Effects Of Greenness And Fine Particulate Matter Exposure On Overweight/Obesity In Older Adults Aged 65 Years And Above

ObjectiveExplore the relationship between greenness,fine particulate matter(PM2.5)exposure and the risk of overweight/obesity in older adults,to provide research evidence for the development of suitable prevention and control strategies for overweight/obesity in older adults in China.MethodsThis study is based on the Chinese Longitudinal Healthy Longevity Survey(CLHLS)project,and focuses on individuals aged 65 and above from the baseline and follow-up cohorts between 2000 and 2018.Physical measurements such as weight,knee height,and waist circumference(WC)were obtained.Normalized Difference Vegetation Index(NDVI)and PM2.5 concentration values within a 1000-meter radius around the residential address were matched.Cox proportional hazards regression model,mixed-effects linear model,multiple regression model,and restricted cubic spline model were used to evaluate the association between NDVI and PM2.5 exposure and overweight/obesity.Multiplicative and additive interaction models were used to explore the interaction between NDVI and PM2.5 exposure on overweight/obesity.Results1.Based on the data of the CLHLS cohort from 2000-2018,the average age of the 21355 subjects was(87.2±11.3)years old,among whom 1895(8.9%)developed overweight/obesity during follow-up.2.For each 0.1 unit increase in NDVI,the risk of overweight and obesity decreased by 8%(HR=0.92,95%CI:0.88-0.96),and the Body Mass Index(BMI)decreased by 0.15 kg/m2(β=-0.15,95%CI:-0.18～-0.12).For each 10 μg/m3 increase in PM2.5,the risk of overweight and obesity increased by 10%(HR=1.10,95%CI:1.06-1.14),and BMI increased by 0.11 kg/m2(β=0.11,95%CI:0.09～0.14).Similar results were obtained from sensitivity analysis.3.The interaction model of multiplying NDVI and PM2.5 showed that the HR(95%CI)of the multiplication interaction term of NDVI and PM2.5 was 1.04(1.00～1.08)(P=0.042);there was no statistically significant difference in indicators for the additive interaction model.4.Based on 2018 cross-sectional survey data,for each 0.1 unit increase in NDVI,the waist circumference(WC)decreased by 0.76 cm(β=-0.76,95%CI:-0.91～-0.61),and the risk of central obesity decreased by 15%(OR=0.85,95%CI:0.83-0.88).For each 10 μg/m3 increase in PM2.5,WC increased by 0.84 cm(β=0.84,95%CI:0.64～1.04),and the risk of central obesity increased by 16%(OR=1.16,95%CI:1.11～1.21).No interaction effect was found in both multiplicative and additive interaction models.ConclusionThere is an association between exposure to greenness and PM2.5 and the risk of overweight/obesity among older adults.The results suggest that increasing greenness around residences and controlling particle pollution may be important measures for effectively addressing the issue of overweight/obesity in older adults.