Low Fitness as a Predictor of Morbidity and Mortality Steven N. Blair Director of Research Cooper Institute

Lecture Outline Cardiorespiratory fitness (CRF) as an indicator of habitual physical activity CRF and mortality Health Adults Older Women and Men Chronic Disease Longevity CRF and Functional Limitation

An Underlying Concept of the Aerobics Center Longitudinal Study Cardiorespiratory Fitness (CRF) is an excellent objective indicator of total physical activity in recent months CRF increases by a predictable amount in controlled studies CRF is strongly associated with detailed activity records - R2 0.7-0.8 Genetic contribution of CRF is 25-40% The Cooper clinic is unique in that since its inception everyone has had maximal oxygen consumption testing on a treadmill.

Fitness and Mortality in Men, ACLS Fitness Categories Age Groups (years) Fitness and Mortality in Women, ACLS Fitness Categories Age Groups (years) The traditional cut points for fitness are high, medium and low. The levels are lower for women. Table values are maximal METS attained during the exercise text

Questions and Issues Regarding Overweight, Obesity and Health How many believe that overweight is a threat to health? How many believe that sedentary habits are an important cause of overweight? How many believe that sedentary habits are a threat to health? Inactivity, overweight an health are highly interrelated, therefore extensive efforts must be made to disentangle this issue. Much has been made about obesity and health. Few have untangled the relationship of fitness, obesity and health. This can be done at the Cooper clinic.

Fitness, Body Composition Distribution and Mortality in ACLS men Cohort of 21,925 men, followed on average 8 years (176,742 man years) Baseline exclusion for MI, Stroke or Cancer Outcomes All Cause Mortality (428 deaths) CVD mortality (144 deaths) Exposures: CRF from maximal exercise test on a treadmill as an objective marker of habitual physical activity patterns Body composition and fat distributions determined by hydrostatic weighing, sum of 7 skins folds and waist circumference.

Adjusted RR for All-Cause Mortality by Fitness and % Body Fat (<16%) (>25%) (16-24%) Adjusted RR for CVD Mortality by Fitness and % Body Fat Individuals who are fit are much less likely to die than those who are not fit. Adj.RR* for age, exam year, smoking, alcohol, and family history Lee CD et al. Am J Clin Nutr, 1999

Cardiorespiratory Fitness as a Co-Morbidity of Obesity 25,734 men in the Aerobics Center Longitudinal Study, followed <10 years During 258,940 man-years of observation, there were 1025 deaths (439 from CVD) BMI (kg/m2) distribution Normal=18.5-24.9 --10,623 men (41%) Overweight = 25.0 to 29.9--11,798 men (46%) Obese = 30.0--3293 men (13%) With the fitness testing, one can partial out the relationship of obesity and fitness to subsequent morbidity. Wei M. Et. Al. JAMA 1999;282:1547

RR for CVD and All-Cause Mortality by BMI categories, 25,714 Men, ACLS Obesity proved to be a strong determinant of risk of dying.

RR of All-Cause Death by BMI Categories for Selected Mortality Predictors RR Adj for age and Exam Year Ref Category= Normal Weight without Risk Factor Population Attributable Risk (PAR) for CVD and All-Cause Mortality in 3293 Obese Men, ACLS However, within each of the individual categories, fitness proved to be a powerful determinant of death, even when controlling for obesity. Perhaps physician’s guidelines should not only assess obesity and weight loss, but also low fitness, and aerobic training as well. Wei et al. JAMA, 1999;282:1547

All-Cause Mortality by BMI and # of Risk Factors, 24,335 Men, ACLS Men with baseline CVD or CA were excluded Men followed for approximately 10 years 809 Deaths Risk Factors considered--high blood pressure, high cholesterol, diabetes, smoking, history of parental CVD, and low cardiorespiratory fitness.

Relative Risk of All-Cause Mortality by BMI and # of Risk Factors, 24,335 Men, ACLS Number of Risk Factors Increasing numbers of risk factors are associated with increased risk of death at every obesity stratum. *Age-Adjusted RR #Deaths/#Men

Risk Factors in 24,335 Norman Weight, Overweight, or Obese Men, ACLS Percent of Men with 0 or 1 risk factor Obese = 45% Overweight = The prevalence of individuals with at least one risk factor increases with higher levels of obesity. Perhaps we should be treating risk factors rather than obesity. 65% Normal Weight = 80%

Physical Inactivity Leads to Insulin Resistance Syndrome 8,633 men with two examinations normal ECG and free of diabetes, heart attack, stroke, or cancer at baseline average age = 43.5 yrs. (30 to 79 yrs) Definitions (ADA/WHO criteria) FPG--Fasting Plasma Glucose Impaired fasting glucose (IFG) 110<FPG<126 mg/dl Type 2 diabetes--FPG>126 mg/dl 7,442 of the men were free of IFG at baseline Average follow-up = 6 years 52,588 man-years of observation 149 new cases of type 2 diabetes 593 new cases of impaired fasting glucose Incidence of type 2 diabetes = 2.8/1,000 man-years (similar to other white populations) Very few studies have investigated physical activity and diabetes. Fewer still have investigated fitness and diabetes. Wei M. et al. Ann Int Med 1999

Impaired Fasting Glucose by Cardiorespiratory Fitness Groups Type 2 Diabetes by Cardiorespiratory Fitness Groups A consistent pattern appears with increased fitness there is lower blood glucose levels and an increased risk of diabetes. This appeared in both men and women, and all ages. *Adjusted for age, parental diabetes and follow-up

Fitness and Type 2 diabetes by IFG Groups

Low Fitness an Inactivity as Mortality Predictors in Men with Diabetes Prospective study of 1263 men aged = 50 +10 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) Physically inactive = no reported activity in the past 3 months Follow-up of 11.7 years, 14,777 man-years 180 deaths (92 CVD) If we examine only those men who have diabetes, the relationship holds as well.

