heart failure, heart attacks, strokes, or angina, and were selected from the NHANES 2005–2006 cycle, during which IgE levels were specifically measured. Participants with incomplete data on ige levels or other necessary variables for calculating vascular age were excluded from the analysis.
Defining Exposure
understanding the exposure variables is crucial for interpreting the results of the NHANES study. The survey utilized standardized questionnaires to gather dietary information, focusing on liquid milk consumption, including the type and quantity consumed over the past 30 days. Additionally, participants reported thier frequency of milk use in cereals over the past year. Cow’s milk was the primary focus, encompassing whole, 2%, and nonfat/skim varieties. Egg and peanut consumption were also assessed through 12-month food frequency questionnaires, although the peanut questions included nuts and seeds, which may have led to some misclassification.
Vascular age and Early Vascular Aging
In 2008, D’Agostino et al.introduced the Framingham Risk Score (FRS) as a tool for assessing cardiovascular risk. This score incorporates various factors, including age, systolic blood pressure, treatment for hypertension, levels of high-density lipoprotein, total cholesterol, diabetes, and smoking status. To enhance understanding of cardiovascular risk, they proposed the concept of ‘vascular age’—a metric that reflects the age of an individual with the same FRS-predicted risk score, assuming all other risk factors are at normal levels. The difference between chronological age (CA) and vascular age (VA), termed Δ-age, is used to define early vascular aging (EVA), with the 10th percentile of Δ-age serving as a critical cutoff.
Food Consumption Patterns
Dietary habits play a critically important role in vascular health. Participants provided detailed information regarding their consumption of various foods, especially focusing on liquid milk, eggs, peanuts, and shrimp. The survey aimed to quantify these dietary patterns over specified time frames,which is essential for understanding their potential impact on vascular aging.
Covariates and Lifestyle Factors
Demographic data, including age, sex, ethnicity, marital status, income, and education, were self-reported by participants. Lifestyle factors such as alcohol consumption, physical activity levels, sleep duration, and adherence to the Healthy Eating Index (HEI) were also recorded. Comorbidities, including asthma, chronic kidney disease (CKD), hypertension, and depression, were considered in the analysis. Body mass index (BMI) was calculated using the standard formula, providing a complete view of the participants’ health status.
Statistical Analysis Methodology
Before conducting the analysis, the research team employed the ‘random forest’ method to impute missing values across all 15 covariates. Continuous variables were reported as means with standard deviations or medians with interquartile ranges, while categorical variables were expressed as counts and percentages. Various statistical tests, including the Wilcoxon rank sum test and Pearson’s Chi-squared test, were utilized to compare group differences.
Logistic regression models were developed to explore the association between food sensitization and early vascular aging.The models were adjusted for various factors, including age, ethnicity, marital status, income, education, and lifestyle behaviors.Additionally, the analysis examined how allergen consumption might modify these relationships.
Sensitivity Analyses and Findings
Multiple sensitivity analyses were conducted to ensure the robustness of the findings. These included Poisson regression to estimate prevalence ratios and ordinal logistic regressions to assess the relationship between sensitization and vascular age status. Linear regressions were also performed to evaluate the association between sensitization, total IgE levels, and Δ-age. The statistical analyses were executed using R (version 4.3.2), with a significance threshold set at P < 0.05.
Understanding Your “Vascular Age”: An Interview with Dr. Anya Sharma on the NHANES Study on Heart Health
Time.news: Welcome, Dr. Sharma! Today,we’re diving deep into a fascinating topic: vascular age. Recent data from the NHANES study has shed light on this critical indicator of heart health. Can you explain what vascular age is and why itS important for our readers to understand it?
Dr. Anya Sharma: Thanks for having me. In simple terms, vascular age is an estimate of the “age” of your arteries based on your cardiovascular risk profile. It doesn’t necessarily align with your chronological age. The NHANES study, and specifically the use of the Framingham Risk Score (FRS), allows us to see how well your lifestyle and risk factors are treating your arteries. If your vascular age is higher than your chronological age, it indicates that you may have early vascular aging (EVA), putting you at increased risk for cardiovascular events.
Time.news: The Time.news article mentions the Framingham Risk Score and the concept of Δ-age. How are these used to determine vascular age and identify those with EVA?
Dr. Sharma: Exactly. The Framingham Risk Score, developed many years age but still relevant, considers factors such as age, blood pressure, cholesterol levels, diabetes status, and smoking habits to predict your 10-year risk of developing cardiovascular disease.From there you get your risk score, and your vascular age is calculated by finding the actual age of an individual with the same risk score, assuming everythign else is normal.The difference between your actual age and vascular age is the Δ-age which tells you how old your arteries really are. If your Δ-age falls in the bottom 10th percentile, you’re looking at EVA, which is crucial to identify early on for preventative measures.
Time.news: The NHANES study focused on specific dietary factors like milk, eggs, and peanuts. What sort of food/allergen sensitivities were researchers analysing in relation to vascular age?
Dr. Sharma: That’s correct. As the NHANES study, specifically the year selected, measured IgE levels, the purpose of studying milk, peanut and egg consumptions was geared towards identifying food sensitivities that might be related to vascular aging. Many studies have suggested that diet plays an critically important role in cardiovascular health and the specific dietary intake was recorded over a given time-frame to understand it’s impact on vascular aging.
Time.news: So, were sensitivities to these foods really critically important to vascular age?
Dr. Sharma: Good question, and it’s what the study hoped to find out. However, although food sensitivities are important for our health and quality of life, the Time.news article does not provide any insight into what was specifically discovered in regards to the relationship between food senitivity and vascular age, likely because that’s not what the article was about. What the article does show, is that the research team did a thorough analysis for different factors by conducting sensitivity analyses and using multiple regression methods to evaluate results and provide a statistically significant outcome.
Time.news: The study also considered various covariates and lifestyle factors like income, marital status, alcohol consumption, and sleep duration.How do these influence vascular age?
Dr. sharma: These lifestyle factors act as confounders in the study. Think of it this way: smoking drastically increases your risk of CVD, and your vascular age will reflect as such. Though,if the study found that there was a relationship between sensitivities to various allergens,it may need to rule out that the vascular risk wasn’t really as of smoking or alcohol consumption.
Time.news: The article mentions statistical methods and approaches, like imputation using “random forest” methods and regression models. can you briefly explain why such methods are necessary in studies like these?
Dr. Sharma: Absolutely! In large-scale surveys like NHANES, it’s almost unavoidable that some participants will have missing data. The “random forest” imputation is a refined way to fill in those gaps with the most likely values, ensuring we can use as much of the available data as possible. The regression models, adjusted for various covariates, tease out the specific relationships between potential exposures – like specific food allergies – and vascular aging, while accounting for other influential factors like age, lifestyle, or pre-existing conditions. This gives us a more accurate picture of the real connections.
Time.news: What would you highlight in terms of practical advice that readers can take away from understanding vascular age and the NHANES study?
Dr. Sharma: The key takeaway is that your cardiovascular health is largely within your control. Work closely with your doctor to understand your cardiovascular risk factors and vascular age, take control over your lifestyle, diet, and exercise and quit smoking. It’s about making informed choices based on your individual risk factors and working towards a healthier future.