Effect of zinc supplementation in the treatment of diabetic retinopathy

Placebo-controlled clinical trial to determine the effects of dietary zinc supplementation on serum levels of brain-derived neurotrophic factor, vascular endothelial growth factor, advanced glycation end products, metalloproteinas 9 and caspase 3 in patients with diabetic retinopathy

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

IRCT

Registry ID

IRCT2014040617150N1

Enrollment

Registered

2014-08-02

Start date

2014-07-23

Completion date

Unknown

Last updated

2018-02-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diabetic retinopathy. Non-insulin-dependent diabetes mellitus

Interventions

Intervention 1: 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 p

Treatment - Drugs

Placebo

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 rec

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 Medic

Eligibility

Sex/Gender

All

Age

40 Years to 70 Years

Inclusion criteria

Inclusion criteria: Age range 40-70 years old suffering from type 2 diabetes without insulin Subject diagnosed with diabetic retinopathy

Exclusion criteria

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

Design outcomes

Primary

Measure	Time frame
Serum concentration of zinc. Timepoint: At baseline and after 3 months of intervention. Method of measurement: atomic absorption spectrophotometry.;Serum concentration of brain derived neurotrophic factor. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration of vascular endothelial growth factor. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration of Methylglyoxal. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Pentosidine. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Carboxymethyl lysine. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Metalloproteinase 9. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Caspase 3. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.	—

Measure

Time frame

Serum concentration of zinc. Timepoint: At baseline and after 3 months of intervention. Method of measurement: atomic absorption spectrophotometry.;Serum concentration of brain derived neurotrophic factor. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration of vascular endothelial growth factor. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration of Methylglyoxal. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Pentosidine. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Carboxymethyl lysine. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Metalloproteinase 9. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.;Serum concentration Caspase 3. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.

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Secondary

Measure	Time frame
Serum concentration of Insulin. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Chemiluminescence.;Fasting blood sugar. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Enzymatic colorimetric method.;Serum concentration of HbA1c. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Turbidimetry.;Insulin Resistance Index. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Based on the formula of Insulin Resistance Index.;Systolic blood pressure. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Stethoscope and sphygmomanometer.;Diastolic blood pressure. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Stethoscope and sphygmomanometer.	—

Measure

Time frame

Serum concentration of Insulin. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Chemiluminescence.;Fasting blood sugar. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Enzymatic colorimetric method.;Serum concentration of HbA1c. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Turbidimetry.;Insulin Resistance Index. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Based on the formula of Insulin Resistance Index.;Systolic blood pressure. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Stethoscope and sphygmomanometer.;Diastolic blood pressure. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: Stethoscope and sphygmomanometer.

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Countries

Iran (Islamic Republic of)

Contacts

Public ContactDr. Sorayya Kheirouri

Tabriz University of Medical Sciences

kheirouris@tbzmed.ac.ir+98 41 1335 7580

Outcome results

None listed

Source: IRCT (via WHO ICTRP) · Data processed: Feb 4, 2026