Definizione di Igiene e principi di Epidemiologia 2) 23/10/07 Prof Gianluca Perseghin 10 lezioni Esame orale a partire da Febbraio 2008 Libro di testo: Igiene Generale della Scuola e dello Sport di A Boccia e G Ricciardi Idelson-Gnocchi Ed 1) 16/10/07 Definizione di Igiene e principi di Epidemiologia 2) 23/10/07 Epidemiologia malattie infettive 3) 30/10/07 Epidemiologia malattie cronico degenerative: Obesità 4) 6/11/07 Malattie cardiovascolari e diabete 5) 13/11/07 Tumori 5) 13/11/07 Epidemiologia dello sport 6) 20/11/07 Alimentazione e sport 7) 27/11/07 Infortuni nello sport e osso 8) 4/12/07 Igiene negli impianti sportivi 9) 11/12/07 Impianti natatori artificiali 10) 18/12/07 Tutela sanitaria delle attività sportive e il doping nello sport

Obesità: definizione

Obesità: definizione DXA, Total Body Water, Total Body K, CT, MRI,

Obesità: definizione Peso in kg 75 BMI = = 23.9 (1.77)2 (Altezza in m)2 75 (1.77)2 = 23.9

Obesità: definizione

Waist circumference is a surrogate marker of visceral fat Women >88 cm = Increased risk1 Men >102 cm = Increased risk1 1Lean MEJ, et al. Lancet;1998:351:853–6 cm Slide 5: Waistline circumference is a surrogate marker of visceral fat Waistline circumference, perhaps the simplest of all measurements, provides an accurate assessment of visceral fat mass which has been shown to be a key indicator of risk factors for major cardiovascular disease. A waistline circumference >88 cm in women and >102 cm in men reflects a significantly increased risk of developing many of the co-morbidities associated with obesity. Xenical Slide Kit August 1998 Section 1 5 5

Other measures of obesity Skinfold thickness Bio-electric impedance Body fat distribution by CT or MRI scans Example of a CT scan Slide 6: Other measures of obesity Skinfold thickness, the determination of fat mass by bio-electric impedance and the use of computerised tomography (CT) or magnetic resonance (MRI) scanning may also be used to evaluate obesity. The last two techniques are, however, limited to use in specialist centres and are particularly expensive. Xenical Slide Kit August 1998 Section 1 6 6

In 1990, among states participating in the Behavioral Risk Factor Surveillance System, 10 states had a prevalence of obesity less than 10% and no states had prevalence equal to or greater than 15%. By 1998, no state had prevalence less than 10%, seven states had a prevalence of obesity between 20-24%, and no state had prevalence equal to or greater than 25%. In 2006, only four states had a prevalence of obesity less than 20%. Twenty-two states had a prevalence equal or greater than 25%; Two of these states (Mississippi and West Virginia) had a prevalence of obesity equal to or greater than 30%.

Obesity Trends* Among U.S. Adults BRFSS, 1990, 1998, 2006 (*BMI 30, or about 30 lbs. overweight for 5’4” person) 1990 1998 2006 No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%

Obesità: prevalenza

Obesità = Problema Medico Donne Obesità = Problema Medico Uomini

Body weight regulation Genetic & environmental factors Metabolic factors Diet Physical activity Social factors Energy Intake Expenditure Energy expenditure Resting energy expenditure Postprandial thermogenesis Physical activity

Dispendio energetico Metabolismo a riposo Termogenesi indotta dal cibo Dispendio energetico indotto dall’esercizio fisico

Termogenesi a riposo Tessuto adiposo bruno: ruolo prevalente nella termogenesi dei roditori. Poco rappresentato nell’uomo dopo la prima infanzia Tessuto adiposo bianco: prevalente funzione di deposito. Nell’uomo il tessuto adiposo periviscerale conserva alcune delle caratteristiche metaboliche del tessuto adiposo bruno Muscolo scheletrico: ruolo verosimilmente centrale nella termogenesi dell’adulto

Non-obese Obese Resting energy expenditure Postprandial thermogenesis Physical activity Non-obese Obese kcal/[kg LBM]/day Non-obese Obese kcal/day

Termogenesi indotta dal cibo Dovuta a digestione, assorbimento, metabolizzazione dei nutrienti A parità di energia introdotta, i carboidrati inducono maggior termogenesi dei lipidi La restrizione calorica si accompagna a riduzione della termogenesi indotta dal cibo

man: no evidence for “luxuskonsumption”. Resting energy expenditure Postprandial thermogenesis Physical activity Ravussin E et al. Short-term mixed-diet overfeeding in man: no evidence for “luxuskonsumption”. Am J Physiol 249: E470-E477, 1985.

