Effect of Dietary Sodium Intake on Vascular Endothelium
This trial is active, not recruiting.
|Condition||postural tachycardia syndrome (pots)|
|Treatments||pulsitile arterial tonometry (pat) protocol, calf blood flow in reactive hyperemia (cbf-rh), evaluation of forearm-mediated dilation|
|Collaborator||National Institutes of Health (NIH)|
|Start date||April 2012|
|End date||March 2017|
|Trial size||50 participants|
|Trial identifier||NCT01550315, 111577, R01HL102387|
The investigators will test the hypothesis that markers of vascular endothelial dysfunction will be exaggerated acutely with an extreme high sodium diet compared to an extreme low-sodium diet. The investigators will compare patients with postural orthostatic tachycardia (POTS) to healthy control subjects.
|Intervention model||crossover assignment|
|Primary purpose||basic science|
time frame: On steady state (after 5 days) low and high sodium diets
fasting glucose and insulin levels
time frame: after steady state has been reached (>5 days) on low and high sodium diets
Male or female participants from 18 years up to 60 years old.
Inclusion Criteria: - Subjects will be enrolled in the parent study "Dietary Salt in Postural Tachcyardia Syndrome" funded by R01 HL102387 Postural Tachycardia Syndrome - Diagnosed with postural tachycardia syndrome by the Vanderbilt Autonomic Dysfunction Center - Subjects will be enrolled in the parent study "Dietary Salt in Postural Tachcyardia Syndrome" funded by R01 HL102387 - Postural Tachycardia Syndrome - Diagnosed with postural tachycardia syndrome by the Vanderbilt Autonomic Dysfunction Center - Increase in heart rate ≥30 beats/min with position change from supine to standing (10 minutes) - Chronic symptoms consistent with POTS that are worse when upright and get better with recumbence Control Subjects - Healthy, non-obese, non-smokers without orthostatic tachycardia - Selected to match profiles of POTS patients (gender, age) - Not using vasoactive medication - Age between 18-60 years - Male and female subjects are eligible. - Able and willing to provide informed consent Exclusion Criteria: - Overt cause for postural tachycardia (such as acute dehydration) - Inability to give, or withdrawal of, informed consent - Pregnant - Other factors which in the investigator's opinion would prevent the subject from completing the protocol.
|Official title||A Pilot Study of the Effect of Dietary Sodium Intake on Assessments of Vascular Endothelium|
|Principal investigator||Satish R Raj, MD MSCI|
|Description||The study will involve a crossover design in which each subject will be assessed (as below) while on a very low-sodium (10 mEq/day) diet compared with a very high-sodium diet. These acute dietary interventions will be part of the parent study ("Dietary Salt in Postural Tachcyardia Syndrome" funded by R01 HL102387) for 4-5 days at the time of the study. Dietary success will be assessed using a 24h urine for sodium and creatinine as a part of the parent study. Blood will be drawn and collected in a fasting state for future assay and analysis of the following tests: - Glucose, Insulin (glucose impairment, insulin resistance) - Fasting lipid profile - C-Reactive Protein (hsCRP) (inflammatory state) - Inflammatory cytokines (inflammatory state) - aliquots (future analysis) Pulsitile Arterial Tonometry (PAT) Protocol Calf Blood Flow in Reactive Hyperemia (CBF-RH) - venous occlusion plethysmography Evaluation of Forearm-Mediated Dilation|
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