Malnutrition in a child: Obesity Flashcards
Define obesity.
BMI > 85th centile (overweight) or > 95th centile (obese) for sex and age
Explain the aetiology of obesity.
Accumulation of adipose tissue when total energy intake > total energy expenditure. Multifactorial.
What are risk factors for obesity?
Diet: Quantitative terms and relative fat content
Psychosocial: Lifestyle, poor physical activity (sedentary lifestyle= decrease energy expenditure), food preferences, personal/family structure and stability
Genetic predisposition: Leptin deficiency (obesity, hyperphagia and insulin resistance). Concordance rates for obesity are increased in monozygotic versus dizygotic twins
Genetic syndromes: Prader-willi syndrome, Lawerence-Moon-Biedl syndrome, muscular dystrophy (late presentation), turner syndrome, trisomy 21
Hormonal diseases: GH deficiency/resistance, hypothyroidism, PCOS, prolactin-secreting tumours, precocious puberty
Acquired syndromes: Cushing syndrome
Associated/Related: Obese parents or siblings, maternal diabetes
What is the pathophysiology of leptin deficiency causing obesity?
Leptin conveys a signal from adipose tissue to hypothalamic nuclei that integrate whole-body fuel metabolism, informing those nuclei about the magnitude of fuel reserves. With decreased leptin there is an incorrect perception of insufficient energy availability and therefore activation of pathways to restore fuel depots occurs.
Summarise the epidemiology of obesity.
10% of 5-17 year olds are overweight with 2-3% being obese (WHO international obesity task force). Underlying disease roughly 5% of cases.
What are the signs and symptoms of obesity?
Dietary history including details of physical activites. Psychosocial history. Screen for potential complications, in addition to specific syndromes associated to obesity. Detailed examination of stigmata of disease.
What are appropriate investigations for obesity?
Nutritional assessment: BMI and triceps skinfold thickness
Bloods: Cholesterol and triglyceride level. Endocrine assays for specific conditions e.g. adrenal disease
Urine: Glucosuria (type 2 diabetes)
Radiology: USS/CT/MRI head for specific conditions/syndromes
What is the management for obesity?
Exclusion of underlying medical condition. Early intervention is important. Confidentiality, self-esteem building and development of a positive body image are important factors. Parental involvement vs patient’s independence. Multicomponenet interventions that address lifestyle within the family and social settings.
What are the therapeutic aims for managing obesity?
- Gradual reduction of excessive weight (growth needs should be included).
- Dietary counselling with vitamin and micronutrient supplementation. Availability of healthy food.
- Behaviour modification.
- Stepwise physical activity programe; increase activity and decrease inactivity.
- Adherence to the plan which requires strong support for the child and family.
- Fat intake < 30% of diet (WHO).
What is the surgical management for obesity?
Various bariatric surgical procedures have been used in adults. Possibility of adolescent application but not currently recommended.
What are complications associated with obesity?
- Psychosocial: Peer discrimination, bullying, decreasedd college acceptance, social isolation.
- Growth: Advanced bone age, increased height, early menarche.
- Respiratory: Sleep apnoea, pickwickian syndrome (obesity hypoventilation syndrome).
- Orthopaedic: Slipped capital femoral epiphysis, Blount disease (idiopathic varus bowing of tibia).
- Metabolic syndrome X: Characterised by insulin resistance and atherogenic dyslipidemia secondary to increased triglycerides/decrease HDL cholesterol and hypertension.
- Hepatobiliary: Hepatic steatosis, gallstones.
What is the prognosis of obesity?
Obese children are likely to be obese in adulthood. Patients with metabolic syndrome X are at significant risk of atherosclerosis. There is also an increasing incidence of Type II diabetes.
