الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 32 |  |  |
| | | from | 32 | | |
Abstract
Childhood obesity is an increasing epidemiologic problem that can be considered as a risk factor for adult cardiovascular diseases. Hence research into childhood obesity is of paramount importance in preventing obesity-related mortality and morbidity in adults.
Adipose tissue is recognized as an endocrine organ that secretes bioactive substances known as adipokines.
Retinol binding protein 4 (RBP4) is a recently identified adipokine suggested to link obesity with its comorbidities, especially insulin resistance, type 2 diabetes (T2D), (RBP4) is considered to be the primary carrier of retinol to the tissues. RBP4 secretion in the liver is strongly influenced by abundance of retinol
Resistin is also an adipokine secreted from adipose tissue, which is likely involved in the development of obesity and insulin resistance via its interaction with other organs, as well as affecting adipose tissue function.
In this study we investigated fasting serum retinol,retinol binding protein 4 and resistin in overweight and obese adolescence and healthy non-obese age and sex matched controls our aim is:
1) To detect the level of retinol , retinol binding protein 4 and resistin hormones in overweight and obese adolescents.
2) To identify the relation between retinol, retinol binding protein 4, resistin hormones and BMI in overweight and obese adolescents
3) to study the relationships between RBP4, insulin resistance and weight status in overweight and obese adolescents.
The study included 88 case ,Forty five overweight and obese children and young adolescents were included, 15 males and 30 females, all cases were diagnosed as exogenous obesity with BMI ≥ 85th percentile on Egyptian growth curves 2002 for overweight cases and BMI≥95th percentile for the obese cases Their mean age was 14.9±2.0years, the mean BMI was 33.9±4.7 kg/m2 and the mean body mass index standard deviation score (BMI- SDS) Med IQR was 3.0 (2.6–3.3).
The study also included 43 ages and sex matched healthy subjects 17 males and 26 females, their mean age was 14.7±1.8years, their mean BMI was 19.5±2.9 kg/m2 and the mean BMI- SDS Med IQR was 0.1 (-1.0–1.1)
All cases and control subjects subjected to
1- Informed consent taken from the parents or guardians
2- A complete history taking
3- Complete physical examination: including anthropometric data [height, weight, body mass index, waist circumference, hip circumference, and waist/hip ratio], arterial blood pressure measurement, pubertal assessment,
4- Body composition and fat distribution
5- Investigation:
• Measurement of fasting serum retinol,RBP4 and resistin (ELISA).
• Fasting blood glucose.
• Fasting blood insulin.
• Lipid profile (total cholesterol, triglycerides, LDL-c, HDL-c).
• The homeostasis model assessment method (HOMA-IR) = [fasting insulin (µU/mL) x fasting glucose (mmol/l)/22.5].
The study gave the following results:
- Comparing between the three study groups regarding serum retinol,RBP4 and resistin , no significant difference in Resistin level in the three groups were detected While significant difference in Retinol ,and RBP4 level in the study groups was detected .
- Case group had significantly higher BMI, waist circumference, hip circumference,W/H ratio ,fasting insulin, and HOMA-IR than those of control group.
- Systolic and diastolic BP, RBP4, total cholesterol, triglyceride, of case group were significantly higher than those of control group.
- There were no significant differences among control, case groups for age, sex, puberty, height, , fasting glucose, LDL,SGOT,SGPT
- Serum retinol and RBP4 levels of case group were higher than those of control group wheras no significant difference in serum resistin was found between the three groups.
- No gender difference was found in retinol,RBP4 and resistin.
- There was positive correlation between fasting serum retinol,RBP4 and anthropometric and clinical data (weight SDS, BMI SDS, waist/hip ratio, systolic, and diastolic blood pressure), laboratory data (Fasting serum insulin, HOMA-IR, total cholesterol, LDL-c), body composition data ( body fat percent, fat mass and fat free mass),
- There were significant negative correlations between resistin and weight sds, BMI sds, cholesterol, triglycerides, LDL and TBF% , insulin& HOMA-IR,SBP,DBP,BMR in case group. There were significant positive correlations between resistin and HDL and TBW% in the case group.
CONCLUSION:
1. RBP4 is positivity correlated to serum insulin level, HOMA/IR, and lipid profile, so RBP4 can be used as a marker for insulin resistance and obesity.
2. Studies with large sample size and high power are needed to explain the link between resistin and obesity associated insulin resistance especially in children.
3. Retinol (vitamin A) concentration was positively associated with measures of obesity and that vitamins A have a role on lipid metabolism.