Definition of Obesity body mass index BMI weight

Definition of Obesity (body mass index) BMI = weight (kg)/ height(m)2 WHO classification of adult categories of BMI Caucasian Asia Classification BMI (kg/m 2) Underweight <18. 5 Normal range 18. 5 -24. 9 18. 5 -22. 9 Overweight (pre-obese) 25 -29. 9 23 -24. 9 Obese 30 25 Criteria and classification of obesity in Japan and Asia-Oceania Asia Pacific J Clin Nutr (2002) 11(Suppl): S 732–S 737

Definition of Obesity Children BMI percentile > 5 th and < 85 th = normal weight for height ≥ 85 th and < 95 th = at risk for overweight ≥ 95 th = obese Weight for height ≥ 120 th percentile = obesity ≥ 110 th percentile < 120 = overweight

Trends in the prevalence of overweight Children’s ages (in years) Australia: 2– 18, Brazil: 6– 18, Canada: 7– 13, China: 6– 18, Spain: 6– 14, UK: 7– 11, USA: 6– 18. The International Association for the Study of Obesity. obesity reviews 5 (Suppl. 1), 4– 85

Complications of childhood obesity Childhood obesity: public-health crisis, common sense cure Lancet 2002, 360: 473– 82

Pulmonary involvement in obesity: overview n Lung function in obesity n Asthma and obesity n Obstructive sleep apnea and obesity n Obesity hypoventilation syndrome n Postoperative pulmonary complications in obese patients

Lung function in obesity n n n Lung volume q FRC, ERV, TLC, VC, TV q RV Lung mechanics q respiratory system compliance q work of breathing (WOB) Flow limitation q n FEV 1 Others: diffusion capacity (DLco) ventilation-perfusion mismatch O 2 consumption and CO 2 production

Obesity and asthma n Consistent association between obesity and asthma n Temporal association - Obesity precedes the development of asthma n Dose-response association - the greater the obesity, the greater the effect on asthma Obesity and asthma; AJRCC 2006: 174, 112 -9 Obesity and asthma: cause for concern; Curr Opin Pharm 2006, 6: 230 -6 Obesity and asthma, what are the link? ; Curr Opin Allergy Clin Immunol 2005, 5: 185 -93

Obesity and asthma : pathophysiology Obesity and Asthma, Am J Respir Crit Care Med 2006 ; 174. 112– 119,

Obesity and asthma: pathophysiology Inflammatory factors Obesity and Asthma, Am J Respir Crit Care Med 2006; 174. 112– 119

Obesity and asthma: pathophysiology Mechanical factor Systemic inflammation Obesity Shared genetic factor Gender GERD

Obesity and asthma Studies in children or adolescents • Inconsistent results in the asthma-obesity relation • No convincing evidence for a gender difference Prospective studies of obesity and asthma among paediatric patients Reference Follow-up (years) Age (Year) Sample size No. with asthma Adjust for Physical activity Is increased BMI associated with asthma Chinn & Rona G and et al. God et al. Castro-Rodriguez et al. Camago et al. 12 4 5 -6 7 -18 6 -14 6 -11 6744 MF 3792 MF 9828 MF 1288 MF Approx 285 288 805 - No No No Yes (M only) Yes (F only) Yes (11 years/F only) - 9 -14 16862 MF 2212 No yes Paediatric asthma and obesity, Paed Resp Rev 2006; 7, 233 -8 Obesity and asthma; AJRCC 2006: 174, 112 -9

Obstructive Sleep Apnea (OSA) and Obesity n OSA : Disorder of breathing during sleep characterized by prolonged partial upper airway obstruction / intermittent complete obstruction that disrupts normal ventilation during sleep and normal sleep pattern. (ATS. AJRCC. 1996; 153: 866 -878) n Prevalence of OSA in obesity 37%- 46% n Correlation between degree of obesity and apnea index Mallory GB. et al. J Pediatr. 1989: 115(6): 892 -7 Silvestri JM. et al. Ped Pulm. 1993; 16(2): 124 -9 Marcus CL. et al. Ped Pul. 1996; 21(3): 176 -83

OSA: History * Physical examination Nighttime n n snoring, labored breathing, paradoxical breathing, restless sleep, apnea, cyanosis, enuresis Daytime n n n adenotonsillar hypertrophy, mouth breathing nasal obstruction adenoid facies systemic hypertention prominent 2 nd heart sound Polysomnography(PSG(

OSA and obesity : pathophysiology OBESITY Pharyngeal fat ↑ Abdominal and chest wall fat ↑ Lung volumes ↓ UA caliber ↓ UA compliance ↑ UA collapsibility ↑ OSAS Obesity and weight loss in obstructive sleep apnea: a critical review. Sleep 1996; 19: 104 -115

OSA and obesity : pathophysiology n Increased pharyngeal fat n Increased chest wall and abdominal fat n Tonsil or adenoid enlargement n Shared genetic factors between OSA and obesity • Respiratory complications of obesity. Int J Clin Pract 2004; 58: 573 -80. • Obesity and obstructive sleep apnea in children. Paediatr Respir Rev 2006; 7: 247 -59. • Obstructive sleep apnea, morbid obesity, and adenotonsillar surgery: a review of the literature. Int J Pediatr Otorhinolaryngol 2005; 69: 1475 -82.

