北台灣社區老年人代謝症候群與成功老化之關聯: 六年世代研究

Abstract

背景 代謝症候群在老年人與失能、認知功能缺損及憂鬱症狀均有相關。然而，過去關於代謝症候群的文獻缺乏對成功老化採取周全評估之研究，代謝症候群與成功老化的關聯仍未知。 材料與方法 本研究乃'台灣老年認知功能流行病學研究'之一部分。在基線(2011-2013)時有467位有完整代謝症候群及成功老化變項資料的65歲以上長者納入進行分析，並於4年及6年後進行追蹤。代謝症候群於基線時進行評估，診斷標準乃依據美國國家膽固醇教育計畫成人治療指引第三版National Cholesterol Education Program’s Adult Treatment Panel III (ATP III)。成功老化是在基線、第四年追蹤及第六年追蹤時進行評估，包含三個領域：生理、心理、社會及經濟，並由以下變項組成：受試者的慢性病數量、日常生活活動(activity of daily living)、工具性日常生活活動(instrumental activities of daily living)、走路速度、認知功能、憂鬱症狀、自評健康、社會及休閒活動參與頻率、家庭支持及年度可支配收入。統計分析方法使用廣義線性混合模型來估算代謝症候群與成功老化的關聯，並校正時間(追蹤年數)、年齡、性別、教育年數、飲酒及代謝症候群×時間的交互作用項。 結果 基線時沒有罹患代謝症候群對於成功老化的機會有正向影響。(校正後勝算比=2.71, 95%信賴區間=1.67-4.39)。沒有代謝症候群的老年人在生理及心理領域的成功老化有較佳的表現[校正後勝算比(95%信賴區間)分別為5.03 (3.04-8.34)及1.67 (1.06-2.65)]。沒有腹部肥胖、高血糖、高密度膽固醇偏低及高血壓與生理領域的成功老化均有顯著相關，其中以沒有高血壓的相關性最為強烈[校正後勝算比(95%信賴區間)= 2.76 (1.67-4.58), p<0.0001]。沒有三酸甘油脂偏高及沒有腹部肥胖分別對心理和社會及經濟領域的成功老化有保護效果[校正後勝算比(95%信賴區間)分別為1.95 (1.02-3.74)及1.63 (1.04-2.56)]。我們發現隨著代謝症候群程度的改善，生理、心理領域及整體的成功老化機會有顯著的增加趨勢(Ptrend <0.05)。 結論 本研究發現對於社區老年人而言，代謝症候群是不利於成功老化的危險因子。 公共衛生上的應用 本研究填補了代謝症候群與成功老化之間的研究缺口。並為高齡化社會的健康促進議題提供重要的資訊。預防代謝症候群有助於社區老年人的成功老化。公共衛生政策應著重於避免代謝症候群的發生，以促進老年族群的成功老化。

Background: Metabolic syndrome (MetS) was associated with disability, cognitive impairment and depressive symptoms in older adults. However, studies about MetS adopting a comprehensive consideration of successful aging are lacking. The association between MetS and successful aging remains unclear. Methods: This study is part of the cohort study “Taiwan Initiatives for Geriatric Epidemiological Research”. A total of 467 (age 65+) older adults with complete data of MetS and successful aging at baseline (2011-2013) were included for analyses. Participants were followed up after 4 years and 6 years. MetS was assessed at baseline by the National Cholesterol Education Program’s Adult Treatment Panel III (ATP III) guideline. Successful aging, which was evaluated at baseline, 4-year and 6-year follow-ups, included three major domains: physiological, psychological, and sociological and economic domains. The variables of successful aging were number of chronic diseases, activities of daily living, instrumental activities of daily living, gait speed, cognition, depressive symptoms, self-rated health, social and leisure activities, family support, and annual disposable income. Generalized linear mixed model were used to assess the association between MetS and successful aging adjusting for time (follow-up years), age, sex, years of education, alcohol consumption and MetS×time interaction term. Results: The absence of baseline MetS was associated with a higher probability of successful aging over six years [adjusted odds ratio (aOR)= 2.71, and 95% confidence interval (CI)=1.67-4.39]. Older adults without MetS performed better on the physiological and psychological domains of successful aging [aOR (95% CI)= 5.03 (3.04-8.34) and 1.67 (1.06-2.65), respectively]. The absences of abdominal obesity, hyperglycemia, reduced high-density lipoprotein cholesterol, and hypertension were associated with the physiological domain of successful aging. Among them, the absence of hypertension showed the strongest effect [aOR (95% CI)= 2.76 (1.67-4.58), p<0.0001]. We also found that the absence of elevated triglycerides was associated with the psychological successful aging [aOR (95% CI)= 1.95 (1.02-3.74)]. The absence of abdominal obesity was associated with the sociological and economic successful aging [aOR (95% CI)= 1.63 (1.04-2.56)]. Significant increased trend was found in the overall and physiological successful aging across MetS status (No MetS, pre-MetS, MetS; Ptrend <0.0001). Conclusion: We found that either MetS as a whole, components of MetS, or MetS status are risk factors of successful aging among community-dwelling older adults. This study addressed the research gap between MetS and successful aging, and provided important information for health promotion in the aging society. Prevention of MetS in earlier life will be beneficial to successful aging in later life. Public health policy could aim at avoidance of MetS in order to facilitate successful aging in older population.