Correlation between metabolic, liver profile, dietary habits and ultrasound scan determined non-alcoholic fatty liver disease changes in children aged 6- 18 years with body mass index

Introduction: Non-alcoholic fatty liver disease (NAFLD) is the commonest cause of liver disease worldwide and this is linked to the change in lifestyle and rise in prevalence of overweight and obesity among children. Objectives: To study the correlation between metabolic, liver profile, dietary habits and ultrasound scan determined NAFLD changes in children aged 6–18 years old with their body mass index (BMI). Method: A tertiary care hospital based comparative, prospective study was conducted on 159 children aged 6-18 years at Indira Gandhi Medical College and Hospital, Shimla, India over a period of one year. Children presenting to the outpatient department (OPD) were assigned to two groups based on their BMI, group I with BMI of ≤85th centile and group II with BMI >85th centile. Those with acute and chronic liver ailments and on drugs like vitamin E, statins or antihypertensives were excluded. These were subjected to venepuncture for estimating fasting blood sugar (FBS), liver function tests (LFTs) and complete lipid profile. Ultrasound scan was done to look for NAFLD changes. Results: Children in group II had increased incidence of dyslipidaemia 93.7% vs 41.2%, deranged LFTs 49.4% vs 12.5%, increased FBS 10.1% vs 2.5% and NAFLD 40.5% vs 2.5% when compared to children in group I. Conclusions: BMI and dietary habits have an important bearing on occurrence of NAFLD in children aged 6–18 years old. DOI: http://dx.doi.org/10.4038/sljch.v47i2.8477 _________________________________________ Indira Gandhi Medical College, India *Correspondence: drrohitvohra87@gmail.com (Received on 12June 2017: Accepted after revision on 28 July 2017) The authors declare that there are no conflicts of interest Personal funding was used for the project. Open Access Article published under the Creative Commons Attribution CC-BY License (


Introduction
Non-alcoholic fatty liver disease (NAFLD) is characterised by abnormal lipid deposition in hepatocytes in the absence of excess alcohol intake 1 . Obesity, type 2 diabetes, hypertension, and hypertriglyceridaemia are risk factors for NAFLD 2 which is a hepatic manifestation of metabolic syndromes 3 . During the last 20 years, prevalence of NAFLD has doubled probably due to the increased prevalence of overweight and obesity in the paediatric population worldwide 4 . Till now, NAFLD remained an incidental finding but looking at its consequences the American Academy of Pediatrics suggests biannual screening for liver disease with serum liver enzymes in obese and overweight 10 year old children with other risk factors 5 .

Method
This was a tertiary care hospital based prospective study done over a period of one year from 1 st June 2014 to 31 st May 2015 in children aged 6-18 years attending the outpatient department (OPD) of Indira Gandhi Medical College and Hospital, Shimla, India. Children with pathologic conditions involving the liver such as hepatitis B or hepatitis C virus infections, acute or chronic liver failure, cholestasis, metabolic diseases like alpha 1-antitrypsin deficiency, Wilson disease, diabetes mellitus, hypothyroidism, alcohol consumption, severe malnutrition, etc or on treatment with vitamin E, statins, ursodeoxycholic acid, metformin, antihypertensives, valproate, prednisolone or methotrexate at the time of enrolment were excluded from the study.
The subjects of the study were enrolled randomly from children and adolescents of the age group 6-18 years attending the OPD and were assigned to each group based on their body mass index (BMI). Informed consent was taken from the parents or caregivers. The subjects were screened for obesity, deranged liver profile, dyslipidaemia and fatty liver changes by doing physical examination and relevant investigations.
Weight of the child was recorded on an electronic type of weighing scale, with minimal clothing and weight was measured to ±0.1 kg. Height was measured using a stadiometer to ±0.1 cm. BMI was measured by dividing the weight in kilograms by the square of the height in metres. After a thorough physical and systemic examination, the enrolled children were subjected to venepuncture under aseptic conditions for estimating fasting blood sugar, liver profile and lipid profile after overnight fasting for a minimum of 6 hours. An ultrasound hepatic scan was also performed in the study population to observe for evidence NAFLD.
The data thus collected were analysed using SPSS program for windows, version 17.0. Continuous variables are presented as mean ± SD, and categorical variables are presented as absolute numbers and percentages. Data were checked for normality before statistical analysis. Normally distributed continuous variables were compared using the unpaired t-test, whereas the Mann-Whitney U test was used for those variables that were not normally distributed. Categorical variables were analysed using either the Chi square test or Fischer's exact test. For the two group comparisons, student t-test was used to evaluate the significance of the variables. For all statistical tests, a p value less than 0.05 was considered significant.

Results
A total of 159 children aged 6-18 years qualified for inclusion in the study. They were then divided into two groups: Group I: Study population with normal BMI comprising 80 (50.3%) children Group II: Study population with increased BMI comprising of 79 (49.7%) children Table 1 compares the consumption behaviour of junk food in both groups. Table 2 compares the liver profile in groups I and II. Table 3 compares the lipid profile in groups I and II. Table 4 compares the ultrasound scan (USS) determined fatty liver changes in groups I and II     Table 5 shows the correlation of ultrasound scan findings with the consumption of junk food. Deranged lipid profile was seen in 73 out of 79 subjects in group II as compared to 33 of 80 children in group I. The participants with increased BMI had higher prevalence of hypercholesterolemia (cholesterol >90th percentile, 16.5%, p = 0.003) and hypertriglyceridemia (triglycerides >95th percentile, 69.6%, p < 0.001) and lower HDL (HDL <10th percentile, 15.2%, p = 0.003) levels as compared children with normal BMI. Plourde et al reported that overweight and obese children are at increased risk of dyslipidaemia as compared to normal children 9 .

Figure 1: Correlation of liver and lipid profile with fatty liver findings on ultrasound scan
In our study we found that children with increased BMI consumed more junk food and beverages when compared to children with normal BMI and were more likely to have fatty liver disease as determined by ultrasound (p < 0.001). A positive correlation was seen between lipid profile and SGPT levels and USS changes of fatty live disease in children of group II.

Conclusions
BMI and dietary habits have an important bearing on occurrence of NAFLD in children aged 6-18 years old.