Clinical trial of the effect of combined omega-3 and vitamin D supplementation compared with the placebo on carotid intima-media thickness and metabolic profiles in type 2 diabetic patients with coronary heart disease

The aim of this study is to determine the effects of combined omega-3 and vitamin D supplementation on carotid intima-media thickness (CIMT) and metabolic profiles in type 2 diabetic patients with coronary heart disease (CHD).

Randomized double-blind placebo-controlled trial.

Among patients with coronary heart disease referred to Cardiology Clinic affiliated to Kashan University of Medical Sciences, 74 patients will be selected according to inclusion and exclusion criteria. Participants, investigators or the assessors of the outcomes are unaware of the study groups. Supplements and placebos are similar in shape and size. Fasting blood samples will be taken at the beginning and the end of intervention.

Inclusion criteria: Individuals aged 45-85 years diagnosed with type 2 diabetes, CHD and vitamin D-deficient. Exclusion criteria: Consuming vitamin D supplements and omega-3 fatty acids within the last 3 months, experiencing an acute myocardial infarction or cardiac surgery within the past 3 months, renal or hepatic disorder.

Intervention group: 2000 mg omega-3 daily (Barij Essence, Kashan, Iran) and 50000 IU vitamin D every 2 weeks (Zahravi, Tabriz, Iran), for 24 weeks orally. Control group: Placebo capsule (Barij Essence, Kashan, Iran), every 2 weeks for 24 weeks orally.

Carotid intima-media thickness (primary outcome) and metabolic profiles (secondary outcomes) will

Due to an error, the request for an update in our website has conducted after paper published. However, the revisions were accordance with coordination with Vice Chancellor of Research at the University.

Vice chancellor for research, Kashan University of Medical Sciences

To decrease potential confounding effects, all participants will have stratified randomization according to BMI and age. Then, participants in each block will be randomly allocated into two treatment groups to take either omega-3 and vitamin D supplement or placebo. Randomization will be done by the use of Stat Trek software. Participants, investigators or the assessors of the outcomes are also unaware of the study groups. https://stattrek.com/statistics/random-number-generator.aspx

Randomization and allocation will be concealed from the researchers and participants until the final analyses are completed. Another person at the Cardiology clinics affiliated with Kashan University of Medical Sciences, who is not involved in the trial and not aware of random sequences, will be assigned the participants to the numbered bottles of capsules. Supplements and placebo are in the same packaging at the Barij Essence pharmaceutical company. Only the code is written on the packages. Patients and researcher do not know the type of drug and after analyzing the data, packet codes are decoded.