Obesity is a state of excess adipose tissue mass. BMI ≥30 obesity BMI ≥ 25 overweight abdominal (android or apple-shaped) obesity generalized (gynoid or 'pear-shaped) obesity

Obesity Many complications of obesity, as insulin resistance, diabetes, hypertension, hyperlipidemia, are linked more strongly to intraabdominal than to overall adiposity.

Obesity Prevalence 30.5% American adult population had obesity 64% of U.S. adults were overweight 4.7% of the population Extreme obesity Obesity is more common in women and in the poor.

Factors control the appetite

Factors released from the adiposity tissue

Obesity Etiology The environmental factors plays a key role in obesity Evidence Famine protect against obesity Recent and rapid increase in the prevalence of obesity

Obesity Factors increase prevalence Increasing energy intake ↑ Portion sizes ↑ Snacking and loss of regular meals ↑ Energy-dense food (mainly fat) ↑ Affluence Decreasing energy expenditure ↑ Car ownership ↓ Walking to school/work ↑ Automation; ↓ manual labour ↓ Sports in schools ↑ Time spent on video games and watching

genes influence the susceptibility to obesity The genetic factors genes influence the susceptibility to obesity Evidence: Obesity is commonly seen in families identical twins have very similar BMIs Obesity is part of specific genetic syndromes (Laurence-moon biedl)

Obesity Gene mutation detected ob gene coding the peptide leptin. High leptin levels decrease food intake increase energy expenditure. Db gene coding leptin receptor.(leptin resistant) POMC coding proopiomelanocortin ( neuropeptides)

Obesity To date, there is no evidence to suggest that mutations in the leptin or leptin receptor genes play a prominent role in common forms of obesity

Obesity Secondary causes (reversible) Endocrine factors Hypothyroidism Hypothalamic tumours or injury Cushing's syndrome Insulinoma Drug treatments Corticosteroids Tricyclic antidepressants Sulphonylureas Sodium valproate Oestrogen-containing contraceptive pill β-blockers

Obesity Complications Obesity is associated with an increase in mortality, mostly due to cardiovascular causes Mortality rates rise as obesity increases Obesity related 300,000 deaths per year. Life expectancy shortened by( 2–5 years) moderately obese BMI > 45 may lose 13 years of life.

Obesity Complications Metabolic complications: Insulin resistance, diabetes type 2, hyperlipidemia Most obese individuals do not develop diabetes. 80% of patients with type 2 diabetes mellitus are obese Increase the risk coronary heart disease, Stroke

Obesity Metabolic syndrome Central obesity: waist circumference ≥ 94 cm (male) ≥ 80 cm (female) AND any two of the following Raised triglycerides: > 150 mg/dL, Reduced HDL cholesterol < 40 mg/dL in males, < 50 mg/dL in females Raised blood pressure systolic BP > 130 or diastolic BP >85 mm Hg Raised fasting plasma (FPG): >100 mg/dL or previously diagnosed type 2 diabetes

Obesity 2. Cardiovascular Disease coronary disease stroke congestive heart failure (CHF) atherogenic lipid profile increase (LDL) ,VLDL, and triglyceride. decreased HDL Hypertension increased peripheral resistance, cardiac output increased sympathetic nervous system tone increased salt sensitivity, and insulin-mediated salt retention

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Obesity 3. Endocrine Disorders : In men : plasma testosterone often reduced estrogen levels increased Gynecomastia may be seen. In women: menstrual abnormalities increased androgen increased conversion of androgen to estrogen. oligomenorrhea polycystic ovarian syndrome (PCOS)

Obesity 4. Pulmonary Disease: Exertional dyspnoea Sleep apnoea Respiratory failure (Pickwickian syndrome) caused by (restrictive ventilation) reduced chest wall compliance decreased functional residual capacity and expiratory reserve volume

Obesity 5. Gastrointestinal  : Gallstones: cholesterol gallstones caused : enhanced biliary secretion of cholesterol supersaturation of bile nonalcoholic fatty liver disease : simple steatosis steatohepatits cirrhosis Gastroesophageal reflux disease:

6. Musculoskeletal : increased risk of osteoarthritis Obesity 6. Musculoskeletal : increased risk of osteoarthritis 7.Skin : Skin infection (submammary Candida) varicose vein 8. cancer: colorectal CA, uterine CA, breast CA 9. Psychological : depression, Social stigmatization 10. Socioeconomic : low income, unemployment

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