Prevalence of and risk factors for hepatic steatosis in Northern Italy.

BACKGROUND

Although hepatic steatosis is seen with increasing frequency in clinical practice, its prevalence and risk factors are unknown.

OBJECTIVE

To investigate the prevalence of and risk factors for hepatic steatosis, such as alcohol consumption and obesity.

DESIGN

Cross-sectional, observational study.

SETTING

Participants in the Dionysos Study.

PATIENTS

257 participants assigned to one of four categories (67 controls, 66 obese persons, 69 heavy drinkers, and 55 obese heavy drinkers).

MEASUREMENTS

Ethanol intake, assessed by a validated questionnaire and expressed as daily (g/d) and lifetime (kg) consumption, and body mass, expressed as body mass index. Biochemical tests of liver and metabolic function and hepatic ultrasonography were done.

RESULTS

The prevalence of steatosis was increased in heavy drinkers (46.4% [95% CI, 34% to 59%]) and obese persons (75.8% [CI, 63% to 85%]) compared with controls (16.4% [CI, 8% to 25%]). Steatosis was found in 94.5% (CI, 85% to 99%) of obese heavy drinkers. Compared with controls, the risk for steatosis was higher by 2.8-fold (CI, 1.4-fold to 7.1-fold) in heavy drinkers, 4.6-fold (CI, 2.5-fold to 11.0-fold) in obese persons, and 5.8-fold (CI, 3.2-fold to 12.3-fold) in persons who were obese and drank heavily. In heavy drinkers, obesity increased the risk for steatosis by twofold (CI, 1.5-fold to 3.0-fold) (P < 0.001), but heavy drinking was associated with only a 1.3-fold (CI, 1.02-fold to 1.6-fold) increase in risk in obese persons (P = 0.0053). Elevated alanine aminotransferase and triglyceride levels are the most reliable markers of steatosis.

CONCLUSIONS

Steatosis is frequently encountered in healthy persons and is almost always present in obese persons who drink more than 60 g of alcohol per day. Steatosis is more strongly associated with obesity than with heavy drinking, suggesting a greater role of overweight than alcohol consumption in accumulation of fat in the liver.