Nonalcoholic Fatty Liver Disease Screening in Type 2 Diabetes Mellitus Patients in the Primary Care Setting

Abstract

Nonalcoholic fatty liver disease (NAFLD) is a major public health problem worldwide and the most common chronic liver disease. NAFLD currently affects approximately one in every four people in the United States, and its global burden is expected to rise in the next decades. Despite being a prevalent disease in the general population, only a minority of patients with NAFLD will develop nonalcoholic steatohepatitis (NASH) with advanced liver fibrosis (stage 3-4 fibrosis) and liver-related complications. Certain populations, such as patients with type 2 diabetes mellitus (T2DM), are recognized to be at the highest risk for developing NASH and advanced fibrosis. Both the American Diabetes Association and the European Association for the Study of Diabetes recommend screening of all T2DM for NAFLD. Incorporating a simple noninvasive algorithm into the existing diabetic care checklists in the primary care practice or diabetologist's office would efficiently identify patients at high risk who should be referred to specialists. The proposed algorithm involves a first-step annual fibrosis-4 score (FIB-4) followed by vibration-controlled transient elastography (VCTE) for those with indeterminate or high-risk score (FIB-4 ≥1.3). Patients at low-risk (FIB-4 <1.3 or VCTE <8 kPa) can be followed up by primary care providers for lifestyle changes and yearly calculation of FIB-4, while patients at high risk (FIB-4 ≥1.3 and VCTE ≥8 kPa) should be referred to a liver-specialized center. Conclusion: Patients with T2DM or prediabetes should be screened for NASH and advanced fibrosis. The proposed simple algorithm can be easily incorporated into the existing workflow in the primary care or diabetology clinic to identify patients at high risk for NASH and advanced fibrosis who should be referred to liver specialists.

FIG. 1

Schematic representation of the proportions of patients with NAFL, NASH, and advanced fibrosis in the general population and among patients with T2DM. In the general population, approximately 25% of patients have NAFLD; among those, up to 30% have NASH, of whom up to 20% have developed or will develop advanced liver fibrosis (stage 3‐4 fibrosis). T2DM represents approximately 10% of the U.S. population. It is estimated that 40%‐70% of patients with T2DM have underlying NAFLD, and among those ≈37% have NASH and ≈17% will develop advanced fibrosis.

FIG. 2

Stepwise approach for screening, risk stratification, and referral of patients with NAFLD between primary care and diabetic clinics and liver specialists. A pragmatic risk stratification algorithm is crucial to identify patients at high risk of advanced liver fibrosis. In this algorithm, we propose screening all patients with T2DM or prediabetes for advanced liver fibrosis by using FIB‐4. The proposed algorithm involves a first‐step annual FIB‐4 score followed by VCTE for those with indeterminate or a high‐risk score (FIB‐4 ≥1.3). Patients at low risk (FIB‐4 <1.3 or VCTE <8 kPa) can be followed up by PCPs for lifestyle changes and yearly calculation of FIB‐4, while patients at high risk (FIB‐4 ≥1.3 and VCTE ≥8 kPa) should be referred to liver‐specialized clinics for further assessment and evaluation.