Associations of Mutually Exclusive Categories of Physical Activity and Sedentary Time With Metabolic Syndrome in Older Adults: An Isotemporal Substitution Approach

Associations between time spent in sedentary behaviors and metabolic syndrome risk in physically active and inactive European older adults

OBJECTIVES

To determine how clustered metabolic risk based on a validated continuous metabolic syndrome risk score is associated with objectively assessed time in sedentary behaviors (SB) in physically active and inactive older adults, while considering adherence to healthy eating habits.

DESIGN

Cross-sectional study SETTING AND PARTICIPANTS: The study comprises 871 community-dwelling older adults (age 65-79 years) recruited from four European countries.

MEASUREMENTS

Daily times spent in SB and physical activity (PA) were assessed by accelerometers (Actigraph GT3X) for a week. Waist circumference, triglycerides, HDL-cholesterol, mean arterial blood pressure, fasting glucose and insulin were determined, and a continuous metabolic syndrome risk score (cMSy) was generated using principal component analysis. Healthy eating habits were assessed by food record. General linear models stratified by adherence to PA guidelines (active/inactive) were used to examine differences in cMSy across tertiles of time in SB (Low, Medium, High) with adjustment for covariates, including healthy eating habits.

RESULTS

A significantly (p < 0.05) lower cMSy was observed among older adults in the low SB tertile compared to medium and high SB tertiles, with no difference between the latter tertiles. The favorable effect of low amounts of SB on cMSy was indicated in both active and inactive groups, and regardless of healthy eating habits. Further, being active was related to a more favorable cMSy across all SB tertiles.

CONCLUSION

Low amounts of time spent in SB are related to a lower metabolic syndrome risk regardless of adherence to PA guidelines and healthy eating habits in older adults, supporting guidelines targeting limited amounts of SB alongside engagement in moderate-to-vigorous PA for promotion of metabolic health.

Effects of Core Stabilization Exercise Programs on Changes in Erector Spinae Contractile Properties and Isokinetic Muscle Function of Adult Females with a Sedentary Lifestyle

This study aimed to investigate the effect of core stabilization exercises on the contractile properties and isokinetic muscle function of adult females with a sedentary lifestyle. We enrolled 105 adult females. Tensiomyography was performed on the erector spinae, and the isokinetic muscular functional test was performed on the trunk at an angular velocity of 60°/s and 90°/s. All participants performed the exercise for 60 min per day, 3 times a week, for 7 weeks. A Wilcoxon signed-rank test was performed at a significance level of 0.05. Tensiomyography (TMG) of the erector spinae revealed no significant post-exercise change in the contraction time; however, there was a significant post-exercise increase in the maximum radial displacement and mean velocity until 90% of the TMG was displaced. Additionally, the isokinetic muscular functional test of the trunk revealed a significant post-exercise increase in almost all variables. Our findings demonstrated that the core stabilization exercise reduced stiffness in the erector spinae, increased the velocity of erector spinae contraction, and effectively improved the isokinetic muscular function of the trunk.

Isotemporal Substitution Analysis of Accelerometer-Derived Sedentary Behavior and Physical Activity on Cardiometabolic Health in Korean Adults: A Population-Based Cross-Sectional Study

Reducing sedentary behavior and increasing physical activity may be important for maintaining good cardiometabolic health. However, many studies have focused on the independent effect of sedentary behavior and physical activity, but it is unclear whether replacing time spent in sedentary behavior with physical activity is beneficial for cardiometabolic health. Therefore, this population-based cross-sectional study aimed to investigate the effect of behavioral transformations between sedentary behavior and level of physical activity on cardiometabolic health in Korean adults using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2014-2017. The study participants included 2197 adults from the KNHANES. In the partition model, moderate-to-vigorous physical activity (MVPA) was significantly associated with adverse cardiometabolic health, adjusted for potential confounding factors. The odds ratio for adverse cardiometabolic health significantly decreased with the replacement of sedentary behavior and light intensity activity with MVPA in the isotemporal substitution model (p < 0.05). In the models stratified by sex, we observed significant associations between handgrip strength and cardiometabolic health in women (p < 0.001), but not in men. Thus, our findings suggest that replacing sedentary behavior with MVPA may contribute to improved cardiometabolic health.