Vascular health in severely obese adolescents: effects of weight loss

Macro- and microcirculation in severely obese adolescents: effects of a 4-month weight loss program

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN99414527

Enrollment

Registered

2013-04-16

Start date

2011-06-01

Completion date

Unknown

Last updated

2021-04-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Severe obesity in adolescents Nutritional, Metabolic, Endocrine Obesity

Interventions

Since their admission in the pediatric weight center, the SOA group will undergo a 4-month weight loss program consisting of diet and exercise. SOA will receive a moderately hypocaloric diet (reductio

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Adolescents with severe obesity. BMI z-scores greater than 3 defined severe obesity 2. Healthy normal-weight matched for gender and pubertal stage to serve as controls 3. All subjects will be normotensive (defined as a pressure < 95th sex-, age-, and height-specific percentiles), non-diabetic, and free from further known obesity-related comorbidities

Exclusion criteria

Exclusion criteria: 1. A family history of premature cardiovascular disease 2. Intake of any medication 3. Pubertal status assessed by Tanner stage 3 h of exercise per week) to minimize training effects

Design outcomes

Primary

Measure	Time frame
1. Endothelium-dependent and ?independent dilation in the brachial conduit artery: Macrovascular assessment of the brachial conduit artery will be performed according to the International Brachial Reactivity Task Force Guidelines (Corretti et al., 2002). Brachial measurements will be achieved using high-resolution vascular ultrasonography (MyLab30, Esaote SpA, Firenze, Italy), with a 10-MHz multi-frequency linear probe. The ultrasound probe will be placed approximately midway between the antecubital and axillary regions. To assess endothelium-dependent vasodilation, the brachial artery diameter will be measured before, during and after reactive hyperemia (flow-mediated dilation, FMD). Reactive hyperemia will be induced by inflating a pneumatic cuff on the right forearm near the elbow to 250 mm Hg for 5 minutes and then deflating it. Fifteen minutes later, baseline measurements will be repeated, before and after sublingual administration of 0.4 mg of isosorbide dinitrate (Isocard, Schwarz Pharma, Monheim, Germany), an organic nitrate considered to be an endothelium-independent vasodilator (nitrate-mediated dilation, NMD) assessing arterial smooth muscle function. This procedure is described in detail elsewhere (Karpoff et al., 2009). B-mode images, Doppler signals and electrocardiographic data will be recorded and stored for offline analysis. FMD and NMD will be expressed as the percentage change of peak diastolic brachial diameter after reactive hyperemia and organic nitrate administration, respectively, relative to the baseline diastolic diameter. Time-averaged mean blood flow velocity and blood flow will be determined, as previously described (Walther et al., 2006). Shear rate (s-1) will be calculated as 4 × time-averaged mean blood flow velocity/mean brachial diameter, to estimate resting and peak shear stress (Betik et al., 2004). Normalization of FMD by the net shear rate stimulus (peak minus resting shear rate, ?shear rate) will be explored to	—

Measure

Time frame

1. Endothelium-dependent and ?independent dilation in the brachial conduit artery: Macrovascular assessment of the brachial conduit artery will be performed according to the International Brachial Reactivity Task Force Guidelines (Corretti et al., 2002). Brachial measurements will be achieved using high-resolution vascular ultrasonography (MyLab30, Esaote SpA, Firenze, Italy), with a 10-MHz multi-frequency linear probe. The ultrasound probe will be placed approximately midway between the antecubital and axillary regions. To assess endothelium-dependent vasodilation, the brachial artery diameter will be measured before, during and after reactive hyperemia (flow-mediated dilation, FMD). Reactive hyperemia will be induced by inflating a pneumatic cuff on the right forearm near the elbow to 250 mm Hg for 5 minutes and then deflating it. Fifteen minutes later, baseline measurements will be repeated, before and after sublingual administration of 0.4 mg of isosorbide dinitrate (Isocard, Schwarz Pharma, Monheim, Germany), an organic nitrate considered to be an endothelium-independent vasodilator (nitrate-mediated dilation, NMD) assessing arterial smooth muscle function. This procedure is described in detail elsewhere (Karpoff et al., 2009). B-mode images, Doppler signals and electrocardiographic data will be recorded and stored for offline analysis. FMD and NMD will be expressed as the percentage change of peak diastolic brachial diameter after reactive hyperemia and organic nitrate administration, respectively, relative to the baseline diastolic diameter. Time-averaged mean blood flow velocity and blood flow will be determined, as previously described (Walther et al., 2006). Shear rate (s-1) will be calculated as 4 × time-averaged mean blood flow velocity/mean brachial diameter, to estimate resting and peak shear stress (Betik et al., 2004). Normalization of FMD by the net shear rate stimulus (peak minus resting shear rate, ?shear rate) will be explored to

—

Secondary

Measure	Time frame
Blood analysis: Fasting blood samples will be collected after an overnight fast. Biochemical markers related to vascular function such as leptin, resistin, C-reactive protein, myeloperoxidase, and tissue plasminogen activator will be determined in plasma by bead-based multiplex immunoassays (FlowCytomix, eBioscience, San Diego, CA, USA). Plasma insulin will be measured using the radioimmunoassay method (coat-a-count radioimmunoassay kit TKIN2, Siemens, Berlin, Germany).	—

Measure

Time frame

Blood analysis: Fasting blood samples will be collected after an overnight fast. Biochemical markers related to vascular function such as leptin, resistin, C-reactive protein, myeloperoxidase, and tissue plasminogen activator will be determined in plasma by bead-based multiplex immunoassays (FlowCytomix, eBioscience, San Diego, CA, USA). Plasma insulin will be measured using the radioimmunoassay method (coat-a-count radioimmunoassay kit TKIN2, Siemens, Berlin, Germany).

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Countries

France

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 24, 2026