Obesity By: Dr. Wael Thanoon C.A.B.M. College of medicine,Mosul University.

Obesity Obesity is widely regarded as a pandemic, with potentially disastrous consequences for human health. There is increasing public awareness of the health implications of obesity. Many patients will seek medical help for their obesity, others will present with one of the complications of obesity, and increasing numbers are being identified during health screening examinations

Complications of obesity: 1. 'Metabolic syndrome‘:Type 2 diabetes, Hypertension, dyslipidaemia and central obesity which lead to increase risk of Coronary heart disease,stroke, and complication of diabetes. 2. Liver fat accumulation:Non-alcoholic steatohepatitis(NASH),cirrhosis. 3. Restricted ventilation:Exertional dyspnoea, Sleep apnoea, Respiratory failure (Pickwickian syndrome). 4. Mechanical effects of weight:Urinary incontinence,Osteoarthritis,Varicose veins.

5. Increased peripheral steroid interconversion in adipose tissue:Hormone-dependent cancers (breast, uterus),Polycystic ovary syndrome (infertility, hirsutism) 6. Others:Psychological morbidity (low self- esteem, depression), Socioeconomic disadvantage (lower income, less likely to be promoted), Gallstones, Colorectal cancer, Skin infections (groin and submammary candidiasis; hidradenitis).

For some complications of obesity, the distribution rather than the absolute amount of excess adipose tissue appears to be important. Increased intra-abdominal fat causes 'central' ('abdominal', 'visceral', 'android' or 'apple-shaped') obesity, which contrasts with subcutaneous fat accumulation causing 'generalised' ('gynoid' or 'pear- shaped') obesity; the former is more common in men and is more closely associated with type 2 diabetes, the metabolic syndrome and cardiovascular disease.

Aetiology : Accumulation of fat results from a discrepancy between energy consumption and energy expenditure which is too large to be defended by the hypothalamic regulation of BMR. A continuous small daily positive energy balance of only MJ ( kcal; < 10% of intake) would lead to weight gain of 2-20 kg over a period of 4-10 years. Given the cumulative effects of subtle energy excess, body fat content shows 'tracking' with age such that obese children usually become obese adults. Weight tends to increase throughout adult life, as BMR and physical activity decrease.

Reversible causes of obesity and weight gain : 1. Endocrine factors: Hypothyroidism Cushing's syndrome Insulinoma Hypothalamic tumours or injury 2. Drug treatments: Tricyclic antidepressants Sulphonylureas Oestrogen-containing contraceptive pill Corticosteroids Sodium valproate β -blockers

Quantifying obesity with body mass index (weight/height2): BMI (kg/m2)ClassificationRisk of obesity comorbidity Normal rangeNegligible OverweightMildly increased > 30.0Obese Class IModerate Class IISevere > 40.0Class IIIVery severe

Management:

Management : 1) Lifestyle advice :Regular eating patterns and maximising physical activity are advised. 2) Weight loss diets : 3) Drugs:Currently recommended: A. Orlistat:a Pancreatic lipase inhibitor B. Sibutramine,a Serotonergic in CNS. 4) Surgery:'Bariatric' surgery to reduce the size of the stomach is by far the most effective long-term treatment for obesity and is the only anti-obesity intervention that has been associated with reduced mortality. Bariatric surgery should be contemplated in motivated patients who have very high risks of complications of obesity, in whom extensive dietary and drug therapy has been inadequately effective.

5) Treatment of additional risk factors : Obesity must not be treated in isolation and other risk factors must be addressed, including smoking, excess alcohol consumption, diabetes mellitus, hyperlipidaemia and hypertension.