Associations and pathways between residential greenness and metabolic syndromes in Fujian Province

Abstract

BackgroundGreenness exposure is beneficial to human health, but its potential mechanisms through which the risk for metabolic syndrome (MetS) could be reduced have been poorly studied. We aimed to estimate the greenness-MetS association in southeast China and investigate the independent and joint mediation effects of physical activity (PA), body mass index (BMI), and air pollutants on the association.MethodsA cross-sectional study was conducted among the 38,288 adults based on the Fujian Behavior and Disease Surveillance (FBDS), established in 2018. MetS was defined as the presence of three or more of the five components: abdominal obesity, elevated triglyceride, reduced high-density lipoprotein cholesterol (HDL-C), high blood pressure, and elevated fasting glucose. The residential greenness exposure was measured as the 3-year mean values of the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) within the 250, 500, and 1,000 meters (m) buffer zones around the residential address of each participant. Logistic regression models were used to estimate the greenness-MetS association. The causal mediation analysis was used to estimate the independent and joint mediation effects of PA, BMI, particulate matter with an aerodynamic diameter of 2.5 μm (PM2.5), particulate matter with an aerodynamic diameter ≤ 10 μm (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2).ResultsEach interquartile range (IQR) increase in greenness was associated with a decrease of 13% (OR = 0.87 [95%CI: 0.83, 0.92] for NDVI500m and OR = 0.87 [95%CI: 0.82, 0.91] for EVI500m) in MetS risk after adjusting for covariates. This association was stronger in those aged < 60 years (e.g., OR = 0.86 [95%CI: 0.81, 0.92] for NDVI500m), males (e.g., OR = 0.73 [95%CI: 0.67, 0.80] for NDVI500m), having an educational level of primary school or above (OR = 0.81 [95%CI: 0.74, 0.89] for NDVI500m), married/cohabitation (OR = 0.86 [95%CI: 0.81, 0.91] for NDVI500m), businessman (OR = 0.82 [95%CI: 0.68, 0.99] for NDVI500m), other laborers (OR = 0.77 [95%CI: 0.68, 0.88] for NDVI500m), and non-smokers (OR = 0.77 [95%CI: 0.70, 0.85] for NDVI500m). The joint effect of all six mediators mediated about 48.1% and 44.6% of the total effect of NDVI500m and EVI500m on the MetS risk, respectively. Among them, BMI showed the strongest independent mediation effect (25.0% for NDVI500m), followed by NO2 and PM10.ConclusionExposure to residential greenness was associated with a decreased risk for MetS. PA, BMI, and the four air pollutants jointly interpreted nearly half of the mediation effects on the greenness-MetS association.

Simulating the impact of greenspace exposure on metabolic biomarkers in a diverse population living in San Diego, California: A g-computation application

“…37,41 Another study identified physical activity, body mass index, and air pollution including PM 2.5 , PM 10 , nitrogen dioxide, and sulfur dioxide, as mediators in the relationship between exposure to greenness and metabolic syndrome risk. 47 Additionally, it may be possible that increased green space improves social capital and reduces stress, which may in turn reduce the risk of metabolic syndrome. 13,[48][49][50][51] However, given the limited focus of previous literature on this topic, future work should improve understanding of the underlying mechanisms that result in greenspace impacts on these biomarkers and metabolic syndrome.…”

Editorial: Occupational exposure and cardiometabolic disorders

“…Most of the observational studies examining the prevalence and risk factors of MetS have been conducted in western countries before (7). Recently, an increasing number of MetS studies on the basis of large population cohorts in eastern countries have emerged (1,8). For example, a recent retrospective cohort study of the 3,777 employees (aged 44.9 ± 12.9 years on average, with 42.2% being females) from five institutions in Luzhou, China, receiving an annual physical examination during 2018-2020, shows that the prevalence of MetS and the level of metabolic risk had significantly increased in general after the COVID-19 lockdown (Xu et al).…”

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“…Numerous Mets studies based on sizable demographic cohorts in eastern countries have recently appeared. 6,7 In contrast to the Dutch population, where the converse is true, more women in Indonesian than men have MetS. The main cause of MetS prevalence in both the populations of Indonesia and the Netherlands is hypertension.…”