從脂肪到心臟 － 心外脂肪組織量在具心臟代謝風險因子族群與左心室射出分率正常之心衰竭族群的相關性研究

From Fat to Heart: The Associations among Epicardial Adiposity, Cardiometabolic Profiles and Heart Failure with Preserved Ejection Fraction

林君璐(Jiun-Lu Lin)

指導教授 ： 楊偉勛

共同指導教授 ： 陳祈玲

國立臺灣大學/醫學院/臨床醫學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.02771

摘要

代謝症候群通常與胰島素阻抗和內臟脂肪的分佈有所關連，並且與糖尿病和心血管疾病的發展有直接作用相關聯。 胰島素阻抗與內臟脂肪組織的增加會在非脂肪細胞內引發異常的脂質積累，進而引起相關器官之功能衰竭，如脂肪肝。心外膜脂肪組織（EAT），作為內臟腹內脂肪的一環，被認為會以類似的方式直接影響到心臟與心臟血管的功能。 當心肌細胞內的脂肪有異常的增加，會損害心臟功能，誘發心臟衰竭（HF）。 在心臟超音波檢查時量測心外膜脂肪組織（EAT）的厚度已被確認是與數種代謝異常與心血管疾病的風險增加有相關性。然而，EAT在左心室射出分率正常之心衰竭（HFpEF）的研究與認知有限。
本研中我們測量了 254 個受試者(男性89人，女性165人，平均年齡65.7± 9.8歲)的EAT。 受試者被分為三組：曾有舒張性心衰竭的患者(HFpEF 組, 人數 = 55)、有大於等於一種心血管代謝風險者 (心血管代謝風險組, 人數= 150)、與健康成年人(正常對照組, 人數= 49)。 HFpEF組在EAT 的厚度上與正常對照組、心血管代謝風險組相比較皆有有意義的增加 (p=0.000, p= 0.002 separately)。 此外，在經由多變量分析去調整各項心血管代謝風險因子, 包括年齡、性別、身體質量指數、左心室質量、與相關biomarkers之後，EAT 的厚度與代謝症候群和左心室射出分率正常之心衰竭仍能呈現持續性的相關性，其勝算比與信賴區間分別是：OR 8.02, 95% CI 1.3- 49.7 與OR 3.59, 95% CI 0.7- 18.2。
在此研究顯示 EAT在健康到擁有心血管代謝風險到演變成左心室射出分率正常之心衰竭的過程中，是一個重要的影響因子 。 EAT不僅與心臟結構變化相關，亦與左心室的舒張功能變化相關。由於心臟本身即覆蓋著脂肪，而EAT，這個相當具有代謝活性的內臟脂肪，由於它與相鄰的心肌和冠狀動脈分離沒有物理屏障，通過旁分泌的作用，EAT扮演著重要的局部代謝角色。 上述的作用涉及到發炎反應及相關脂肪激素的分泌。確認心外脂肪量、心血管代謝風險因子和心臟舒張功能之間的關係可有助於在更早、更恰當地辨識和治療有舒張性心衰竭風險的個人。

關鍵字

心臟衰竭 ； 心外脂肪組織 ； 左心室射出分率正常之心衰竭 ； 心臟超音波 ； 重塑 ； 肥胖 ； 代謝症候群 ； 心血管疾病 ； 危險因子

並列摘要

The metabolic syndrome is usually associated with insulin resistance and visceral fat distribution, which appear to play a direct role in the development of diabetes and cardiovascular disease (CVD). Insulin resistance and increased visceral adipose tissue are also associated with an abnormal ectopic accumulation of lipids in non-adipocytes to cause organ failure, like steatosis hepatitis. The epicardial adipose tissue (EAT), in a similar fashion as visceral intra-abdominal fat, might directly affect the pathophysiology of cardiac vessels and function of the heart. Accordingly, ectopic accumulation of fat within cardiac muscle cells can impair the heart function and predispose to heart failure (HF). The echocardiography-based epicardial adipose tissue (EAT) measurement has been recognized to be related to several metabolic abnormalities and increase the risk of cardiovascular diseases. However, clinical data on the EAT’s association with HF with preserved ejection fraction (HFpEF) are limited.
We measured the echocardiography-based EAT thickness in 254 subjects (female/male 165/89 and mean age 65.7± 9.8 years) divided into 3 group: Those with HF (HFpEF group, n = 55), those with ≥1 cardiometabolic risks (at-risk group, n = 150), and normal controls (n = 49). HFpEF group showed significantly greater amount of EAT than both normal and at-risk groups (p=0.000, p= 0.002 separately). Logistic regression was used to estimate the cross-sectional association of the EAT, metabolic syndrome and HFpEF. Models were adjusted for age, sex, body mass index (BMI), LV mass, and related biomarkers. The echocardiography-based EAT thickness was significantly related in multivariate analysis to MS (OR 8.02, 95% CI 1.3- 49.7), and HFpEF (OR 53.95, 95% CI 0.7- 18.2).
Our study suggests that EAT can be an important factor correlated with LV diastolic dysfunction and the heart structural change. Moreover, the heart itself is covered by fat. The EAT, a metabolically active fat depot with no physical barrier separating it from the adjacent myocardium and coronary arteries, plays an important local metabolic role by a paracrine effect, related to inflammation and the secretion of related adipokines. Confirm the relationships between cardiac fat burden, cardiometabolic risk factors and diastolic heart failure may contribute to identify and treatment of diastolic heart failure risk individuals earlier and more appropriately.
Conclusions - These results indicate a strong, consistent relationship of the EAT with prevalent metabolic syndrome and HFpEF.

並列關鍵字

heart failure ； epicardial adipose tissue ； HFpEF ； echocardiography ； remodeling ； obesity ； metabolic syndrome ； cardiovascular disease ； risk factor

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