Mild Hypophosphatemia-Associated Conditions in Children: The Need for a Comprehensive Approach

Abstract

To better understand the causes of hypophosphatemia in children, we evaluated all serum phosphate tests performed in a tertiary hospital with unexpected but persistent temporary or isolated hypophosphatemia over an 18 year period. We collected 29,279 phosphate tests from 21,398 patients, of which 268 (1.2%) had at least one result showing hypophosphatemia. We found that endocrinopathies (n = 60), tumors (n = 10), and vitamin D deficiency (n = 3) were the medical conditions most commonly associated with mild hypophosphatemia, but in many patients the cause was unclear. Among patients with endocrinopathies, those with diabetes mellitus were found to have lower mean serum phosphate levels (mean 3.4 mg/dL) than those with short stature (3.7 mg/dL) or thyroid disorders (3.7 mg/dL). In addition, we found a correlation between glycemia and phosphatemia in patients with diabetes. However, despite the potential relevance of monitoring phosphate homeostasis and the underlying etiologic mechanisms, renal phosphate losses were estimated in less than 5% of patients with hypophosphatemia. In the pediatric age group, malignancies, hypovitaminosis D, and endocrine disorders, mostly diabetes, were the most common causes of hypophosphatemia. This real-world study also shows that hypophosphatemia is frequently neglected and inadequately evaluated by pediatricians, which emphasizes the need for more education and awareness about this condition to prevent its potentially deleterious consequences.

Calcium, Phosphate, and Vitamin D in Children and Adolescents with Chronic Diseases: A Cross-Sectional Study

“…Age had an inverse correlation and significant association with serum P in the entire series and in all groups. These results support evidence from previous observations that phosphatemia decreased with age [18,[133][134][135][136]. Serum P levels vary depending on several factors such as bone mineralization, growth, age [134], and chronic conditions.…”

“…These results support evidence from previous observations that phosphatemia decreased with age [18,[133][134][135][136]. Serum P levels vary depending on several factors such as bone mineralization, growth, age [134], and chronic conditions. In young patients, it is crucial to consider P levels based on age since as long as it has a lower regular value at birth, it is nevertheless higher than the upper regular level in adulthood [133].…”

“…In 747 children with HA < −2 SD, serum P had a non-linear relationship with IGF-1 and the IGF-1 increase with the increase in serum P when the serum P level was >3.9 mg/dL [127]. Endocrinopathies, tumors, and VDD were the most common medical conditions associated with hypophosphatemia, finding a correlation between glycemia and phosphatemia in DM patients [134]. In the eutrophic group, serum P and the Ca/P ratio had a significant association with glucose, and in the whole series, serum P had an association with AST and Cr.…”

“…There is no universally accepted definition of chronic hypophosphatemia. In a retrospective-prospective study on 29,279 serum P tests from 21,398 Spanish children (1 to 16 years), 1.2% of them (268 cases) had at least one result with hypophosphatemia (serum P < 4 mg/dL in children from 1-11 years and <3 mg/dL in children > 11 years [134]. Likewise, out of 349 critically ill children admitted to the PICU, 71.6% had hypophosphatemia (serum P < 3.8 mg/dL in children < 2 years and <3.5 in children ≥ 2 years).…”