MS Has Greater Impact on Women’s Physical Activity, Study Reveals

Multiple sclerosis (MS) has a greater impact on women, reducing their levels of physical activity and increasing sedentary behavior, a recent study has found.

The study, “Does Multiple Sclerosis Differently Impact Physical Activity in Women and Man? A Quantitative Study Based on Wearable Accelerometers” was published in the International Journal of Environmental Research and Public Health.

In patients with MS, symptoms such as fatigue, weakness, and spasticity (muscle stiffness) may reduce mobility and promote sedentary behavior. However, little is known about the possible differences in the way MS changes the propensities of men and women engaging in physical activity, “since few studies have explicitly considered sex as a main variable of interest.”

To fill this knowledge gap, a team of researchers at the University of Cagliari, in Italy, investigated the existence of possible differences between women and men with MS, when it comes to the amount and intensity of physical activity they practiced weekly.

The study included 45 patients with relapsing-remitting MS (RRMS) (23 women and 22 men, with a mean age of 50.3 years) and 41 age- and sex-matched healthy participants, who served as controls (21 women and 20 men, with a mean age 48.2).

Patients with RRMS also were divided into two different groups, based on their expanded disability status scale (EDSS) scores (a measure of MS disability) in mild (16 women and 13 men), and moderate-severe disability (seven women and nine men).

Data regarding the participants’ physical activity was acquired 24 hours a day for a week via a wrist-worn accelerometer (Actigraph GT3X). At the end of the week data was downloaded and processed with ActiLife software and analyzed using statistical models.

Researchers then analyzed different variables, including the average number of daily steps, vector magnitude counts (a measure of physical activity), and the percentage of time participants spent engaging in sedentary behavior and in physical activity of different intensities (light and moderate-to-vigorous physical activities).

Analyses revealed that women with MS spent more time engaging in sedentary behavior (68.6% for women vs. 62.6% for men) and tended to practice less light-intensity physical activity than men (20.9% vs. 27.1%). However, the time women and men with MS spent practicing moderate-to-vigorous physical activity was similar (10.5% vs. 10.3%).

Researchers also found sex had a significant effect on both step and vector magnitude counts. They discovered the disease significantly reduced step and vector magnitude counts in women (by 32% and 45% decrease, respectively), but not in men. Vector magnitude counts also were significantly higher (24%) in healthy women compared to men.

Regarding step counts, the hourly trends and the average number of daily steps taken by healthy individuals and MS patients of different levels of disability followed a similar trend, with two peaks of activity between 9–10 a.m. and 6–7 p.m.

Yet, they found that mobility tended to decrease with increasing disability, with differences particularly evident in the women’s group. Their findings showed that women with MS, regardless of disability level, had a lower number of daily steps compared to healthy women (9,116 in mild disability, 6,679 in moderate-severe disability vs. 12,283).

Researchers also found a significant effect of sex and disease status on physical activity intensity levels. Women with MS remained sedentary longer (68.6%) than healthy women and men with the disease (59.3% and 62.6%, respectively). Men with MS also tended to engage more frequently in light intensity physical activity (27.1%) when compared to both healthy men and women with MS (23% and 20.9%, respectively).

They also found that healthy women spent more time practicing moderate-to-vigorous physical activity than men (15.9% vs. 10.8%), while among MS patients these values were nearly identical. Furthermore, compared to healthy women, those with MS spent much less time practicing moderate-to-vigorous physical activity (15.9% vs. 10.5%).

“Our data also suggest that the disease has a stronger impact on women, since a significant reduction in daily steps, VM [vector magnitude] counts, and percentage of time spent in MVPA [moderate-to-vigorous physical activity], as well as an increase in sedentary behavior, were observed in women with MS with respect to those unaffected, while this phenomenon was not detected in men,” the researchers wrote.

However, researchers pointed out their findings should be interpreted taking into account study limitations, including that the calculation of number of steps and classification of the physical activity intensity might be, in some cases, influenced by the device’s position on the wrist, and the fact that physical activities not involving the arms might result in an overestimation of sedentary behavior.

“Our data confirm the urgency of including sex as a variable in all studies on PA [physical activity] in pwMS [people with MS], as well as selecting, whenever possible, quantitative objective measurements of PA. These strategies would be of great benefit in planning adequate interventions, in terms of training, physical therapy and even lifestyle guidelines, tailored to individuals’ needs to maximize their effectiveness,” the team concluded.