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

2. 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

3. 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 - R
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.

4. 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

5. 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.

6. 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.

7. 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

8. 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= ,623 men (41%)
Overweight = 25.0 to ,798 men (46%)
Obese = 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

9. 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.

10. 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

11. 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.

12. 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

13. 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%

14. 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

15. 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

16. Fitness and Type 2 diabetes by IFG Groups

17. Low Fitness an Inactivity as Mortality Predictors in Men with Diabetes
Prospective study of 1263 men aged =
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.

18. 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.

19. 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
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.

20. 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.

21. 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

22. 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

23. 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

24. Fitness and Functional Limitations
Prospective study of 1175 women and 3495 men age 40 years and older
Medical Exam during
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

25. 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

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

27. 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

28. 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
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

29. 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

30. Musculoskeletal Fitness, Cardiorespiratory Fitness and Functional Limitations
589 women and 3,069 men (30-82 years)
Received both musculoskeletal and cardiorespiratory fitness assessments between
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

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

32. 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

33. 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.