Endocrine Abstracts

JOINT729

Background: Iron deficiency anemia (IDA) is the most prevalent micronutrient deficiency globally, affecting over 40% of children under five years old, particularly in low- and middle-income countries. Beyond its hematological impact, IDA can disrupt endocrine functions, including growth, thyroid, pituitary, and adrenal systems. These disruptions contribute to growth retardation, hormonal imbalances, and altered metabolic homeostasis. This review synthesizes evidence from clinical and experimental studies to evaluate the effects of IDA on growth and endocrine functions and highlights the reversibility of these effects following iron therapy.

Objectives: To assess the impact of IDA on growth and endocrine functions (thyroid, pituitary, and adrenal) and to evaluate the effectiveness of treatment in reversing these impairments.

Methods: A systematic review of 12 studies published between 1990 and 2023 was conducted, including 567 patients with IDA and several experimental animal models. The studies were analyzed for the impact of IDA on growth velocity, IGF-I secretion, thyroid hormones, and adrenal reserve (ACTH and cortisol), and the reversibility of these effects with treatment.

Results: 1. Growth: IDA significantly reduces growth velocity and IGF-I secretion. Among 567 patients across the studies, most exhibited impaired height-for-age z-scores and reduced BMI. Post-treatment, iron therapy restored growth velocity and improved IGF-I levels in all studies.

2. Thyroid Function: Mild hypothyroidism, characterized by reduced thyroid hormone secretion, was documented in 5 studies, accounting for 220 patients. Iron supplementation normalized thyroid hormone levels in all treated patients.

3. Pituitary Function: Suppressed GH and IGF-I secretion were reported in 6 studies, including 345 patients. Post-treatment normalization of GH and IGF-I secretion significantly improved growth and metabolic markers.

4. Adrenal Function: Reduced adrenal reserve (low ACTH and cortisol levels) was observed in severe IDA cases in 4 studies, involving 145 patients. Iron supplementation restored adrenal function, demonstrating reversibility with therapy.

Discussion: The review highlights the systemic impact of IDA on growth and multiple endocrine axes. The reversibility of these effects with iron therapy underscores the critical importance of early diagnosis and treatment. Thyroid and adrenal functions were particularly sensitive to IDA but improved significantly post-treatment. Growth markers such as IGF-I and BMI responded robustly, showcasing the critical link between iron availability and endocrine health.

Conclusions: IDA profoundly affects growth and endocrine functions, including thyroid, pituitary, and adrenal systems. Iron therapy effectively reverses these impairments, emphasizing the importance of timely intervention. Future research should explore long-term outcomes and optimize treatment strategies for IDA-related endocrine dysfunctions.