Screening for Insulin Resistance in Patients with Liver Disease in Tertiary Centers

Abstract

Background: Liver is a vital organ that plays a major role in glucose production and regulationthroughout the body (Musso et al., 2012). Liver disease has long been linked with insulin resistance (IR), dating back to 1906 (Megyesi et al., 1967). IR has been found to be prevalent in a range of liver diseases, including chronic Hepatitis C Virus (HCV), hemochromatosis, and alcoholic liver disease (Goswami et al., 2014). Liver disease is highly prevalent in the United States population with 30 million people (or one out of ten Americans) suffering from some type of liver disease (Peery et al., 2015). Although research demonstrates a significant relationship between liver disease and IR, the University of Arizona (UA) hepatology clinic does not currently screen liver disease patients for IR. Homeostatic model assessment for insulin resistance (HOMA-IR) score is used to study IR in non-insulin resistant population. HOMA-IR score is calculated using formula fasting plasma glucose (mmol/l) times fasting serum insulin (mU/l) divided by 22.5 (Bonora et al., 2002). Low HOMA-IR (HOMA< 2.0) values indicate high insulin sensitivity, whereas high HOMA-IR (HOMA> 2.0) values indicate low insulin sensitivity (insulin resistance) (Bonora et al., 2002). Objective: The purpose of this quality improvement (QI) project is to show the prevalence of IR in euglycemic liver disease patients at the UA hepatology clinic by using their HOMA-IR scores as a screening tool. By screening euglycemic liver disease patients for IR based on their HOMA-IR score, providers at the UA hepatology clinic can prevent liver disease progression and complications associated with IR early on. By doing so, the providers can improve the quality of care for liver disease patients. An essential part of calculating HOMA-IR is the availability of labs (serum glucose and serum insulin). A part of this QI project is to determine if the UA hepatology clinic has necessary labs to calculate HOMA-IR for euglycemic liver disease patients. A related matter is whether there is a correlation between liver disease patients' HOMA-IR score and Model for End-stage Liver Disease (MELD) score. If there is a direct correlation between HOMA-IR and MELD scores, providers can identify severity and progression of liver disease in euglycemic liver disease patients. Design: A case control retrospective study. Study Questions: 1) Do UA Hepatology clinic providers order sufficient labs (fasting plasma glucose and fasting plasma insulin) to calculate HOMA-IR in euglycemic patients? 2) What is the prevalence of IR in euglycemic liver patients indicated by HOMA-IR score? 3) Is there any correlation between HOMA-IR score and MELD score in euglycemic liver disease patients? Participants: Data will be collected from 1000 liver disease patients' at the UA hepatologyclinic, a tertiary level referral center. Settings: Banner University Medical Center (UMC) in Tucson, Arizona from January 1, 2011 until December 31, 2014. Measurements: HOMA-IR score using serum fasting glucose and serum fasting insulin levels laboratory values. MELD score to identify the severity of liver disease in euglycemic liver disease patients. Results: Among 1000 patients, 506 (60.5%) were found to have a previous diagnosis of T2DMand 395 (39.5 %) were euglycemic liver disease patients (Figure 1). Out of the 395 euglycemic liver disease patients, 217 (55%) participants were found to have both insulin level and glucose11level in their charts; 178 (45%) euglycemic liver disease patients were missing either insulin level or glucose level needed to calculate HOMA-IR score (Figure 2). Of the 217 euglycemic liver disease patients, 54.8% of had HOMA-IR> 2 and 45.2% patients had HOMA-IR<2 (Figure 3). The Pearson Correlation between HOMA-R>2 and MELD scores was 0.092 and the significance value using 2-tailed was 0.321 (Table 4). Conclusion: The results showed a significant high prevalence of IR in euglycemic patients with HOMA-IR score> 2 (54.8%) compare to those patients with HOMA-IR score<2 (45.2%). Furthermore, about 178 (45%) euglycemic liver disease patients were missing either insulin level or glucose level needed to calculate HOMA-IR score. This is a significant number of patients missing important labs to identify them as high risk for IR. This QI project identified HOMA-IRas an important screening tool that should be used both in hepatology clinics and primary healthcare settings. Use of such tool will lead to improved quality of care for euglycemic liver disease patients.