There’s a Fatty Liver Epidemic. AI Could Help Get Ahead of It
There’s a Fatty Liver Epidemic. AI Could Help Get Ahead of It
脂肪肝流行病来袭，人工智能或能助一臂之力
All over the world, a slow, insidious change is taking place in the composition of the livers of more than a billion people. While the presence of fat in a normal, healthy liver is negligible, many adults and even children have livers where fat exceeds 5 percent or even 10 percent of the organ’s total weight. Its unnatural presence causes inflammation, cell damage, and the formation of scar tissue known as fibrosis, all hallmarks of fatty liver disease, a condition that now impacts approximately 30 percent of adults worldwide.
在全球范围内，超过十亿人的肝脏正在发生缓慢而隐蔽的变化。在正常健康的肝脏中，脂肪含量微乎其微，但许多成年人甚至儿童的肝脏脂肪含量已超过器官总重量的 5% 甚至 10%。这种不正常的脂肪堆积会导致炎症、细胞损伤以及被称为纤维化的疤痕组织形成，这些都是脂肪肝疾病的标志。目前，全球约有 30% 的成年人受到该病的影响。
If left to linger, progressive fat accumulation can ultimately lead to liver failure, and it has been linked to an increased risk of cardiovascular disease and various cancers. But the condition typically develops without noticeable symptoms, so it is rarely detected at an early and treatable stage. Even in cases of cirrhosis or advanced scarring of the liver, three-quarters of people are only diagnosed once their condition has become life-threatening.
如果任其发展，进行性的脂肪堆积最终可能导致肝功能衰竭，并与心血管疾病和多种癌症的风险增加有关。然而，这种疾病通常在发展过程中没有明显症状，因此很少能在早期可治疗阶段被发现。即使在肝硬化或肝脏出现严重疤痕的情况下，四分之三的患者也只有在病情危及生命时才被确诊。
As a result, growing numbers of specialists are investigating how AI might help. Jeffrey Lazarus, a professor at the CUNY Graduate School of Public Health and Health Policy, suggests that AI tools could be used to comb through vast numbers of electronic health records and pinpoint the people most likely to have accrued worrying amounts of liver fat. “AI can retrospectively go through massive numbers of hospital visits and lab reports,” says Lazarus. “You can use that to really prioritize who’s at most risk.”
因此，越来越多的专家正在研究人工智能如何提供帮助。纽约市立大学公共卫生与卫生政策研究生院教授杰弗里·拉扎勒斯（Jeffrey Lazarus）认为，人工智能工具可以用来梳理海量的电子健康记录，并精准定位那些肝脏脂肪堆积达到令人担忧程度的人群。“人工智能可以回顾性地处理大量的就诊记录和实验室报告，”拉扎勒斯说，“你可以利用这一点，真正筛选出风险最高的人群。”
If fatty liver disease can be identified early, much of the damage is highly reversible. In the initial stages, lifestyle changes such as reducing alcohol intake, losing weight through dietary improvements and exercise, and even drinking more coffee have all been shown to be capable of reversing scarring and inflammation. Even for people with moderate to advanced liver scarring, novel treatments such as the GLP-1 medication semaglutide and a drug called resmetirom have been shown to be highly effective therapeutics.
如果能及早发现脂肪肝，大部分损伤是高度可逆的。在初期阶段，改变生活方式（如减少饮酒、通过改善饮食和运动来减肥，甚至多喝咖啡）已被证明能够逆转疤痕和炎症。即使对于中度至重度肝疤痕患者，GLP-1 药物司美格鲁肽（semaglutide）和一种名为 resmetirom 的药物等新型疗法也被证明是非常有效的治疗手段。
“The liver is a very versatile and interesting organ because it can regenerate, fibrosis can be reversed, and you can be completely healthy again,” says Lazarus. “But traditionally, we’ve focused more on late-stage care and trying to see how long we can keep a patient alive rather than finding them early and preventing the condition from advancing.”
“肝脏是一个非常多功能且有趣的器官，因为它具有再生能力，纤维化可以逆转，人可以恢复完全健康，”拉扎勒斯说，“但传统上，我们更多地关注晚期护理，试图延长患者的生命，而不是在早期发现并阻止病情恶化。”
One of the frustrations for Lazarus and others is that while simple, noninvasive means of assessing liver health exist, they are rarely used, even in people known to be at a much higher risk of the consequences of fatty liver disease, such as those with obesity and type 2 diabetes.
令拉扎勒斯等人感到沮丧的是，尽管目前存在评估肝脏健康的简单、无创手段，但它们却很少被使用，即使是在已知患脂肪肝后果风险较高的人群（如肥胖和 2 型糖尿病患者）中也是如此。
The Fib-4 index, for example, rates a person’s risk of advanced liver fibrosis through computing a score of between 0 and 6, based on their age, their levels of two liver enzymes, and their blood-clotting ability. This requires physicians to run a liver blood test, something which is often carried out as part of an annual medical checkup in the US. Doctors also have access to a more accurate, second-line blood test known as the enhanced liver fibrosis test, which measures the levels of two proteins involved in creating scar tissue and an enzyme which inhibits the clearance of scars in the liver.
