體重及體重減輕預測台灣中老年人長期死亡風險之功能

Usefulness of extreme body weight and weight loss in predicting follow-up mortality risk of older Taiwanese

蕭美蘭(Hsiao mei-lan)

指導教授 ： 蔡仲弘

亞洲大學/健康學院/長期照護研究所在職專班/碩士(2010年)

摘要

背景--體重太重或太輕或體重顯著改變會影響健康，西方國家的研究顯示老人體重太輕，或體重顯著減輕都會增加死亡風險。研究發現體重過重雖有失能的風險，卻不增加死亡風險。體重太重或太輕或體重改變對我國老人的健康會有多大影響尚無深入的研究。健康促進單位常以適用於較年輕者的理想體重標準套用於老年人。其適宜性需深入評估及探討。
目的--本研究目的在探討台灣中老年人體重過輕或過重及體重減輕對隨後死亡風險的影響。
方法--本研究分析國民健康局「台灣地區中老年人身心社會生活狀況長期追蹤調查」1999年及2003年的訪談縱貫資料。以1999年自述身高及體重，及自述過去一年內體重是否有減輕≥3 kg分析隨後四年的死亡風險。以卡方檢定(Chi-Square Test)檢視依年齡分析BMI及體重減輕≥3 kg逐年存活的差異。再以Cox迴歸(Cox regression analysis)分析在控制年齡、性別和抽菸等變項的狀況下預測隨後四年的死亡風險。以死亡風險比(HR)及95%信賴區間(CI)及p<0.05表示風險及顯著性。
結果--本研究結果以BMI 21-27者為對照組，BMI <21而年齡53-64歲者其隨後48個月的死亡風險(HR)為2.84，95% 信賴區間(CI)為1.64-4.91，65-74歲者為1.75 (1.28-2.41)，>75歲者為1.69 (1.36-2.10)，均p<0.05；而BMI >27者各年齡層均不顯著。體重減輕≥3 kg者比無減輕者之相對風險為53-64歲者，3.86 (2.27-6.58)；65-74歲者，3.64 (2.70-4.91)；>75歲者，2.02 (1.61-2.52)，均p<0.05。又，依BMI分析體重減輕≥3 kg對隨後48個月的死亡風險，女性BMI <21，21-27及>27者均呈顯著，但男性BMI >27者不顯著。
結論--體重太輕及體重減輕對65歲以上老人具有預測長期死亡風險之功能。體重過輕(BMI <21)或減輕均增高隨後四年的死亡風險。體重不足或不預期的體重減輕為健康惡化的警訊，應予重視。本研究結果可供我國日後國民健康促進及老人健康體位的政策擬訂之依據。

關鍵字

身體質量指數 ； 體重減輕 ； 死亡風險預測

並列摘要

Background--Extreme body weight or extreme weight change poses health thread. Studies conducted in Western countries have shown that underweight or extreme body weight increases risk of mortality whereas overweight may impact functional ability but does not increase mortality risk in older adults. These issues have not been robustly examined in Taiwanese.
Objective--The objective of this study, therefore, is to examine the impact of extreme body weight and weight changes on mortality risk in elderly Taiwanese.
Methods--This study analyzed the 1999 and 2003 data of the “Survey of Health and Living Status of the Elderly in Taiwan” (SHLSET), a cohort study initiated in 1989 with a multi-stage national probability sample of 4049 non-institutionalized Taiwanese 60 years of age or older. The 1999 weight status (BMI status derived from self-reported weight and height) and weight change of each subject were used to predict follow-up four-year mortality risk. Results were analyzed with Cox regression adjusted for age, gender and smoking statuses.
Results--Compared to elderly with desirable weight (BMI=21-27 kg/m2), elderly underweight (BMI≤21) had increased risk of mortality regardless of age. Elderly over-weight or obese (BMI≥27) were not different from those had desirable BMI. Severe weight reduction (≥3kg) significantly increased mortality risk in all age ranges and in those who had lighter weight. Weight loss of 3 kg or more had less impact in overweight/obese males.
Conclusion--Underweight or severe weight loss predicts increased follow-up 4-year mortality risk in older Taiwanese whereas overweight/obese does not increase mortality risk. These results suggest that we need to reexamine our current policy of encouraging weight reduction in over-weight/obese elderly.

並列關鍵字

Body Mass Index ； Weight loss ； Mortality risk prediction

參考文獻

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