Interaction between vitamin D and the growth hormone/insulin-like growth factor 1 axis in children: a systematic review and meta-analysis.
Vitamin D supplementation appears to increase IGF-1 levels in children, and rhGH treatment can elevate vitamin D levels, but the clinical significance of these findings needs careful consideration.
Where it sits
this study against the rest of the hgh (somatropin) corpusSummary and findings
This systematic review and meta-analysis examined the relationship between vitamin D and the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis in children. It analyzed the effect of recombinant human growth hormone (rhGH) on vitamin D levels and IGF-1 levels. The study found that vitamin D supplementation increased IGF-1 levels and that rhGH treatment also elevated vitamin D levels.
Abstract
<h4>Background</h4>This article presents a systematic review and meta-analysis of relevant studies to clarify the relationship between vitamin D and the growth hormone/insulin-like growth factor 1(GH/IGF-1) axis.<h4>Methods</h4>PubMed/MEDLINE, Web of Science, SCOPUS, Embase, and CNKI databases were searched. Relevant articles on the effect of vitamin D on IGF-1 levels were reviewed. The effect of recombinant human growth hormone supplementation on 25-hydroxyvitamin D[25(OH)D] levels was meta-analyzed, and subgroup analyses were conducted.<h4>Results</h4>IGF-1 levels increased after vitamin D supplementation. Vitamin D combined with rhGH therapy resulted in higher IGF-1 levels than rhGH alone. The meta-analysis included 24 studies. Vitamin D levels increased after rhGH treatment (WMD: 5.83 ng/mL, 95% CI: 3.72 to 7.94, I² = 99%, p < 0.00001), both in children with GHD (WMD: 7.78 ng/mL, 95% CI: 2.02 to 13.55, I² = 99%, p = 0.008) and ISS(WMD: 2.74 ng/mL, 95% CI: 1.25 to 4.23, I² = 98%, p = 0.0003). Results showed that vitamin D levels in children with growth hormone deficiency (GHD) were significantly lower than those in healthy children (WMD: -8.69 ng/mL, 95% CI: -15.91 to -1.46, I² = 96%, p = 0.02). There was no significant difference in vitamin D levels between children with idiopathic short stature (ISS) and healthy children (WMD: -3.86 ng/mL, 95% CI: -7.70 to -0.01, I² = 98%, p = 0.05). However, vitamin D levels in short children remained lower than those in healthy children after rhGH treatment (WMD: -1.68 ng/mL, 95% CI: -2.53 to -0.82, I² = 84%, p = 0.0001).<h4>Conclusion</h4>The increase in IGF-1 levels following vitamin D supplementation should be accounted for in clinical practice when evaluating IGF-1 values to optimize the diagnosis of short stature causes. Children with GHD have lower vitamin D levels, and rhGH supplementation can increase vitamin D levels. Combined vitamin D and rhGH therapy can better promote growth and development in children with short stature.
Background
This paper addresses the interaction between vitamin D and the GH/IGF-1 axis, which is crucial for growth and development in children. Previous studies have suggested a link between vitamin D levels and growth hormone activity, but the exact nature of this relationship has been unclear. This systematic review and meta-analysis aims to clarify how vitamin D affects IGF-1 levels, which could have implications for diagnosing and treating short stature in children.
Methods
The study conducted a systematic review and meta-analysis of relevant articles from PubMed/MEDLINE, Web of Science, SCOPUS, Embase, and CNKI databases. The analysis included 24 studies focusing on the effect of vitamin D on IGF-1 levels and the impact of rhGH supplementation on 25-hydroxyvitamin D levels. Subgroup analyses were performed to assess differences between children with growth hormone deficiency and those with idiopathic short stature.
Results
The primary finding was that vitamin D levels increased significantly after rhGH treatment, with a WMD of 5.83 ng/mL (95% CI: 3.72 to 7.94, p<0.00001). In children with GHD, vitamin D levels increased by 7.78 ng/mL (95% CI: 2.02 to 13.55, p=0.008), while in those with ISS, the increase was 2.74 ng/mL (95% CI: 1.25 to 4.23, p=0.0003). Children with GHD had significantly lower vitamin D levels compared to healthy children, with a WMD of -8.69 ng/mL (95% CI: -15.91 to -1.46, p=0.02).
Interpretation
The results indicate a statistically significant increase in vitamin D levels following rhGH treatment, which aligns with previous literature suggesting a positive interaction between vitamin D and growth hormone. However, the clinical significance of these findings may be limited by the small effect sizes observed in some comparisons. The high heterogeneity among the studies included in the meta-analysis raises concerns about the robustness of the conclusions. Practitioners should consider these factors when interpreting IGF-1 values and assessing growth in children.
Key findings
- WMD: 5.83 ng/mL increase in vitamin D levels after rhGH treatment, 95% CI: 3.72 to 7.94, p<0.00001.
- WMD: 7.78 ng/mL increase in vitamin D levels in children with GHD after rhGH treatment, 95% CI: 2.02 to 13.55, p=0.008.
- WMD: 2.74 ng/mL increase in vitamin D levels in children with idiopathic short stature (ISS) after rhGH treatment, 95% CI: 1.25 to 4.23, p=0.0003.
- WMD: -8.69 ng/mL lower vitamin D levels in children with GHD compared to healthy children, 95% CI: -15.91 to -1.46, p=0.02.
- WMD: -1.68 ng/mL lower vitamin D levels in short children after rhGH treatment compared to healthy children, 95% CI: -2.53 to -0.82, p=0.0001.
Limitations
- high I² values indicating significant heterogeneity among studies
- potential publication bias
- variability in study designs and populations
- not all studies may have controlled for confounding factors