11/18/2013 Outline State of knowledge (evidence base) Sedentary - PDF document

11/18/2013 Outline • State of knowledge (evidence base) – Sedentary behaviour (too much sitting ) as a unique public health problem – paradigm shift • Current & future research directions towards Is Sitting the new smoking? building the evidence-base in relation to sitting – Controlled laboratory studies Professor David Dunstan Head – Physical Activity ARC Future Fellow Baker IDI Heart & Diabetes Institute Melbourne, Australia Adjunct Professor - UWA David.Dunstan@bakeridi.edu.au Baker IDI Heart and Diabetes Institute Acknowledgements • Prof Neville Owen, Dr Alicia Thorp, Prof Bronwyn Kingwell, Dr Robyn Larsen, Dr Brigid Lynch, Beth Howard : Baker IDI Heart and Diabetes Institute Dr Genevieve Healy Prof Elizabeth Eakin Prof Jo Salmon • Dr Genevieve Healy, Prof Elizabeth Eakin, Dr Elisabeth Winkler, Dr Paul Gardiner, Dr Bronwyn Clark : The University of Queensland • Professor Jo Salmon : Deakin University Beth Howard • Australian Research Council • Victorian Health Promotion Foundation Dr Alicia Thorp Dr Brigid Lynch Prof Neville Owen Population Health – Through a Sedentary Behaviour Lens The problem of “ Too much sitting ” Owen N, Healy GN, Matthews CE, Dunstan DW. Exerc Sports Sci Rev 2010 Volume 38: 105-113 Commentary: Medical Hazards of Prolonged Sitting Page: 101-102 1

11/18/2013 Current Public Health Problem – The “Flat Line Issue” From Occupations to Exercise to Active Living 1950 1960 1970 1980 1990 2000 2010 Active Living Occupational Exercise Activity Physical Sedentary Activity Behaviour Morris, et al. Lancet . 1953;265:1053-7. Blair SN, et al. Am J Clinic Nutri. 2004;79:913S − 920S. Sallis JF, et al . Am J Prev Med. 2005;28:93S−95S. Dunstan DW, et al .Diabetes Care. 2004;27:2603−2609. Australian Bureau of Statistics. National Health Survey 2004 – 05 . Modern Society: Minimising Daily Muscular Activity! The Sobering Reality Then Now Meet NHANES 2005-2006 Transport The Rare & Potentially Extinct Creature Domestic Work Source: Tucker et al. (2011) Am J Prev Med: 40: 454-461 Our technologically advanced, ‘sitting orientated’ society Too much sitting: a unique health problem – right     under our noses? Work on Breakfast Transport computer Watch TV 15 mins 3.5 hrs From work 4 hrs 45 mins Lunch Awake Sleep 30 mins Transport to 7 am 11pm work 45 mins Evening meal 30 mins Work on computer Exercise – 30 min 4 hrs Sitting Opportunities 15.5 hrs 2

11/18/2013 Device-Based Measurement of Movement What Is Sedentary Behaviour? and Posture Inclinometer Accelerometer Any waking behaviour characterized by an energy expenditure ≤1.5 METs while in a sitting or reclining posture Sedentary Behaviour Research Network (SBRN) 2012 From whose output The ‘market dominator’ we can derive from whose output posture-based indices (counts of less than 100 of ‘sitting’ time pm) we infer ‘sedentary’ time Device-measured sitting time The Population ‘Reality’ Pie Chart You Can Be ‘Active’, But Mostly Sit The ‘Active’ Couch Potato Activity Energy Morning Intensity Expenditure Moderate/vigorous Very High Time (minutes) Light Night Sedentary Very Low Mean mod-to-vigorous time = 31 mins/day % Waking hours spent in Sedentary = 71% Time to re-think the physical activity paradigm 3

11/18/2013 The ‘Breaks In Sedentary Time’ Hypothesis Prolonged Sitting - Not a New Concern • ‘Breaking - up’ sedentary time (frequent transitions from sitting to standing) has beneficial associations with health outcomes “...those who sit at their work and are therefore (independent of sedentary time) called 'chair workers,' such as cobblers and tailors, suffer from their own particular diseases ... [T]hese workers ... suffer from “Prolonger” “Breaker” general ill-health and an excessive accumulation of unwholesome humors caused Sedentary by their sedentary life” CPM < 100 “ All sedentary workers ... suffer from the itch, Not sedentary are a bad colour, and in poor condition ... for CPM 100+ when the body is not kept moving the blood becomes tainted, its waste matter lodges in the skin, and the condition of the whole body deteriorates ”. (1700) Bernadino Rammazzini 1633-1714 De Morbis Artificum Diatriba “Disease of Workers” Healy GN, Dunstan DW et al. Diabetes Care 2008; 31: 661-666 BIOLOGICAL GRADIENT PLAUSABILITY TEMPORAL & RELATIONSHIP COHERENCE SITTING SITTING STRENGTH OF STRENGTH OF EXPERIMENTAL ASSOCIATION/ ASSOCIATION/ EVIDENCE CONSISTENCY CONSISTENCY Source: Bradford-Hill A. Source: Bradford-Hill A. 1965 Proc of Royal Soc 1965 Proc of Royal Soc Med 58: 295-300 Med 58: 295-300 Causality Causality Sedentary (sitting) Behaviours & All-Cause Mortality – Meta Analysis TEMPORAL RELATIONSHIP SITTING STRENGTH OF ASSOCIATION/ CONSISTENCY Source: Bradford-Hill A. 1965 Proc of Royal Soc 49% ↑ RR Med 58: 295-300 Causality Source: Wilmot E.G et al. Diabetologia 2012; 55: 2895-2905 4

