In a recent study published in Circulation, researchers investigated the effects of socioeconomic position and race on the link between closeness to urban green and blue areas and cardiovascular health.
Study: Associations of Urban Blue and Green Spaces With Coronary Artery Calcification in Black Individuals and Disadvantaged Neighborhoods. Image Credit: Monkey Business Images/Shutterstock.com
Background
Cardiovascular disease (CVD) is a worldwide health problem with racial health inequalities. Individuals from racial and ethnic minority groups are more likely to develop cardiovascular disease (CVD) and face higher mortality rates. Societal factors, such as lower socioeconomic status and living in underserved communities, contribute to these health disparities.
Exposure to blue areas, such as rivers and green areas, such as parks, is linked to various health outcomes and CVD risk factors. Understanding the possible contribution of these regions to CVD development in early and midlife might aid in targeting strategies to lessen the CVD burden.
About the study
In the present longitudinal study, researchers investigated whether the correlations between green and blue spaces and cardiovascular health differ by social determinants of health, such as socioeconomic status (SES) and race.
Researchers investigated the relationship between metropolitan green and blue spaces and coronary artery calcification (CAC) development in middle-aged adults in four cities in the United States (Birmingham, Chicago, Minneapolis, and Oakland), considering SES and racial background.
They examined data from the Coronary Artery Risk Development in Young Adults (CARDIA) project, eliminating participants who did not complete CAC evaluations or had missing demographics, socioeconomic characteristics, health-related activities, or morbidity.
In 2010–11, the researchers assessed coronary artery calcification (CAC) by non-contrast cardiac computed tomography (CT). They assessed green and blue spaces, including the proportion of green and blue space covered, distance from the most proximal large park, and proximity to rivers.
They measured participants' exposure and accessibility to blue space using two metrics: the proportion of blue spaces within 1.0 km and the distance to the most proximal river from their home location.
They used the Normalized Difference Vegetation Index (NDVI) to determine the age of green space covered and the distance from the nearest big park (≥200 acres).
The researchers collected NDVI data using two separate systems: the Global Inventory Modeling and Mapping Studies and the Moderate Resolution Imaging Spectroradiometer. They geocoded residence locations at each follow-up period and connected them to adjacent green and blue cover data from each year.
They utilized a 5.0-kilometer buffer of the yearly NDVI average to calculate the percentage of green space cover within a 5.0-kilometer radius of participants' home locations.
The researchers used generalized estimating equations and regressions to calculate the odds ratios (OR) for analysis, adjusting for demographic characteristics, individual-level and neighborhood SES, health-associated habits, and medical conditions.
Demographics included age, race, gender, and study center. SES factors included education years, married status, and income. Health-related habits included smoking, alcohol use, physical activity, diabetes, hypertension, and excessive cholesterol.
Results
The sample population comprised 1,555 white and 1,365 black individuals, and the participants’ mean age was 50 years. Of the 2,920 individuals with non-contrast CT scan data, 819 (28%) had coronary artery calcifications.
Individuals with coronary arterial calcification were older, less educated, more physically active, former or current smokers, and current alcohol drinkers with a higher body mass index (BMI) and comorbidities such as diabetes, hypercholesterolemia, and hypertension.
Among black individuals, the team noted shorter distances to rivers and more green space covering associated with a decreased risk of developing coronary arterial calcification [for each interquartile range (IQR) drop in the distance (1.5 km) from the river: OR, 0.9; every 10% increase in green space covering: OR, 0.9].
Increased green space was related to a lower risk of CAC in individuals living in disadvantaged neighborhoods (per 10% rise: OR, 0.9), whereas shorter distances from the nearest parks were related to an increased risk of coronary arterial calcification development [per IQR decrease in the distance (5.30 kilometers): OR, 1.1].
Black individuals in impoverished neighborhoods were less likely to acquire coronary artery calcifications when they lived closer to rivers (per IQR reduction: OR, 0.9) and had more green spaces (per 10% rise: OR, 0.9).
The researchers found no statistically significant CAC-related relationships between the green and blue spaces, neighborhood socioeconomic level, or participant race.
Time-specific associations indicated that early, long-term exposure to blue space and recent exposure to green space may have a more profound role in promoting cardiovascular health.
Conclusion
Based on the study findings, urban blue and green areas, such as rivers, are associated with improved cardiovascular health, particularly among black individuals residing in impoverished districts.
This protective connection emphasizes the potential advantages of urban infrastructure for underserved groups more likely to develop cardiovascular disease and the importance of quality control and environmental management in socioeconomically challenged areas.
The findings indicate that environment-related policies could improve the accessibility and quality of residential neighborhoods around these places, promoting public health and resolving racial and neighborhood inequities.