The Effect of a Nutritional Supplement in Individuals With Type 2 Diabetes Mellitus: a Pilot Study

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
University of Sydney
ClinicalTrials.gov Identifier:
NCT01505803
First received: October 25, 2011
Last updated: January 5, 2012
Last verified: January 2012
  Purpose

Diabetes Mellitus (DM) is a major risk factor for cardiovascular disease, with 50% of diabetes-associated deaths being attributed to cardiovascular complications. The characterising features of DM include: the presence of chronic hyperglycaemia, consequent upon decreased secretion or action of insulin; dyslipidaemia; and enhanced levels of oxidative stress and inflammation. Zinc and omega 3 polyunsaturated fatty acids have been shown to influence each of these outcomes via several mechanisms. This pilot study will examine the effect of nutritional supplements containing zinc and omega 3 on these outcomes in a population with type 2 DM.


Condition Intervention Phase
Diabetes Mellitus, Type 2
Insulin Resistance
Dietary Supplement: Zinc supplements
Dietary Supplement: Omega 3 supplements
Dietary Supplement: Placebo supplements
Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: The Effect of a Nutritional Supplement on Cardiometabolic, Inflammatory, and Oxidative Stress Markers in Individuals With Type 2 Diabetes Mellitus: a Pilot Study

Resource links provided by NLM:


Further study details as provided by University of Sydney:

Primary Outcome Measures:
  • Plasma lipids (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides) [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  • Glycaemic control (glucose, insulin, HbA1c) [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  • Inflammation & oxidative stress (CRP, TNF-α, IL-1, IL-2, IL-6, IL-10 F2 isoprostanes, NF-κB, MPO, other) [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Zinc transporter mRNA expression in peripheral blood mononuclear cells [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  • Plasma zinc [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  • Plasma fatty acids [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]

Enrollment: 48
Study Start Date: July 2010
Study Completion Date: December 2011
Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Zinc supplement Dietary Supplement: Zinc supplements
Participants will receive 40 mg of zinc each day for 12 weeks.
Dietary Supplement: Placebo supplements
Participants will receive placebo supplements each day for 12 weeks.
Active Comparator: Omega 3 supplement Dietary Supplement: Omega 3 supplements
Participants will receive 2 g of omega 3 fatty acids each day for 12 weeks.
Dietary Supplement: Placebo supplements
Participants will receive placebo supplements each day for 12 weeks.
Active Comparator: Zinc and omega 3 supplements Dietary Supplement: Zinc supplements
Participants will receive 40 mg of zinc each day for 12 weeks.
Dietary Supplement: Omega 3 supplements
Participants will receive 2 g of omega 3 fatty acids each day for 12 weeks.
Placebo Comparator: Placebo supplement Dietary Supplement: Placebo supplements
Participants will receive placebo supplements each day for 12 weeks.

Detailed Description:

The prevalence of type 2 DM and related-complications continues to increase. Diet is a significant factor in the aetiology of type 2 DM. Intakes of zinc and omega 3 fatty acids may modulate glycaemic control, lipid metabolism, and inflammatory processes in the disease. Zinc is involved in many biological processes that include enzyme action, stabilisation of cell membranes, regulation of gene expression, and cell signalling. Zinc supplementation has been demonstrated to improve glycaemic control in both animals and humans. The normalising effect of zinc on glucose homeostasis may relate to its involvement in insulin metabolism. Zinc functions in the synthesis, storage, secretion, and action of insulin. Omega-3 also enhances glycaemic control and dietary supplementation with omega-3 polyunsaturated fatty acids has been shown to improve insulin sensitivity in subjects with DM. Both zinc and omega-3 function to mediate lipid metabolism. Zinc supplementation has been found to be associated with a beneficial increase in HDL cholesterol concentrations in individuals with type 2 DM. The mechanism may again involve insulin, which has been proposed as an independent predictor of plasma HDL. Omega-3 directly activates transcription factors that regulate lipid metabolism and is known to decrease serum triglyceride levels in DM. Zinc appears to beneficially impact oxidative stress-related parameters in DM via a range of mechanisms, including the regulation of copper,zinc superoxide dismutase, metallothionein, NF-κB and nitric oxide signaling. The purpose of this pilot study is to explore the effect of zinc and omega 3 supplementation on hyperglycaemia, dyslipidaemia, chronic inflammation, and oxidative stress in a population with type 2 DM.

This study will recruit 48 postmenopausal women with type 2 DM. Participants will be randomly allocated to one of 4 groups for a period of 12 weeks: placebo, zinc, omega 3, or zinc + omega 3 supplementation. Usual dietary intake will be assessed before and after the trial period using 2-day estimated food records, which will be checked by a research dietitian. Blood samples will be collected from all participants at the start of the intervention (week 0) then at 4 weekly intervals (weeks 4, 8, 12) by qualified phlebotomists. Blood samples will be analysed for plasma zinc, plasma lipids and fatty acids, markers of inflammation and oxidative stress, and indicators of glycaemic control. An aliquot of blood will also be used for the measurement of zinc transporter mRNA levels utilising real-time quantitative PCR techniques.

  Eligibility

Ages Eligible for Study:   48 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Female, postmenopausal
  • Type 2 diabetes (controlled by diet and lifestyle; or oral hypoglycaemic medication (i.e. metformin) for not more than 7 years)
  • Normal Glomerular Filtration Rate (GFR) and normal microalbumin/creatine ratio
  • No nutritional supplements in the 6 weeks prior to the trial & continuing through the trial period
  • Non-smoking

Exclusion Criteria:

  • Diagnosed with current major illness (renal disease, significant cardiovascular disease, gastrointestinal disorders, cancer, or other significant disorder likely to interfere with zinc metabolism)
  • Taking medications that are likely to interfere with zinc metabolism
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01505803

Locations
Australia, New South Wales
University of Sydney
Sydney, New South Wales, Australia, 2006
Sponsors and Collaborators
University of Sydney
Investigators
Principal Investigator: Samir Samman University of Sydney
Principal Investigator: Meika Foster University of Sydney
  More Information

Publications:
Responsible Party: University of Sydney
ClinicalTrials.gov Identifier: NCT01505803     History of Changes
Other Study ID Numbers: HREC 12392
Study First Received: October 25, 2011
Last Updated: January 5, 2012
Health Authority: Australia: Human Research Ethics Committee

Keywords provided by University of Sydney:
Type 2 diabetes mellitus
Dietary supplements
Hyperglycemia
Insulin resistance
Dyslipidemia
Inflammation
Oxidative stress
Zinc
Omega 3

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hyperinsulinism
Zinc
Trace Elements
Micronutrients
Growth Substances
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on July 22, 2014