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Fitness or Obesity: What Is the Major Target for Intervention? German Diabetes Meeting Stuttgart, GERMANY May 15, 2010. Steven N. Blair Professor Departments of Exercise Science & Epidemiology/Biostatistics University of South Carolina.
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Fitness or Obesity: What Is the Major Target for Intervention?German Diabetes MeetingStuttgart, GERMANYMay 15, 2010 Steven N. Blair Professor Departments of Exercise Science & Epidemiology/Biostatistics University of South Carolina
Is too much attention given to obesity and not enough to physical activity?
Global Trends in Childhood Overweight International Obesity Taskforce. http://www.iotf.org/database/index.asp.
Global Trends in Childhood Overweight International Obesity Taskforce. http://www.iotf.org/database/index.asp.
Global Trends in Adult Obesity International Obesity Taskforce. http://www.iotf.org/database/index.asp.
It’s calories that count Energy Out Energy In Portion size High-fat foods Energy dense Low-fiber Soft drinks Snack foods BMR Thermic effect of food Media (TV,PC) Cars No heavy labour Exercise
Trends in Energy Intake1971 to 2000, Women, NHANES Kcal/day Source: MMWR Feb 6, 2004
NHANES Survey Methods 1971-2000 • NHANES I and NHANES II • 24-hour dietary recall, Monday-Friday • NHANES III and NHANES • 24-hour dietary recall, Monday-Sunday • Other changes in methodology included better probing techniques and better training of interviewers • Other changes in dietary behavior included more meals eaten away from home and increasing portion sizes
Trends in Chinese Energy Intake: Adults 18-45 years Energy Intake (MJ) Zhai F., Wang H., Du S., He Y., Wang Z., Ge K., Popkin B.M., Nutr Rev., 2009.
Trends in Energy Intake in Men from Tanushimaru , Japan Energy Intake (kcal) Adachi H., Hino A., J Epidemiol., 2005
Proportion of households with car or van ownership, 1951 to 2004, Great Britain Department of Transport, Scottish Executive and Welsh Assembly. (2005)
Trends in Riding Lawnmower Sales in the US: 1981-2001 In thousands Slide from L DiPietro, Stock Conference, 2002
The 30-year trends of leisure time, occupational and commuting physical activity among Finnish adults Borodulin, K. et al. Eur J Public Health 2008 18:339-344; doi:10.1093/eurpub/ckm092
Occupational and Domestic PA trends in Chinese Adults, 1991-2000 Monda et al. Eur J Clin Nutr. 2008; 62: 1316-1325
Design of the ACLS 1970 More than 80,000 patients 2005 Cooper Clinic examinations--including history and physical exam, clinical tests, body composition, EBT, and CRF Mortality surveillance to 2003 More than 4000 deaths 1982 ‘86 ‘90 ‘95 ’99 ‘04 Mail-back surveys for case finding and monitoring habits and other characteristics
All-Cause Death Rates by CRF Categories—3120 Women and 10 224 Men—ACLS Blair SN. JAMA 1989
Amount of Specific Physical Activities for Moderately Fit Women and Men • Detailed physical activity assessments in women and men who also completed a maximal exercise test • Average min/week for the moderately fit who only reported each specific activity Mean Min/week N=3,972 13,444 Stofan JR et al. AJPH 1998; 88:1807
Interrelationships Among the Twin Epidemics of Obesity, Low Fitness, and Health Obesity/Fat Distribution Morbidity or Mortality No grants should be awarded nor papers published on fitness or obesity, and a health outcome unless both exposures are accurately measuredand taken into account in analyses Activity/Fitness
Cardiorespiratory Fitness, BMI, and Mortality, ACLS Men • 25,389 men followed 8.5 years • 673 deaths in 212,364 MY • Cardiorespiratory fitness assessed by a maximal exercise test • Calculated age-adjusted death rates for BMI and fitness categories Barlow et al. Int J Obes 1995; 19:Suppl 4, S41-4
Age-Adjusted Death Rates by Fitness and BMI Categories Deaths/10,000 MY # deaths 133 189119 63 6717 7519 Man-Yrs 25,53764,10357,00415,00020,7497,34114,3018,240 Results held after adjustment for health status, smoking, glucose, cholesterol, & BP Barlow et al. Int J Obes 1995; 19:Suppl 4, S41-4