OSA and obesity : Treatment n Weight reduction n CPAP or BIPAP n Adenoidectomy and/or tonsillectomy Postoperative care in ICU n RDI ≥ 40 n RDI < 40 accompanied by desaturation nadir < 80% n Presence of cardiac sequelae from OSA Obstructive sleep apnea, morbid obesity, and adenotonsillar surgery. Int J Pediatr Otorhinolaryngol. 2005 Nov; 69(11): 1475 -82

Obesity Hypoventilation Syndrome n Definition: Obesity and awake arterial hypercapnia (Pa. CO 2 >45 mm. Hg) in the absence of other known causes of hypoventilation n Prevalence: 1 -3% of obese children n Risk factor: morbid obesity

Obesity Hypoventilation Syndrome n n n Sleep-related breathing disorder Hypersomnolence, fatigue Morning headache Hypoventilation: Pa. CO 2>45 mm. Hg Polycythemia Cor pulmonale

Obesity Leptin Insensitivity ? Impaired Respiratory System Mechanics Increased Work of Breathing Increased Ventilatory Drive Normal Ventilation, Eucapnia Normal or Diminished Ventilatory Drive Hypoventilation, Hypercapnia Obstructive Sleep Apnea Maintain Normal Ventilation Eucapnia Hypoventilation Severe Steep Hypoxemia Severe Steep Fragmentation Hypercapnia The obesity hypoventilation syndrome. Am J Med 2005; 118: 948

Obesity Hypoventilation Syndrome: treatment n Weight reduction n CPAP or BIPAP n Adenoidectomy and/or tonsillectomy Reversibility of hypercapnia to normal Obesity and obstructive sleep apnea in children. Paed resp rev. 2006; 7: 247

Postoperative pulmonary complications in obese patients n n Atelectasis: obesity, anesthesia Pulmonary embolism : severe obesity, OHS, decreased mobility n Respiratory failure Postoperative care n n Closed monitoring Early mobilization Chest physiotherapy Semiupright position Pulmonary complications of obesity. Am J Med sci 2001; 321: 249

Pulmonary involvement in obesity PFT OSA Asthma OHS

PAEDIATRIC RESPIRATORY REVIEWS (2006) 7, 233 -238 Paediatric asthma and obesity Review of controlled trials on the benefits of exercise conditioning in paediatric in patients with asthma Reference Subjects (n) Controls (n) Fitch et al. 70 Orenstein et al. 71 Sevonius et al. 72 Graff- Lonevig et al. 73 Chai et al. 74 Vamay et al. 75 46 23 25 11 80 7 10 H 13 25 9 10 7 Fitness measurement and trend PWA VO 2 & PWC PWA VO 2 Fitness VO 2 and Vth Time (weeks) 20 16 12 -16 80 40 12 increased decreased ; unchanged; PWC peak word capacity at a heart rate of 170 beatsiminc, VO 2, maximum oxygen consumption Vth, ventilatory threshold; H, healthy.

Comorbidities Related to Overweight in Youth Metabolic Type 2 DM Metabolic syndrome Orthopedic Psychological Depression Poor quality of life Neurological Pseudotumor cerebri Slipped capital femoral epiphysis Hepatic Nonalcoholic fatty liver disease Blount’s disease Nonalcoholic steatohepatitis Cardiovascular Dyslipidemia Hypertension Left ventricular hypertrophy Atherosclerosis Pulmonary Obstructive sleep apnea Asthma Central hypoventilation syndrome Renal Proteinuria

A n Tidal breathing asthma B Obesity FRC Large cyclic strains on ASM n Peribronchial pressure Tidal Breathing ASM cells compliant n Small cyclic strains on ASM cells stiff n ASM cells long, airway caliber large ASM cells short, airway caliber narrowing

OSA n The increased prevalence and severity of childhood obesity has translated into increases in the prevalence of obesity-associated morbidities. n Among the multiple morbidities associated with obesity, OSA and OHS should be considered and evaluated. n The classic presentation of children with OSAS as underweight children with adenotonsillar hypertrophy is now being substantially replaced by patients being overweight. n Obese children are at increased risk for developing sleep-disordered breathing and the severity of OSAS is at least partially explained by the degree of obesity. n Obstructive sleep apnea may represent an important contributor to the association between obesity and metabolic and cardiovascular morbidities, by amplification of inflammatory cascades.

Obstructive sleep apnea and obesity: pathophysiology n Increased pharyngeal fat n Increased chest wall and abdominal fat n Tonsil or adenoid enlargement n Leptin resistance n Shared genetic factors between OSA and obesity • Respiratory complications of obesity. Int J Clin Pract 2004; 58: 573 -80. • Obesity and obstructive sleep apnea in children. Paediatr Respir Rev 2006; 7: 247 -59. • Obstructive sleep apnea, morbid obesity, and adenotonsillar surgery: a review of the literature. Int J Pediatr Otorhinolaryngol 2005; 69: 1475 -82.

Obesity Hypoventilation Syndrome Obesity > Leptinresistance Leptin Hypercapnia Leptinresistance Increases in Visceral fat Apneas (intermitent Hypoxemia) OSA predisposition

Inflammatory factors Figure 1. In obesity, visceral adiposity is correlated with circulating levels of proinflammatory cytokines, and adipose tissue propagates inflammation both locally and systemically, in part through recruitment of macrophages via chemokines such as monocyte chemoattractant protein-1 (MCP-1) and in part via elaboration of cytokines and chemokines such as (but not limited to) leptin, interleukin 6 (IL-6), tumor necrosis factor � (TNF-�), transforming growth factor � 1 (TGF-� 1), eotaxin. and Although the precise relationship between obesity and asthma remains to be determined, modifications of atopy, lung development, Th 1–Th 2 balance, immune responsiveness, and airway smooth muscle have been hypothesized to be mechanisms by which obesity might increase asthma risk or modify asthma phenotype. CRP � C-reactive protein. Obesity and Asthma, David A. Beuther, Scott T. Weiss, and E. Rand Sutherland Am J Respir Crit Care Med Vol 174. pp 112– 119, 2006