例如，Fib-4 指数通过计算 0 到 6 之间的分数来评估一个人患晚期肝纤维化的风险，该分数基于患者的年龄、两种肝酶水平以及凝血能力。这需要医生进行肝功能血液检查，而在美国，这通常是年度体检的一部分。医生还可以使用一种更准确的二线血液检查，即增强型肝纤维化测试（ELF），该测试测量参与疤痕组织形成的两种蛋白质水平，以及一种抑制肝脏疤痕清除的酶。
Using both of these tests in patients with worrying amounts of liver fat has been shown to improve the diagnosis of those with advanced fibrosis by four-fold. But for physicians facing a growing workload and administrative burden, simply adding more testing to the workflow is not felt to be a sustainable option. “You have to have something that can run in the background or it’s easy to just hit a button and do it,” says Jonathan Dranoff, a professor of medicine at Yale University.
研究表明，对肝脏脂肪堆积令人担忧的患者同时使用这两种测试，可以将晚期纤维化患者的诊断率提高四倍。但对于面临日益沉重的工作量和行政负担的医生来说，在工作流程中简单地增加更多测试并非可持续的选择。耶鲁大学医学教授乔纳森·德拉诺夫（Jonathan Dranoff）表示：“你必须拥有一种能在后台运行的工具，或者能够通过点击一个按钮就能轻松完成操作的系统。”
As a result, Dranoff and Lazarus both foresee a role for AI in taking existing data from routine blood testing and automating the calculation of Fib-4 scores, making it easier for primary care physicians to identify the right patients to refer to a liver specialist.
因此，德拉诺夫和拉扎勒斯都预见到人工智能可以发挥作用，利用常规血液检查的现有数据自动计算 Fib-4 分数，从而使初级保健医生更容易识别出需要转诊给肝病专家的患者。
AI could also do this using x-ray images. Last year, scientists at Osaka Metropolitan University in Japan published a study using an AI model capable of ingesting and analyzing routine chest x-ray scans. While primarily intended to examine the lungs and the heart, these images also pick up parts of the liver. The researchers found that their model was capable of identifying people with fatty liver disease with an accuracy of 82 percent.
人工智能还可以利用 X 光影像来实现这一目标。去年，日本大阪公立大学的科学家发表了一项研究，使用了一种能够摄取和分析常规胸部 X 光扫描的人工智能模型。虽然这些影像主要用于检查肺部和心脏，但它们也包含了部分肝脏信息。研究人员发现，他们的模型能够以 82% 的准确率识别出脂肪肝患者。
Lazarus suggests that AI-powered algorithms could be incorporated into all routine x-ray analyses where the liver happens to be scanned alongside other organs. “The AI could pick up cases of excess liver fat, check for other risk factors such as if the person is overweight, has high cholesterol or type 2 diabetes, and then make a recommendation to the doctor,” says Lazarus. “It could tell them, ‘This might not have been what you were looking for, but this is what was picked up, and you should refer to hepatology or endocrinology who can do further tests.’”
拉扎勒斯建议，可以将人工智能算法整合到所有常规 X 光分析中，只要肝脏在扫描其他器官时被同时摄入。“人工智能可以识别出肝脏脂肪过多的病例，检查其他风险因素（如患者是否超重、是否有高胆固醇或 2 型糖尿病），然后向医生提出建议，”拉扎勒斯说，“它可以告诉医生：‘这可能不是你原本要检查的内容，但这是系统发现的问题，你应该将其转诊至肝病科或内分泌科进行进一步检查。’”
Training AI algorithms on routine blood tests is also beginning to yield better diagnostics for progressive fatty liver disease. While Fib-4 is a quick and low-cost tool, it is less accurate in certain age groups, such as adolescents and seniors, and studies have raised concerns about rates of false positives and unnecessary referrals unless combined with additional testing.
利用常规血液检查训练人工智能算法，也开始为进行性脂肪肝疾病提供更好的诊断方案。虽然 Fib-4 是一种快速且低成本的工具，但在某些年龄段（如青少年和老年人）中准确性较低，且研究指出，除非结合额外测试，否则该方法存在假阳性率高和不必要转诊的风险。
As a result, the Danish health tech startup Evido has developed an AI-powered algorithm called LiverPRO which can assess a patient’s risk of liver fibrosis based on their age and nine routine blood-based biomarkers. Now being commercialized in partnership with the pharmaceutical company Roche, it has been shown to outperform Fib-4 in predicting risk of serious liver problems in more than 470,000 middle-aged people.
因此，丹麦健康科技初创公司 Evido 开发了一种名为 LiverPRO 的人工智能算法，该算法可以根据患者的年龄和九种常规血液生物标志物来评估其肝纤维化风险。目前，该技术正与制药公司罗氏（Roche）合作进行商业化推广，研究显示，在预测超过 47 万名中年人的严重肝脏问题风险方面，其表现优于 Fib-4。
Other AI-based tests could also help doctors select the most appropriate patients for resmetirom treatment without requiring them to undergo an invasive liver biopsy.
其他基于人工智能的测试也可以帮助医生筛选出最适合接受 resmetirom 治疗的患者，而无需进行侵入性的肝活检。