Maximal handgrip strength can predict maximal physical performance in patients with chronic fatigue, 2020, Jammes et al

[Andy]

Highlights

• Patients with chronic fatigue have often difficulties to perform a maximal exercise test.
• Maximal handgrip strength was used to predict maximal exercise performance.
• We explored 98 severely fatigued patients, 66 of them with chronic fatigue syndrome.
• Handgrip strength was correlated with peak values of oxygen uptake and work rate.
• Thus, handgrip strength is helpful when an ergometric cycle test cannot be performed.

Abstract
Background
Maximal handgrip strength is used to predict exercise performance in healthy older subjects and in patients with chronic obstructive pulmonary disease, breast cancer or cirrhosis. Our objective was to evaluate the ability of maximal handgrip strength to predict maximal exercise performance in patients with chronic fatigue.

Methods
Sixty-six patients with myalgic encephalomyelitis/chronic fatigue syndrome and 32 patients with chronic fatigue but no diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome were included. The maximal physical performance was measured on a cycle ergometer to measure the peak oxygen uptake and the maximal work rate. We searched for linear regressions between maximal handgrip strength and maximal performances.

Findings
No significant differences in slopes and ordinates of regression lines were noted between patients with or without a diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome, allowing to pool the data. Maximal handgrip strength was significantly and positively correlated with peak oxygen uptake and maximal work rate in all patients with chronic fatigue.

Interpretation
We conclude that handgrip strength can predict maximal exercise performance in patients with chronic fatigue.

Paywall, https://www.clinbiomech.com/article/S0268-0033(19)30701-6/
Sci hub, https://sci-hub.se/10.1016/j.clinbiomech.2020.01.003

@PhysiosforME , one of interest to you?

 

[adambeyoncelowe]

Interesting. I think we need more research into commonplace devices which can be used to assess symptoms.

They don't have to be biomarkers, but if we have tests that corroborate symptoms like fatigue, cognitive dysfunction and loss of function on repetition of effort, it'll make it easier to a) diagnose patients and b) take them seriously.

 

[Snow Leopard]

The 'Chronic Fatigue' participants:

We also examined 32 patients suffering from chronic fatigue for at least 6 months in whom the clinical criteria for ME/CFS were not validated. In these patients, multiple sclerosis was diagnosed in fifteen individuals, ankylosing spondylitis in five, meningitis sequelae in two and a psychiatric disorder was suspected in ten.

I still don't quite know what the relevance of an estimate of maximal exercise performance is in ME or CFS patients though.

The (combined) correlation coefficient for right handgrip and left handgrip strength predicting maximal workrate was R=0.725, 0.767 and 0.463, 0.509 for VO2Peak.

So there clearly is an association but it is not a very strong association overall. Interestingly, the workrate data is discrete/stepped and you might expect this to reduce the correlation coefficient, yet it was higher for workrate than VO2Peak (which was continuously measured). Also interestingly, the left handgrip strength predicted peak workrate in ME/CFS patients more strongly, with R=0.86.

 

[Cheshire]

As a reminder, there was this study on handgrip in 2018 by Nacul et al.:
Hand grip strength as a clinical biomarker for ME/CFS and disease severity
https://www.s4me.info/threads/hand-...l-biomarker-for-me-cfs-2018-nacul-et-al.6612/

 

[Andy]

The 'Chronic Fatigue' participants:


I still don't quite know what the relevance of an estimate of maximal exercise performance is in ME or CFS patients though.

"Proof" of illness, in this case without having to be pushed to the level used in a CPET?

 

[Snow Leopard]

"Proof" of illness, in this case without having to be pushed to the level used in a CPET?

But maximal exercise performance on a single CPET has little to do with proving illness, simply lack of fitness or motivation.

 

[adambeyoncelowe]

But maximal exercise performance on a single CPET has little to do with proving illness, simply lack of fitness or motivation.

Some people have still used the one-day CPET to prove functional impairment in disability cases, etc. It almost doesn't matter what the cause is or whether it's reversible; it's still an objective measure of current functioning.

 

[Trish]

I've been doing a bit of exploring of other papers and there seem to be quite a few that find correlations between CPET results, hand grip strength and 6 minute walking test results in all sorts of groups - healthy and sick. It seems to be generally regarded as simply 3 different ways of measuring physical fitness.

Given that men and women have significantly different results on these tests, it seems odd to me to mix the two gender groups together in the results. How much of the correlation significance found is simply reflecting that men have higher values on each scale than women? Or have I missed something?

This particular study seems to me to be simply confirming that hand grip strength is quite a good substitute for a single CPET for gauging the physical fitness of the patients. And as I suggested, men and women should, I think, be analysed separately.

Here are a couple of the papers I skimmed:
Hand Grip Strength and Gender...
6MWT Performance and its Correlations with VO2 and Handgrip Strength in Home-Dwelling Mid-Aged and Older Chinese

It's a pity the researchers didn't use the opportunity to go one step further and see if their results of the 3 repetitions of hand grip strength supported the findings from the UK biobank researchers (Nacul et al.), and do a 2 day CPET rather than just one day, and compare their two groups of patients on those.

 

[Invisible Woman]

I'm not so sure about this, perhaps I've got the wrong end of the stick?

I have always had very strong hands and I'm not sure that my level of function would be accurately assessed by this.

Although I am a small female I was always very strong for my size. Surprisingly so. Probably to do with a lot of the sports and activities I was involved in as a youngster.

Throughout my career I have had to lug heavy kit about and dismantle and reassemble kit. All of my colleagues are male and many of them seemed to think twisting a screw to "hand tight" meant twist it as hard as you could by hand. So in my early years of illness I still had a grip that was easily as strong as some men.

