Metabolic Syndrome | Effects of Pioglitazone Treatment on Sympathetic Nervous System Function in Metabolic Syndrome Obesity

Metabolic Syndrome research study

What is the primary objective of this study?

An abdominal distribution of fat is associated with the greatest heart disease risk, because commonly, several risk factors of metabolic origin cluster in these individuals. When this occurs the condition is called the 'metabolic syndrome'. Increased activity of the sympathetic nervous system resulting in enhanced release of the stress hormone 'noradrenaline', may be one mechanism by which adverse cardiovascular and metabolic sequela of the metabolic syndrome might be mediated. Impaired insulin action may be one factor contributing to increased noradrenaline release. The aim of this Study is to determine whether treatment with a drug called pioglitazone which is known to improve insulin action, results in reduced sympathetic nervous system activity and stress hormone release when compared to treatment with a dummy drug (placebo).

Who is eligible to participate?

Inclusion Criteria: - Males and females aged 45-65 years, - non-smokers, - HOMA index > 2.5 and - who meet ATP III criteria for the metabolic syndrome Exclusion Criteria: - History of diabetes, - previous MI, stroke, heart failure, impaired hepatic or renal function. - Inability to cease medications which may affect study parameters.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Metabolic Syndrome

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:Pioglitazone15 mg per day for 6 weeks and 30 mg per day for further 6 weeks

Drug:sugar pillOne capsule daily for 6 weeks followed by two capsules per day for next 6 weeks

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Pioglitazonepioglitazone 15 mg for 6 weeks followed by 30 mg for 6 weeks

sugar pillPlacebo comparator

Study Status

Unknown status

Start Date: November 2008

Completed Date: February 2013

Phase: Phase 3

Type: Interventional


Primary Outcome: Sympathetic nervous system activity, measured as muscle sympathetic nervous activity and whole-body noradrenaline spillover

Secondary Outcome: Baroreflex function, adrenoceptor expression

Study sponsors, principal investigator, and references

Principal Investigator: Nora E Straznicky, PhD, MPH

Lead Sponsor: Baker Heart Research Institute

Collaborator: National Heart Foundation, Australia

More information:

Esler M, Straznicky N, Eikelis N, Masuo K, Lambert G, Lambert E. Mechanisms of sympathetic activation in obesity-related hypertension. Hypertension. 2006 Nov;48(5):787-96. Epub 2006 Sep 25. Review.

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