Placebo-controlled clinical trial to determine the effects of dietary zinc supplementation on serum levels of brain-derived neurotrophic factor and vascular endothelial growth factor in patients with diabetic retinopathy
The aim of this randomized, placebo-controlled trial is to investigate the effects of zinc supplementation on serum levels of brain derived neurotrophic factor(BDNF) and vascular endothelial growth factor(VEGF) in diabetic retinopathy patients. Fifty diabetic retinopathy patients that their disease was confirmed by pathologic assessment will include in this study according inclusion and exclusion criteria. The participants will be assigned into control and treatment groups using permuted-blocks randomization. Treatment group will receive a 30mg zinc gloconate tablet and control group will receive a 30mg maltose-dextrin tablet for 3 month one to two hours after lunch. For determination of zinc supplementation on serum levels of BDNF and VEGF these factors will measure by conventional lab method at baseline and endpoint of the study in both the groups. Finally, to manage effects of any confounder variables, anthropometric indices, physical activity level and psychological stress status will be measured and a 24-hour recall will be kept simultaneously with the measurements.
General information
Acronym
IRCT registration information
IRCT registration number:IRCT2014040617150N1
Registration date:2014-08-02, 1393/05/11
Registration timing:registered_while_recruiting
Last update:
Update count:1
Registration date
2014-08-02, 1393/05/11
Registrant information
Name
Siamack Naghizadeh
Name of organization / entity
Tabriz University of Medical Sciences
Country
Iran (Islamic Republic of)
Phone
+98 45 1661 8685
Email address
kheiroouris@tbzmed.ac.ir
Recruitment status
Recruitment complete
Funding source
Vice chancellor for Research, Tabriz University of Medical Sciences
Expected recruitment start date
2014-07-23, 1393/05/01
Expected recruitment end date
2015-01-21, 1393/11/01
Actual recruitment start date
empty
Actual recruitment end date
empty
Trial completion date
empty
Scientific title
Placebo-controlled clinical trial to determine the effects of dietary zinc supplementation on serum levels of brain-derived neurotrophic factor and vascular endothelial growth factor in patients with diabetic retinopathy
Public title
Effect of zinc supplementation in the treatment of diabetic retinopathy
Purpose
Treatment
Inclusion/Exclusion criteria
Inclusion criteria: Age range 40-70 years old; suffering from type 2 diabetes without insulin; Subject diagnosed with diabetic retinopathy
Exclusion criteria: Insulin injection; Having chronic diseases such as cardiovascular disorders, renal and hepatic; Having malabsorption syndrome and inflammatory bowel disease; Pregnancy and lactation; Drugs interfering with zinc (Penicillin amine, Diethylenetriamine pentaacetate); Inhibitor drugs vascular endothelial growth factor (Avastin); Receiving nutritional supplements from 2 months before the study (zinc, calcium, vitamin A and iron); Exercise on a regular basis; Having a mental illness such as depression; Infectious diseases and AIDS; Alcoholism.