?? Reduced physical activity (sedentary lifestyle) Resting energy expenditure (REE) Postprandial thermogenesis (PT) Physical activity (PA) ?? Energetic efficiency ?? Reduced physical activity (sedentary lifestyle) Non-obese Obese 25 % REE PT PA PA Non-obese Obese REE PT PA Total energy expenditure

Genetic & environmental factors Metabolic factors Diet Physical activity Social factors Energy Intake Energy Expenditure Energy intake Models of weight gain Models of weight reduction Role of macronutrients Body weight regulation

Models of weight reduction Role of macronutrients Models of weight gain Models of weight reduction Role of macronutrients FFM (kg) Total energy expenditure (kcal/day) non-obese obese weight gain

Models of weight gain Models of weight reduction Role of macronutrients obese Total energy expenditure (kcal/day) non-obese weight reduction FFM (kg)

High carbohydrate meal Models of weight gain Models of weight reduction Role of macronutrients High carbohydrate meal plasma glucose and insulin plasma free fatty acids High fat meal plasma lipids and insulin Glucose oxidation Lipid oxidation plasma glucose Lipid storage plasma lipids

Role of macronutrients Models of weight gain Models of wt reduction Role of macronutrients Lipidi Glucidi Protidi Kcal/day Isocaloric Diet Hypercaloric Intake Oxid Net lipid uptake

Weight Gain ?? Genetic & environmental factors Metabolic factors Diet Physical activity Social factors Energy Intake Energy Expenditure Weight Gain Body weight regulation

? Lipid Oxidation UK adult males Role of Increasing Proportion of Dietary Fat Higher energy density of high-fat foods Delayed gastric empting satiation intervenes too late UK adult males Low fat diet Obesity virtually absent High fat diet Minor proportion of obesity Zurlo F et al. Low ratio of fat to carbohydrate oxidation as predictor of weight gain: studyof 24-hour RQ. Am J Physiol 59: E650-E657, 1990 Lipid Oxidation ?

Ruolo Endocrino del Tessuto Adiposo Leptin Adiponectin Resistin Omentin Vistafin RBP4 alpha-TNF, IL6, IL1beta

Sensing of energy balance Adaptation Increased nutrients’ availability Insulin resistance Increased Body Weight Sensing of energy balance

malattie neurologiche fattori genetici disturbi dell’umore disturbi d’ansia abitudini alimentari COMPORTAMENTO - iperfagia prandiale - grignottage - disturbo da alimentazione incontrollata obesità da farmaci fattori genetici malattie endocrine stile di vita sedentario stile di vita sedentario forme genetiche disturbi mentali aumentato introito alimentare malattie neurologiche ridotto consumo energetico Essenziale Secondaria OBESITA’

Consequences of obesity Stroke Respiratory disease Cardiovascular risk factors Heart disease Diabetes Gall bladder disease Osteoarthritis Hormonal abnormalities Cancer Slide 13: Consequences of obesity The slide illustrates the most common co-morbidities and risk factors associated with obesity. These range from type 2 diabetes, osteoarthritis, cancer of the breast and prostate, major cardiovascular disease, stroke and respiratory disease to gallstones and gout. In short, obesity predisposes patients to a variety of diseases and, accordingly, should be considered by the medical profession as a serious, potentially life-threatening condition rather than an affliction brought on by lack of self-control. Hyperuricaemia and gout Xenical Slide Kit August 1998 Section 1 13 13

Obesità = Problema Medico Donne Obesità = Problema Medico Uomini

Obesità e funzione CV Cardiopatia Ipertensiva Ipertrofia Cardiopatia Ischemica

Obesità and T2DM

Obesità e alterazioni funzione respiratoria

Obesità e ghiandole endocrine/ metabolismo Calcolosi della colecisti: supersaturazione di colesterolo nei sali biliari soprattutto a digiuno Normale funzionalità tiroidea (recettori T3 ? Ridotti in monociti umani) Normale funzionalità corticale surrenale nel 90% diagnosi differenziale con Sindrome di Cushing test soppressione al desametazone overnight dubbio (consigliato il test “lungo”) Growth Hormone ridotto con IGF 1 normale Funzionalità testicolare Testosterone tot ridotto binding globulin molto ridotta free-testosterone aumentato Funzionalità ovarica nella norma; diagnosi differenziale con Ovaio Cistico

Evidence-based medicine Obesità: terapia Evidence-based medicine Hypo-caloric Diets Behavioral therapy Exercise Surgery

Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin Diabetes Prevention Program Research Group NEJM 346:393, 2005

Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin Diabetes Prevention Program Research Group NEJM 346:393, 2005

Randomized Trial of Lifestyle Modification and Pharmacotherapy for Obesity Wadden TA, NEJM 353: 2111, 2005

Esercizio fisico Aumento del Consumo energetico Aumento dispendio energetico da esercizio fisico Aumento metabolismo basale Aumento termogenesi da cibo (?) Aumento del Consumo energetico