REFERENCE and syndromes associated with endocrine dysfunction
REFERENCE ID: TITLE: Non-Alcoholic Fatty Liver Disease IN GENERAL POPULATION AND ITS ASSOSCIATION WITH METABOLIC SYNDROME.INTRODUCTION: Non-Alcoholic Fatty Liver Disease (NAFLD) is a disease in which fat gets accumulated in the hepatocytes (>5 to 10% by weight) in the absence of any pathology known in the liver or excessive consumption of alcohol 1. NAFLD shows an asymptomatic involvement of liver which if left untreated, can progress into chronic liver disease 2. NAFLD is the commonest aetiology of chronic liver disease in paediatric population in western countries 3. Prevalence of NAFLD in children of normal-weight is found to be 3-10% and in overweight and obese children, it is between 8-80% 4. Although NAFLD is not conventionally a part of the definition of metabolic syndrome, it is widely considered the hepatic manifestation of the metabolic syndrome. NAFLD is associated with IR, obesity, hypertriglyceridemia, and metabolic syndrome in adults. Children with biopsy proven NAFLD had greater incidence of metabolic syndrome. There is also an association between the histologic severity of disease and some components of metabolic syndrome. It has also been found that increased ALT is associated with developing metabolic syndrome over 20 years on follow-up. Finally, NAFLD independently also increases the relative risk of cardiovascular events. However, there is also very little information available regarding the prevalence of NAFLD in general population and its relation with metabolic syndrome. This study aims to establish the prevalence of NAFLD in general population in children and its relation with metabolic syndrome.OBJECTIVES: To estimate the prevalence of NAFLD in normal Indian children.To correlate the prevalence of NAFLD with metabolic syndrome in children. METHODOLOGY: This is proposed to be a cross-sectional study to be performed on school going children, 5-15 years of age, presenting to Out Patient Department of a 999-bedded large multi-speciality hospital in North India. Subjects diagnosed with any chronic medical illnesses or taking any chronic medications will be excluded. The study group will consist of randomly selected 100 healthy children visiting the Paediatric Out Patient Department of Base Hospital, Delhi Cantonment, New Delhi for any non-specific illnesses or for regular health check-up. Depending upon the subject’s Body Mass Index, they would be categorised into three groups: Group 1 with BMI of ? 27 kg/m2 (obese), Group 2 with BMI of ? 27 kg/m2 (overweight) and Group 3 with BMI of 18.5-22.9 kg/m2 (non obese)6.A written informed consent from the parents of the participants of the study would be taken. This study protocol will be performed according to the guidelines of WMA Declaration of Helsinki – Ethical Principles for Medical Research7. The approval of Institutional Medical Ethics Committee of the College will also be taken. Children suffering from any long term illnesses of cardiac, pulmonary or renal diseases, or those on any medications for an extended duration of time will be excluded from the study. Children with past history of any surgical intervention (cardiac, pulmonary or abdominal) or subjects undergoing any program for physical conditioning pertaining to obesity will also be excluded. A thorough medical history will be obtained and a detailed physical examination (including evaluation for syndromes and endocrine diseases) will be performed to exclude any unidentified concomitant disease. Children having syndromes associated with obesity like Prader-Willi syndrome, Laurence- Moon-Biedl syndrome, etc. and syndromes associated with endocrine dysfunction such as Cushing’s syndrome, hypothyroidism, etc. will also be excluded from the study. The Gold Standard for diagnosis of NAFLD is liver biopsy. Using liver biopsy for diagnosing NAFLD in healthy populations would be unethical, hence other modalities like ultrasonography and biochemical markers like alanine aminotransferase( ALT) and aspartate aminotransferase (AST) will be used for diagnosis8,9 . Ultrasonography (USG ) of liver will be done by using machine with probe of MHz. Ultrasound findings will be categorized into absent, mild, moderate and severe fatty liver disease according to Needleman criteria 10. Anthropometric measurements of the children would be taken. Measurement of weight in kg and height in cms will be done with the children wearing light clothing and without footwear. Weight will be rounded off to the closest 0.5 kg with clothing, by using a standard portable weighing machine. Height will be rounded off to the nearest 1 cm without footwear. The BMI or Quetelet Index will be calculated as weight (in kg)/height (in meters2) for all subjects. Abdominal circumference will be measured using a non-stretchable tape above the upper iliac border horizontally. Evaluation of primary cardiovascular risk factors such as systolic blood pressure (SBP), diastolic blood pressure (DBP), high density lipoproteins (HDL) and fasting glucose will be done. Arterial blood pressure will be measured manually by using a mercury sphygmomanometer with a appropriate cuff size for each participant after a period of 5-minute rest and in the supine position. SBP will be determined by the onset of the tapping Korotkoff sound and DBP would be determined after the disappearance of the Korotkoff sound. The average of six measurements (three taken by each of two examiners) with a mercury sphygmomanometer would be used in all analyses. The fourth Korotkoff phase is considered to be the diastolic blood pressure.Consent for the second part of the study would be taken from the parents of the children with fatty liver on ultrasound. Blood biochemistry and virological evaluation would also be done later. Venous Blood samples will be collected and evaluated for AST, ALT, high density lipoprotein-c, triglycerides on a fully automated analyser. The venous blood samples would be collected in the laboratory of the department between 8 to 10 am. For estimation of lipid profile and liver function tests, 3 ml of blood would be collected from each subject after overnight fasting period of 12 hours. Estimation of fasting blood sugar (FBS) would be done by using a medical device (One Touch Glucometer). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) >40 IU/L would be considered as raised levels. Metabolic syndrome would be defined by abnormality of any three of the parameters: fasting glucose >100 mg/dL, triglyceride >110 mg/dL, high-density lipoprotein (HDL) <38 mg/dL, hypertension (blood pressure >95th percentile for systolic blood pressure/diastolic blood pressure/mean arterial blood pressure). 9. Serum ceruloplasmin estimation and Hepatitis B antigen (HBsAg) and Anti-hepatitis C (HCV) assays would be done by ELISA using kits. Statistical analysis would be done using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.). For continuous data, descriptive analyses used would be mean and standard deviation (SD). P-values below 0.05 were considered as significant. IMPLICATIONS: This study will establish the current prevalence of NAFLD and its association with risk factors of metabolic syndrome in children. Early detection of NAFLD and control of risk factors of metabolic syndrome may help in the prevention of progression of NAFLD to chronic liver disease in later years.