February 28 - 29, 2008 Advisory Committee Meeting
I-Min Lee, M.D., Sc.D., summarized major outcomes to cover among the adult
population sub-group as follows:
The studies consist of Type 3a level of evidence data. There is about a 30% risk
reduction with at least 2 to 2.5 hours per week of moderate-to-vigorous
activity. There appears to be a dose-response relationship and it is curvilinear
in shape. There is limited data on dose-response for intensity.
The studies consist of Type 3a level of evidence for CHD, CVD and stroke. There
is approximately a 20 – 35% risk reduction with at least 800 MET minutes per
week. This includes specific data on walking at least 2 hours per week. The data
is primarily based on aerobic activities. One can start to see risk reductions
at levels below 800 MET minutes per week. There is very limited data on
accumulation. Studies consisting of Type 1 evidence support the conclusions for
CVD and CHD.
For colon and breast cancer the research consists of Type 3a data. The data
suggests about a 30% risk reduction for colon cancer and 20% for breast cancer
based on at least 30 – 60 minutes per day of moderate-to-vigorous activity.
There appears to be a dose-response relation; however, the shape of the curve is
unclear. There is no information on accumulation.
The level of evidence for QOL and breast cancer survivors is Type 1 but
consists of a very small body of evidence. The available data suggests physical
activity improves outcomes. There is limited data on dose-response since most
trials used currently recommended levels of physical activity.
Data consists of Type 2a and 3a for Type 2 Diabetes, Type 3a for macrovascular
complications and Type 3a and 3b for metabolic syndrome. There appears to be
about a 30 – 40% risk reduction based on 120 – 150 minutes per week. The data is
based primarily on aerobic activity. There appears to be a dose-response
relation for volume of physical activity. Risk reductions can be seen at levels
below 120 – 150 minutes per week. There is limited data on accumulation.
For gestational diabetes data consists of Type 3a data; however, it is a
relatively small body of data. The data supports benefit based on 30 minutes per
day of moderate-to-vigorous activity. There is limited data on a dose-response
relationship. There is no evidence that physical activity can prevent Type 1
Diabetes. The level of evidence for the positive effect for treatment of
complications resulting from Type 1 Diabetes is 3b. Physical activity can help
control HbA1c and may prevent progression of nephropathy and neuropathy.