Developmental Stage Modulates Mineral-Hormonal Adaptation After Roux-en-Y Gastric Bypass: A Translational Life-Course Study.

BACKGROUND

Vitamin D deficiency is highly prevalent in individuals with severe obesity and may worsen after malabsorptive bariatric procedures. Adolescence represents a critical period of skeletal and metabolic maturation and may influence mineral-hormonal adaptation after Roux-en-Y gastric bypass (RYGB).

OBJECTIVE

To investigate whether developmental stage influences longitudinal mineral-hormonal adaptation after RYGB in adolescents and adults with severe obesity.

METHODS

This prospective observational cohort study included 120 participants undergoing RYGB: 60 adolescents (15-19 years) and 60 adults (20-49 years) with a history of severe obesity. Assessments were performed preoperatively and at 6 and 12 months postoperatively. Serum 25-hydroxyvitamin D, ionized calcium, phosphorus, and parathyroid hormone (PTH) were measured. Group comparisons were performed using non-parametric tests within a translational life-course framework.

RESULTS

Vitamin D inadequacy (<30 ng/mL) was highly prevalent at baseline in both groups (78.3% vs. 85.0%). Despite substantial weight loss in both cohorts, adolescents exhibited higher frequencies of hypocalcaemia and hypophosphataemia (p < 0.001), progressive elevation of PTH levels, and a higher prevalence of secondary hyperparathyroidism at 12 months. Adults showed a comparatively less pronounced endocrine-mineral response but also experienced persistent increases in PTH throughout follow-up. Vitamin D inadequacy remained highly prevalent in both groups despite standardized supplementation.

CONCLUSIONS

Postoperative mineral-hormonal adaptation after RYGB differs according to developmental stage. Adolescents exhibited greater endocrine-mineral vulnerability during a critical period of skeletal maturation, suggesting that biological stage may influence postoperative adaptation beyond anthropometric response alone. These findings support developmental stage-specific monitoring and individualized postoperative management after metabolic surgery.