RR* for All-Cause Mortality by Fitness and BMI Levels in Men with Type 2 diabetes With increasing fitness levels for people with Type 2 diabetes there is a marked reduction in the risk of death.

Cardiorepiratory Fitness and Mortality in the ACLS Follow-up of 891 women an 2135 men in the ACLS who were >60 years of age Examined at the Cooper Clinic during 1970-1994 Followed for mortality through 1994 Average Follow-up ~10years Deaths 61 women during > 7,000 woman years 365 men during > 20,000 man years __ There are only limited reports on fitness and mortality in older individuals.

Risk of Death by Fitness Groups, 749 Women and 1758 Men 60 and Older, ACLS Age, exam-year, BMI, cholesterol, high blood pressure, diabetes, smoking, CVC, parental CVD, adjusted RR for all cause mortality Patients with cancer and failure to achieve at least 85% of predicted max HR were excluded There was a consistent pattern in older individuals with a reduction of mortality in higher fitness categories.

Death Rates/1000 by Fitness Groups 2135 Men aged 60 and Older, ACLS CHD death rate /100,00 PY The relationship held even in people above 70 years of age. The life expectancy of a low fit compared to a high fit individual is 9 years. # of Deaths 91 111 66 47 26 11 7 3 3

Gall Bladder Disease Materials and Methods Study subjects were 2666 women and 7987 men age 21 to 79 years (mean 44.9 years) 97% were white, more than 75% had a college degree, and most were employed in executive or professional occupations Follow-up period was an average of 12 years between the baseline examination and 1995 mail-back survey Gallbladder Disease Criteria Outcome was self-reported physician-diagnosed gallbladder disease. Patients were also asked the number of years since the diagnosis was made. Patients were excluded if the had: History of cardiovascular disease or cancer at baseline Abnormal resting ECG or Exercise ECG at Baseline Maximal Heart Rate less than 85% of their age-predicted rate (220-age in years) History of jaundice or liver disease

Relative Risk of fit groups from gallbladder disease in 10,653 persons There was a consistent relationship whereby with increasing fitness there is a marked reduction in the risk of gallbladder disease. Type of Adjustment

Fitness and Functional Limitations Prospective study of 1175 women and 3495 men age 40 years and older Medical Exam during 1980-88 Average follow-up of 5.5 years Self-report of functional limitations in 1990 by mail-back survey Are your able to do? Personal Care Activities Household Activities Recreational Activities The 10 questions were scored as-- Yes = 0 Yes, with assistance or no = 1 All with a score of 1 or more were classified as having functional limitation This represents the 5 year follow up evaluating the relationship of fitness to development of functional limitations. Huang et al. MSSE 1998,39:1430-5

Fitness and Functional Limitations Prevalence (%) of functional limitations The 10 questions were scored as-- Yes = 0 Yes, with assistance or no =1 All with a score of 1 or more were classified as having functional limitation Huang et al. MSSE 1998,39:1430-5

Prevalence of Self-reported functional limitations by fitness and age groups Huang et al. MSSE 1998,39:1430-5

Fitness and Functional Limitations Women and Men, ACLS *OR for self-reported functional adjusted for age, follow-up, BMI, smoking, alcohol intake, baseline disease, and disease at follow-up Quite consistently with increasing fitness there was a lower risk of functional limitations. Huang et al. MSSE 1998,39:1430-5

Methods Assessment of Functional Limitation in 1995 1635 men and 418 women >46 years of age at baseline (mean=56, range, 46-77 Received clinical assessments during 1987-1989 Reported no functional limitations in 1990 Reported functional health status on a 1995 mail-back survey Average follow-up from baseline to 1995 survey=6.7 years (range 6-8 years) Assessment of Functional Limitation in 1995 Series of questions on whether or not participants had difficulty performing or were not able to perform Moderate daily activity e.g. Lifting/carrying 10 pounds stooping, crouching, kneeling Strenuous daily activity walking 1/4 mile climbing 10 stairs without resting lifting/carrying 25 pounds

Incidence of Functional Limitation by Sex-and Age-Groups Incidence of functional limitations (%) Age groups (years) Adjusted* Odds Ratios for Development of Functional Limitations *Adjusted for age, BMI, length of follow-up, smoking status

Musculoskeletal Fitness, Cardiorespiratory Fitness and Functional Limitations 589 women and 3,069 men (30-82 years) Received both musculoskeletal and cardiorespiratory fitness assessments between 1980-1989 Completed mail-back survey on functional limitations in 1990 after an average follow-up of 5 years Musculoskeletal fitness assessment 1 RM bench press 1 RM leg press Maximal bent leg sit-up in 60 seconds Tertiles for each test were coded 0,1, or 2 Scores summed, and those with a summary score of 5 or 6 were classified as high strength Brill et al. MSSE 2000; 32:412-6

Age and Follow-up Adjusted OR for Functional Limitations Women Men

Amount of Specific Physical Activities for Moderately Fit Women and Men Detailed physical activity assessments in women an men who also completed a maximal exercise test Average min/week for the moderately fit who reported each specific activity This represents the amount of time needed in physical activity to health benefits. Storan JR et al. AJPH;88:1807

Conclusions Low Cardiorespiratory fitness is a strong and independent predictor of mortality in women and men, young and old, health and unhealthy an fat and lean Low Cardiorespiratory fitness and low muscular strength are predictors of functional limitations Low fitness is highly prevalent and constitutes a major public health problem There is also the concern that physicians should should target improved fitness for the improvement of health.