The PASE scale, used to estimate activity levels, has proven reliable in many of our clinical trials [ 43].
A major benefit of objective measurement methods is that they are unlikely to produce biased measures, unlike subjective measures which quantify the individual's perception of activity, and therefore frequently over-estimate activity levels[ 43].
In summary, we believe that the difference in populations studied between Iozzo et al.'s study and ours combined with the differences in the experimental protocols especially in regards to plasma insulin level may explain the 50% differences in the estimated glucokinase activity levels.
Pedometers have been found to be a simple and inexpensive means to estimate physical activity levels [ 53].
Pedometers have been found to be a simple and inexpensive means to estimate physical activity levels [ 35, 36].
For the analysis, respondents with incomplete information for all study variables (n = 39) and extreme estimated physical activity level from IPAQ (n = 20) were excluded.
Given a set of known pathways, these methods estimate the activity level of each pathway by summarizing the expression values of its member genes, and use the pathway activities for classification.
Secondly, our definitions of moderate and vigorous activities were not precise, and tend to over-estimate the activity level.
The scale estimates the activity level over the past year, including a score for both the summer and winter seasons, and has previously been validated among older adults in Sweden [ 16].
When we considered a transcription factor to be active at a significance level of 5% (the z-score corresponding to each activity level was calculated from the background distribution estimated from all activity levels), on average 13 TFs were active per condition in our data set (11 – in the Affymetrix data set).
