Effect of zinc supplementation on serum levels of nerve growth factor in the treatment of diabetic retinopathy

Placebo-controlled clinical trial to determine the effects of dietary zinc supplementation on serum levels of nerve growth factor in patients with diabetic retinopathy

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

IRCT

Registry ID

IRCT2014042117150N2

Enrollment

Registered

2014-05-12

Start date

2014-06-15

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. Diabetic retinopathy

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: Inclusion criteria: age range 40-70 years old; suffering from type 2 diabetes; subject diagnosed with diabetic retinopathy based on ETDRS and the DRS criteria. Exclusion criteria: insulin injection; hving chronic diseases such as cardiovascular disorders, renal and hepatic,asthma and allergy; having malabsorption syndrome and inflammatory bowel disease; pregnancy and lactation; drugs interfering with zinc (Penicillin amine, Diethylenetriamine pentaacetate); 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.

Exclusion criteria

Exclusion criteria:

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 nerve growth factor. Timepoint: At baseline and after 3 months of intervention. Method of measurement: ELISA.	—

Secondary

Measure	Time frame
Insulin Resistance Index. Timepoint: At baseline and after 8 weeks of intervention. Method of measurement: HOMA-IR.;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: Sphygmomanometer.	—

Countries

Iran (Islamic Republic of)

Contacts

Public ContactSiamack Naghizadeh

Tabriz University of Medical Sciences

siamg22@yahoo.com

Outcome results

None listed

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