Prediction of Serum Zinc Levels in Mexican Children at 2 Years of Age Using a Food Frequency Questionnaire and Different Zinc Bioavailability Criteria

Dietary Intake of Selenium in Relation to Pubertal Development in Mexican Children

Alterations in pubertal timing have been associated with long-term health outcomes. While a few reports have shown that dietary intake of selenium is associated with fertility and testosterone levels in men, no human studies have considered the association between selenium and pubertal development in children. We examined the cross-sectional association of childhood dietary intake of selenium with pubertal development among 274 girls and 245 boys aged 10–18 years in Mexico City. Multiple logistic and ordinal regression models were used to capture the association between energy-adjusted selenium intake (below Recommended Dietary Allowance (RDA) vs. above RDA) and stages of sexual maturity in children, adjusted for covariates. We found that boys with consumption of selenium below the RDA had lower odds of a higher stage for pubic hair growth (odds ratio (OR) = 0.51, 95% confidence interval (95% CI): 0.27–0.97) and genital development (OR = 0.53, 95% CI: 0.28–0.99) as well as a lower probability of having matured testicular volume (OR = 0.37, 95% CI: 0.15–0.88) compared with boys who had adequate daily dietary intake of selenium (above RDA). No associations were found in girls. According to our results, it is possible that inadequate consumption of selenium may be associated with later pubertal development in boys, suggesting a sex-specific pattern. Future work with a larger sample size and measures of selenium biomarkers is needed to confirm our findings and improve understanding of the role of this mineral in children’s sexual development.

A short 18 items food frequency questionnaire biochemically validated to estimate zinc status in humans

Inadequate dietary zinc intake is wide-spread in the world's population. Despite the clinical significance of zinc deficiency there is no established method or biomarker to reliably evaluate the zinc status. The aim of our study was to develop a biochemically validated questionnaire as a clinically useful tool that can predict the risk of an individual being zinc deficient. From 71 subjects aged 18-55 years blood and urine samples were collected. Zinc concentrations in serum and urine were determined by atomic absorption spectrometry. A food frequency questionnaire (FFQ) including 38 items was filled out representing the consumption during the last 6 months obtaining nutrient diet scores. Latter were calculated by multiplication of the particular frequency of consumption, the nutrient intake of the respective portion size and the extent of the consumed quantity. Results from the FFQ were compared with nutrient intake information gathered in 24-h dietary recalls. A hemogram was performed and cytokine concentrations were obtained using Enzyme-linked Immunosorbent Assay. Reducing the items of the primary FFQ from 38 to 18 did not result in a significant variance between both calculated scores. Zinc diet scores showed highly significant correlation with serum zinc (r = 0.37; p < 0.01) and urine zinc concentrations (r = 0.34; p < 0.01). Serum zinc concentrations and zinc diet scores showed a significant positive correlation with animal protein intake (r = 0.37; p < 0.01/r = 0.54; p < 0.0001). Higher zinc diet scores were found in omnivores compared to vegetarians (213.5 vs. 111.9; p < 0.0001). The 18 items FFQ seems to be a sufficient tool to provide a good estimation of the zinc status. Moreover, shortening of the questionnaire to 18 items without a loss of predictive efficiency enables a facilitated and resource-saving routine use. A validation of the questionnaire in other cohorts could enable the progression towards clinical utilization of this promising tool.

Evaluating the Role of Zinc in Beta Thalassemia Major: A Prospective Case-Control Study from a Tertiary Care Teaching Hospital in India

Background

Thalassemia is a common hereditary anemia in humans, and beta thalassemia represents a group of recessively inherited hemoglobin disorders first described by Cooley and Lee and characterized by the abnormal synthesis of β-globin chain. The homozygous state results in severe anemia, which needs regular blood transfusion. Although such treatments increase the patient's life span, a variety of complications, including endocrine, metabolic, skeletal, and growth disorders are being observed due to increased iron storage in the body.

Objective

There are some reports emphasizing the role of zinc deficiency and its associated outcomes among thalassemia patients, but none from this part of the world. The aim of this study was to determine the serum zinc levels in children with beta thalassemia major.

Methods

This is a prospective case-control study, which included 35 children between the ages five and 15 years, who were diagnosed as suffering from beta thalassemia major. An equal number of age matched healthy subjects were recruited as controls. The study was carried out at the thalassemia center attached to the Prathima Institute of Medical Sciences (PIMS), Karimnagar, Telangana, India, during the year 2016. Blood samples were collected from both the cases and control subjects and serum zinc activities were analyzed using a semi-automated analyzer. Statistical Package for the Social Sciences (SPSS, Version 15.0) (SPSS Inc., Chicago, USA) was used to calculate the unpaired and independent Student's t-test (p value) to find the significance of the results.

Results

The mean concentrations of serum zinc among the cases and the controls were 39.25 ± 13.45 and 85.31 ± 13.53 (p <0.0001), respectively. Among the cases, 26 (65%) thalassemia patients had zinc concentration below 60 μg/dl, confirming hypozincemia. 

Conclusion

This study revealed that hypozincemia was prevalent in beta thalassemia major patients. Further evaluation regarding the role of zinc in the development and progression of thalassemia is recommended.