~Teachingcenter的醫學筆記~

抽血驗血脂一定要空腹嗎？Fasting and Lipid Test

抽血驗lipid profile，中文為脂肪組合測試，其中的項目包含總膽固醇、高密度膽固醇、低密度膽固醇、三酸甘油脂(Total Cholesterol / HDL-Cholesterol / LDL-Cholesterol / Triglycerides)，俗稱口語就是”驗血脂”

而在驗血脂的時候，一般都會要求病人禁食至少8個小時以上，甚至有些比較嚴格的地方，會要求病人禁食12個小時，此要求常常會讓一些不太能耐餓、容易胃痛、無法早上翹班來抽血等的病人，心生不滿而讓配合意願降低，

然而，一定要空腹嗎？如果一定要，那又是為什麼？

這不僅是病人關注的問題，醫療端也很在意，畢竟配合意願低就很難辦很多事情，如果能把它弄得簡單點，何樂不為~
所以有了以下的研究(刊於impact factor 15分以上的好文章~)
Association of Nonfasting vs Fasting Lipid Levels With Risk of Major Coronary Events in the Anglo-Scandinavian Cardiac Outcomes Trial–Lipid Lowering Arm (Samia Mora, MD, MHS; C. Lan Chang, PhD; et al. JAMA Intern Med. Published online May 28, 2019)
概略的中文標題翻譯：在一個名為ASCOT-LAA的臨床試驗中，”禁食”和”非禁食”血脂濃度與”心血管疾病”的關聯
(major coronary events應該翻”主要心血管事件”，但這個字實在不是病解的時候用的…所以先用心血管疾病說明，跪求更好的翻譯…)

以下是這篇文章免費的摘要部分~取自
https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2733560
(由於我的英翻中不是完全精準，所以請大家讀原文~如果哪一段真有問題，再來討論~)
Importance
Recent guidelines have recommended nonfasting for routine testing of lipid levels based on comparisons of nonfasting and fasting populations. However, no previous study has examined the association of cardiovascular outcomes with fasting vs nonfasting lipid levels measured in the same individuals.
Objective
To compare the association of nonfasting and fasting lipid levels with prospectively ascertained coronary and vascular outcomes and to evaluate whether a strategy of using nonfasting instead of fasting lipid level measurement would result in misclassification of risk for individuals undergoing evaluation for initiation of statin therapy.
Design, Setting, and Participants
This post hoc prospective follow-up of a randomized clinical trial included 8270 of 10305 participants from the Anglo-Scandinavian Cardiac Outcomes Trial–Lipid Lowering Arm (ASCOT-LLA) with nonfasting and fasting lipid levels measured 4 weeks apart (including 6855 participants with no prior vascular disease) (median follow-up, 3.3 years; interquartile range, 2.8-3.6 years). Data were collected from February 1, 1998, to December 31, 2002, and analyzed from February 1, 2016, to November 30, 2018. Multivariable Cox models, adjusted for cardiovascular risk factors, were calculated for 40-mg/dL (1-mmol/L) higher values of nonfasting and fasting lipids.
Main Outcomes and Measures
The trial’s primary end point consisted of major coronary events (nonfatal myocardial infarction [MI] and fatal coronary heart disease [212 events]). Secondary analyses examined atherosclerotic cardiovascular disease (ASCVD) events (including MI, stroke, and ASCVD death [351 events]).
Results
Among the 8270 participants (82.1% male; mean [SD] age, 63.4 [8.5] years), nonfasting samples had modestly higher triglyceride levels and similar cholesterol levels compared to fasting samples. Associations of nonfasting lipid levels with coronary events were similar to those for fasting lipid levels. For example, adjusted hazard ratios (HRs) per 40-mg/dL of low-density lipoprotein cholesterol were 1.32 (95% CI, 1.08-1.61; P = .007) for nonfasting levels and 1.28 (95% CI, 1.07-1.55; P = .008) for fasting levels. For the primary prevention group, adjusted HRs were 1.42 (95% CI, 1.13-1.78; P = .003) for nonfasting levels and 1.37 (95% CI, 1.11-1.69; P = .003) for fasting levels. Results were consistent by randomized treatment arm (atorvastatin calcium, 10 mg/d, or placebo) and similar for ASCVD events. Concordance of fasting and nonfasting lipid levels for classifying participants into appropriate ASCVD risk categories was high (94.8%).
Conclusions and Relevance
Measurement of nonfasting and fasting lipid levels yields similar results in the same individuals for association with incident coronary and ASCVD events. These results suggest that routine measurement of nonfasting lipid levels may help facilitate ASCVD risk screening and treatment, including consideration of when to initiate statin therapy.

