Factors Predictive of Non-Alcoholic Fatty Liver Disease in Non-Obese Pakistani Population

Background: Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent causes of chronic liver disease worldwide, with a rising incidence in developing countries. In Pakistan, the estimated prevalence ranges from 14-47%. Studies have shown that NAFLD is also not uncommon among the non-obese lean population. Objective: The aim of this study was to evaluate the factors predictive of non-alcoholic fatty liver disease in a non-obese Pakistani population, defined by a body mass index (BMI) of less than 23 kg/m². Methods: This cross-sectional study was conducted at the Department of Hepatogastroenterology, Sindh Institute of Urology and Transplantation from November 1, 2020, to October 31, 2021. A total of 194 patients with BMI < 23 kg/m² presenting with abdominal pain were included. Exclusion criteria were viral hepatitis, significant alcohol intake, hepatocellular carcinoma, or other malignancies. Data collection involved recording demographic information, medical history, and clinical parameters. Ultrasound abdomen examinations were performed after 8-10 hours of fasting to diagnose NAFLD. Clinical assessments included history of hypertension and smoking, and laboratory tests such as liver function tests, fasting blood sugar levels, and lipid profiles. The primary outcome was the presence of fatty liver on ultrasound. Statistical analysis was conducted using SPSS version 25.0. Continuous variables were analyzed using the Student t-test and categorical variables using the Chi-square test. Significant variables in univariate analysis underwent multivariate logistic regression to identify independent predictors of lean NAFLD. A p-value ≤ 0.05 was considered significant. Results: Out of the 194 patients, 107 (55.2%) were females. The mean age was 36.1 ± 9.6 years, and the mean BMI was 21 ± 1.7 kg/m². NAFLD was detected in 48 (24.7%) patients. Among the study population, 78 (40.2%) were hypertensive, 40 (20.6%) were diabetic, 49 (25.3%) were smokers, and 54 (27.8%) had increased triglyceride levels. Decreased HDL-C levels were observed in 72 (37.1%) patients. Univariate analysis identified hypertension (p ≤ 0.001), diabetes (p ≤ 0.001), smoking (p ≤ 0.001), hypertriglyceridemia (p ≤ 0.001), and decreased HDL-C levels (p ≤ 0.001) as significant factors. Multivariate logistic regression showed that diabetes (OR: 9.4, p = 0.037), smoking (OR: 46.4, p ≤ 0.001), hypertriglyceridemia (OR: 4.75, p = 0.016), and decreased HDL-C levels (OR: 36.8, p ≤ 0.001) were independently associated with lean NAFLD. Conclusion: Non-obese individuals with a BMI less than 23 kg/m² can develop NAFLD and related complications. The study identified diabetes, smoking, hypertriglyceridemia, and decreased HDL-C levels as significant predictors of lean NAFLD. Further studies are needed to enhance the understanding of the disease's risk factors and behavior in this population.