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fenfluramine-phentermine (Fen-Phen) were found to cause valvular heart disease and primary pulmonary hypertension (withdrawn)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