11/18/2013 TV Viewing and Reduced Life Expectancy Sedentary Behaviour and Health Outcomes Associations reported from prospective studies: 1996-2011 Thorp et al. Am J Prev Med 2011 Every hour of TV from age 25 reduces your life Obesity risk/incidence: expectancy by 22 minutes Weight gain: Veerman et al 2011 Br J Sp Med Diabetes: Cancer: Cardiovascular disease: Mortality (all-cause & CVD): +ve association mediated by BMI / one gender no association Source: Veerman L et al. British J Sports Med 2011 BIOLOGICAL Prolonged Sitting GRADIENT Sun Exposure TEMPORAL Then Now RELATIONSHIP SITTING STRENGTH OF ASSOCIATION/ CONSISTENCY ? Source: Bradford-Hill A. 1965 Proc of Royal Soc Med 58: 295-300 Causality Sitting Time and All-Cause Mortality BIOLOGICAL GRADIENT Risk in 222,497 Australian Adults PLAUSABILITY TEMPORAL & Hidde P van Der Ploeg, Tien Chey, Rosemary J Korda, Emily Banks, Adrian Bauman RELATIONSHIP COHERENCE Arch Intern Med. 2012; 172 (6) : 494-500 Sedentary Behaviour Adjusted for: STRENGTH OF EXPERIMENTAL age, sex, education, ASSOCIATION/ EVIDENCE marital status, CONSISTENCY urban/rural residence, physical activity, BMI , smoking Source: Bradford-Hill A. 1965 Proc of Royal Soc Med 58: 295-300 Causality 5

11/18/2013 The ‘ Circulatory ’ Perils of Too Much Sitting Sitting Induces Muscular Inactivity • Limited mobility = Less demand on circulatory system → reduced blood flow • Insufficient blood flow » Pooling of blood in the lower limbs » Swollen or numb legs and eventually varicose veins » Accelerates muscle fatigue » Reduces the efficiency of the body’s regulatory processes CONDITION 1: A single bout of prolonged sitting Standardised mixed meal: ~75g CHO and ~50g Fat Blood sample: glucose, insulin, triglycerides, FFA ’ s Muscle and adipose tissue Dunstan et al. (2012) Diabetes Care -2 -1 0 1 2 3 4 5 hrs biopsy (optional) 35: 976-983 2012 EXPERIMENTAL SET UP ACTIVPAL PROFILE AIM: To examine the acute effects of postprandial glucose and insulin levels of uninterrupted sitting compared with sitting interrupted by brief bouts of light- or moderate-intensity walking CONDITIONS 2 & 3: Sitting + light/moderate-intensity activity bouts Results: Glucose Light-intensity walking (2mins): Treadmill Speed = 3.2 km/hr > 24%  Moderate-intensity walking (2mins): Treadmill Speed = 5.8-6.4 km/hr -2 -1 0 1 2 3 4 5 hrs EXPERIMENTAL SET UP ACTIVPAL PROFILE Dunstan DW et al. (2012) Diabetes Care 35: 976-983 2012 6

11/18/2013 NHMRC Centre of Research Excellence (2014-2018) Exposure beyond one day Length of breaks – short vs. long-term Sitting Time and Chronic Disease Prevention – Measurement, Mechanisms and Interventions Owen, Salmon, Trost, Dunstan, Eakin, Healy, Kingwell, Lambert, Timperio ? ? ? ? ? Moderating factors ? ? - Age ? ? - Sex ? - Ethnicity ? Other mechanisms - Adiposity levels - inflammatory? - Disease presence - haemostasis? - Fitness Levels – Regular Exerciser - endothelial? - ?????? - autonomic? Frequency of breaks – high vs. low Type of breaks – ambulation vs. standing Workplace Health Promotion & Chronic Disease: Looking Through a Workplace Sitting Lens DUTY OF CARE “A person conducting a Organisational business or undertaking must ensure so far as is reasonably Policy & Culture practicable the provision and maintenance of a work environment without risks to health and safety” Workplace Model Work Health and Safety Bill 23/06/2011 Individuals Physical Environment The Stand Up Australia Program of Research Program of research investigating benefits from reducing sitting time in the workplace Epidemiology  Experimental laboratory  Interventions Translational research A National collaboration between the Baker IDI Heart & Diabetes Institute University of Queensland, University of Melbourne, Deakin University Government & Non-Government Partner Organizations Proportion of prolonged (≥30 mins) Activity distribution (%) Australia sedentary time (%) Thorp AA et al. Int J Behav Nutr Phys Act 2012; 26: 128 7