Criticisms of 1995 Int J Obes Study on Fitness & Fatness • “What a lot of rubbish” • Findings counter to “what we know” • Fit men with a high BMI were not fat, but had a high level of muscular development • Category of low fit men with a low BMI had an excess of smokers • Statistical adjustment for health status did not remove confounding by chronic disease
RR for All-cause and CVD Mortality in Fit and Unfit ACLS Men by Body Fat Categories Body Fat% Body Fat% All-cause Mortality CVD Mortality *adjusted for age, exam year, smoking, alcohol, & parental history Lee CD, Blair SN, & Jackson AS. Am J Clin Nurt 1999; 69:373-80
Adjusted RR for All-Cause Mortality by Fitness and Waist Circumference • Waist circumference measurements in a subgroup 14,043 men • 162 deaths in 78,008 man-years • RR adjusted for age, examination year, smoking habit, alcohol intake, and parental history of CHD <87 87-<99 99 Lee CD, Blair SN, & Jackson AS. Am J Clin Nurt 1999; 69:373-80
Adjusted RR for All-Cause Mortality by Fitness and BMI, ACLS Women *adj for age, exam year, smoking, & health status Farrell et al. Obes Res. 2002; 10:417-423
Low Fitness and Inactivity as Mortality Predictors in Men with Diabetes • Prospective study of 1,263 men, age=50±10 years • All men had type 2 diabetes at baseline • FPG 126 mg/dL • history of physician-diagnosed diabetes • taking anti-diabetic medication • Low fit=least fit 20% (42% of the men) • Inactive=no reported activity, past 3 months • Follow-up of 11.7 years, 14,777 man-years • 180 deaths (92 CVD) Wei et al. Ann Int Med 2000; 132:605-11
RR for Mortality by Fitness Level in Men with Type2 Diabetes *Adjusted for age and examination year Wei et al. Ann Int Med 2000; 132:605-11
RR* for All-Cause Mortality by Fitness and BMI Levels in Men with Type 2 Diabetes *Adjusted for age and examination year Wei et al. Ann Int Med 2000; 132:605-11
RR for All-Cause Mortality in Low Fit Men with Type 2 Diabetes, Adjusted for Age and Exam Year Adj R R 95% CI >1.0 for all analyses BMI25 High Chol Baseline CVD Known Diab High BP Smoker Parental CVD Reference Category (RR=1.0) is fit men Wei et al. Ann Int Med 2000; 132:605-11
CVD Mortality Risk* by Fitness and BMI Categories, 2316 Men with Diabetes, 179 CVD Deaths p for trend <0.0001 p for trend <0.0001 p for trend <0.002 Church TS et al. Arch Int Med 2005; 165:2114 *Adj for age and examination year
Survival curves by fitness levels within BMI categories in 831 men with type 2 diabetes, Veterans Exercise Testing Study (1995-2006) ≥5 METs <5 METs 1.000 1.000 1.000 0.875 0.875 0.875 0.750 0.750 Survival 0.750 0.625 0.625 0.625 0.500 0.500 0.500 0.0 2.0 4.0 6.0 8.0 0.0 2.0 4.0 6.0 8.0 0.0 2.0 4.0 6.0 8.0 Follow-up (years) Follow-up (years) Follow-up (years) Normal weight (n = 78) Overweight (n = 330) Obese (n = 423) McAuley et al. Diabetes Care 2007;30:1539-43 Slide from P McAuley
Attributable Fractions of Health Outcomes For Low Cardiorespiratory Fitness and Other Predictors, ACLS • Attributable fraction (%) is the estimated number of deaths due to a specific characteristic • Based on strength of association • Prevalence of the condition
Attributable Fractions for All-Cause Mortality Blair S.N., Br J Sports Med., 2009
Relative Risks and Attributable Fractions of All-Cause and CVD Mortality by BMI Categories in Men • 25,714 (1,025 all-cause and 439 CVD deaths) men aged ≥20 years in the ACLS. • 10 years of follow-up. • Attributable fractions are adjusted for age, examination year, BMI, parental history of CVD, and each other item in the table. Wei M. et al., JAMA, 1999
Relative Risks (RR) and Attributable Fractions (AF) of All-Cause Mortality by BMI Categories in Men Wei M. et al., JAMA, 1999
Summary • Inactivity and low fitness are major determinants of morbidity and mortality • Patients with type 2 diabetes should be strongly advised to become and stay physically active • More attention should be paid to regular physical activity in public health and clinical settings
Ranking of selected risk factors: 6 leading causes of death by income group, estimates for 2004 Percentage of total (total: 1.53 billion) World Health Organization. http://www.who.int/healthinfo/global_burden_disease/global_health_risks/en/index.htm
Final Message • Focus on • Healthful eating habits • Fruits and vegetables • Whole grain • Regular physical activity • Three 10 minute walks/day