超过 90% 的人面临纤维化 NASH 的风险不需要肝脏专家

StephenW

超过 90% 的人面临纤维化 NASH 的风险不需要肝脏专家

AASLD—肝脏会议，2022 年 11 月 4 日至 8 日，华盛顿特区

马克·马斯科里尼

一个简单的算法（决策树）应用于美国有纤维化非酒精性脂肪性肝炎 (NASH) 风险的代表性人群，确定其中只有 8% 的人需要转诊给肝脏专家 [1]。来自亚利桑那肝脏健康中心和其他中心的研究人员认为，结果意味着大多数有纤维化 NASH 风险的人可以由初级提供者进行护理，而无需转诊给肝病学家。

最近的研究确定，非酒精性脂肪性肝病 (NAFLD) 影响美国 38% 的中年人，而更晚期的 NASH 影响 14% 的中年人。健康专家估计，美国有 9500 万 NAFLD 患者和 7500 名肝病专家。如果每个 NAFLD 患者都去看专科医生，那么每位肝病医生就有超过 12,600 名 NAFLD 患者。

为了弄清楚有多少 NAFLD 患者真正需要肝病专家，美国胃肠病学协会 (AGA) 提出了 NAFLD“临床护理路径”算法。该途径可帮助初级保健提供者筛查有纤维化 NASH（伴有 F2 至 F4 纤维化的 NASH）风险的人，以判断他们是否应将该人转诊给肝脏专家 [2]。

AGA 算法依次使用两个标准肝功能测量仪——FIB-4 指数和通过瞬时弹性成像 (FibroScan) 进行的肝硬度测量 (LSM)。患有晚期纤维化（具有 2 个或更多代谢危险因素，或 2 型糖尿病，或任何扫描显示脂肪变性，或高转氨酶 [2]）的 NAFLD 风险的人应进行 FIB-4 纤维化的无创检测：

FIB-4：

· 如果一个人的 FIB-4 指数低于 1.3，则可以认为他们发生肝脏并发症的风险较低，并由其主要提供者跟进。

· 高于 2.67 的指数发出危险信号，需要转诊给肝病专家。

· 1.3 和 2.67 之间的指数告诉从业者通过 FibroScan 测量 LSM。

纤维扫描：

· LSM 低于 8 kPa 表示低风险。

· 超过 12 kPa 的 LSM 需要转诊给肝病专家。

· 8 至 12 kPa 的 LSM 还需要转诊至肝病专家进行肝活检或 MR 弹性成像或监测，并在 2 至 3 年内重新评估风险

有关详细信息，请参阅 AGA 临床护理途径 [2]

为了确定该算法是否适用于美国普通成年人群，研究人员在具有全国代表性的数据库（2017-2018 年全国健康和营养检查调查 (NHANES) 数据集）中对 AGA 临床护理路径进行了验证，并寻找成年人具有有效的 FibroScan 结果和实验室数据，可让他们计算 FIB-4 指数。他们专注于患有 2 型糖尿病、两个或更多代谢危险因素和天冬氨酸氨基转移酶升高的人，并且不包括重度饮酒者，他们遵循上述 FIB-4/FibroScan 算法。

在符合这些标准的 4459 人中，3196 人风险低，不需要转诊，151 人风险高，需要看专科医生，其余 1112 人的中等结果不确定，需要 FibroScan 来确定 LSM。在有 LSM 值的中档组 1021 人中，838 人风险低（LSM 低于 8 kPa）并且不需要专科护理，115 人有不确定的中档 LSM（8 至 12 kPa），需要肝脏科医生进一步评估，68 人的 LSM 高于 12 kPa，也需要转诊给专家。

整个研究组的平均年龄为 49.3 岁，其中 48% 为男性，10.4% 为西班牙裔，体重指数平均为 31.9 kg/m2——处于肥胖范围内。应用 FIB-4 测试将该组 73% 的人归类为低风险，从而避免将他们转诊给肝病学家或 FibroScan 评估。在继续接受 FibroScan 的人中，该测试将另外 19% 的参与者归类为低风险，无需转诊。总而言之，在这个具有纤维化 NASH 风险的全国代表性群体中，AGA 临床护理途径决策树 [2] 仅将 8% 的患者发送给了肝病专家，其中仅包括 11% 的 2 型糖尿病患者。

将低风险组与高风险组进行比较，研究人员发现高风险人群显着变老（平均 66.43 对 47.68，P < 0.001），但在性别、体重指数和种族方面具有统计学相似性。与肝脏相关的实验室值（例如总胆红素、转氨酶、血小板计数和 HbA1C）在高危转诊组中始终明显更差。

研究小组得出结论，这种简单的算法可以识别需要专科护理的有风险的 NAFLD 患者，并向初级保健提供者（和保险公司）保证，绝大多数 NAFLD 患者“可以由他们的主治医生管理，而无需专科护理如果实施筛查指南。”
参考
1. Alkhouri N、Payne J、Phuc Le P 等人。 验证 AGA 临床护理途径以对 NAFLD 患者进行风险分层，并确定在美国人群水平上是否需要转诊肝病。 AASLD—肝脏会议，2022 年 11 月 4 日至 8 日，华盛顿特区。 摘要 89。
2. Kanwal F、Shubrook JH、Adams LA 等人。 非酒精性脂肪肝患者风险分层和管理的临床护理途径。 胃肠病学。 2021；161:1657-1669。 doi: 10.1053/j.gastro.2021.07.049。 https://www.gastrojournal.org/article/S0016-5085(21)03384-9/

StephenW

Over 90% at Risk for Fibrotic NASH Don’t Need Liver Specialist

AASLD—The Liver Meeting, November 4-8, 2022, Washington, DC

Mark Mascolini

A simple algorithm (decision tree) applied to a representative US population at risk for fibrotic nonalcoholic steatohepatitis (NASH) determined that only 8% of them needed referral to a liver specialist [1]. Researchers from Arizona Liver Health and other centers believe the results mean most people at risk for fibrotic NASH can be cared for by primary providers without referral to hepatologists.

