# Exercise and Arterial Stiffness in the Elderly: A Combined Cross-Sectional and Randomized Controlled Trial (EXAMIN AGE) PMID: 31551805 Journal: Frontiers in Physiology Published: 2019 Sep 04 Authors: Deiseroth A, Streese L, Köchli S, Wüst RS, Infanger D, Schmidt-Trucksäss A, Hanssen H ## 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. ## Population - Adults aged 50-80 years categorized as healthy active, healthy sedentary, or sedentary at cardiovascular risk; intervention focused on sedentary at-risk adults. - Sample size: 147 - Age: Mean 59 +/- 7 years overall; 50-80 year inclusion range. - Sex: Cross-sectional: HA 17/35 female, HS 24/33 female, SR 41/79 female; intervention final analysis: 18 females in HIIT, 19 in control. - Fitness level: Healthy active, healthy sedentary, and sedentary at-risk; SR VO2max 26.1 +/- 4.4 ml/min/kg. - Health status: Healthy adults without cardiovascular risk factors or sedentary adults with at least two cardiovascular risk factors. ## Methodology - Combined cross-sectional study and randomized controlled intervention trial. - 12 weeks for the intervention; cross-sectional comparison at baseline. - University/clinical research setting with supervised Nordic walking-based HIIT. - Randomized and controlled study design. ## Protocol - Nordic walking-based HIIT. - Modality: Nordic walking. - Work intervals: 4 minutes. - Recovery: 3 minutes. - Sets or repetitions: 4 intervals. - Intensity: 80-90% HRmax during intervals; 60-70% HRmax during recovery. - Session duration: Average 60 minutes including warmup and cooldown. - Frequency: 3 sessions per week. - Program length: 12 weeks. - Progression: Stepwise increase of intensity during the first two weeks before full 4 x 4-minute intervals. - Standard physical activity recommendations. - Program length: 12 weeks. ## Outcomes ### Cross-sectional VO2max and PWV association Status: improved 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 Status: mixed 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 Status: improved 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 Status: no clear change 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 Status: mixed 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 Status: improved 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). ## Practical 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 And Adherence - 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. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/31551805/) (pubmed) - [DOI](https://doi.org/10.3389/fphys.2019.01119) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6738015/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.