Heat Therapy and Cardiometabolic Health in Obese Women
- Conditions
- Polycystic Ovary SyndromePrehypertensionMetabolic SyndromePreDiabetesCardiovascular Risk FactorObesity
- Interventions
- Behavioral: Heat therapy
- Registration Number
- NCT03644524
- Lead Sponsor
- University of Oregon
- Brief Summary
Traditional medical treatments are often based on research done exclusively in males, and recent research efforts in the physiology community have highlighted critical sex differences in disease presentation and progression. For example, the relative risk of fatal heart disease is 50% greater in obese, diabetic women as compared to their male counterparts, and women appear to respond differently to lifestyle interventions such as exercise compared with men. Chronic passive heat exposure (hot tub use) provides alternative or supplemental therapeutic potential for improving cardiovascular and metabolic health in obese women. In addition, passive heat exposure may offer specific cellular protection from stresses like a lack of blood flow (ischemia), which is the primary cause of fatal coronary heart disease. This study is investigating the possible cardiovascular and metabolic health benefits of chronic passive heat exposure, and whether regular hot tub use (3-4 days per week for 8-10 weeks) may reduce obese womens' cardiometabolic risk. The investigators are examining cardiovascular health through blood pressure, blood vessel stiffness, sympathetic ('fight or flight') activity, and responsiveness to stresses like increased or decreased blood flow. The investigators are also examining metabolic health through an oral glucose tolerance test and a subcutaneous fat biopsy. The goal of this research is to develop a therapy targeted toward the specific health needs and complications of obese women, in an effort to improve cardiovascular and metabolic health and provide therapeutic alternatives in this high-risk population.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Female
- Target Recruitment
- 20
- Age 18-40
- Body mass index (BMI) between 30-45 kg/m2.
- Willing to maintain consistent diet and activity patterns through the study
- Willing to refrain from food, physical activity, supplements, and medications as required before testing days
- Willing to refrain from blood donations over the course of the study
- overt cardiovascular disease or diabetes
- medications that affect blood vessel function (i.e. Spironolactone), insulin sensitivity (Metformin), or blood coagulation (i.e. Warfarin)
- Recent rectal, anal, or vaginal surgery
- pregnant, breastfeeding, or trying to conceive within 6 months.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Heat Therapy Heat therapy Subjects assigned to heat therapy underwent 30 1-hour hot tub sessions over 8-10 weeks (3-4 per week). The hot tub was set to 40.5 Celsius, and core temperature and heart rate were monitored throughout each session.Subjects were instructed to not make any other dietary or lifestyle changes.Cardiovascular and metabolic health assessments were made Pre (0 heat sessions), mid (after 14-16 heat sessions, \~4-5 weeks), and post (after all 30 heat sessions; \~8-10 weeks).
- Primary Outcome Measures
Name Time Method systolic blood pressure through study completion, an average of 10 weeks Resting supine blood pressure, measured in triplicate with median recorded
diastolic blood pressure through study completion, an average of 10 weeks Resting supine blood pressure, measured in triplicate with median recorded
oral glucose tolerance test through study completion, an average of 10 weeks glucose and insulin responses to a 75-g, 2-hr oral glucose tolerance test after a 12+hr fast
- Secondary Outcome Measures
Name Time Method arterial wall thickness (femoral) through study completion, an average of 10 weeks intimal thickness of superficial femoral artery assessed using doppler ultrasonography
flow mediated dilation after ischemia-reperfusion through study completion, an average of 10 weeks flow-mediated dilation of brachial artery, expressed as % change in diameter, following 20 minute ischemia-20 minute reperfusion. A measure of vascular tolerance to ischemia-reperfusion stress.
muscle sympathetic nerve activity burst frequency through study completion, an average of 10 weeks recording of sympathetic nerve traffic during supine rest, quantified as burst count per minute
dynamic arterial compliance (carotid) through study completion, an average of 10 weeks arterial compliance of common carotid artery measured using ultrasonography
dynamic arterial compliance (femoral) through study completion, an average of 10 weeks arterial compliance of superficial femoral artery measured using ultrasonography
flow mediated dilation through study completion, an average of 10 weeks flow-mediated dilation of brachial artery, expressed as % change in diameter. A measure of endothelial function.
arterial wall thickness (carotid) through study completion, an average of 10 weeks intimal thickness of common carotid artery assessed using doppler ultrasonography
Abdominal subcutaneous fat biopsy through study completion, an average of 10 weeks Adipose tissue sample analyzed for insulin signaling, markers of inflammation, and heat shock protein expression
Trial Locations
- Locations (1)
University of Oregon
🇺🇸Eugene, Oregon, United States