The Influence of Tai Chi Practice on Blood Pressure and Brain Health Among Older Adults With Hypertension (ACTION)

Hypertension is a major cardiovascular disease risk factor affecting \>70% older adults in the United States. It is also a major contributor to cognitive impairment and dementia that affect over 8 million US older adults. Hypertension can cause deteriorations in brain structure and function such as reduced cerebral blood flow, leading to various types of cognitive dysfunction with declines in executive function being the most common. Of note, executive function is a strong predictor of older adults' ability to live independently in the community. Meta-analyses showed that Tai Chi reduces blood pressure (BP) by 12-15 mmHg for systolic BP and 4-6 mmHg for diastolic BP, and improves cognitive function with an effect size of 0.5 for global cognitive function and 0.9 for executive function. Surprisingly, no study has investigated the relationship between the heart and brain health benefits of Tai Chi among older adults with hypertension. The primary purposes and hypotheses are presented below. Of note, investigators will define the changes of BP, cognitive function focusing on executive function, and brain structure and functions in response to the 12-week online Tai Chi intervention as the chronic change (see primary outcomes 1 to 9). 1. To examine the relationship between the BP and cognitive function, focusing on executive function, response to a 12-wk online Tai Chi intervention. Investigators hypothesize that the BP and cognitive function, focusing on executive function, response to a 12-wk online Tai Chi intervention will be positively correlated. 2. To examine changes in measures of brain structure and functions in response to a 12-wk online Tai Chi intervention, and explore their associations with the BP and cognitive function, focusing on executive function, responses to Tai Chi. Investigators hypothesize that the relationship between the BP and cognitive function, focusing on executive function, responses to the 12-wk online Tai Chi intervention is mediated by the changes in brain structure and function. The secondary purposes are to examine the relationship between the BP and cognitive function, focusing on executive function, response to a single session of Tai Chi exercise. Investigators hypothesize that the BP and cognitive function, focusing on executive function, response to a single session of Tai Chi exercise will be positively correlated. Of note, investigators will define the changes of BP, cognitive function focusing on executive function in response to a single session of Tai Chi exercise as the acute change (see secondary outcomes 1 to 5). The participants will be randomized to either a Tai Chi (n=10) or control group (n=10). Participants will receive informed consent material and attend live online Q\&A sessions. Participants who signed the informed consent form will attend online visits 1 and 2, and in-person visit 3 to complete eligibility screening. For pre-intervention measures, participants will attend online visit 3 and in-person visits 4 and 5. In-person visits 4 and 5 will be in randomized order and include: 1) the Acute Exercise Visit A during which participants will attend a 45-minute Tai Chi exercise session at the local senior center; and 2) the Control and Magnetic Resonance Imaging \[MRI\] Visit A at the Brain Imaging Research Center \[BIRC\] at UConn Storrs during which participants will attend a 45-minute sham control session (i.e., watching Tai Chi themed video). A trained, blinded research assistant will: 1) measure resting BP and cognitive function before and after the 45-minute Tai Chi session in the Acute Exercise Visit A and the 45-minute sham control session in the Control and MRI Visit A; and 2) attach participants to a 24-hour ambulatory BP (ABP) monitor at the end of both the Acute Exercise Visit A and the Control and MRI Visit A that will be worn to the next morning. In addition, participants will participate in an 60-minute MRI scanning session at BIRC in the Control and MRI Visit A. The 12-week online Tai Chi intervention will start after in-person visit 5, participants assigned to the Tai Chi group will attend live online Tai Chi sessions led by a certified Tai Chi instructor for 3 sessions/week, 45 minutes/session for 12 weeks. The participants will also practice Tai Chi at home between sessions using instructional video that will be shared with them at the end of each live online Tai Chi session. Meanwhile, participants in the control group will perform only their regular habitual daily activities throughout the 12-week study. After the 12-week intervention period, participants will attend in-person visit 6 (Control and MRI Visit B) at the BIRC with procedures identical to those conducted in in-person visit 4 or 5 (Control and MRI Visit A). Participants will attend in-person visit 7 (Acute Exercise Visit B) at the local senior center with procedures identical to those conducted in in-person visit 4 or 5 (Acute Exercise Visit A).