An interventional study of Betacarotene and Controls. No treatment in Diabetes Mellitus, Oxidative Stress and Iron Metabolism Disorders, sponsored by Instituto Venezolano de Investigaciones Cientificas. Completed at 1 site in Venezuela. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2011-11-22.
Sponsored by Instituto Venezolano de Investigaciones Cientificas · Not applicable, Interventional, and Basic science
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.
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.
8,290 studies on the registry are indexed under Diabetes Mellitus; 1,077 are open to participants now.
This study's enrollment of 117 is above the median of 80 across 6,023 interventional studies indexed under Diabetes Mellitus.
Browse Diabetes Mellitus studies →Instituto Venezolano de Investigaciones Cientificas is the lead sponsor of 5 studies on the registry; 3 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Diabetics supplemented with betacarotene for 45 days
Dietary Supplement: Betacarotene
Diabetics without betacarotene supplementation
Dietary Supplement: Controls. No treatment
Controls supplemented with betacarotene for 45 days
Dietary Supplement: Betacarotene
Controls without betacarotene supplementation
Dietary Supplement: Controls. No treatment
6 mg betacarotene in caplets for 45 days (daily)and reevaluate parameters 30 days after finishing supplementation
Also known as: β-carotene as a soft gel capsule (GNC, Pennsylvania-USA)
Evaluate at time 0, 45 days and 75 days, but without receiving betacarotene supplements
Also known as: No supplements
Changes in oxidative status
Time frame: Time 0, 45 days and 75 days after supplementation
Hemoglobin and hematocrit
Time frame: Time 0, 45 days and 75 days after supplementation
Ferritin
Enzyme linked immunosorbent assay (ELISA) with monoclonal antibodies
Time frame: Time 0, 45 days and 75 days after supplementation
Iron metabolism markers
Serum iron, total iron binding capacity (TIBC) and unsaturated iron binding capacity (UIBC) were determined by the methods proposed by the International Committee of Standardization of Hematology.
Time frame: Time 0, 45 days and 75 days after supplementation
Blood Chemistry
Glycemia, triglycerides, total cholesterol, LDL, and HDL were determined automatically in a Ciba Corning 550 Express autoanalizer, using classic enzymatic methods for the determination of these variables.
Time frame: Time 0, 45 days and 75 days after supplementation
Glycosylated Hemoglobin
It was determined using a commercial kit (Bioscience, Caracas, Venezuela),
Time frame: Time 0, 45 days and 75 days after supplementation
Oxidized LDL
Analyzed by a solid phase two-site enzyme immunoassay from Mercodia (Sweden), which contains 2 monoclonal antibodies directed against separated antigenic determinants on the oxidized apolipoprotein B molecule.
Time frame: Time 0, 45 days and 75 days after supplementation
Thiobarbituric Acid Reactive substances (TBARS)
Were detected by the quantification of malondialdehyde present in the sample, by reacting 2 molecules of thiobarbituric acid with 1 molecule of malondialdehyde, which produces an abduct that is detected at 535 mn.
Time frame: Time 0, 45 days and 75 days after supplementation
Ferric Reducing ability of Plasma (FRAP).
Measured after 4 and 10 min incubation, was used to determine the ability of plasma to reduce iron from ferric to ferrous state, based on the formation of a triazine-Fe+3 complex, that when reduced to Fe+2, generate a change in color that is measured at 593 nm.
Time frame: Time 0, 45 days and 75 days after supplementation
Activities of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx).
Determined by commercial kits (Cayman Chemicals, Pittsburg) following the recommended protocols
Time frame: Time 0, 45 days and 75 days after supplementation
Serum zinc and copper.
By flame atomic absorption spectrophotometry
Time frame: Time 0, 45 days and 75 days after supplementation
β-carotene.
It was determined by HPLC, with a reverse fase C18 column.
Time frame: Time 0, 45 days and 75 days after supplementation
Serum retinol
It was determined by HPLC, with a reverse fase C18 column, as an indirect measure of betacarotene metabolism.
Time frame: Time 0, 45 days and 75 days after supplementation
Serum nitrites
Were determined as an indirect measure of the concentration of nitric oxide, since nitrites are the stable end products of its degradation. Nitrates were reduced to nitrites by activated cadmium. Then sulfanilamide and nitrites generate a chromophore that reacts with naftilethylenediamine, to generate a product visible at 540 nm.
Time frame: Time 0, 45 days and 75 days after supplementation
Serum and erythrocyte folates.
The method is based in the folate-dependent controlled growth of a Lactobacillus strain that is measured spectrophotometrically and quantified against a standard curve.
Time frame: Time 0, 45 days and 75 days after supplementation
This study is completed, as verified in Nov 2011. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Beta Carotene
Instituto Venezolano de Investigaciones Cientificas