Recent research determined that nonalcoholic fatty liver disease (NAFLD) affects 38% of middle-aged people in the United States and NASH, a more advanced condition, affects 14% of middle-aged people. Health experts figure the US has 95 million people with NAFLD and 7500 hepatologists. That comes to more than 12,600 NAFLD patients per liver doctor if everyone with NAFLD saw a specialist.

To figure how many people with NAFLD really need a hepatologist, the American Gastroenterological Association (AGA) proposed a NAFLD “Clinical Care Pathway” algorithm. The pathway helps primary care providers screen people who risk fibrotic NASH (NASH with F2 to F4 fibrosis) to judge whether they should refer that person to a liver expert [2].

The AGA algorithm uses two standard liver function gauges in sequence—FIB-4 index and liver stiffness measurement (LSM) by transient elastography (FibroScan). A person at risk for NAFLD with advanced fibrosis (having 2 or more metabolic risk factors, or type 2 diabetes, or steatosis on any scan, or high aminotransferases [2]) should have noninvasive testing for fibrosis with FIB-4:

FIB-4:

·      If a person has a FIB-4 index below 1.3, they can be considered at low risk for liver complications and followed by their primary provider.

·      An index above 2.67 raises a red flag that calls for referral to a hepatologist.

·      An index between 1.3 and 2.67 tells the practitioner to measure LSM by FibroScan.

FibroScan:

·      An LSM below 8 kPa indicates low risk.

·      An LSM above 12 kPa calls for referral to a hepatologist.

·      An LSM from 8 to 12 kPa also calls for referral to a hepatologist for liver biopsy or MR elastography or monitoring with risk reevaluated in 2 to 3 years

See the AGA Clinical Care Pathway [2] for more details

To determine whether this algorithm can work in the general US adult population, researchers conducted this validation of the AGA Clinical Care Pathway in a nationally representative database—the 2017-2018 National Health and Nutrition Examination Survey (NHANES) data set—and looked for adults with valid FibroScan results and lab data that would allow them to calculate FIB-4 index. Focusing on people with type 2 diabetes, two or more metabolic risk factors, and elevated aspartate aminotransferase, and excluding heavy drinkers, they followed the FIB-4/FibroScan algorithm described just above.

Of the 4459 people with met those criteria, 3196 had low risk and no need for referral, 151 had high risk and needed to see a specialist, and the remaining 1112 had an indeterminate midrange result and needed FibroScan to determine LSM. Among 1021 people in the midrange group who had LSM values available, 838 had low risk (LSM below 8 kPa) and did not need specialist care, 115 had an indeterminate midrange LSM (8 to 12 kPa) that called for further evaluation by a hepatologist, and 68 had an LSM above 12 kPa that also warranted referral to a specialist.

The whole study group averaged 49.3 years in age, 48% were men, 10.4% were Hispanic, and body mass index averaged 31.9 kg/m2—in the obese range. Applying FIB-4 testing classified 73% of the group as low risk and thus spared them referral to a hepatologist or FibroScan evaluation. Among people who went on to get a FibroScan, that test classified another 19% of participants as low risk with no need for referral. All told, in this nationally representative group at risk for fibrotic NASH, the AGA Clinical Care Pathway decision tree [2] sent only 8% to a hepatologist, including only 11% of people with type 2 diabetes.

Comparing the low-risk group with the high-risk group, the researchers found high-risk people significantly older (average 66.43 vs 47.68, P < 0.001) but statistically similar by sex, body mass index, and race. Liver-relevant lab values—such as total bilirubin, aminotransferases, platelet count, and HbA1C—proved consistently significantly worse in the high-risk referred group.

The research team concluded that this simple algorithm can identify at-risk NAFLD patients who need specialist care and assure primary care providers (and insurers) that a big majority of people with NAFLD “can be managed by their treating physicians without the need for specialty care if screening guidelines are implemented.”
References
1. Alkhouri N, Payne J, Phuc Le P, et al. Validation of the AGA Clinical Care Pathway to risk stratify patients with NAFLD and determine if hepatology referral is warranted at the United States population level. AASLD—The Liver Meeting, November 4-8, 2022, Washington, DC. Abstract 89.
2. Kanwal F, Shubrook JH, Adams LA, et al. Clinical Care Pathway for the risk stratification and management of patients with nonalcoholic fatty liver disease. Gastroenterology. 2021;161:1657-1669. doi: 10.1053/j.gastro.2021.07.049. https://www.gastrojournal.org/article/S0016-5085(21)03384-9/