quiz #2 Flashcards
chapter 4 overview
preventable death
a death that could be avoided through changes in behavior
non-preventable death
a death that occurs due to factors beyond one’s control (genetics, accidents)
life expectancy
statistical measure indicating the average number of years a person can expect to live based on current mortality rates.
> insight into overall health and well-being of populations
premature death
death that occurs earlier than the expected age of mortality, often due to preventable health conditions
ex: cvd, type II, certain cancer, obesity related
behavioral risk factors
- diet
- smoking
- alcohol use
- physical inactivity
- unsafe sex
- drug use
strength of evidence
-role of chance
p > 0.05 association is non-significant (risk factor and outcome are likely due to chance)
p< 0.05 association is significant ( risk factor and outcome highly unlikely to be due to chance
temporal sequence
risk factor comes before outcome
ex: prospective cohort studies
strength of association
- studies report significant (p <0.05) associations
- meta analyses report risk reductions for all-cause mortality 31% for those who are physically active
- many studies, if not all, adjusted for important variables that might influence both PA and mortality
consistency of results
many studies reported similar findings across different PA measurements and different populations (men and women)
biological plausibility
risk factors and causes of mortality that we discussed - PA can influence those
- low PA contributes to top causes of death, such as heart disease & cancer
dose response
- many studies showed graphs with an inverse dose-response relationship ( > PA <mortality)
- curvilinear meaning the slope is likely steep going from no PA to low/mod PA
- currently consensus is 2-2.5 mod PA will reduce the risk of ACM
Nurses’ Health Study
classification: PA assessment based on Hrs/wk (volume)
Findings: mortality risk reduction tapered after approximately two hours/ week of PA
Indicated diminishing returns beyond this point but still beneficial overall.
- clear negatively accelerating decrease in relative risk of dying associated with increased hours spent in PA
Harvard Alumni Health Study (1986)
classifications: PA assessment quantified volume; daily stairs, blocks walked, type of sports etc
- total energy expenditure estimated in kilocalories per week
Findings:
1. Comparison of mortality rates across volume of physical activity
- all cause death rates showed a steady decline across increasing categories of weekly energy expenditure
- more volume of PA = better
2. life expectancy gains
- were observed in active men compared with inactive men
- greater in younger populations
Harvard alumni health study 1995
PA assessment: focused on vigorous intensity
- vig > 6mets
- non < 6 mets
Findings: significant inverse dose- response relationship between vigorous activities and all-cause mortality
- non-vigorous activities showed no relationship with all-cause mortality
- possibly due to imprecise reporting of non-vigorous activities
Harvard alumni health study 2000
PA assessment: focused on moderate intensity
light < 4met
mod 4-5.9 met
vig > 6met
Findings:
light intensity: no association with all-cause mortality
Moderate: trends were observed towards decreased ACM
Vigorous: a clear inverse association was also observed with ACM
aerobics center longitudinal study (8-year follow up)
PA components: cardiorespiratory fitness and changes (f/m) follow ups
Findings:
- greatest risk reductions were seen between the bottom fitness quintile and the next 20% of fitness
> least fit men had MR 3x higher
> least fit women had MR 4.65x higher
ACLS ( 5-year follow up)
findings: regardless of BMI, unfit group had a significantly greater risk of ACM compared to fit
3 groups based on fitness changes: 1 exam > 2 exam
findings:
lowest MR: observed in men who were fit at both
Highest MR: observed in men who were unfit at both
1. Fit at both vs. unfit at both
- RR = 0.33,
2. Unfit to fit
- RR = 0.52
Dose Response: for every minute increase in treadmill time ( approx 1 MET increase) between examinations, MR was reduced by nearly 8%
males vs females
females (81) have a higher life expectancy than males (76)
USA standings
USA is ranked in the 50s globally for life expectancy
males at 53rd
females at 51st
metabolic risk factors
high systolic blood pressure, high fasting blood glucose, high BMI, high low-density cholesterol, low bone mineral density
