Enhanced effect of zinc and calcium supplementation on bone status in growth hormone-deficient children treated with growth hormone: a pilot randomized controlled trial

The Role of Zinc in Developed Countries in Pediatric Patients: A 360-Degree View

Zinc is an important trace element for growth and health at pediatric ages. Zinc is fundamental in inflammatory pathways, oxidative balance, and immune function. Zinc exhibits anti-inflammatory properties by modulating Nuclear Factor-kappa (NF-κB) activity and reducing histamine release from basophils, leukocytes, and mast cells. Furthermore, its antioxidant activity protects against oxidative damage and chronic diseases. Finally, zinc improves the ability to trigger effective immune responses against pathogens by contributing to the maturation of lymphocytes, the production of cytokines, and the regulation of apoptosis. Given these properties, zinc can be considered an adjunctive therapy in treating and preventing respiratory, nephrological, and gastrointestinal diseases, both acute and chronic. This review aims to deepen the role and metabolism of zinc, focusing on the role of supplementation in developed countries in pediatric diseases.

Regulation of GH and GH Signaling by Nutrients

Growth hormone (GH) and insulin-like growth factor-1 (IGF-I) are pleiotropic hormones with important roles in lifespan. They promote growth, anabolic actions, and body maintenance, and in conditions of energy deprivation, favor catabolic feedback mechanisms switching from carbohydrate oxidation to lipolysis, with the aim to preserve protein storages and survival. IGF-I/insulin signaling was also the first one identified in the regulation of lifespan in relation to the nutrient-sensing. Indeed, nutrients are crucial modifiers of the GH/IGF-I axis, and these hormones also regulate the complex orchestration of utilization of nutrients in cell and tissues. The aim of this review is to summarize current knowledge on the reciprocal feedback among the GH/IGF-I axis, macro and micronutrients, and dietary regimens, including caloric restriction. Expanding the depth of information on this topic could open perspectives in nutrition management, prevention, and treatment of GH/IGF-I deficiency or excess during life.

Dietary Zinc and Incident Calcium Kidney Stones in Adolescence

PURPOSE

We determined the association between dietary zinc intake and incident calcium kidney stones in adolescents. We also examined the relationship between dietary zinc intake and urinary zinc excretion between cases and controls.

MATERIALS AND METHODS

We conducted a nested case-control study within a large pediatric health care system. Three 24-hour dietary recalls and spot urine chemistry analyses were obtained for 30 participants 12 to 18 years old with a first idiopathic calcium based kidney stone and 30 healthy controls matched for age, sex, race and month of enrollment. Conditional logistic regression models were used to estimate the association between daily zinc intake and incident calcium kidney stones, adjusting for dietary phytate, protein, calcium, sodium and oxalate. Multivariable linear regression was used to estimate the association between dietary and urine zinc, adjusting for urine creatinine and dietary phytate and calcium.

RESULTS

Cases had lower daily zinc intake (8.1 mg) than controls (10 mg, p = 0.029). Daily zinc intake of boys and girls with calcium stones was 2 mg and 1.2 mg less, respectively, than the daily intake recommended by the Institute of Medicine. Odds of incident stones were reduced by 13% for every 1 mg increase in daily zinc intake (OR 0.87, 95% CI 0.75-0.99). There was an estimated 4.5 μg/dl increase in urine zinc for every 1 mg increase in dietary zinc (p = 0.009), with weak evidence of a smaller increase in urine zinc in cases than in controls (interaction p = 0.08).

CONCLUSIONS

Decreased dietary zinc intake was independently associated with incident calcium nephrolithiasis in this population of adolescents.

Magnesium, zinc, and chromium levels in children, adolescents, and young adults with type 1 diabetes

BACKGROUND & AIMS

Several trace elements are involved in insulin signal transduction and glucose metabolism. Our aim for this present study was to determine the levels of three important elements-magnesium, chromium, and zinc-as well as one oxidative stress marker-malondialdehyde (MDA)-in young type 1 diabetic patients at different periods of their growth, and to realize the relationships between trace elements, oxidative stress, and growth stages.

