探討臺灣綠地空間對於代謝症候群發生之影響

Long-term exposure to residential greenness and occurrence of metabolic syndrome in Taiwan

林宛俞(Wan-Yu Lin)

指導教授 ： 郭育良

國立臺灣大學/公共衛生學院/環境與職業健康科學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202102227

摘要

目的：隨著社會環境的變遷，人類壽命不斷延長、生活飲食型態轉變，慢性病逐漸成為現代人生活一大隱憂，而代謝症候群作為一集結現代常見慢性病之疾病總稱，更為近年來社會討論之議題，而綠地對於自然生態、社會環境、人類生心理健康皆有許多好處，包含提供就業機會、增加社會互動、促進人們外出運動、維持室外空氣品質、溫度等，然而過往研究中，不論是在全球或是臺灣皆缺乏探討綠地暴露與代謝症候群之相關研究證據，因此本研究目的為利用臺灣某醫療系統健檢服務資料庫以探究綠地暴露對於代謝症候群發生之影響。
方法：本研究為一長期追蹤世代研究，利用臺灣某醫療系統健檢服務資料庫以探討綠地暴露對於代謝症候群發生之影響，該健檢服務自1994年開始針對臺灣本土居民提供一系列之健康檢查、醫療諮詢服務，而本研究將2001年至2005年曾經使用過此健檢服務的民眾納入作為本研究樣本，並排除曾經被診斷患有心血管疾病、代謝症候群、年齡小於20歲、綠地暴露與疾病資料不完整之樣本後，持續追蹤至每位樣本在2016年前的最後一次健檢紀錄，探討該研究族群代謝症候群之發生率，綠地暴露所使用的資料為常態化差值植生指標(NDVI)及國土利用調查，利用此兩種資料所計算的綠地指標包含常態化差值植生指標之平均值、森林比例及森林最近距離三種，分析方法採用時間相依共變數之存活分析，Stata14.0為本研究所使用之資料整理與統計軟體。
結果：本研究最終納入34,329位研究樣本，並持續追蹤至每位參與者最後一次健檢紀錄，共計有5,385位研究樣本發生代謝症候群，在控制研究樣本之年齡、性別、婚姻狀況、吸菸、喝酒、飲食、運動習慣後，結果發現越多的綠地暴露可降低代謝症候群的發生風險卻未達顯著，在最高綠地暴露之組別中，發生代謝症候群之風險在500公尺與1000公尺緩衝區中分別下降4% (HR=0.959, 95% CI=0.883-1.042)及3% (HR=0.968, 95% CI=0.892-1.052)，在後續分層分析中可發現女性、年齡大於65歲、居住在郊區的研究樣本對於綠地之效應更為明顯，對於居住在郊區之樣本而言，隨著綠地暴露越高，發生代謝症候群之風險在500公尺與1000公尺緩衝區中分別下降32% (HR=0.677, 95% CI=0.545-0.842)及27% (HR=0.730, 95% CI=0.576-0.924)，而在代謝症候群五項判定標準中，綠地效應僅與三酸甘油酯有較為一致且呈保護作用之結果，隨著綠地暴露越高，發生三酸甘油酯超標之風險在500公尺與1000公尺緩衝區中分別下降13% (HR=0.875, 95% CI=0.809-0.946)及11% (0.890, 95% CI=0.823-0.962)。
結論：綠地暴露確實可有效降低代謝症候群與三酸甘油酯超標之發生，且對於居住於郊區之民眾，該效應更為明顯且達顯著，建議未來可思索如何利用更為科學化方式量化民眾在綠地所暴露的時間，並且多加探討各種綠地型態、植物種類對於健康效應之影響及途徑。

關鍵字

代謝症候群 ； 綠地 ； 健檢資料庫 ； 常態化差值植生指標 ； 國土利用調查

並列摘要

Introduction
Greenness exposure can not only provide urban beautification, but also a series of environmental, social, and economic benefits such as providing green job, increasing space and opportunity for social interaction, promoting people go out for physical activity, maintaining air quality and temperature, and so on. However, evidence for the health effect of greenness on metabolic syndrome still lacks in Taiwan. Therefore, the purpose of the study was to explore the relationship between greenness exposure and incident metabolic syndrome by using Taiwan Mei Jau (MJ) database.
Methods
The study participants were from an ongoing nationwide MJ health screening database in Taiwan, which has provided a series of health screening and medical evaluation for Taiwanese residents since 1994. Metabolic syndrome was defined by ATP III and modified by WHO. Residential greenness was assessed using the Normalized Difference Vegetation Index (NDVI) and the second National Land Use Investigation. We finally included 34,329 participants who engaged in the health screening in 2001 to 2005 with the exclusion of subjects who had been diagnosed with cardiovascular diseases or metabolic syndrome before 2000 or at baseline year, age younger than 20 years old, and with incomplete data of greenness exposure. The study population was then followed until their last health check record. Cox proportional-hazards regression model with time-dependent covariates was used to estimate the adjusted hazard ratio (HR) with a 95% confidence interval (CI) for examining the association between greenness exposure and incident metabolic syndrome. Statistical analyses were conducted with Stata version 14.0.
Results
A total of 5,385 subjects were diagnosed with metabolic syndrome after follow-up. After adjusting for gender, age, marital status, smoking habit, alcohol consumption, dietary pattern, and exercise habit, participants who exposure to higher greenness had lower risk of incident metabolic syndrome but not significant. As for NDVI, we found that the highest quartile of greenness level was associated with lower risk of incident metabolic syndrome in the buffers of 500 m (HR=0.959, 95% CI=0.883-1.042) and 1000 m (HR=0.968, 95% CI=0.892-1.052), respectively. In the stratified analyses, female participants, with older age, and lived in suburban areas had the strongest effect of greenness exposure on incident metabolic syndrome. In suburban areas, the results showed that the highest quartile of greenness level was significant associated with lower risk of incident metabolic syndrome in the buffers of 500 m (HR=0.677, 95% CI=0.545-0.842) and 1000 m (HR=0.730, 95% CI=0.576-0.924), respectively. In addition, greenness exposure was also associated with lower risk of elevated triglycerides (HR=0.875, 95% CI=0.809-0.946 for 500 m buffer of NDVI; HR=0.890, 95% CI=0.823-0.962 for 1000 m buffer of NDVI).
Conclusion
Higher residential greenness exposure was associated with lower risk of incident metabolic syndrome and elevated triglycerides. The health effects of greenness varied from exposure indicators. Participants lived in suburban areas may be more susceptible to the effect of greenness exposure. Well-designed longitudinal studies with improved tools for evaluating the types of greenness and the time of people spend on greenness are needed in the future.

並列關鍵字

Metabolic Syndrome ； Greenness Exposure ； MJ health screening database ； Normalized Difference Vegetation Index ； National Land Use Investigation

參考文獻

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