Abstract and Introduction
Background and Aim: Obesity is an important health-care problem in developed countries. It is considered a multisystemic disease, but it may also affect the liver, thus provoking non-alcoholic fatty liver disease. This disease has been less extensively studied among children than among adults. We propose to analyze the prevalence of hepatic steatosis among a pediatric population within an area in southern Europe besides the variables associated with its development and severity.
Methods: Cross-sectional study carried out on a population of children aged 6–14 years inclusive, using abdominal ultrasound as a method to determine the presence and severity of hepatic steatosis; in addition, anthropometric and blood-tested parameters were examined to determine which of these were associated with steatosis.
Results: One hundred forty-four children were analyzed, 84 male (58.3%). Steatosis was detected in 50 children (34.7%; 95% confidence interval [CI]: 26.0–42.0%). In six of these cases (12%), elevated aminotransferase levels were recorded. Factors found to be associated with steatosis were body mass index ≥ 99th percentile (odds ratio [OR] 3.58, 95% CI 1.16–15.6) and the level of alanine aminotransferase (ALT) (OR 1.08, 95% CI 1.03–1.13), while its severity was associated with ALT (OR 1.17, 95% CI 1.09–1.28). A level of ALT < 23.5 UI/dL predicted lack of severe steatosis with an area under receiver operating characteristic curve of 0.805 (95% CI 0.683–0.927).
Conclusions: Non-alcoholic fatty liver disease is common in the obese pediatric population in our geographical area. High levels of ALT are associated with severe steatosis, although having ALT above the normal range is not common. Also, the lack of severity of steatosis can be predicted in a subgroup of children with obesity.
Obesity is one of the most important healthcare problems within developed countries, where its prevalence has been estimated at 30% among the adult population and 12–22% among children. Non-alcoholic fatty liver disease (NAFLD) is an obesity-associated clinical condition that spans a wide range of lesions from simple steatosis to most severe with necroinflammatory and fibrotic phenomena termed non-alcoholic steatohepatitis (NASH). When this histological progression takes place, around 15–25% of cases develop cirrhosis within 10 years, and once this becomes established, 30–40% of patients die within 10 years; this rate of mortality being similar to or even higher than that for hepatitis C.
NAFLD is the most common liver pathology among the adult population, affecting 10–24% of the general population and 57–75% of obese subjects. Moreover, it is the most common cause of hypertransaminasemia in the USA.
The prevalence of overweight and obesity among the pediatric population is coming to be of a pandemic nature. The figures vary between countries, but for example it has been estimated at around 16% in the USA and increasing in recent years, the level is somewhat less in Scandinavia, France, and Australia, while in Spain, it is about 14%.
Obesity may be considered a multisystemic disease of devastating consequences, and longitudinal studies suggest that pediatric obesity is a risk factor for the development of adult obesity.
Pediatric obesity is associated with NAFLD and even with severe forms of the disease. The exact prevalence of NAFLD during childhood is as yet insufficiently documented. Nevertheless, figures have been published that provide an impression of the problem. Thus, elevated aminotransferase levels have been reported among 10–14% of young obese subjects in the USA, among 24% of young Hispanics, and among 24% of Japanese subjects. Using non-invasive techniques such as ultrasound or magnetic nuclear resonance, estimates of the prevalence of NAFLD among the obese pediatric population range from 23% to 77%.
There are few data about NAFLD in our country, and therefore, the primary aim of the present study was to determine, in our geographical area, in southern Europe, the prevalence and severity of hepatic steatosis, defined by ultrasound criteria, among a pediatric obese population.