此篇講到了一個驗血脂的重點(粗體底線有紅字的那一段)，也就是非禁食的血脂濃度，對於預測心(腦)血管疾病有差不多的效果，建議非禁食血脂濃度也可以用於篩檢高風險族群和決定statin類藥物使用的時機
※稍微瀏覽了一下完整的全文，沒有特別提到非禁食組在抽血的時候，距離前一次吃東西的時間(總不可能邊吃邊抽吧？)，稍微有一點可惜…
※這該不會是打算推出像血糖機差不多的東西，以後叫病人每天扎每天記錄血脂吧~？(感覺商機龐大~)

 那看完了以上的內容，以後有病人要驗血脂，該怎麼做呢？

嗯…我還是會說：「禁食八個小時以上再去驗吧！」 

難道我食古不化、不知變通？？！！
這部分請容我解釋(找藉口？)

個人認為禁食八小時還是有必要的原因，有三個
1.目前”非禁食血脂”的標準還沒有訂出來
2.禁食後的最低血脂會影響治療方針
3.驗血脂不一定只有在看心腦血管疾病風險

目前”非禁食血脂”的標準還沒有訂出來
這個很重要啊！驗血的數值要有一個標準參考範圍的最高值和最低值，這兩個值是經由大量的統計和分析而來的，但目前非禁食血脂還不是主流，也還沒看過有機構為非禁食血脂訂定通用的參考值，最後就會變成隨機驗了個非禁食血脂後，不知道是正常、太高或太低，可能可以和自己之前的變化做比較，但相對價值就沒有那麼高了，而且現在健保給付也是以空腹時的血脂為準~
可以參考這個：
--冠心症與膽固醇與三酸甘油脂用藥http://teachingcenter1.pixnet.net/blog/post/344972786
--降血脂藥物使用建議http://teachingcenter1.pixnet.net/blog/post/353872247
另外更重要的，就是非禁食血脂要什麼時候抽？剛吃完1小時和吃完2小時的血脂標準，不會是一樣的，就算真的定了通通飯後2小時檢驗，病人的配合度高了，換檢驗科要暴動了XD，要去確認每個驗血脂的病人是不是差不多飯後2小時XD，大概會被翻桌抗議吧？(退單拒抽！要抽自己抽！)

禁食後的最低血脂會影響治療方針
雖然不像低血糖那麼危險，但這一類太高不好、太低也不好的指標，我會比較在意”最低”時候的數值，低血糖是會有生命危險，而低血脂(或膽固醇過低)我則是認為沒有必要
先複習一下藥物種類：高血脂用藥http://teachingcenter1.pixnet.net/blog/post/351488411
一般來說，藥物機轉就是減少合成或減少吸收，如果只關注了血脂過高而開始治療，那麼血脂低的時候就有過低的風險，雖然說肝臟應該還是有辦法(甚至突破部分的藥物抑制XD)，強行製造足夠的三酸甘油脂、膽固醇等供身體使用，但這種治療就有點太超過了…享受到的副作用可能大於藥物帶來的好處…
個人會認為，如果進食後會有短暫血脂過高，但禁食時血脂又正常的病人，應該先從飲食的種類先做調整(吃太油啦！)，真有需要才使用一些短效減少吸收的藥物，而不是直接比照現行的用藥建議

驗血脂不一定只有在看心腦血管疾病風險
有些動完大手術或重病的病人，驗血脂是要觀察營養狀況、肝膽功能、復原進度等情形，不同的目的會有一些檢驗需求的微調，該禁食多久就是多久，若有其他需求，醫生會另外說明