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NCT Number: NCT06776081

Adipocyte-Derived Extracellular Vesicles, Weight Loss, and Endothelial Function

Changes in adipose tissue biology are now recognized as a key factor underlying the increased risk of metabolic and cardiovascular disease with obesity. Clinical interest in adipocyte-derived extracellular vesicles (Ad-EVs) has intensified due to their potential as circulating biomarkers of adipose tissue health and systemic messengers, regulators and mediators of cardiometabolic health and disease with obesity.

The investigators hypothesize that elevated Ad-EVs in adults with obesity will be negatively associated with endothelium-dependent vasodilation. Furthermore, the investigators hypothesize that in adults with obesity, intentional weight loss-induced reduction in circulating Ad-EVs is associated with greater endothelium-dependent vasodilation.

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Key information

Conditions

Obesity Body Weight Body Weight Changes Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms Weight Loss

Age range

40 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Colorado Boulder Clinical and Translational Research Center (CTRC)

Boulder, Colorado, 80309, United States

Location status: Recruiting

Location contact

Jared Greiner, MS

CONTACT

[email protected]

303-735-3056

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥40 years
  • BMI <25 kg/m2 and BMI >25 kg/m2 for Phase 1 and BMI >25 kg/m2 for Phase 2. Rationale for defining obesity as BMI >25 kg/m2

Exclusion criteria

  • Current smoker
  • Chronic overt medical condition (e.g., evidence of coronary artery disease on resting ECG, any history of myocardial infarction or stroke, or cancer, diabetes based on fasting blood glucose concentration)
  • Alcohol abuse or dependence defined as more than 14 standard drinks/week and no more than 4 standard drinks/day for men and 7 standard drinks/week and 3 standard drinks/day for women (a standard drink is defined as 12 ounces of beer, 5 ounces of wines, 1 ½ ounces of 80-proof distilled spirits) reported during the medical history/physical exam
  • Stage III hypertension (systolic blood pressure >160 mmHg and/or diastolic blood pressure >100 mmHg)
  • Regular vigorous aerobic/endurance exercise (>3 bouts/week, >30 minutes/bout at a workload >6 METS)
  • Women who are pregnant or breastfeeding
  • History of anaphylaxis to betadine, lidocaine, iodine
  • Raynaud's disease
  • History of clotting disorders
  • Anyone taking blood thinners and clotting medications
  • Anyone taking statin medication
  • Planned pregnancy in coming 4-6 months

Treatment and study plan

Weight loss without pharmacotherapy

Other

Adults with obesity participating in the 12-week hypocaloric diet-induced weight loss intervention will be individually counseled by the Clinical and Translational Research Center (CTRC) bionutritionist to consume a hypocaloric diet consistent with current dietary recommendations for weight loss until a 6-10% weight loss is achieved.

Primary outcomes

  1. Phase 1: Circulating adipocyte-derived extracellular vesicles (Ad-EVs)

    Time frame: Circulating Ad-EVs will measured during Phase 1 visit 2 which is ~2 weeks from their respective start date.

    Circulating Ad-EVs will be determined from a peripheral blood sample in normal weight and obese adults. Ad-EVs will be determined using flow cytometry. The samples will be incubated with perilipin A. Ad-EVs will be defined as perilipin A positive cells ranging in size 0.2-0.8 um.

  2. Phase 2: Circulating adipocyte-derived extracellular vesicles (Ad-EVs)

    Time frame: Circulating Ad-EVs will be measured during Phase 2 visit 15 which is ~17 weeks from their respective start date.

    Circulating Ad-EVs will be determined from a peripheral blood sample following the obese participants 12-week weight loss intervention.

  3. Phase 1: Forearm Blood Flow (FBF) Response to Acetylcholine (ACh)

    Time frame: FBF response to ACh will be measured during Phase 1 and the participant's visit 2 which is ~ 2 weeks from their respective start date.

    FBF is measured via strain-gauge venous occlusion plethysmography in response to saline for 5 minutes and then to ACh (4.0, 8.0 and 16.0 ug/100 mL tissue/min; the doses of ACh infused into the brachial artery) for 5 minutes at each dose. Flows during the last minute of saline and each drug dose are measured and the mean value reported.

  4. Phase 2: Forearm Blood Flow (FBF) Response to Acetylcholine (ACh)

    Time frame: FBF response to ACh will be measured during Phase 2 and the participant's visit 15 which is ~17 weeks from their respective start date.

    FBF is measured via strain-gauge venous occlusion plethysmography in response to saline for 5 minutes and then to ACh (4.0, 8.0 and 16.0 ug/100 mL tissue/min; the doses of ACh infused into the brachial artery) for 5 minutes at each dose. Flows during the last minute of saline and each drug dose are measured and the mean value reported.

  5. Phase 1: Forearm Blood Flow (FBF) Response to Sodium Nitroprusside (NTP)

    Time frame: FBF response to NTP will be measured during Phase 1 and the participant's visit 2 which is ~ 2 weeks from their respective start date.

    FBF is measured via strain-gauge venous occlusion plethysmography in response to saline for 5 minutes and then to NTP (1.0, 2.0 and 4.0 ug/100 mL tissue/min; the doses of NTP infused into the brachial artery) for 5 minutes at each dose. Flows during the last minute of saline and each drug dose are measured and the mean value reported.

  6. Phase 2: Forearm Blood Flow (FBF) Response to Sodium Nitroprusside (NTP)

    Time frame: FBF response to NTP will be measured during Phase 2 and the participant's visit 15 which is ~17 weeks from their respective start date.

    FBF is measured via strain-gauge venous occlusion plethysmography in response to saline for 5 minutes and then to NTP (1.0, 2.0 and 4.0 ug/100 mL tissue/min; the doses of NTP infused into the brachial artery) for 5 minutes at each dose. Flows during the last minute of saline and each drug dose are measured and the mean value reported.

Study contacts

Contact information is provided by the study sponsor or research team.

Jared Greiner, MS

CONTACT

[email protected]

303-735-3605

Sponsors and collaborators

Lead sponsor

University of Colorado, Boulder

Other

Registry information

Official study title

Adipocyte-Derived Extracellular Vesicles; Novel Biomarker and Mediator of Obesity-Related Endothelial Dysfunction

Important dates

Study start
2024
Primary completion
2027
Study completion
2027
First posted
Jan 15, 2025
Registry last updated
Apr 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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