Over 20 years in I have lost a lot of that strength through disuse, but even sick my grip is probably as strong as my sister's was at my age. She's the family weakling.

So perhaps I am being a bit slow here but -
Some people will have much stronger grip than others due to natural variance, jobs and hobbies. Length of illness and severity of illness will also affect strength at time of measurement.

I can see that the fatigability of hand muscles in terms of grip and strength might tell you something helpful, but not strength alone.

 

[Trish]

I can see that the fatigability of hand muscles in terms of grip and strength might tell you something helpful, but not strength alone.

I agree that single measures of hand grip strength simply tell you how strong your hand muscles are. Those whose occupations require hand strength would be likely to be outliers on the graphs compared with those with just ordinary hand use. I suspect potters and bread makers who spend their days kneading clay or dough might not fit this pattern either.

This study doesn't tell us anything unique about ME/CFS. It's the fatiguability shown by repeated testing that Nacul et al found that may be more useful for diagosing ME/CFS.

 

[Kitty]

I agree that single measures of hand grip strength simply tell you how strong your hand muscles are.

Indeed, and it's pretty useless as an indicator if you also have arthritis...

 

[Sean]

Agree that strength alone is not a useful guide, and could even be quite misleading in our case.

I had an assessment by physios some time back for lower back issues, and they were surprised at my strength, particularly leg and lower torso strength, as they was expecting it to be poor (because that correlates with lower back issues).

It is not lack of strength that is my problem, it is almost complete loss of sustainable capacity (stamina).

IOW, I am not deconditioned.

 

[feeb]

Possibly worth noting that grip strength, like HRV, isn't a static value and can depend on fluctuating factors. E.g. if you have a cold coming on, your grip strength will decrease. That can act as an early warning system for athletes that they need to take it easy for a few days, because they're not at peak health. "Not at peak health" is pretty much the definition of an ME patient.

I'm not really sure where the authors are going with this study, but if it's something like using grip strength as a proxy for CPET performance so that patients don't have to undergo a potentially ruinous exercise test, then maybe that's not a bad thing.

 

[Snow Leopard]

Some people have still used the one-day CPET to prove functional impairment in disability cases, etc. It almost doesn't matter what the cause is or whether it's reversible; it's still an objective measure of current functioning.

I understand that some people who don't understand what it measures may consider it evidence, but well, the fact remains that the (average) peak workrate and VO2Peak found in this study are still more than sufficient to do most jobs.

 

[adambeyoncelowe]

I understand that some people who don't understand what it measures may consider it evidence, but well, the fact remains that the (average) peak workrate and VO2Peak found in this study are still more than sufficient to do most jobs.

Define 'sufficient to do most jobs'. Who decides that? If a person displays only 60% of the strength of an average person of their age, then that may be significant. If it's 80%, maybe not.

The other reason you might want to do this is to assess whether the person is capable of doing a two-day CPET in the first place. If they score very poorly, you might decide not to do one at all.

In general, I'm for measurable things, whatever they are, for patients. Obviously there's still a lot of work to do here, and no one here is saying this is a biomarker, but the less we have to rely on 'subjective report', the more we can move away from a condition measured (in clinicians' eyes) solely by questionnaires.

 

[Snow Leopard]

The other reason you might want to do this is to assess whether the person is capable of doing a two-day CPET in the first place. If they score very poorly, you might decide not to do one at all.

I'd suggest we already know that before they do the handgrip test too, mostly-bedbound patients are too ill to do CPETs...

Define 'sufficient to do most jobs'. Who decides that? If a person displays only 60% of the strength of an average person of their age, then that may be significant. If it's 80%, maybe not.

Many jobs (office jobs and many, but not all service industries) these days do not rely on high strength or high aerobic performance.

 

[Mithriel]

In ME, the important measure is how quickly performance deteriorates. No one seems to look at that properly but it is the crucial thing that I believe defines ME as opposed to other fatiguing illnesses. It is neglected because of the perception we are deconditioned.

When I was first diagnosed in the 80s, one of the doctors would get patients to write by hand a description of their problem while they sat in the waiting room. The change from the first sentence to the last he felt was a good indication of ME. It is the change that is important.

It is possible to be reasonably fit with ME but even then performance drops.

People have often said how they can play a game on the computer but after a while they get worse and worse. Healthy people get better as they practice. It wouldn't be that difficult to set up a test. The advantage over hand grip strength is that people with severer disease could still do it.

 

[It's M.E. Linda]

https://www.s4me.info/threads/hand-...l-biomarker-for-me-cfs-2018-nacul-et-al.6612/

This previous thread has various posts describing the use of the Hand Grip Test undertaken by all participants in research studies at Cure ME: U.K. ME/CFS Biobank.

Note the same test is carried out at the identical point in the meeting for all patients, whether Severe, Serious or Moderate. Only once (out of 3 so far) has my 2nd grip been a little more than my 1st and my 3rd has always dropped, despite hard gripping.

 

[adambeyoncelowe]

I'd suggest we already know that before they do the handgrip test too, mostly-bedbound patients are too ill to do CPETs...

But not all patients are bedbound. I think you're being either pedantic or contrary, but I'm trying to give you the benefit of the doubt here.

Many jobs (office jobs and many, but not all service industries) these days do not rely on high strength or high aerobic performance.

Obviously it's an abstraction. But many OTs use it as a measure of general stamina and physical capacity. I doubt anyone is suggesting to use this in isolation.

It's much harder to do a service job (which may require lots of running around) with reduced physical function. Likewise, even working in an office can be strenuous if you have a low physical capacity, even if it's not overtly physical. As pwME, we know this.

And I'll say it again: not having to measure this illness entirely by questionnaire is potentially a good thing.

 

[Sean]

In ME, the important measure is how quickly performance deteriorates.

This.