Course of nonalcoholic fatty liver worse in black youth

Last Updated: 2018-05-16

By Anne Harding

NEW YORK (Reuters Health) - Nonalcoholic fatty liver (NAFL) is more common among obese youth who are white or Hispanic, but the course of the disease is more severe among African Americans, new findings suggest.

"African American children had the most dramatic changes in insulin and glucose homeostasis with NAFL," Dr. Nicolo Santoro of Yale University School of Medicine in New Haven, Connecticut, the study's senior author, told Reuters Health by phone.

Physicians should screen obese African American children and adolescents for hepatic fat content, and if they have NAFL they should be screened for prediabetes and diabetes, Dr. Santoro said. "The two things are really very much connected."

About 7 million children and adolescents in the U.S. have NAFL, which is now the leading cause of chronic liver disease in pediatric patients, Dr. Santoro and colleagues note in Hepatology, online April 17.

Previous studies in both adults and children have found that Hispanics have the highest rate of NAFL, while African Americans are less likely to develop hepatic fat accumulation, even if they are morbidly obese and severely insulin resistant, Dr. Santoro and his team note.

They looked at 503 overweight and obese adolescents taking part in an ongoing study of youth-onset NAFL. The group was 38% Caucasian, 26.6% African American and 35.4% Hispanic. Forty-one percent were male.

Overall, 41.6% had NAFL. The prevalence was 42.9% in whites, 15.7% in African Americans and 59.6% in Hispanics. Significantly more boys than girls had NAFL (53.6% vs. 46.4%).

African Americans with NAFL had significantly higher fasting glucose, fasting insulin, fasting C peptide, two-hour glucose, hemoglobin A1c, insulinogenic index and whole-body insulin sensitivity index compared with whites and Hispanics with NAFL.

However, age, sex and Tanner stage distribution, as well as visceral fat volume, were similar across the three groups.

Two-thirds of African Americans with NAFL had impaired glucose tolerance, versus 24.4% of whites and 31.1% of Hispanics.

Among study participants who did not have fatty liver at baseline, the risk for developing it during a two-year follow-up was higher in whites and Hispanics, as well as those with high fasting C-peptide levels. Weight gain was also associated with incident NAFL. Baseline hepatic fatty fraction and weight loss were associated with resolution of NAFL at follow-up.

Study participants without NAFL at baseline who were Hispanic or white, had insulin resistance and carried one of three single nucleotide polymorphisms associated with fatty liver had almost a 100% chance of developing fatty liver during follow-up, Dr. Santoro noted.

"Although our longitudinal analyses involved a relatively small sample, they clearly demonstrate that taking into account the ethnic background, tracking some simple clinical information . . . and knowing the genotype of one of the major genetic risk factors for NAFLD might represent a strong tool for the clinician in the follow-up of obese adolescents," he and his colleagues conclude.

SOURCE: https://bit.ly/2k1Skhj

Hepatology 2018.