The Association of Metabolically Healthy Status and Body Weight on All-cause Mortality: A Representative Cohort Study in Taiwan

代謝健康與體重與全死因死亡風險之相關性：台灣世代研究

陳信豪(Hsin-Hao Chen) ； 蕭雅純(Ya-Chun Hsiao) ； 劉俞旻(Lawrence Yu-Min Liu)

《台灣家庭醫學雜誌》 31卷1期 (2021/03) Pp. 38-52

https://doi.org/10.3966/168232812021033101005

摘要

Objective: The objective of this study was to investigate the impact of metabolically healthy status and body weight on all-cause mortality in Taiwan using an updated definition of metabolic health. Methods: The cohort comprised 5,763 participants from the Taiwanese Survey on Hypertension, Hyperglycemia, and Hyperlipidemia (TwSHHH) from 2002 to 2015. Overweight/obesity was defined as BMI ≥ 24 kg/m^2 and metabolically healthy status was defined as absence of hypertension, diabetes, or hyperlipidemia, combined with a healthy cardiometabolic profile. We used a Cox proportional hazards regression model to investigate the relationship between baseline BMI-metabolic groups and mortality. We also performed subgroup analysis to explore potential effect modifiers. Results: We observed a total of 621 deaths over a median of 13.7 years of follow-up. Metabolically healthy overweight/obesity (MHOO) (HR 0.94, 95% CI 0.59-1.50) was not associated with elevated risk of all-cause mortality compared with metabolically healthy normal weight (MHNW) after adjusting for covariates. The three BMI groups of metabolically unhealthy all showed a significantly higher risk of mortality. Subgroup analysis showed that age is a significant effect modifier. People less than 65 years old that were metabolically unhealthy had elevated risk of mortality even when they were within normal weight (HR 2.06, 95% CI 1.39-3.04). Among elderly people, those underweight and metabolically unhealthy showed significantly elevated risk (HR 2.91, 95% CI 1.64-5.17), but those metabolically unhealthy and with normal weight or overweight/obesity did not. Conclusion: MHOO without cardiometabolic risk factors was not associated with increased all-cause mortality. People under 65 years old should maintain a metabolically healthy status even within normal weight. More attention should be paid to the elderly with underweight and metabolically unhealthy status.

關鍵字

all-cause mortality ； body weight ； metabolic health ； obesity

並列摘要

目的：代謝健康的過重／肥胖者（metabolically healthy overweight／obesity, MHOO）定義為過重／肥胖卻沒有代謝異常等因子，如高血壓，糖尿病或高血脂。在先前研究中，MHOO的全死因死亡風險與代謝健康且正常體重（metabolically healthy normal weight, MHNW）者相比，結果分岐，因此本研究目的是使用代謝健康的最新定義，探討MHOO是否與較高的全死因死亡風險相關。方法：本研究由2002－2015年台灣高血壓，高血糖和高血脂調查的5,763名參與者組成，過重／肥胖定義為BMI（body mass index）≥24 kg／m^2，代謝健康定義為沒有高血壓，糖尿病或高血脂且具有健康的代謝狀態（收縮壓＜130 mmHg且舒張壓＜85 mmHg，飯前血糖＜100 mg／dL，三酸甘油酯＜150 mg／dL，HDL男性＞40 mg／dL或女性＞50 mg／dL）；我們使用Cox比例風險回歸模型研究不同BMI與代謝狀態分組與全死因死亡率間的關係。結果：在經過中位數13.7年的追蹤共621例死亡。在調整共變項後，MHOO（HR 0.94，95％CI 0.59－1.50）與MHNW相比，死亡率無明顯差異。次族群分析和敏感性分析顯示相似結果，而年齡可能是重要的修飾因子（effect modifier）；與老年人相比，小於65歲代謝不健康者即使體重正常，死亡風險仍較高（HR 2.06，95％ CI 1.39－3.04）；而老年人體重過輕且代謝不健康其死亡風險顯著升高（HR 2.91，95％ CI 1.64－5.17），但代謝不健康之過重肥胖長者且其風險並未升高。結論：代謝健康之過重肥胖者並不會增加全死因死亡風險，而小於65歲者即使正常體重也應保持代謝健康的狀態，而體重過輕且代謝不健康之長者更應該值得關注。

並列關鍵字

代謝健康 ； 體重 ； 肥胖 ； 全死因死亡

參考文獻

Phillips CM: Metabolically healthy obesity across the life course: epidemiology, determinants, and implications. Ann N Y Acad Sci 2017; 1391: 85-100.

Smith GI, Mittendorfer B, Klein S: Metabolically healthy obesity: facts and fantasies. J Clin Invest 2019; 129: 3978-89.

Dehlendorff C, Andersen KK, Olsen TS: Body mass index and death by stroke: no obesity paradox. JAMA Neurol 2014; 71: 978-84.

Kuk JL, Rotondi M, Sui X, Blair SN, Ardern CI: Individuals with obesity but no other metabolic risk factors are not at significantly elevated all-cause mortality risk in men and women. Clin Obes 2018; 8: 305-12.

Sims EA: Are there persons who are obese, but metabolically healthy? Metabolism 2001; 50: 1499-504.