Body Composition and Cardiometabolic Risk in Children.

Importance: Understanding secular patterns in body composition and cardiometabolic risk factors (CMRFs) is essential for identifying early-life determinants of cardiovascular health, guiding public health policies, and developing early prevention strategies. Objective: To examine secular patterns in the prevalence of underweight, overweight, obesity, and CMRFs among schoolchildren in Spain from 1992 to 2022. Design, Setting, and Participants: Repeated cross-sectional study analyzing data from 7 time points over a 30-year period in public primary schools from the Cuenca province in Spain. Participants were children aged 8 to 11 years (fourth to fifth grade) from 7 cohorts studied in 1992, 1996, 1998, 2004, 2010, 2018, and 2022. Data were analyzed from April 2024 to May 2025. Main outcomes and measures: Prevalence of weight status (underweight, normal weight, overweight, and obesity), lipid parameters, glycemic markers, and resting systolic blood pressure (SBP) and diastolic blood pressure (DBP). Results: In a total of 4280 participants (mean [SD] age, 9.6 [0.7] years; 2137 [50.0%] girls), patterns in the prevalence of weight status show that increases in obesity appear to have slowed down and plateaued since 2018 (13.4%; 95% CI, 11.5% to 15.5% in 2010; 8.1%; 95% CI, 6.0% to 10.5% in 2018; 10.4% 95% CI, 8.1% to 13.2% in 2022; P < .001). A statistically significant decrease in mean (SD) total cholesterol (184.6 [27.4] to 160.3 [27.4] mg/dL) and low-density lipoprotein cholesterol (113.6 [24.0] to 90.1 [24.0] mg/dL) was observed, which was reflected in a reduction in non-high-density lipoprotein cholesterol (HDL-C) (125.3 [26.2] to 99.8 [26.1] mg/dL) from 1992 to 2022. Mean (SD) serum HDL-C appear to have peaked from 1998 to 2004 (66.2 [13.3] vs 66.9 [13.3] mg/dL, respectively), and its levels have decreased since then (60.5 [13.4] mg/dL in 2022; P < .001). Mean (SD) resting blood pressure showed a substantial decrease over the study period (SBP: 113.5 [9.6] to 101.0 [9.7] mm Hg and DBP: 70.4 [7.2] to 60.7 [7.3] mm Hg; P < .001). However, mean (SD) insulin levels show a significant rise from 2004 to 2022 (6.3 [5.3] to 8.7 [5.2] μIU/mL; P < .001). Conclusions and Relevance: This repeated cross-sectional study provides a picture of the evolution of CMRFs in children over the last 30 years, showing that, in Spain, despite the concerning prevalences of excess weight, lipid parameters and blood pressure have improved over the studied period.