The effects of selenium supplementation on advanced glycation end products, biomarkers of inflammatory and oxidative stress in diabetic nephropathy patients in comparison with placebo: a randomized double-blinded controlled clinical trial

The aim of this study is to determine the effects of selenium supplementation on advanced glycation end products (AGEs), inflammatory factor and biomarkers of oxidative stress in diabetic nephropathy patients.

Randomized double-blinded controlled clinical trial. Blinding is carried out for patients and researchers and randomization in done by random table numbers. Patients will be assigned to receive either selenium (intervention group: n=30) or placebo (control group: n=30).

Among patients with diabetic nephropathy referred to the Shahid Beheshti Clinic affiliated to Kashan University of Medical Sciences, 60 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 baseline and 12 weeks after the intervention.

Patients with diabetic nephropathy aged 40 to 85 years will be included in this study. Inclusion Criteria: Patients with diabetic nephropathy with a proteinuria level of >0.3 g/24 hours, with or without circulating levels of serum creatinine. Exclusion criteria: The consuming selenium supplements within 3 months before beginning of the study, history of hospital admission within 3 months, bacteriuria, haematuria, urinary tract infection, patients with uncontrolled diabetes, pregnant women and those with liver or inflammatory diseases.

Patients will be assigned to receive either selenium (intervention group: n=30) or placebo (control group: n=30).

Outcomes: Markers of insulin, insulin resistance and high-sensitivity C-reactive Protein (primary outcomes) and other metabolic profiles (secondary outcomes) will be quantified at study baseline and end-of-trial.

Vice chancellor for research, Kashan University of Medical Sciences

At study baseline and after stratification for pre-intervention BMI and age, subjects will be randomly divided into two groups to take either selenium supplements (n = 30) or placebo (n = 30). Randomization will be done by the use of computer-generated random numbers.

Randomization and allocation will be concealed from the researchers and participants until the final analyses are completed. Another person at the Shahid Beheshti Clinic, who is not involved in the trial and not aware of random sequences, will be assigned the participants to the numbered bottles of capsules.