Obesity

Definitions

·         20% or greater above ideal body weight (IBW) (Met. Life Ins. tables); 170% of IBW or BMI > 40 is morbid obesity

·         Most practical index is BMI (body mass index) = weight/height²(kg/m2 )

o   BMI < 20 or > 27 leads to increased health risk

Epidemiology

15-25% of North American adults

Possible Risk Factors

• Increasing age
• Genetic - variations in energy expenditure
• Behaviour/lifestyle - diet and exercise
• Secondary causes

o   Endocrine: e.g. Cushing’s syndrome, polycystic ovarian disease (PCOD)

o   Drugs: e.g. antidepressants, antiepileptics and antipsychotics

• Hypothalamic injury: trauma, surgical, lesions in ventromedial or paraventricular median nucleus

Pathophysiology- positive energy balance: energy input > energy output

Complications

Cardiovascular

• Hypertension, CAD, CHF, varicose veins, sudden death from arrhythmia

Respiratory

• dyspnea, sleep apnea, pulmonary embolus, infections

Gastrointestinal

• Gallbladder disease, gastroesophageal reflux disease (GERD), fatty liver

Musculoskeletal

• Osteoarthritis

Endocrine/metabolic

• impaired glucose tolerance (IGT) to type 2 DM, hyperuricemia, hyperlipidemia

• PCOD, hirsutism, irregular menses, infertility

Increased risk of neoplastic diseases

• Endometrial, post-menopausal breast, prostate, colorectal cancers

Treatment

General recommendations

• Treatment should be based on medical risk

• Safest and best therapy is a comprehensive approach including caloric restriction,increased physical activity and behaviour modification

Diet

• Caloric restriction with a balanced diet with reduced fat, sugar and alcohol

Exercise

Behavior modification

• Individual or group therapy

• Self-monitoring, stimulus control, stress management, cognitive change, crisis intervention

Drug therapy

• serotonergic-appetite suppressants fenfluramine-phentermine (Fen-Phen) were found to cause valvular heart disease and primary pulmonary hypertension (withdrawn)

• Pancreatic lipase inhibitor: orlistat (Xenical) found to be mildly to moderately effective 

Surgical therapy

• gastroplasty (“stomach stapling”) is treatment of last resort (controversial)

• Liposuction

• Weight loss is regained by fat accumulation at the same site or elsewhere