Recent studies have shown an association between obstructive sleep apnea and elevated liver enzymes in patients with nonalcoholic fatty liver disease.
Dr Eric Kallwitz and colleagues compared biochemical and histologic findings in patients with nonalcoholic fatty liver disease as a function of obstructive sleep apnea status.
|19% of subjects had fibrosis on liver biopsy|
|Journal of Clinical Gastroenterology|
The team evaluated 85 patients who had a sleep study followed by a liver biopsy performed at the time of obesity surgery.
The diagnosis of obstructive sleep apnea was based on an apnea hypopnea index of 15 or more.
Demographic and laboratory data were collected retrospectively.
Liver biopsies were systematically evaluated for features of nonalcoholic fatty liver disease including degree of steatosis, inflammation, and fibrosis.
The researchers found all but 1 patient had histologic evidence of nonalcoholic fatty liver disease, and 51% of the study population had obstructive sleep apnea.
A higher proportion of patients with obstructive sleep apnea had elevated alanine aminotransferase levels compared with those without obstructive sleep apnea.
The team noted that only 19% of subjects had fibrosis on liver biopsy, and 5% had bridging fibrosis or cirrhosis.
There was a trend toward a higher prevalence of obstructive sleep apnea in patients with evidence of progressive liver disease.
The researchers observed that this was indicated by inflammation plus fibrosis, compared with those with inflammation alone.
Dr Kallwitz' team concluded, "In obese patients with nonalcoholic fatty liver disease, obstructive sleep apnea was associated with elevated alanine aminotransferase levels and a trend toward histologic evidence of progressive liver disease."