Zinc Intake and Status and Risk of Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Abstract

Zinc could have a protective role against type 2 diabetes mellitus (T2DM). This systematic review and meta-analysis aimed to evaluate the association between dietary, supplementary, and total zinc intake, as well as serum/plasma and whole blood zinc concentration, and risk of T2DM. Observational studies, conducted on cases of incident diabetes or T2DM patients and healthy subjects that reported a measure of association between zinc exposure and T2DM, were selected. Random effects meta-analyses were applied to obtain combined results. Stratified meta-analyses and meta-regressions were executed to assess sources of heterogeneity, as well as the impact of covariates on the findings. From 12,136 publications, 16 studies were selected. The odds ratio (OR) for T2DM comparing the highest versus lowest zinc intake from diet was 0.87 (95% CI: 0.78–0.98). Nevertheless, no association between supplementary or total zinc intake from both diet and supplementation, and T2DM was observed. A direct relationship was found between serum/plasma zinc levels and T2DM (OR = 1.64, 95% CI: 1.25–2.14). A moderately high dietary zinc intake, in relation to the Dietary Reference Intake, could reduce by 13% the risk of T2DM, and up to 41% in rural areas. Conversely, elevated serum/plasma zinc concentration was associated with an increased risk of T2DM by 64%, suggesting disturbances in zinc homeostasis.

Assessment of heavy metals by ICP‐OES and their impact on insulin stimulating hormone and carbohydrate metabolizing enzymes

“…They conducted a systematic review of 16 clinical‐based studies and concluded that Zn reduced the risk of DM by 41%. But conversely more interestingly, increased serum Zn level enhanced the risk of DM by 64% 13 . There is ample evidence which revealed that Zn supplementation to diabetic animal model enhanced the synthesis of metallothionein in liver, kidney, heart, and pancreas 38 .…”

“…Moreover, Zn is also implicated in the suppression of pro‐inflammatory cytokines and NF‐kβ and protects the β‐cells of pancreatic islets from death. All these properties of Zn may make it a potential candidate for DM prevention 12,13 . In addition to these, a number of studies have been done showing Zn to be effective in ameliorating DM‐associated complications in various animal models 14 …”

Relationship between BMI, Physical Activity, Zinc Serum with Fasting Blood Glucose in Diabetes

“…However, the risk of losing some nutrients on diabetics, especially micro nutrients must also be taken into consideration. One of the micro nutrients that is lower on diabetics compared to non-diabetics is zinc [7]. Thus, the research is aimed at analyzing the correlation between BMI, physical activities, and the zinc level of zinc serum and blood glucose on the same subjects, the type 2 DM patients to control blood glucose level to avoid further complications.…”

“…Significally lower zinc concentration on DM patients than non-DM is unrelated with the lower zinc intake. The duration of DM is also an impact on zinc concentration in the blood [7]. Type 2 DM is characterized by significant loss of important micronutrients because of the basis of disease metabolites and their complications.…”

“…Some nutrients (other than carbohydrates) associated with blood glucose levels are: protein, fatty acids, vitamin D, vitamin K, zinc, magnesium, chromium and sodium [6]. Zinc concentrations is significantly lower on diabetic than non-diabetics [7]. The lower zinc level on Type 2 DM patients is correlated with a higher prevalence of diabetes microvascular complications.…”