Exercise and Arterial Stiffness in the Elderly: A Combined Cross-Sectional and Randomized Controlled Trial (EXAMIN AGE)
Question
To investigate associations between long-term physical activity and central pulse wave velocity in healthy and diseased older adults, and to examine the effect of 12 weeks of HIIT on pulse wave velocity in older sedentary adults with increased cardiovascular risk.
Summary
This combined cross-sectional and randomized intervention study examined arterial stiffness in older adults and tested whether 12 weeks of supervised Nordic walking-based HIIT changed pulse wave velocity in sedentary older adults with cardiovascular risk factors. Long-term active participants had lower arterial stiffness and higher VO2max was associated with lower pulse wave velocity, but the 12-week HIIT intervention improved VO2max without significantly reducing central pulse wave velocity.
Methodology
- Adults aged 50-80 years categorized as healthy active, healthy sedentary, or sedentary at cardiovascular risk; intervention focused on sedentary at-risk adults.
- 147 participants.
- Nordic walking.
- Work intervals: 4 minutes.
- Recovery: 3 minutes.
- Intensity: 80-90% HRmax during intervals; 60-70% HRmax during recovery.
- Average 60 minutes including warmup and cooldown.
- 3 sessions per week.
- 12 weeks.
- Combined cross-sectional study and randomized controlled intervention trial.
- Central pulse wave velocity, Maximal oxygen uptake, Blood pressure, and Body composition were tracked.
Outcomes
Cross-sectional VO2max and PWV association
Higher CRF was associated with lower central PWV across participants; each 10 ml/min/kg higher VO2max corresponded to 0.8 m/s lower PWV.
p<0.001; VO2max explained 18% of PWV variance after adjustment for age and sex.
Cross-sectional group differences in PWV
Central PWV was lowest in healthy active participants and highest in sedentary at-risk participants.
HA 7.0 +/- 1.1 m/s, HS 7.5 +/- 1.6 m/s, SR 8.2 +/- 1.4 m/s; ANOVA p<0.001.
VO2max after HIIT
HIIT improved VO2max compared with control in sedentary at-risk participants.
Adjusted difference 3.4 ml/min/kg; 95% CI 2.5 to 4.3; p<0.001.
Central PWV after HIIT
Twelve weeks of HIIT did not significantly change central PWV compared with control.
Adjusted difference 0.1 m/s; 95% CI -0.3 to 0.6; p=0.60. Additional adjustment for systolic BP change: 0.2 m/s; 95% CI -0.2 to 0.6; p=0.29.
Blood pressure and PWV relation after HIIT
Changes in systolic blood pressure were associated with changes in central PWV after HIIT.
Baseline PWV p<0.001 and changes in systolic BP p<0.018 were determinants of PWV adaptation.
Body composition after HIIT
HIIT reduced fat mass percentage and increased muscle mass percentage compared with control.
Fat mass adjusted difference -2.0 percentage points (95% CI -3.6 to -0.5, p=0.01); muscle mass adjusted difference 1.0 percentage point (95% CI 0.2 to 1.9, p=0.02).
Insights
- In older sedentary adults with cardiovascular risk, 12 weeks of supervised 4x4 HIIT can improve VO2max without necessarily improving arterial stiffness.
- Claims about HIIT and vascular stiffness should be qualified by age, risk status, duration, and blood pressure response.
- A two-week familiarization period is a useful programming feature when introducing high-intensity training to formerly sedentary older adults.
Limitations
- Sample size was relatively small and the control group did not reach the originally planned size.
- The study cannot determine whether 16 weeks or longer would improve PWV.
- Sex distribution was unbalanced in the healthy sedentary group.
- Only sedentary persons at increased cardiovascular risk performed HIIT.
- Participants had multiple treated and untreated cardiovascular diseases that may differentially affect arterial stiffness.
Safety
- Adverse events were not reported in the article text.
- Participants underwent initial medical screening including clinical assessment, 24-hour blood pressure, and blood sampling.
- HIIT sessions were supervised by sport scientists and included a two-week familiarization period.