| dc.description.abstract | Background and objective: Diabetes mellitus is one of the most
important health problems in the world and Iran due to the spread of
the disease, its complications, its mortality and related costs. One of
the common complications of diabetes is diabetic retinopathy.
Increased oxidative stress has been reported in diabetes and diabetic
retinopathy patients. Besides, evidence linking oxidative stress to
enhancement of advanced glycation end products (AGE), matrix
metalloproteinase9 (MMP9) and caspase3. Considering the prevalence
of zinc deficiency in diabetic patients and the ability of zinc to
decrease oxidative stress, therefore, with the assumption of the effect
of zinc on the modification of the AGEs, MMP9 and caspase3, the
aim of this study was to investigate the effect of zinc on reducing of
serum levels AGEs, MMP9 and caspase3 in patients with
nonproliferative diabetic retinopathy.
Method: In a randomized double-blind placebo-controlled clinical
trial study, 36 patients with diabetic retinopathy and 18 healthy
subjects (54 subjects in total) from 40 to 70 years have participated.
Initially, serum levels of AGEs, MMP9 and caspase3 were compared
between healthy subjects and patients with diabetic retinopathy.
Patients with diabetic retinopathy were divided into two groups of
zinc (N= 18) and placebo (N= 18). The zinc group received a 30
mg/day of zinc gluconate capsule and a placebo group received 30
mg/day dextrin maltose, for 1–2 hours after lunch for 3 months.
During the intervention period, the type and dose of the drug were
kept constant. Serum levels of AGEs and Precursors of its (including
methylglyoxal (MGO), carboxymethyl lysine (CML), and pentosidine
(PEN)), and MMP9 and caspase3 were measured by ELISA method
and compared before and after the intervention. To assess dietary
intake and physical activity of the subjects, 24-hour recall and
international physical activity questionnaire were used respectively.
Results: There was no significant difference in terms of height,
weight, body mass index, physical activity and hip circumference
between the two groups (P>0.05). But waist circumference (p = 0.001)
and waist to hip ratio (p = 0.019) in diabetic retinopathy group were
significantly higher than healthy subjects. There was no significant
difference between patients with diabetic retinopathy and healthy
subjects regarding the serum levels of AGEs (MGO, CML and PEN),
MMP9 and Caspase3 (P>0.05). Zinc supplementation significantly
increased the serum level of zinc in the Zn intake group (p <0.001).
But zinc supplementation did not significantly alter the serum levels
of AGEs (MGO, CML and PEN), MMP9, and Caspase3 in diabetic
retinopathy patients (P>0.05). After examining the relationship
between variables in patients with diabetic retinopathy before
intervention, there was a positive significant correlation between
Caspase3 and energy (r = 0.432, p = 0.009), protein (p = 0.004, r =
0.468, p) and fat (r = 0.486, p = 0.003) and Also, there was a positive
and significant correlation between MGO and protein (r = 0.393, p =
0.018) Also, there was a significant correlation between serum levels of
AGEs (MGO, CML and PEN), MMP9, and Caspase3 (p <0.001).
Conclusion: In the present study, there was no significant difference
in serum levels of AGEs, MMP9 and caspase3 between diabetic
retinopathy and healthy subjects. Additionally, zinc also
supplementation did not differ in serum levels of AGEs, MMP9 and
caspase3 in diabetic retinopathy patients. | en_US |
