Global NAFLD incidence on the rise

Current estimates of nonalcoholic fatty liver disease (NAFLD) incidence across the world show an increasing trend, with 4,613 new cases per 100,000 person-years, reveals a study.

NAFLD incidence rates are significantly higher in males and individuals with overweight/obesity than in females and those with normal weight.

A systematic review and meta-analysis was conducted involving cohort studies of adults without NAFLD at baseline. The investigators then assessed the global incidence of ultrasound-diagnosed NAFLD.

Sixty-three studies including a total of 1,201,807 individuals met the eligibility criteria. Of these, 63.8 percent were clinical centre studies (median study year, 2000 to 2016) and 87 percent were of good quality. These analyses were conducted in China/Hong Kong, South Korea, Japan, Israel, and Sri Lanka.

Among the participants assessed, 242,568 developed NAFLD (incidence rate, 4,612.8 per 100,000 person-years, 95 percent confidence interval, 3,931.5‒5,294.2), with no statistically significant differences by sample size (p=0.90) or setting (p=0.055).

NAFLD incidence was higher in males than in females (5,943.8 vs 3,671.7; p=0.0013). Moreover, obese (vs nonobese) and overweight/obese groups (vs normal weight) had threefold higher odds of developing NAFLD (8,669.6 vs 2,963.9 and 8,416.6 vs 3,358.2, respectively; p<0.0001 for both). Smokers also had greater NAFLD incidence than nonsmokers (8,043.2 vs 4,689.7; p=0.046).

After adjusting for study year, setting, and location, increased NAFLD incidence showed an association with study period of 2010 or after (p=0.010) and setting (p=0.055).

By country, higher NAFLD incidence was observed in China compared with non-China regions (p=0.012), while a lower incidence was seen in Japan compared with non-Japan regions (p=0.005).

“Public health interventions for prevention of NAFLD are needed with a special emphasis on males, overweight/obese individuals, and higher risk regions,” the investigators said.