Objective: Prevalence, localization and potential risk factors for focal sparing were prospectively assessed in subjects with sonographically detectable hepatic steatosis as part of a population-based cross-sectional study.
Material and Methods: A total of 1,624 persons were evaluated using ultrasonography, laboratory testing and a standardized questionnaire. Excluded from the analysis were subjects with reported alcohol consumption >40g/day (males) or >20g/day (females), those with known chronic hepatitis B or C infection, elevated serum transaminases (AST: m>44U/l, f>33U/l; ALT: m>45U/l, f>35U/l) and prior right nephrectomy. Ultrasonographic examinations were performed using four identical HDI 5000 ultrasound scanners (2-5 MHz probe) under standardized conditions.
Results: Prevalence of focal sparing in patients with hepatic steatosis (grade I according to criteria proposed by Saverymuttu et al.) was 26.5% for men and 13.0% for women; in patients with grade II/III disease, the prevalence was 70.9% for men and 77.6% for women. The most common site of focal sparing was in liver segment IV. The average diameter was 22.3mm (range 7-84mm). No correlation was found for postulated risk factors “Age” (p=0.09) or “Status post Cholecystectomy” (p=0.09). Male sex (p=0.02) and metabolic syndrome (modified ATP III criteria) (Odds ratio, 2.1; 95% confidence interval, 1.1-4.1; p=0.02) were confirmed as risk factors.
Conclusions: Sonographic evidence of focal sparing in subjects with hepatic steatosis is associated with an increased risk for metabolic syndrome and represents an easily obtained diagnostic criterion in routine clinical settings.