METHODS

A total of 88 patients with type 1 diabetes mellitus in different growth stages and 76 gender- and age-matched healthy subjects were included in this study. The levels of MDA were measured through HPLC using a C-18 column. Zinc, magnesium, and chromium concentrations in serum were assessed using atomic absorption spectrophotometry.

RESULTS

We found higher levels of blood malondialdehyde (MDA; p < 0.001), significantly lower levels of magnesium (p < 0.001), and no differences in zinc and chromium levels (p = 0.153 and 0.515, respectively) in younger type 1 diabetic subjects relative to those of control subjects. Only 3.4% (3/88) of younger diabetic subjects exhibited hypomagnesemia; similar results were obtained when comparing different subgroups: children, adolescents, and adults. We also observed no differences in the levels of the three elements between the genders and among the growth stages (p > 0.05) of the diabetic subjects. There were no correlations between the three trace elements and HbA1C, diabetes duration, and insulin dose/BMI (all p > 0.05), but there was a significant difference between zinc levels and insulin dose/BMI (p = 0.043) in the diabetic patients.

CONCLUSIONS

We found elevated blood MDA, decreased magnesium, and no changes in zinc and chromium levels in younger type 1 diabetic subjects relative to those of control subjects. Only 3.4% of younger diabetic subjects exhibited hypomagnesemia. Whether magnesium supplementation is suitable for improving insulin sensitivity and decreasing oxidative stress and inflammation will require confirmation through additional studies.

Effect of Zinc Supplementation on GH, IGF1, IGFBP3, OCN, and ALP in Non-Zinc-Deficient Children

OBJECTIVE

Because most publications on growth and development deal with children with zinc deficiency, we decided to study the effects of this micronutrient on the secretion of growth hormone (GH), insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), osteocalcin (OCN), and alkaline phosphatase (ALP) in healthy and eutrophic children. This study is original because the methodology was unique.

METHODS

Forty schoolchildren participated in the study, 17 females and 23 males, aged 8 and 9 years. The study was carried out during a 3-month period. It was characterized as a triple-blind randomized controlled trial. The children were divided in a control group (20 schoolchildren using 10% sorbitol) and experimental group (20 schoolchildren using zinc). All were submitted to oral zinc supplementation (10 mg Zn/day) and venous zinc administration (0.06537 mg Zn/kg of body weight). Blood samples were collected at 0, 60, 120, 180, and 210 min. All schoolchildren were also submitted to anthropometric, clinical, and dietetic assessments as well as biochemistry analyses.

RESULTS

Oral zinc supplementation in the experimental group (1) stimulated an increase in the consumption of protein and fat (p = 0.0007, p < 0.0001, p < 0.0001, respectively), (2) increased basal serum zinc (p < 0.0001), (3) increased plasma ALP (p = 0.0270), and (4) showed a positive correlation for IGF1, IGFBP3, and OCN, comparing before and after oral zinc supplementation (p = 0.0011, p < 0.0001, p < 0.0446, respectively). During zinc administration, plasma IGF1 and IGFBP3 increased significantly in the experimental group (p = 0.0468, p < 0.0001, respectively). Plasma GH increased in the experimental group but without statistical difference comparing before and after oral zinc supplementation.

CONCLUSIONS

Zinc supplementation stimulated an increase in the consumption of some macronutrients and basal serum zinc and improved plasma alkaline phosphatase levels. Zinc administration increased hormones of the GH-IGF1 system.

Unusual effects of GH deficiency in adults: a review about the effects of GH on skin, sleep, and coagulation

Based on the literature data in the last two decades, growth hormone deficiency (GHD) in adults has been accepted as a clinical entity. Due to the presence of GH and IGF-I receptors throughout the body, the physiological effects of the GH-IGF-I axis are still under investigation. The effects of GH on skin, sleep, and coagulation parameters in adults have only been investigated in detail only in the recent years. In this review, our aim was to summarize the literature regarding the effects of GHD and GH replacement treatment on the skin, sleep, and coagulation parameters in adults.