Slide 1Review of Evidence: Observational StudiesHelmrich et al. (1991) Study DesignSlide 4Slide 5Slide 6Helmrich Study ResultsSedentary behavior and T2DM: NHSPhysical Activity, BMI and Diabetes Risk: Nurses’ Health StudyMortality in patients with DM: ACLSEvaluation of Evidence: Observational StudiesSlide 12What about people who have NIDDM?Rogers et al. (1988)Slide 14Slide 15Slide 16Rogers et al. (1988) Study ResultsInactivity, Glucose and Insulin Heath et al. (1983)Slide 19Slide 20Heath et al. (1983) Study ResultsDiabetes and Physical ActivityLecture 2 KIN 247 Fall 2017Review of Evidence:Observational Studies•Does PA participation relate to diabetes prevention?•Does sedentary behavior relate to diabetes risk?• Does BMI interact with PA to determine diabetes outcomes?Helmrich et al. (1991) Study DesignQuestion: Does physical activity participation associate with T2DM Prevention?•Long-term follow-up of 5990 University of Pennsylvania male alumni•Only included those non-diabetic in 1962•202 developed T2D between 1962 and 1976•Simply asked by questionnaire if they had been diagnosed as diabetic•Leisure-time physical activity measured by Paffenbarger questionnaire RELATIVE RISKPHYSICAL ACTIVITY INDEX, (kcal/wk) ALL ACTIVITIESALL ACTIVITIES EXCEPT VIGOROUS SPORTSVIGOROUS SPORTS ONLY< 5001.00 1.00 1.00500 – 999 0.94 0.97 0.691000 – 1499 0.79 0.87 ---1500 – 1999 0.78 0.92 0.532000 – 2499 0.68 0.75 0.862500 – 29990.90 1.29 0.563000 – 34990.86 1.03 0.40≥ 3500 0.52 0.48 0.46P-Value for Trend 0.01 0.07 0.05Table 1. Age-Adjusted Rates of T2D Among 5990 Men, 1962 to 1976, According to Measures of Physical Activity in 1962.Helmrich et al. (1991)RISK FACTOR IN 1962RELATIVE RISKP-VALUEFOR TRENDAge (yr)  <45 1.00  45 – 49 1.690.03 50 – 54 1.51 ≥ 50 2.12 Body-mass index   <24 1.00  24.00 – 25.99 1.90 <0.0001 ≥ 26.00 3.33 Hypertension   No 1.000.004 Yes 1.91Parental history of diabetes  No 1.000.04 Yes 2.88Table 3. Age-Specific and Age-Adjusted Rates of T2D Among 5990 Men, 1962 to 1976, According to Selected Risk Factors in 1962.Helmrich et al. (1991)Helmrich Study Results•Increased leisure-time physical activity is effective in preventing T2D•Vigorous sports activity may be more beneficial to prevent future diabetes•The protective effect of physical activity is greatest in those at highest risk •Every 500kcal/week increase in EE was associated with a 6% reduction in NIDDMSedentary behavior and T2DM: NHSPhysical Activity, BMI and Diabetes Risk:Nurses’ Health StudyAdapted from Rana, J.S. et al. (2007). Diabetes Care. 30 (1). From NHS.Mortality in patients with DM: ACLSAdapted from Church, T.S. et al. (2005). Arch Intern Med. 165:2114-21200Evaluation of Evidence:Observational Studies•EE, especially vigorous exercise, is related to lower risk for type 2 diabetes, especially in high risk people•Sedentary behaviors increase risk for diabetes•PA and BMI appear to BOTH be important indicators for risk of T2DM and death from T2DM•Recommendations are that PA should be part of any T2DM risk-reduction or treatment programReview of Evidence:Experimental StudiesDiabetesWhat about people who have NIDDM?Rogers et al. (1988)•10 sedentary men, 53±3 yrs of age•7 diabetics (NIDDM), 3 impaired glucose tolerance (IGT)•OGTT•Then 1 bout of exercise with OGTT next morning•Then 6 more days of exercise with OGTT morning after the 7th day of exercise1 Bout of Exercise OGTT Results7 Days of ExerciseOGTT Results: Glucose7 Days of ExerciseOGTT Results: InsulinRogers et al. (1988) Study Results•1 day of exercise had no effect in these previously sedentary T2D or impaired glucose tolerant men•7 days of exercise resulted in marked improvement in OGTT glucose and insulin responses•These data demonstrate that physical activity, itself, not weight change, can improve glucose tolerance and insulin sensitivityInactivity, Glucose and InsulinHeath et al. (1983)•6 men, 2 women aged 22-47 yrs – non-diabetic•45 min exercise, 5-7 days/wk for ≥ 6 months•OGTT when training normally and after no exercise for 10 days•Weight measured frequently and diet changed so no weight gain•Then 1 regular training bout and final OGTT the next morningHeath GW, et al. Effects of exercise and lack of exercise on glucose tolerance and insulin sensitivity. Journal of Applied Physiology 55(2): 512-517, 1983.1.2.3.OGTT Results: GlucoseOGTT Results: InsulinHeath et al. (1983) Study Results•Glucose levels in response to OGTT were higher after 10 days of no exercise!!•Insulin levels much higher after 10 days of no exercise (no weight gain)•1 day of exercise returned insulin levels nearly to trained