Light to Moderate Physical Activity Can Lower Stroke Severity

September 25, 2018

New research has added to the growing body of research suggesting a wide range of health benefits from light physical activity.

Malin Reinholdsson, PT, MS

In addition to younger age, physical activity prior to stroke onset can result in less severe stroke, with both light and moderate physical activity appearing beneficial, according to new study data.

As measured by the National Institutes of Health Stroke Scale (NIHSS), in those patients who had a light or moderate level of physical activity pre-stroke, a higher percentage of them—44.7% (n = 330) and 7.2% (n = 53), respectively—experienced a mild stroke, rather than moderate or severe/very severe stroke.1

Led by Malin Reinholdsson, PT, MS, a physiotherapist at the Institute of Neuroscience and Physiology, Sahlgrenska Academy, at the University of Gothenburg, the group of investigators extracted clinical data from more than 2000 patients who experienced stroke, of which 925 patients were included in the final analysis. The mean patient age was 73 years (range, 20 to 104), and 42.5% were women. Ischemic stroke occurred in the vast majority, 93.8% of patients.

Those who had been physically active prior to stroke (odds ratio [OR], 2.02), as well as those who were younger (OR, 0.97), were more likely to have a mild stroke. A univariate logistic regression model predicted 6.8% of stroke severity.

"Health promotion and physical activity is a priority area in health care in general, and in physical therapy in particular, with proven primary preventive effects of stroke incidence," Reinholdsson told NeurologyLive. "In my clinical work, as a physical therapist at an acute stroke unit, secondary prevention with motivational interviewing to promote lifestyle changes and to give specific advice about physical activity is meaningful and rewarding. The secondary prevention is often targetted at patients with mild stroke or [transient ischemic attack]. Still, many patients with moderate or severe stroke are unable to preserve function and abilities in everyday life. We were curious about the effects of pre-stroke physical activity—if there were benefits when physically active pre-stroke."

In total, there were 738 patients with mild strokes, of which 354 (48%) had no physical activity, and 1 (0.1%) were vigorously active, along with the aforementioned percentages. Of the 146 patients with moderate strokes, 98 (67.1%) patients were physically inactive, 42 (28.8%) were lightly active, 6 (4.1%) were moderately active, and none were vigorously active. Of the 41 patients with severe strokes, 29 (70.7%) were physically inactive, 12 (29.3%) were lightly active, and none were moderately or vigorously active.

Using a negative binomial regression analysis to compare groups based on their activity level, as measured by the Saltin-Grimby Physical Activity Level Scale (SGPALS) and NIHSS score, the investigators found that the physically inactive group had more severe stroke compared with both the light PA group (level 2; P <.001) and the moderate PA group (level 3—4; P <.001). There was no significant difference between the light PA group (level 2) and the moderate PA group (levels 3 and 4) on stroke severity as measured with the NIHSS (P = .140).

The study suggested that pre-stroke physical activity, in combination with younger age, is at least partially associated with the incidence of milder stroke, which the authors noted is in agreement with 2 previous studies of smaller populations of 362 and 159 patients. "The potential risk factors such as sex, smoking, diabetes, and protective treatments such as statin and hypertension treatment did not influence stroke severity in this study,” they wrote.

"To work with primary prevention and to identify physically inactive persons in primary care can make a difference," Reinholdsson said. "It is important to give advice about physical activity and if needed provide inactive persons with professional support to incorporate an active lifestyle. The difference is twofold, to prevent the incidence of stroke and other cardiovascular diseases as well as diminsh the consequences if a stroke occurs."

There was no finding of dose dependency for intensity observed, the authors noted, and no significant difference was observed in stroke severity between the light physical activity group (those who walked, or similar exercise, for at least 4 hours per week) and the moderate group (those who trained 2 to 3 hours per week). Reinholdsson and colleagues noted that of 3 previous studies of a similar topic, 2 showed dose dependency for the duration of physical activity and mild stroke severity, while 1 showed none for frequency.

“Therefore, it is difficult to compare results between studies because frequency, intensity, and type of PA differ. However, these results presented here suggest that both light and moderate PAs are beneficial,” they wrote.

"Many middle-aged and older people I meet in the clinic are very physically active on a light level and many hours per week; walking their dogs regularly, socializing when being physically active or have an outdoor lifestyle, so I am very pleased to be able to confirm the benefits of being active at all levels to my patients," Reinholdsson said.

In spite of the findings, in an accompanying editorial,2 Nicole L. Spartano, PhD, from the Section of Endocrinology, Diabetes, Nutrition and Weight Management at Boston University School of Medicine, and Julie Bernhardt, PhD, of the Florey Institute of Neuroscience and Mental Health at the University of Melbourne, pointed to the limitations of the work which the authors acknowledged, mainly the retrospective design and the self-reported pre-stroke activity levels. Spartano and Bernhardt also included recall bias, possible memory deficits associated with stroke, and potential depression in some patients as well.

"Although the results of the study by Reinholdsson et. al. are promising, in light of important limitations of the study design and inconsistent evidence from cohort studies, we must view the results of the current study cautiously," the two wrote. "However, these results do add to the growing body of literature suggesting a wide range of health benefits from light physical activity."

REFERENCES

1. Reinholdsson M, Palstam A, Sunnerhagen KS. Prestroke physical activity could influence acute stroke severity (part of PAPSIGOT). Neurology. 2018;00:e1-e7. doi: 10.1212/WNL.0000000000006354.

2. Spartano NL, Bernhardt J. Prestroke physical activity to reduce stroke severity: moving to lower risk with light activity. Neurology. 2018;00:727. doi: 10.1212/WNL.0000000000006342.