Effects of Oral Zinc Supplementation in Diabetic Children and Adolescents with Asymptomatic Cardiac Insult

Abstract
Background: Diabetes is a pro-inflammatory condition. Chronic inflammation plays an important role in the progres-sion of diabetic complications. High glucose levels induce the release of pro-inflammatory cytokines, including TNF-a, IL-1(3, and IL-6 in patients with both type 1 and type 2 diabetes leading to multiorgan failure. Cardiovascular disease (CVD) is recognized as the major cause of morbidity and mortality among diabetic patients. Oxidative stress is a key risk factor contributing to the development and progression of CVDs. Zinc protects the cell from oxidation damage by free radicals. Zinc also act as anti- inflammatory.
Aim of Study: It was to evaluate the recent echocardio-graphic modalities in detection of silent left ventricular dysfunction in children with type 1 diabetes mellitus, assess the potential role of oxidative stress inflammatory cytokines, apoptosis and fibrosis in diabetic cardiac insult and to inves-tigate the possible protective role of zinc supplement on diabetic left ventricle (LV) in type 1 diabetic children and adolescents.
Patients and Methods: The study was carried out on fifty patients with type 1 diabetes mellitus who were diagnosed and followed-up in Endocrinology Unit and endocrinology outpatient clinic, Pediatric Department, Tanta University Hospital. Subdivided into: Twenty-five patients who received insulin treatment only and twenty-five patients who received insulin and oral zinc supplementation according to their Dietary Recommended Intakes (DRI) (7.5-15mg/d) for 6 months. Also on twenty-five apparently healthy children with matched age and sex who served as a control group. All studied children were subjected to detailed history taking, complete physical examination, measurement of level of IL-6 before and after zinc supplementation also Echocardiography (conventional, tissue Doppler and Speckling Tracking Tech-nique) before and after zinc supplementation.
Results: There was statistical significance between the 2 diabetic groups and the controls according to level of inter-leukin 6 which was markedly elevated in the diabetic patients than the controls. There was statistically significance between the 2 diabetic groups and the controls according to the param-eters detected by Tissue Doppler as E/A ratio and MPI (myo-cardial performance index) which showed subclinical systolic and diastolic impairment in the diabetic patients than the controls. There was statistically significance between the 2 diabetic groups and the controls according to the parameters detected by speckle tracking as 2DS (2 dimensional strain) which show subclinical systolic impairment in the diabetic patients than the controls. There was no statistical significance between the 2 diabetic groups and the controls according to the parameters detected by Tissue Doppler as ejection fraction and mitral annulus systolic velocity. There was no statistically significant difference between the diabetic patients who received oral zinc supplementation for 6 months and the controls according to level of interleukin 6. This shows the effect of zinc supplementation as anti-inflammatory. There was no statistically significant difference between the diabetic patients who received oral zinc supplementation for 6 months according to the parameter detected by Tissue Doppler and speckle tracking (E/A ratio, MPI, 2DS) which show marked improvement in the systolic and diastolic function of the diabetic patient after zinc supplementation.
Conclusion: There is evidence of increase level of serum interleukin 6 in patients with type 1 DM. Also evidence of subclinical systolic and diastolic dysfunction in asymptomatic diabetic patients assessed by two-dimensional speckle tracking echocardiography and Tissue Doppler. Oral Zinc supplemen-tation has a significant beneficial effect in patients with type 1 DM due to the anti-inflammatory and cardio-protective effect of the Zinc.