Clinical trial NCT01477112: Low Dose β-carotene Supplementation Diminishes Oxidative Stress in Type 2 Diabetics and Healthy Individuals
Official title: Effect of the Supplementation With β-carotene to Type 2 Diabetic Patients and Healthy Controls on the Iron Status and Antioxidant Capacity of Plasma
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diabetes Mellitus
Oxidative Stress
Iron Metabolism Disorders
Keywords: Type 2 diabetes
β-carotene
Oxidative balance
Oxidants
Antioxidants
Lead sponsor: Instituto Venezolano de Investigaciones Cientificas
Sponsor class: OTHER
Collaborators: name: Seguros Caracas Foundation
name: National Fund for Science and Technology, Science Mission
First posted: 2011-11-22
Enrollment: 117
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: Since diabetes has multiple etiologies and oxidative stress one of the proposed mechanisms, the objective is to determine the effect of supplementation with β-carotene to type 2 diabetics and healthy individuals, on iron metabolism, oxidative balance, and antioxidant plasma capacity, using doses similar to the daily nutritional requirement.

Detailed description: Type 2 diabetes is a chronic, multifactorial disease, and oxidative stress one of the pathophysiological mechanisms associated with its appearance and development. The objective was to determine the effect of supplementation with β-carotene to type 2 diabetics and healthy individuals, on iron metabolism, oxidative balance, and antioxidant plasma capacity, using doses similar to the daily nutritional requirement.

A total of 117 volunteers participated in the study. Type 2 diabetics (34) and healthy individuals (24), received 6 mg β-carotene for 45 d, and were compared to similar non-supplemented diabetic (33) and control (26) groups. Blood samples were taken at the beginning, end and 30 days after finishing supplementation, to determine hemoglobin, hematocrit unsaturated iron binding capacity, total iron binding capacity, transferrin saturation, ferritin, glycemia, glycosylated hemoglobin, cholesterol, triglycerides, HDL, LDL, oxidized LDL, copper, zinc, TBARS, FRAP, nitrites, GPx, SOD, folates, retinol and β-carotene.

Eligibility criteria: Inclusion Criteria:

Patients with a diagnose of Type 2 diabetes mellitus of at least 5 years of diagnosis, in treatment with oral hypoglycemics Patients in regular control (once a month) in the Hospital

Exclusion Criteria:

* Hospitalized patient
* Diabetic patient with diabetes related acute complications (ketoacidosis, hyperosmolar coma)in the 3 months previous to the study.
* Individuals with infections that required antibiotics in the 3 weeks previous to the study.
* Individuals with antibodies anti-insulin, autoimmune diseases or in treatment with immunosuppressive drugs.
* Individuals with viral infections such as hepatitis B, hematological, renal or hepatic diseases.
* Pregnancy

Primary outcomes:
measure: Changes in oxidative status
timeFrame: Time 0, 45 days and 75 days after supplementation
Secondary outcomes:
measure: Hemoglobin and hematocrit
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Ferritin
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Iron metabolism markers
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Blood Chemistry
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Glycosylated Hemoglobin
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Oxidized LDL
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Thiobarbituric Acid Reactive substances (TBARS)
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Ferric Reducing ability of Plasma (FRAP).
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Activities of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx).
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Serum zinc and copper.
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: β-carotene.
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Serum retinol
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Serum nitrites
timeFrame: Time 0, 45 days and 75 days after supplementation
measure: Serum and erythrocyte folates.
timeFrame: Time 0, 45 days and 75 days after supplementation
Other outcomes:
Locations:
city: Barquisimeto
country: Venezuela
facility: Hospital Baudilio Lara
state: Lara
Study officials:
affiliation: Instituto Venezolano de Investigaciones Cientificas
name: Maria N Garcia-Casal, PhD
role: STUDY_DIRECTOR
affiliation: Instituto Venezolanode Investigaciones cientificas
name: Jose M Moreno, PhD
role: PRINCIPAL_INVESTIGATOR
References:
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citation: Sugiura M, Nakamura M, Ikoma Y, Yano M, Ogawa K, Matsumoto H, Kato M, Ohshima M, Nagao A. The homeostasis model assessment-insulin resistance index is inversely associated with serum carotenoids in non-diabetic subjects. J Epidemiol. 2006 Mar;16(2):71-8. doi: 10.2188/jea.16.71.
citation: Song Y, Cook NR, Albert CM, Van Denburgh M, Manson JE. Effects of vitamins C and E and beta-carotene on the risk of type 2 diabetes in women at high risk of cardiovascular disease: a randomized controlled trial. Am J Clin Nutr. 2009 Aug;90(2):429-37. doi: 10.3945/ajcn.2009.27491. Epub 2009 Jun 2.