Study participants
The present study was a randomized, double-blind, placebo-controlled
clinical trial in which 60 overweight or obese women aged 25 to 50
years, with a body mass index (BMI) 25-35 kg/m2 and
regular menstrual cycles participated. Participants were excluded if
they met one or more of the following criteria: 1) any chronic disease
such as cardiovascular, renal, liver and infectious diseases as well as
cancer, diabetes mellitus, and thyroid disorders, 2) with history of
allergy to flaxseed, 3) being pregnant or lactating, 4) taking any
medications that could affect lipid metabolism (Steroids,
anti-hyperglycemic agents, statins), 5) taking supplements including
multivitamins and minerals and also, herbal preparations, and 6) history
of smoking or alcohol and drug abuse. The minimum sample size estimated
for each group was 25 at a power (1–β) of 80% and α₌0.05 for a two-arm
parallel study with two-tailed testing to detect a difference of 4 ng/mL
in serum adiponectin concentration with a standard deviation of 5 ng/mL,
obtained from a previous study (31).
Assuming a 10% drop out, a total number of 60 participants was
considered for this study. The study protocol, risks, and benefits were
clarified
to the participants, and they signed a written informed consent at the
time of enrollment. This study was approved by the Ethics Committee of
Shiraz University of Medical Sciences, Shiraz, Iran (registration No.
IR.SUMS.REC.1395.22) and was registered at Iranian Registry of Clinical
Trials website (IRCT2016050327733N1).