The goal of this observational study is to investigate the associations between a novel inflammatory marker, high sensitivity C-reactiveprotein to albumin ratio (hsCAR), and steatosis and fibrosis of metabolic dysfunction-associated fatty liver disease (MAFLD).

The main question[s] it aims to answer are:

[question 1] Can hsCAR serve as a clinical indicator to determine whether a patient has MAFD? [question 2] Can hsCAR determine whether MAFLD patients are complicated with liver fibrosis?

Background Inflammation is related to the occurrence and development of fatty liver. Our research aimed to investigate the link between an inflammatory indicator, high-sensitivity C-reactive protein to albumin ratio (hsCAR), and metabolic dysfunction-associated fatty liver disease (MAFLD).

Methods Ultrasonic indices were used to evaluate the severity of liver steatosis and fibrosis of participants from the NHANES database, respectively. The relationship between hsCAR and MAFLD was explored using multivariate logistic regression analysis, restricted cubic splines (RCS) as well as threshold analysis. Finally, subgroup analyses were performed using the same methodology.

Inclusion Criteria:

• Total participants from NHANES 2017-2020

• Participants diagnosed with MAFLD. Metabolic dysfunction-associated fatty liver disease (MAFLD) is the term used to describe hepatic steatosis in the presence of metabolic abnormalities, excess weight, obesity, or type 2 diabetic mellitus.

  1. Diagnosis of diabetes mellitus: (1) taking glucose-lowering drugs; (2) HbA1c ≥ 6.5% (48 mmol/mol); (3) fasting plasma glucose ≥ 7.0 mmol/L (126 mg/dL); (4) 2-hour plasma glucose (2hPG) ≥ 11.1 mmol/L (200 mg/dL).

  2. Overweight or obesity: defined as BMI≥25 kg/m2 in Caucasians or BMI≥23 kg/m2 in Asians

  3. If presence of at least two metabolic risk abnormalities:

     • Waist circumference≥102/88 cm in Caucasian men and women (or≥90/80 cm in Asian men and women)
     • Blood pressure≥130/85 mmHg or specific drug treatment
     • Plasma triglycerides≥150 mg/dl (≥1.70 mmol/L) or specific drug treatment
     • Plasma HDL-cholesterol <40 mg/dl (<1.0 mmol/L) for men and <50 mg/dl (<1.3 mmol/L) for women or specific drug treatment
     • Prediabetes (i.e., fasting glucose levels 100 to 125 mg/dl [5.6 to 6.9 mmol/L], or 2-hour post-load glucose levels 140 to 199 mg/dl [7.8 to 11.0 mmol] or HbA1c 5.7% to 6.4% [39 to 47 mmol/mol])
     • Homeostasis model assessment of insulin resistance score≥2.5
     • Plasma high-sensitivity C-reactive protein level >2 mg/L

Exclusion Criteria:

• Liver ultrasound data not available
• participants without complete clinical data
• participants under 18 years old
• participants with cancer.

They all come from the National Health and Nutrition Examination Survey, which is a database that contains information about demographics, dietary, examination, laboratory and questionnaire of the American population obtained through sophisticated sampling strategies.