Sedentary Behaviour, Physical Activity Patterns, and Cardiometabolic Health

Official title

From Sitting to Moving: How Physical Activity Patterns Can Reduce Sedentary Behaviour and Support Cardiometabolic Health

Overview

According to the World Health Organization (WHO), chronic diseases are a major global public health concern and the leading cause of mortality worldwide. In the absence of evidence-based actions, the global annual deaths from chronic diseases are projected to rise to 55 million deaths in 2030, accompanied by a substantial increase in socio-economic costs. In this context, the WHO identifies type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) as key chronic conditions of concern related to cardiometabolic health. Both sedentary behaviour (SB) and physical inactivity have been recognised as interdependent risk factors for the development of T2DM and CVD. SB refers to any waking behaviour, characterised by a low energy expenditure, while being in a sitting or reclining posture, whereas physical inactivity denotes insufficient levels (\<150 min per week,) of moderate-to-vigorous physical activity (MVPA). Studies using objective measures have demonstrated that on average Western adults spend 8-12h in SB per day, of which the majority is spent in prolonged sedentary bouts (lasting ≥30 min). In addition, up to 30% of adults worldwide are physically inactive, with higher levels of inactivity in high-income countries. Within this context, it has become evident that excessive prolonged SB, often in combination with physical inactivity, negatively impacts cardiometabolic health, contributing to insulin resistance, increased adiposity, poor lipid profiles and endothelial dysfunction. Given their detrimental effects on T2DM and CVD, strategies aimed at reducing SB and promoting physical activity (PA) warrant further investigation. Reducing and regularly interrupting SB, even with low-intensity PA, alongside sufficient MVPA, is crucial for maintaining a healthy cardiometabolic profile. Reflecting this, the WHO guidelines advise individuals to engage in 150-300 minutes of moderate-intensity physical activity, 75-150 minutes of vigorous-intensity physical activity, or an equivalent combination each week. Notably, the 2020 WHO guidelines also included recommendations on SB for the first time, emphasizing the importance of limiting sedentary time. The WHO states that replacing SB with physical activity of any intensity can yield health benefits. However, these recommendations remain non-prescriptive and somewhat vague, primarily due to a lack of robust scientific evidence on the optimal frequency, intensity, and duration of PA needed to interrupt sedentary time. The absence of specific guidelines on prolonged SB reflects this evidence gap. To support policy development, well-designed randomised controlled trials are needed to evaluate effective and practical strategies for reducing sedentary time. So far, the short term cardiometabolic health effects of SB interruptions have been investigated by our research group, laboratory studies of collaborators and other international researchers, demonstrating that; 1) more frequent SB interruptions especially affect glucose metabolism and insulin sensitivity; 2) higher intensity interruptions are associated with cardioprotective adaptations and; 3) longer durations of SB interruptions positively affect lipid metabolism. However, because under real-world conditions frequency, intensity and duration of SB interruptions usually interact, their combined effects on cardiometabolic health need further investigation. Many studies already compared the isolated effects of different SB interruption patterns with respect to frequency, duration and intensity on cardiometabolic health. However, the combined effects of these different approaches matched for energy expenditure are not clear yet. We therefore perform a balanced cross-over study in which the efficacy of distinct activity patterns on cardiometabolic health insulin sensitivity and vascular function) will be compared to a sedentary control condition.

Interventions

• Behavioral Continuous moderate intensity physical activity
  One continuous physical activity bout of moderate intensity will be performed during the 6 hour testing day.
• Behavioral Light-intensity physical activity breaks
  Light-intensity physical activity breaks every 30 minutes during the 6 hour testing day.
• Behavioral High-intensity physical activity breaks
  High-intensity physical activity breaks every 30 minutes during the 6 hour testing day.

Primary outcome measures

• Total and incremental area under the curve of postprandial insulin response [Time frame: Blood samples will be collected at 0, 30, 60, 120, 180, 210, 240, 300, and 360 minutes during the 6-hour testing day.]
• Vascular endothelial function [Time frame: FMD measurement will be performed at the start (08:30 a.m.) and after 6 hours (2:30 p.m.) of the testing day.]

Secondary outcome measures (12)

• Cardiorespiratory Fitness [Time frame: Baseline measurement]
• Sedentary time [Time frame: Measured for 7 consecutive days after the screening visit]
• Body mass index [Time frame: Baseline measurement]
• Moderate-to-vigorous physical activity [Time frame: Measured for 7 consecutive days after the screening visit]
• Body weight [Time frame: Baseline measurement]
• High-density lipoprotein cholesterol concentration [Time frame: Blood samples will be taken at the beginning of the testing day (8 a.m.).]
• Total cholesterol concentration [Time frame: Blood samples will be taken at the beginning of the testing day (8 a.m.).]
• Total and incremental area under the curve of postprandial glucose response [Time frame: Blood samples will be collected at 0, 30, 60, 120, 180, 210, 240, 300, and 360 minutes during the 6-hour testing day.]
• Total and incremental area under the curve of postprandial insulin response [Time frame: Blood samples will be collected at 0, 30, 60, 120, 180, 210, 240, 300, and 360 minutes during the 6-hour testing day.]
• Peak heart rate [Time frame: Baseline measurement]
• Blood pressure [Time frame: Blood pressure will be measured during the screening visit, and hourly at 0, 60, 120, 180, 240, 300, and 360 minutes during the 6-hour testing day.]
• Body fat percentage [Time frame: Baseline measurement]

Eligibility criteria

Inclusion criteria

• Adults aged 40-70 years
• Sedentary (>9 hours per day)
• < 3 exercise sessions per week

Exclusion criteria

• Pregnancy or intend to become pregnant
• Any known contra-indications for physical activity
• >14 alcohol consumptions per week for women and >20 alcohol consumptions per week for men
• Involved in a weight reduction program with an energy restriction diet during the study period
• No consistent body weight over the past month
• Diagnosed with any known cardiometabolic health-related disease

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Prevention

Study locations

Belgium · 1 center

• Hasselt University — Diepenbeek

Identifiers

NCT: NCT07419100 · CME2025/100

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