A new study suggests that exposure to the natural environment may reduce hospitalization rates in patients with neurodegenerative diseases.
In a large open cohort study, living in areas rich in greenery, parks and waterways (blue spaces) was associated with reduced hospitalizations for Parkinson’s disease (PD). Also, living near green spaces was associated with fewer hospitalizations for Alzheimer’s disease and related dementia (ADRD).
These results should help policy makers and urban planners, said lead study author Jochem O. Klompmaker, PhD, a postdoctoral fellow in the Department of Environmental Health at the Harvard TH Chan School of Public Health in Boston, Massachusetts. rice field. Medscape Medical News.
They also provide more evidence of the importance of clinicians getting close to nature and encouraging patients to take walks, Klompmaker said.
“If they live near a park, it might be a good place to be more physically active and reduce stress levels,” he said.
The survey results were published online on December 20. JAMA network opened.
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AD and PD are the most common neurological disorders in the United States and are likely to become even more common as life expectancy increases, researchers note.
There is no cure for ADRD or PD, so identifying modifiable risk factors is important, they add.
Previous studies have shown associations between environmental exposures and AD and PD. However, research so far has mainly focused on green.
The current study examined the association between ADRD and PD hospitalizations and three natural environments: parks, blue spaces, and green spaces.
The study included approximately 61.7 million paying Medicare beneficiaries aged 65 and older living in the United States.
Investigators examined first admissions with a primary or secondary discharge diagnosis of ADRD or PD. From 2000 to 2016, there were 7,737,609 admissions for ADRD and 1,168,940 for PD.
In this study, postal codes were used to determine exposure. To measure greenness, researchers used satellite imagery to calculate the Normalized Vegetation Index (NDVI). NDVI ranges from -1 to 1, with higher values indicating higher levels of vegetation such as trees, gardens, and crops.
For park exposure, researchers used the U.S. Geological Survey Protected Areas Database to identify types of land likely to be used by the public for outdoor recreation, such as playgrounds and basketball courts. They calculated park coverage for each zip code.
Blue spaces include surface water such as rivers and lakes. Using satellite imagery data, we calculated the spatially weighted average blue space value for each postal code.
Covariates included age, gender, race/ethnicity, and eligibility for Medicaid as a surrogate for low socioeconomic status (SES). Additional his SES metrics included median household income, Crompmaker said.
The NDVI hazard ratio (HR) and park coverage were expressed for each interquartile range (IQR) difference. We compared the HR of blue space coverage (≥1%) with the reference category (<1% blue space coverage).
difference due to exposure
Results showed that, after adjusting for potential confounders, NDVI was associated with reduced ADRD hospitalizations (HR, 0.95; 95% CI, 0.94–0.96 per IQR increase).
There was no evidence of an association between park coverage and blueland coverage and ADRD hospitalization.
However, all three exposures were associated with reduced adjusted PD hospitalizations. HR was 0.94 (95% CI, 0.93 – 0.95) for NDVI, 0.97 (95% CI, 0.97 – 0.98) for park coverage, and 0.97 (95% CI, 0.96 – 0.98) for blue space coverage > 1 ) was. %.
Postcodes with higher NDVIs have lower levels of air pollution, which may explain some of the impact, Crompmaker said. “We found that adjusting for air pollution weakened the green impact,” he added.
Neighborhood SES results varied by exposure. For example, for PD admissions, the association of park coverage was greatest in ZIP codes with low SES, whereas the association of NDVI was greatest in ZIP codes with high SES.
When assessing associations by urban zip code only, researchers found associations to be similar to those of the full cohort. This is “a little surprising,” Klompmaker said, because previous studies have shown that the association is generally stronger in urban areas.
He added that it is not clear why ADRD and PD have different outcomes. “PD and AD are different diseases, so there may be different relationships between specific exposures,” he said.
Further analysis showed that increased exposure to the natural environment may reduce hospitalizations.
Assuming that the modeling and observed associations in this study are correct, if NVDI and park coverage increased by half the IQR, and if blue space increased by more than 1% for all zip codes, approximately 15,000 parks would increase each year. ADRD and 4,000 PD hospitalizations could be prevented, Klompmaker said.
Comments on Medscape Medical News, The results make sense, says Michael S. Okun, MD, dean of neurology at Florida Health College in Gainesville and medical adviser to the Parkinson’s Disease Foundation.
“Natural environments are associated with reduced heart disease and depression. It is not unreasonable to think that when people spend time in natural environments, hospitalizations for neurodegenerative diseases will decrease.
He pointed out that conflicting results from studies of the natural environment are potentially related to neurodegenerative diseases. said.
Still, exposure to the natural environment can reduce stress, restore attention, and increase activity and social interaction, all of which improve cognition, Okun said. .
This study was funded by grants from the National Institute of Environmental Health Sciences, the National Institute on Aging, the National Heart, Lung, and Blood Institute, and the National Minority Institute for Health and Health Disparities. Klompmaker received a grant from the National Institutes of Health while conducting research. Okun has not disclosed any related financial relationships.
JAMA net opened. Published December 20, 2022.full text
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