Obesity Linked to Greater Risk of Metabolic Syndrome, Disease Severity in Patients With NAFLD

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Results of a recent cross-sectional study are providing an overview of the relationship between BMI and severity of nonalcoholic fatty liver disease (NAFLD), with findings suggesting risk of metabolic syndrome and disease severity in NAFLD increase with BMI.

“Although non-obese NAFLD patients have been shown to share clinical outcomes with their obese counterparts, there is not enough evidence on the cardiometabolic status and disease severity in lean NAFLD,” wrote investigators.¹ “Also, the differences in the characteristics of obese and non-obese NAFLD patients remain poorly characterized.”

Being classified as overweight or having obesity are often recognized as potential risk factors for NAFLD, although it can still affect patients with a normal weight and BMI.² Obesity is also linked to several risk factors for metabolic syndrome, including high cholesterol, insulin resistance, and high blood pressure.³

A team of investigators led by Zahra Yari, PhD, of the Department of Clinical Nutrition and Dietetics at Shahid Beheshti University of Medical Sciences in Tehran, Iran, sought to compare cardiometabolic risk factors between patients with NAFLD with and without obesity, further exploring the relationship between BMI and severity of NAFLD. Clinical data, including medical history, medications, alcohol consumption, and smoking habits, was collected for more than 400 patients with NAFLD. For inclusion, participants were required to be adults age 18–65 years old with grade ≥ 2 NAFLD confirmed by Fibroscan.¹

All patients underwent laboratory testing and physical examination to assess height, body weight, BMI, waist circumference, blood pressure, and blood serum levels. Among the cohort, 82 participants were classified as normal weight, 121 as overweight, and 249 as obese, according to BMI.¹

Investigators applied univariate and multivariate logistic regression models to calculate odds ratios and 95% confidence interval (CI) for occurrence of metabolic syndrome in each category of BMI. Multivariate logistic regression models were adjusted for potential confounding factors, including age, sex, steatosis, and fibrosis score.¹

Upon analysis, the prevalence of metabolic syndrome was highest among participants with obesity (62.1%), followed by those classified as overweight (27.7%) and normal-weight (10.2%). After adjusting for confounding factors, investigators noted the risk of metabolic syndrome in patients with obesity was 4.85 times greater (95% CI, 2.36-9.99; P < 0.001) than those with BMI less than 25. For patients classified as being overweight, the risk was 3.74 times greater (95% CI, 1.6-8.74; P = 0.002).¹

Linear regression analysis adjusted for confounders showed waist circumference (β, 0.770; P < 0.001), serum concentration of fasting blood glucose (β, 0.193; P = 0.002), and triglyceride (β, 0.432; P < 0.001) determined metabolic syndrome occurrence in patients with NAFLD. Of note, investigators found BMI increase was significantly associated with increased risk of metabolic syndrome, regardless of gender, age, grade of steatosis, and fibrosis.¹

“Our results disclosed that both obese and non-obese NAFLD patients shared several clinical and laboratory characteristics, although MetS was more prevalent among obese participants. In addition, according to the analysis, the risk of metabolic syndrome and the severity of fatty liver increase along with increasing BMI. These results may have significant clinical implications,” concluded investigators.¹

References:

1. Yari, Z., Fotros, D. & Hekmatdoost, A. Comparison of cardiometabolic risk factors between obese and non-obese patients with nonalcoholic fatty liver disease. Sci Rep 13, 14531 (2023). https://doi.org/10.1038/s41598-023-41893-w
2. American Liver Foundation. Nonalcoholic Fatty Liver Disease. Liver Diseases. Accessed September 6, 2023. https://liverfoundation.org/liver-diseases/fatty-liver-disease/nonalcoholic-fatty-liver-disease-nafld/
3. Johns Hopkins Medicine. Metabolic Syndrome. Conditions and Diseases. Accessed September 6, 2023. https://www.hopkinsmedicine.org/health/conditions-and-diseases/metabolic-syndrome