2. Subjects and methods
2.1. Participants
In the current randomized double-blind placebo controlled
clinical trial, patients with DN aged 45e85 years old referred to
Akhavan Clinic in Kashan, Iran from March 2015eJune 2015 were
selected as our subjects. We defined DN as diabetic renal disease
with a proteinuria level>0.3 g/24 h, with or without elevation of
serum creatinine levels [14]. The exclusion criteria were as follows:
the intake of omega-3 fatty acid supplements within 3 months,
patients with uncontrolled diabetes, the current use of warfarin,
malignancy and/or liver cirrhosis. To calculate sample size, we used
the standard formula suggested for clinical trials [15] with
considering type one error (a) of 0.05 and type two error (b) of 0.20
(power ¼ 80%). Based on a previous study [7],we used 2.1 as SD and
1.7 as the distinction in mean (d) of the homeostasis model of
assessment-insulin resistance (HOMA-IR) as key variable. Based on
this, we reached 25 patients in each group. Assuming 5 dropouts in
each group, the ultimate sample size was determined to be 30
subjects per group. The current trial was carried out in accordance
with the Declaration of Helsinki. The informed written consent was
taken from all enrolled patients, with ethical clearance for the study
obtained from the ethics committee of Kashan University of Medical
Sciences (KUMS). The current trial was recorded in the Iranian
website for registration of clinical trials (http://www.irct.