The High Density Lipoprotein and Endothelial Function, Niacin and Nitric Oxide Study (The High-Ennd Study)

Randomized Clinical Trial to Study the Effect of Extended Release Niacin on Endothelial Function, Oxidative Stress and Endothelial Progenitor Cells in Patients With the Metabolic Syndrome.

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00346970

Enrollment

Registered

2006-07-04

Start date

2006-07-31

Completion date

2007-07-31

Last updated

2008-05-06

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

Conditions

Metabolic Syndrome

Keywords

Metabolic Syndrome, High Density Lipoprotein, Extended-Release Niacin, Endothelial Function, Endothelial Progenitor Cells

Brief summary

The aim of the present study is to characterize novel mechanisms whereby HDL may exert potent vasculoprotective effects independent of reverse cholesterol transport, in particular the effect of HDL on the regulation of the vascular NAD(P)H oxidase enzyme system, a major vascular source of superoxide, known to be important for endothelial dysfunction. In addition, the present study will characterize the effect of HDL on endothelial progenitor cell (EPC) mobilization, nitric oxide production and in vivo regenerative capacity.

Interventions

DRUGExtended-Release Niacin

Extended-Release Niacin tablets week 1-4 500 mg/d week 4-8 1000 mg/d week 9-12 1500 mg/d

DRUGPlacebo

Placebo tablets

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

21 Years to 70 Years

Healthy volunteers

Yes

Inclusion criteria

* Statin treatment for at least 3 weeks * Reduced HDL: \< 40 mg/dL (1.03 mmol/L) in men or \< 50 mg/dL (1.29 mmol/L) in women * Plus TWO of the following (thereby defining the patients to have metabolic syndrome (Grundy et al.; Circulation 2005)): * Elevated waist circumference: ≥ 102 cm (≥ 40 inches) in men or ≥ 88 cm (≥ 35 inches) in women * Elevated triglycerides: ≥ 150 mg/dL (1.7 mmol/L * Elevated blood pressure: ≥ 130 mmHg systolic blood pressure or ≥ 80 mmHg diastolic blood pressure or anti-hypertensive treatment * Elevated fasting glucose: ≥ 100 mg/dL or on drug treatment for elevated fasting glucose

Exclusion criteria

* Hypersensitivity to niacin * Active liver disease or impaired liver function * Persistent elevation of transaminases * Cholestasis * Gastric ulcer * Acute coronary syndrome * Gout * Pregnancy, lactation * Active infections * Cancer * Untreated concomitant diseases * Renal insufficiency or renal failure * Hypothyreosis * Alcoholism * Myopathies * Muscle pain under therapy with fibrates or statins * Hereditary muscle diseases in family history

Design outcomes

Primary

Measure	Time frame
Antioxidative Properties of Endothelial Progenitor Cells	3 months
FDD	3 months

Secondary

Measure	Time frame
High Density Lipoprotein (HDL) Elevation	3 months

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 1, 2026