Heat pads versus high-intensity interval training to improve muscle and blood sugar in older adults with prediabetes

Glycemic Control and Frailty Risk in Older People at Risk for Type 2 Diabetes: Impact of Local Heat Therapy

This project will test whether daily thigh heat pads can improve muscle health, physical function, and blood sugar control as well as high-intensity interval training in older adults with prediabetes.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 54 (estimated)
• Ages: 50 Years and up
• Sex: All
• Sponsor: Texas Tech University (other)
• Locations: 1 site (Lubbock, Texas)
• Trial ID: NCT06580964 on ClinicalTrials.gov

What this trial studies

This two-phase interventional study first compares daily local heat therapy applied to the thighs with high-intensity interval training (HIIT) and a temperature-control heat condition for 12 weeks, measuring muscle structure, capillary and mitochondrial markers, glucose tolerance, and physical function. In the second phase, participants who received heat or control therapy will then complete a 12-week HIIT program to see whether prior heat exposure changes the muscle and metabolic response to exercise. Participants attend multiple laboratory visits for baseline, mid, and end-of-phase assessments, keep logs of home heat-pad sessions, and undergo standardized exercise sessions in the lab. Primary outcome measures focus on skeletal muscle architecture, glucose regulation, and frailty-related physical function changes.

Who should consider this trial

Good fit: Ideal candidates are sedentary adults aged 50 or older with prediabetes (fasting glucose 100-125 mg/dL or A1c 5.7-6.4%), who weigh at least 110 pounds and are not on medications that interfere with metabolism or study interventions.

Not a fit: People with peripheral neuropathy, those taking prescription blood thinners, or those on excluded medications are unlikely to benefit or be eligible for this protocol.

Why it matters

Potential benefit: If successful, local heat therapy could offer a lower-effort way to improve muscle health and blood sugar control for older adults who cannot do high-intensity exercise.

How similar studies have performed: Small human and animal studies of passive heat exposure and whole-body heat therapies have shown improvements in blood flow, mitochondrial markers, and glucose metabolism, but direct comparisons of local heat pads to HIIT are limited.

Eligibility criteria

Inclusion Criteria:

* Age ≥ 50 years
* Women who are postmenopausal, defined as no menstrual period for at least 12 consecutive months.
* Sedentary (structured exercise \<30 minutes, 3x/week)
* Body weight is at least 110 lbs
* Meet criteria for prediabetes (fasting blood glucose 100-125 mg/dl, hemoglobin A1c 5.7-6.4%)
* Consume \<8 (women) or \<15 (men) alcohol-containing beverages per week
* Do not use nicotine or cannabis
* Not taking any medications that could interfere with responses to the interventions (e.g., corticosteroids, opiates, benzodiazepines, tricyclic antidepressants, beta blockers, sulfonylureas, insulin, metformin, anticoagulants, barbiturates, insulin sensitizers, fibrates, immunosuppressants). If you don't know, that's okay. We'll ask what medications you are on and check whether they fall into one of these categories.

Exclusion Criteria:

* History of peripheral neuropathies
* Currently taking prescription blood thinners
* Medical complications that could would contraindicate participation in the high intensity interval training (HIIT) intervention including: orthopedic complications that would limit your ability to perform cycling exercise, significant cardiovascular impairments (e.g., history of arrhythmias, severe uncontrolled hypertension, etc.), diagnosed metabolic disease (e.g., diabetes), renal disease, sickle cell anemia, or cancer in remission for \<6 months.
* Known history of slow wound healing
* Lidocaine allergy
* Latex allergy
* Currently pregnant
* \>1.5" subcutaneous fat over the thigh muscle
* Symptoms suggestive of cardiovascular, respiratory, metabolic, or renal diseases including discomfort, pressure, or pain in your chest, neck, jaw, arms, calves, or other areas potentially related to ischemia; shortness of breath at rest or with mild exertion; dizziness or fainting (syncope); difficulty breathing while lying flat (orthopnea) or sudden nighttime breathing difficulties (paroxysmal nocturnal dyspnea); palpitations or rapid heartbeat (tachycardia); pain or cramping in your legs during physical activity (intermittent claudication); a known heart murmur; swelling in your ankles (edema); unusual fatigue or shortness of breath during routine activities or at rest.

Where this trial is running

Lubbock, Texas

• Texas Tech University — Lubbock, Texas, United States (RECRUITING)

Study contacts

• Principal investigator: Hui-Ying Luk, PhD; Danielle Levitt, PhD — Texas Tech University
• Study coordinator: Hui-Ying Luk, PhD

Conditions: Prediabetic State, Exercise, Heat, Aging, Prediabetes, Skeletal Muscle