Low anemia but high dyslipidemia prevalence in Brazilian schoolchildren: a nutritional transition profile.

Brazil is undergoing a rapid nutritional transition, yet data on anemia and dyslipidemia in early school-aged children remain scarce. This study aimed to determine the prevalence of anemia and dyslipidemia and to investigate the relationship between anemia, iron status markers, inflammation, lipid profiles, and nutritional status in schoolchildren from southern Brazil. This cross-sectional study enrolled 204 children aged 5-8 years attending public municipal schools. Data collection included anthropometry, sociodemographic and dietary questionnaires, and blood analysis for hemoglobin, ferritin, transferrin saturation, reticulocyte hemoglobin equivalent (Ret-He), C-reactive protein (CRP), and lipid profile, using standard pediatric cut-offs. Anemia prevalence was low (4.9%; 95% CI: 2.7-8.8%), whereas dyslipidemia prevalence was high, including hypertriglyceridemia (26.8%; 95% CI: 21.2-33.3%) and elevated total cholesterol (31.9%; 95% CI: 25.9-38.6%). Ret-He was significantly lower in anemic children (29.9 vs. 32.7 pg; p < 0.001) and correlated with hemoglobin (Rho=0.335, p < 0.001) and serum iron (Rho=0.280, p < 0.001). CRP was the strongest independent predictor of Ret-He (β = -0.345, p < 0.001), independent of nutritional status and conventional iron markers. Ret-He values did not differ across nutritional status categories, whereas inflammatory and lipid parameters varied according to adiposity. Meanwhile, soda intake was associated with higher triglyceride levels. These findings indicate a nutritional transition profile characterized by low anemia but high dyslipidemia prevalence in children aged 5-8 years. Ret-He reflects functional iron availability and is strongly influenced by systemic inflammation, independently of nutritional status, supporting its use as a complementary marker in the assessment of anemia in pediatric populations.