Age
From 40 years old to 70 years old
Gender
Both
Phase
N/A
Groups that have been masked
No information
Sample size
Target sample size:
50
Randomization (investigator's opinion)
Randomized
Randomization description
Blinding (investigator's opinion)
Double blinded
Blinding description
Placebo
Used
Assignment
Parallel
Other design features
Secondary Ids
empty
Ethics committees
1
Ethics committee
Name of ethics committee
Ethics committee of Tabriz University of Medical Sciences
Street address
Golbad Street
City
Tabriz
Postal code
Approval date
2014-07-17, 1393/04/26
Ethics committee reference number
9359
Health conditions studied
1
Description of health condition studied
Diabetic retinopathy
ICD-10 code
H36.0
ICD-10 code description
Non-insulin-dependent diabetes mellitus
Primary outcomes
1
Description
serum concentration of zinc
Timepoint
At baseline and after 3 months of intervention
Method of measurement
atomic absorption spectrophotometry
2
Description
serum concentration of brain derived neurotrophic factor
Timepoint
At baseline and after 3 months of intervention
Method of measurement
ELISA
3
Description
serum concentration of vascular endothelial growth factor
Timepoint
At baseline and after 3 months of intervention
Method of measurement
ELISA
Secondary outcomes
1
Description
serum concentration of Insulin
Timepoint
At baseline and after 8 weeks of intervention
Method of measurement
Chemiluminescence
2
Description
Fasting blood sugar
Timepoint
At baseline and after 8 weeks of intervention
Method of measurement
Enzymatic colorimetric method
3
Description
serum concentration of HbA1c
Timepoint
At baseline and after 8 weeks of intervention
Method of measurement
Turbidimetry
4
Description
Insulin Resistance Index
Timepoint
At baseline and after 8 weeks of intervention
Method of measurement
Based on the formula of Insulin Resistance Index
5
Description
Systolic blood pressure
Timepoint
At baseline and after 8 weeks of intervention
Method of measurement
Stethoscope and sphygmomanometer
6
Description
Diastolic blood pressure
Timepoint
At baseline and after 8 weeks of intervention
Method of measurement
Stethoscope and sphygmomanometer
Intervention groups
1
Description
The case group will receive a 30mg zinc gloconate tablet for 3 months, one to two hours after lunch. The tablets will provided by jalinous pharmaceutical company in Tehran . All the patients will receive the supplements on a weekly base and will be monitored for consumption continuation and any possible adverse effects by telephone interviews.
Category
Treatment - Drugs
2
Description
The control group will receive a 30mg maltose- dextrin tablet as placebo for 3 months, one to two hours after lunch. The tablets will be provided by the Faculty of Pharmacy, Tabriz University of Medical Sciences.All the patients will receive the placebo on a weekly base and will be monitored for consumption continuation and any possible adverse effects by telephone interviews.
Category
Placebo
Recruitment centers
1
Recruitment center
Name of recruitment center
Alavi Hospital
Full name of responsible person
Dr Habib Ojaghi
Street address
Maadi Street , Ardebili Avenue
City
Ardabil
Sponsors / Funding sources
1
Sponsor
Name of organization / entity
Vice chancellor for Research, Tabriz University of Medical Sciences
Full name of responsible person
Dr. Mohammad Reza Rashidi
Street address
Golbad Street
City
Tabriz
Grant name
Grant code / Reference number
Is the source of funding the same sponsor organization/entity?
Yes
Title of funding source
Vice chancellor for Research, Tabriz University of Medical Sciences
Proportion provided by this source
100
Public or private sector
empty
Domestic or foreign origin
empty
Category of foreign source of funding
empty
Country of origin
Type of organization providing the funding
empty
Person responsible for general inquiries
Contact
Name of organization / entity
Tabriz University of Medical Sciences
Full name of responsible person
Dr. Sorayya Kheirouri
Position
Assistant professor
Other areas of specialty/work
Street address
Attar Neishabouri Street , Golgasht Avenue
City
Tabriz
Postal code
5166614711
Phone
+98 41 1335 7580
Fax
+98 41 1334 0634
Email
kheirouris@tbzmed.ac.ir
Web page address
Person responsible for scientific inquiries
Contact
Name of organization / entity
Tabriz University of Medical Sciences
Full name of responsible person
Dr. Sorayya Kheirouri
Position
Assistant professor
Other areas of specialty/work
Street address
Attar Neishabouri Street , Golgasht Avenue
City
Tabriz
Postal code
5166614711
Phone
+98 41 1335 7580
Fax
+98 41 1334 0634
Email
kheirouris@tbzmed.ac.ir
Web page address
Person responsible for updating data
Contact
Name of organization / entity
Tabriz University of Medical Sciences
Full name of responsible person
Siamack Naghizadeh
Position
MSc student in health sciences in nutrition
Other areas of specialty/work
Street address
Attar Neishabouri Street , Golgasht Avenue
City
Tabriz
Postal code
5166614711
Phone
+98 45 1661 8685
Fax
+98 41 1334 0634
Email
siamg22@yahoo.com
Web page address
Sharing plan
Deidentified Individual Participant Data Set (IPD)