STUDY: Aerobic Capacity Is Not Associated with Most Cognitive Domains in MSers

[ActiveMSers]

Whoa, whoa, before you throw up your arms in disgust and point a finger at me for being a dotard, maaaybe look a little closer at the full study (which is free). I'll break down some of my concerns in a follow-up post below. Feel free to add your own interpretation. -D

J. Clin. Med. 2018, 7(9), 272; https://doi.org/10.3390/jcm7090272

Aerobic Capacity Is Not Associated with Most Cognitive Domains in Patients with Multiple Sclerosis—A Cross-Sectional Investigation

Martin Langeskov-Christensen, Søren Eskildsen, Egon Stenager, et al

Published: 11 September 2018

Abstract

(1) Background: Cognitive impairment is highly prevalent in multiple sclerosis (MS). Staying physically fit may be associated with preservation of cognitive performance in persons with MS (pwMS);

(2) Objective: To investigate the association between aerobic capacity and the cognitive domains of information processing, learning and memory, and verbal fluency as well as single and composite z-scores of the Brief Repeatable Battery of Neuropsychological tests (BRBNT) in pwMS;

(3) Methods: All subjects first performed the BRBNT and then a maximal oxygen consumption (VO2-max) test on a bicycle ergometer as a measure of aerobic capacity. Simple and multiple (adjusting for age, sex, and education level) regression analyses were performed to evaluate the relationship between aerobic capacity and cognitive performance in different domains. Published international norms were used to compute z-scores for each individual and composite BRBNT score. Furthermore, cognitive impairment was defined as one or more z-scores ≤−1.5 standard deviation (SD) of healthy controls; (4) Results: Eighty-four subjects were included (44.9 ± 9 years, 16.3 ± 2 education years, Expanded Disability Status Scale (EDSS): 2.6 ± 1.4, MS-type (relapsing-remitting, primary progressive, or secondary progressive): 73/6/5, disease duration: 9.9 ± 7 years, VO2-max: 28.4 ± 7.0 mL O2/min/kg). No significant associations between aerobic capacity and cognitive performance in the individual BRBNT tests were found, except that a weak relationship was found between aerobic capacity and the composite processing speed z-score (R2 = 0.06, p = 0.02). The average global BRBNT z-score (−0.2 ± 0.66) was not associated with aerobic capacity. Comparison of the cognitively impaired group (34.5%) with the nonimpaired group (65.5%) showed lower aerobic capacity in the impaired group (25.9 ± 1 vs. 29.7 ± 1 mLO2/min/kg, p = 0.02);

(5) Conclusions: Limited support was found for an association between performance in most cognitive domains and aerobic capacity in the present MS group with a third of patients showing signs of cognitive impairments.

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http://www.mdpi.com/2077-0383/7/9/272/htm

[ActiveMSers]

First, the study eliminated the MSers most likely to see cognitive benefit from aerobic exercise: those doing high-intensity interval training, a tactic I've encouraged for years. I and many other fit MSers would not have been eligible to participate in this study. I would be doubly excluded because of my 6.5 EDSS.

Exclusion criteria were dementia (ICD10 diagnosis or dementia symptoms in hospital journals), comorbidities preventing participation (e.g., cardiovascular disease or metabolic diseases), pregnancy, alcohol abuse, pacemaker, relapse within 8 weeks before inclusion, or participation in systematic aerobic training (i.e., moderate to high intensity training more than twice per week) prior to inclusion.

Second, the fitness levels of those in the study rated by VO2max in either the cognitive impaired (25.9) or the non-impaired group (29.7) are low by any standard. The highest recorded VO2max was 42, presumably by a younger male, which would classify as fair. Although subjects are not broken down individually, it would be fair to assume MSers tested fell into the very poor, poor, and fair categories, likely none in the good, excellent or superior ranges.



So what does all of this mean to me? To us? The research was thorough and included a decent number of volunteers, which is fantastic. I applaud the attempt. But the hypothesis that concerted aerobic training affects cognition was not tested. At all. In fact it was excluded.

Researchers, some advice. Follow this lead, but improve on it. We MSers want to know: does HIIT, after 12 weeks, improve cognition or fatigue or both? Get baseline cog, fatigue, and VO2max testing, and then test again in three months. Don't exclude athletes (if they don't see much improvement, at least we have their VO2max scores that may offer key insights into the levels necessary to see stabilization). How hard is this??? Hell, I will work with you.

Gack. Another MS exercise study with promise that falls woefully short. Or am I missing something?

[ActiveMSers]

And Emily had this to say on FB. It is the exact point I was going to make.... -D

If I read it correctly, I think the study is named inaccurately, or at least is misleading. They didn't actually study the effects of aerobic exercise on cognition, the opposite looks to be true--they analyzed cognition before they tested for aerobic capacity. So is there a direct, fractional correlation between the two? No. (And honestly I'm surprised anyone would support that research.) What needs to be done is a longer term study that compares cognition with aerobic improvement--if we improve our aerobic capacity do we then also improve cognition. Of course, that would be a longer and more complex (aka expensive) study, and pharmaceuticals don't make money from exercise as a valid treatment option.

[AMFADVENTURES]

It might be a pretty good study but it doesn't seem to have anything to do with exercise. I suppose if all this study says is that VO2-max is not a factor in the cognitive impairment of PwMS, maybe that's good news.

Since most studies involving exercise indicate that PwMS can improve cognitive performance with exercise, perhaps the hypothesis to test is, are improvements seen independent of the VO2-max a person starts from.

Ah, so many studies to do, so little time.

[ActiveMSers]

Perhaps they did listen to me! And it appears based on the headline, perhaps HIIT isn't helping cognition in MS after all, even though it aids cognition in adults not affected by MS. We'll see where this goes tomorrow and we can discuss.

High-intensity aerobic exercise does not improve cognitive performance in people with multiple sclerosis: a randomised controlled trial

M. Langeskov-Christensen1, L. Grøndahl Hvid1, H. Boye Jensen2, H. Hvilsted Nielsen3, T. Petersen4, E. Stenager5, P. Hämäläinen6, U. Dalgas1 1Aarhus University, Aarhus, 2Lillebaelt Hospital, Kolding, 3Odense University Hospital, Odense, 4Aarhus University Hospital, Aarhus, 5Hospital of Southern Denmark, Sønderborg, Denmark, 6Masku Neurological Rehabilitation Centre, Masku, Finland

The complete abstract will be published on September 11, 2019.