Heat Therapy and Cardiometabolic Health in Obese Women (CMH)

University of Oregon

Status: Completed

Conditions: Prehypertension; Polycystic Ovary Syndrome; Obesity; Cardiovascular Risk Factor; Metabolic Syndrome; PreDiabetes

Treatments: Behavioral: Heat therapy

Study type: Interventional

Funder types: Other

Identifiers

NCT03644524

08282015.026

Details and patient eligibility

About

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.

Enrollment: 20 patients

Sex: Female

Ages: 18 to 40 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 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

Exclusion criteria

• 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.

Trial design

Primary purpose: Prevention

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

---

20 participants in 2 patient groups

Heat Therapy

Experimental group

Description:

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).

Treatment:

Behavioral: Heat therapy

Time Control

No Intervention group

Description:

Subjects were monitored at matched timepoints (start of study, 4-5 weeks, and 8-10 weeks) but not exposed to any intervention. Subjects were instructed to not make any dietary or lifestyle changes.