FROM PLOS ONE
Children with nonalcoholic fatty liver disease should have their blood pressure evaluated, controlled, and monitored regularly to mitigate long-term risks of liver disease, hypertension, and cardiovascular morbidity and mortality, according to a new study.
“NAFLD [nonalcoholic fatty liver disease] is now the most common cause of chronic liver disease in children in the United States with an estimated prevalence of 9.6%,” wrote lead author Dr. Jeffrey B. Schwimmer of the University of California, San Diego, and his associates, adding that their investigation’s twofold purpose was to determine “the prevalence of high blood pressure in children with NAFLD in relation to demographic and key clinical risk factors, and the rate and risk factors of persistent (over 48 weeks) high blood pressure in children with NAFLD.”
For this multicenter, longitudinal cohort study, 448 children aged 2-17 years were enrolled through the National Institute of Diabetes and Digestive and Kidney Diseases Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) between September 2004 and October 2009. Only 382 of the 448 original subjects were monitored and recorded follow-up data after 48 weeks (PLOS ONE 2014 Nov. 24 [doi:10.1371/journal.pone.0112569]).
Diagnosis of NAFLD in these children was based on liver histology, with at least 5% of hepatocytes containing macrovesicular fat, and exclusion of other causes of chronic liver disease by clinical history, laboratory studies, and histology. Baseline analysis excluded children with underlying renal disease, those without a histologic diagnosis of NAFLD, or missing blood pressure at baseline.
Subjects had their physical measurements – height, weight, waist circumference – recorded at enrollment and after 48 weeks, along with their systolic and diastolic blood pressures. High blood pressure at baseline was present in 35.8% of all children, while every one unit increase in body mass index (BMI) increased the odds of a child having high blood pressure by 10%. Children with high blood pressure had a significantly higher mean BMI than did children without high blood pressure (34.6 vs. 31.6 kg/m2). A significant linear relationship between LDL cholesterol and the likelihood of developing high blood pressure also was noted by the investigators (odds ratio, 1.09 per 10 mg/dL).
Children with high blood pressure were significantly more likely to have worse steatosis than were children without high blood pressure (mild, 19.8% vs. 34.2%; moderate, 35.0% vs. 30.7%; severe, 45.2% vs. 35.1%)
Results after 48 weeks indicated that 21% of subjects had persistent high blood pressure and that girls were more predisposed to high blood pressure than boys (28.4% vs. 18.9%), thus increasing their likelihood of developing cardiovascular problems and even liver disease.
“Along with being at an increased risk for cardiovascular disease, we found that children with NAFLD who had high blood pressure were significantly more likely to have more fat in their liver than children without high blood pressure. This could lead to a more serious form of liver disease,” Dr. Schwimmer said in a statement.
There are no “approved and effective” treatments currently available for children with NAFLD, according to the authors, so they urged pediatricians to routinely monitor patients’ blood pressures – particularly those who may be overweight or obese – in order to nip long-term cardiovascular and liver complications in the bud.
“There are some reasons to believe that blood pressure control could be beneficial for NAFLD. Thus, we may be able to decrease the risk of premature cardiovascular disease in these children, and also help their liver,” noted Dr. Schwimmer in a statement. “Parents and doctors need to be aware of the health risks of children who have NAFLD. The sooner high blood pressure is identified and treated in this patient population, the healthier they will be as they transition into adulthood.”
In adults with NAFLD, cardiovascular disease is the leading cause of death.
The study was supported by grants from the National Institute of Diabetes and Digestive and Kidney Diseases. The authors said they had no competing interests.