Improvement of anthropometric and biochemical, but not of vitamin A, status in adolescents who undergo Roux-en-Y gastric bypass: a 1-year follow up study.

BACKGROUND

The aim of this study was to describe anthropometric, biochemical, co-morbidity, and vitamin A nutritional status in severely obese adolescents before and 30, 180, and 365 days after Roux-en-Y gastric bypass (RYGB).

SETTING

Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

METHODS

Sixty-four adolescents (15-19 years old) with a body mass index≥40 kg/m2 were enrolled in a prospective follow-up study. Vitamin A status was evaluated before surgery (T0), and 30 (T30), 180 (T180), and 365 (T365) days after surgery, applying biochemical and functional indicators. Anthropometric measures, lipid profile, glycemia, and basal insulin also were assessed. No patients were lost during follow-up.

RESULTS

Before surgery, 26.6% of the sample group experienced vitamin A deficiency (VAD). Serum retinol levels dropped significantly 30 days after surgery and then returned to basal levels. There was a significant increase in the prevalence of β-carotene deficiency and night blindness throughout the postsurgery period. A significant reduction in blood glucose, insulin resistance, lipid profile, and anthropometric parameters was observed.

CONCLUSION

The finding that oral daily supplementation with 5000 IU retinol acetate failed to reverse VAD and night blindness after RYGB is highly significant. We recommend assessment of VAD and night blindness in extremely obese adolescents before and after RYGB. We further recommend monitoring for an additional 180 days (for VAD) and 365 days (for night blindness) after surgery, with particular attention to daily supplementation needs.