Definizione di Igiene e principi di Epidemiologia 2) 23/10/07

Presentazione sul tema: "Definizione di Igiene e principi di Epidemiologia 2) 23/10/07"— Transcript della presentazione:

1 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

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3 Obesità: definizione

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

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

6 Obesità: definizione

7 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 Section 1 5 5

8 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 Section 1 6 6

9 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%.

10 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% %–14% %–19% %–24% %–29% ≥30%

11 Obesità: prevalenza

12 Obesità = Problema Medico
Donne Obesità = Problema Medico Uomini

13 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

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

15 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

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

17 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

18 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.

19 ?? 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

20 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

21 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

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

23 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

24 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

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

26 ? 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 ?

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

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

29 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’

30 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 Section 1 13 13

31 Obesità = Problema Medico
Donne Obesità = Problema Medico Uomini

32 Obesità e funzione CV Cardiopatia Ipertensiva Ipertrofia Cardiopatia
Ischemica

33 Obesità and T2DM

34 Obesità e alterazioni funzione respiratoria

35 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

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

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

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

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

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

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