Discussion in 'Latest ME/CFS Research' started by Dolphin, Jan 6, 2013.
*I've given each sentence its own paragraph
The introduction section largely came from a CBT/GET perspective, but I'm not sure the authors really found good evidence for a lot of the theories.
One example where they definitely didn't find good evidence is for this section:
The putative slope for the healthies was actually slightly in the wrong direction!
The authors don't say much about the fact that the issue.
The Introduction also says:
While achieving balance is probably good, this makes no mention that basing activity on symptoms can be important - simply doing the same amount every day may not be a good approach.
In the discussion, while focusing a bit more on CBT/GET approaches, they do mention:
The controls weren't chosen to be sedentary per se, although they had a mean BMI of 26.0
The mean daily activity level for the CFS group was 957, 15% less than the control group.
[Aside: it makes the talk of the 50% reduction of activity levels before getting a CFS diagnosis questionable, but then I have often thought that was too strict].
From figure 4, 7 of the CFS patients have higher mean activity levels than the mean for the control mean with 3 being approximately the same.
(comments continued in next message)
The pattern of activity of the two groups across the three time periods is a little interesting:
In the morning, the results are exactly the same (both are 1149 units)
In the afternoon, there is a statistical difference (CFS: 985, controls: 1177)
In the evening, there is also a statistical difference (CFS: 742, controls: 959)
This might suggest that the CFS patients could balance out activities a better by pacing more, and doing less in the morning on average but the authors don't explicitly say that that I can recall.
In terms of the relative distribution of hourly activity levels:
The CFS group have 27% at a high activity level, 23% at moderate activity level and 50% at low activity level.
For the controls, it is 42% had high activity level, 23% at moderate activity level and 35% at low activity level.
There was a statistical difference between the CFS and control groups for the high and low activity levels.
Note: low activity levels are not necessarily sedentary levels (that definition wasn't used). Here is what they said about how they set the thresholds. Hourly activity levels is probably not a good way to measure activity intensity. For example, if somebody sprinted, this might show up. Other researchers often used much shorter periods to measure activity intensity.
They say on this
Aside: sometimes researchers assume fatigue is a measure of severity of the illness. However, this ignores the fact that it can also be influenced by the amount of activity a patient is doing, how the illness is managed along with all sorts of other issues e.g. mood, etc.
I'm afraid there's one part that I'm not fully sure what it means - but perhaps other people will understand it.
This is from the discussion:
I probably need to read up on coefficients of variation.
This is all sort of a "no kidding" to me.
They found out that we're more active in the mornings, and then as the day goes on and we get worn out, we do progressively less. And that some days we feel able to do more and other days we feel like crap and do very little. Also that people with illnesses that result in payback for physical activity pay more attention to their physical activity levels than healthy people. Duh.
The part that gets me about all of these studies is that no matter how they well or not well they set up the experiments themselves, they can look at the results and get the interpretations totally wrong sometimes. They are often not showing what they seem to think that they're showing. And making too many assumptions about cause and effect is just bad science.
But are "cfs patients" less fatigued in the morning?That would seem to go against the cortisol tests which show low morning cortisol AM.
In my experience of ME and CFS patients it seems to be more of a pattern of low AM activity and then rising PM. That's why most ME groups have afternoon appointments as more members can make it out of the home then.
Weird. I always seem to wake up with a finite tank of energy to spend that day. And I often end up using it up before evening. I'm WAY more symptomatic by evening. But not all patients follow that cortisol pattern either, I guess. I know that mine was high first thing in the morning and then dropped below normal by afternoon, back up to normal by night. Though there also seems to be more to my energy levels than just where my cortisol is. I'm a wreck by nighttime.
They measure activity from 8am-10pm. I'm not sure how strict they are but these sort of criteria might mean some types of patients wouldn't have taken part.
I think they're saying that CFS patients varied from one patient to the next in how active they were. And controls had a similar amount of variation from one control to the next.
So maybe each group had a similar distribution of activity levels, just shifted lower for CFS patients.
I too are thinking at seeing that result, that it sounds as if most of their patients are over doing it in the early parts of the day rather then spacing their activity over the whole period they are awake and that better pacing maybe should be thought about... I try to keep my activity level at a degree in which I stay fairly stable and not on a downhill slide by each night (unless there is something I MUST do). If a get a downhill slide by the end of the day, know Ive done too much at some point.
I plan ahead for a certain amount of activity in the morning to a level which wont impact me later that day..and then do most of my activity in the afternoon or at night (with every third day a complete rest day as the affects of activity do accumulate after a time otherwise).
They have not factored in individual circadian rhythms. This constitutes a major uncontrolled confounding variable and renders the study void.
Quite apart from their peculiar bias on interpretation, ie, subjects are too aware of their activity and paying too much attnention to imagined bodily sensations, rahter than listening to their bodies to know when to stop.
They have not differentiated between aerobic activity and anaerobic activity - another MAJOR confounding variable.
They have not stated if the activity involves climbing or arm raising - or any other specific activity that puts excessive strain on our systems within any of the activity sessions.
It's all just meaningless drivel. Nonscience.
I need a good hour to recover from getting up and dressed and coffee-ing myself and drugging the cat and myself.
I seem to have a peak of physical activity around 4 pm.
I think it's the adrenalin rush that comes from:
"Good grief, he'll be home soon and he can't get at any part of the kitchen (for the mess) to make his tea."
so I have a half-hearted attempt at clearing a bit of space and shoving a few dishes in the dishwasher or clothes in the machine.
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