Sit Less or Exercise More: Impact on Cardiometabolic Health in MS
Condition: Multiple Sclerosis
MeSH terms: Multiple Sclerosis; Sclerosis
Study type: Interventional

Summary: 
      This study evaluates the impact of reducing sitting time and increasing exercise time on
      cardiometabolic health in persons with Multiple Sclerosis.
    

Detailed description: 
      To date, it is clear that sedentary behaviour is strongly related to an increased risk of
      type II diabetes, cardiovascular disease and premature mortality. People suffering from
      chronic disabilities appear to be particularly susceptible to a sedentary lifestyle and
      inactivity due to primary disease symptoms. To date, this is an important new research topic
      in Multiple Sclerosis (MS, ~2.3 million people worldwide, ~10-12.000 diagnosed in Belgium)
      treatment, since previous research reported a significantly higher prevalence of sedentary
      behaviour in persons with MS (PwMS) compared to healthy controls (HC). PwMS are reported to
      have a 40% lower daily step count compared to healthy inactive persons and tend to accumulate
      their sedentary time in longer bouts. As described above and similar to other chronic
      conditions, a sedentary lifestyle also makes PwMS more vulnerable to the accumulation of
      important cardiometabolic comorbidities that seem inactivity-related rather than a direct
      result of non-reversible tissue injury. Such comorbidities include impaired whole body
      glycaemic control, an abnormal blood lipid profile, an unhealthy body composition and
      hypertension. In this respect, it is important to note that corticosteroids, which are often
      used to treat MS patients pharmacologically, elevate fasting glucose and insulin
      concentrations and induce insulin resistance in HC therefore probably also increase several
      cardiometabolic risk factors in MS.

      Up to now, research in MS has been focused on structured exercise and its positive effects on
      functional parameters are well-known (e.g. improvements in cardiorespiratory fitness, muscle
      strength, balance, fatigue, cognition, quality of life and respiratory function). However,
      evidence is growing that sedentary time, independent of the (dis)practice of structured
      exercise, is an important independent health risk factor. Consequently, any strategy that
      also improves cardiometabolic health may help to further optimize rehabilitation in MS.
      Breaking up and reducing sedentary time with easy, daily activities such as household
      activities and other activities which increase light-intensity walking and standing, known as
      non-exercise physical activity (NEPA) may be such a strategy.

      NEPA has already been shown to significantly improve cardiometabolic risk markers in healthy,
      sedentary subjects, type II diabetes patients and obese adults and it involves lower
      intensity physical activities that are probably more feasible for PwMS. Moreover, with
      comparable activity workloads, reducing sitting time by NEPA of longer duration decreases
      insulin levels and fasting lipid levels more than performing one structured exercise bout of
      moderate intensity that is usually described in current activity guidelines. So far however,
      acute exercise bouts and NEPA effects on cardiometabolic health in this population have never
      been described. Therefore, the aim of this study is to investigate whether (1)
      cardiometabolic health (glycaemic control, blood lipids, inflammation markers and blood
      pressure) of persons with MS improves when sedentary time is reduced and (2) NEPA results in
      better cardiometabolic health parameters than (a shorter daily bout of) moderate-intensity
      exercise when workload of both activities is identical in this population.
    

Intervention name(s): Baseline activity (control regime); Increased sitting time (sit regime); Non-exercise physical activity (sit less regime); Structured exercise (exercise regime)
Intervention type(s): Other; Other; Other; Other
Intervention description(s): This is a baseline measurement of physical activity during which subjects will be instructed not to change activity patterns during four days and to note all activities they perform.; Participants have to spend 14h of their day sitting, 1h walking and 1h standing, for four consecutive days. According to the compendium of Ainsworth et al. (2011), this corresponds with a daily workload of activities (DWA) of 27 metabolic equivalents (MET's) per day.; Each day (4 days in total) will consist of 3h walking, 4h standing and 9h sitting. These time frames are chosen to result in a comparable DWA increase as the exercise regime compared to the sit regime (+7 MET's)27. The additional 2h of walking and 3h of standing, compared to the sitting regime, will be done in a minimum of four bouts with a time interval of > 1h. The subjects will be instructed to walk on a slow pace. i.e. 2-3 km/h (e.g. walking during shopping and work related walking in an office).; One hour of sitting in the sit regime will be replaced with 1 training session (1h) on a cycle ergometer in the research center. The remaining hours of each day (4 days in total) have to be spent as follows: 13h sitting, 1h walking and 1h standing for daily care. The intensity of the training session (50-60% of Wmax) results in a DWA of 34.5 MET's according to the compendium of physical activities. Duration of training sessions will be adapted individually with ActivPAL data of the sit less and sit regime to identically match DWA increase between the sit less and exercise regime, compared to the sitting regime.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Participants will follow four regimes of 4 days each including a control, a sit less, a sit and an exercise regime. The order of the sit and sit less regimes will be randomized. Each activity regime will be followed by a wash-out period of 10 days during which subjects will continue their normal lifestyle.
Masking: Single (Outcomes Assessor)
Primary purpose: Prevention
Keywords: Multiple Sclerosis; Non-exercise physical activity; NEPA; Cardiometabolic health; Comorbidities