Obesity-independent Association of Human Adenovirus Ad37 Seropositivity With Nonalcoholic Fatty Liver Disease

Abstract

OBJECTIVE: Adenoviruses Ad36 and Ad37 increase adiposity in animals and are associated with obesity in humans; effects on the liver have been reported. The association of Adenovirus Ad36 seropositivity (Ad36+) with obesity but not with the severity of nonalcoholic fatty liver disease (NAFLD) has been previously shown. We investigate whether nondiabetic Ad37+ patients show a different prevalence of NAFLD and ultrasound Bright Liver score. PATIENTS: A total of 268 adult nondiabetic patients (146 men, 122 women) were included after lifestyle counseling including a personalized Mediterranean diet, increase in physical activity, and smoking withdrawal. After an Ad37+/Ad36+ assay, overweight obesity, insulin resistance, C-reactive protein, and bright liver prevalence and severity were compared according to Ad37+. RESULTS: Sixty-five of 268 patients were Ad37+ and 82/268 patients were both Ad37 seronegative (Ad37-) and Ad36-. The prevalence of obesity, defined as body mass index≥30, was not significantly different in Ad37+ (11/65; 16.9%) vs. Ad37- (15/82; 18.2%) patients; Bright Liver was present in 22/65 (33.8%) Ad37+ patients vs. 13/82 (15.8%) Ad37- patients (P<0.019). By odds ratio (OR), a consistent risk for NAFLD was associated with Ad37+, greater insulin resistance, and C-reactive protein. By a predictive multiple linear regression model, 40.0% of variance toward NAFLD and 50.4% toward the severity of Bright Liver score was explained significantly and independently by Ad37+ and by body mass index. CONCLUSIONS: Ad37+ status in nondiabetic patients on an appropriate diet is significantly associated with NAFLD; because fatty liver improves even without weight loss by a "healthy" diet, and not only by lower food caloric intake, Ad37+ may be an adjunctive hallmark of an unfavorable clinical-metabolic profile, if not a causative factor of NAFLD.