Fifteen-year trends in cholesterol levels among children in a universal screening programme

Background Prepubertal cholesterol levels largely reflect genetic determinants, making early childhood ideal for assessing inherited lipid profiles with minimal lifestyle influence. At the same time, secular increases in sedentary behaviour may affect population lipid levels. Whether total cholesterol (TC) in children has shifted over time within a national universal screening programme remains unclear. Purpose To compare TC levels across three cross-sectional cohorts (2009, 2014, 2023) participating in the Slovenian universal cholesterol screening programme and assess whether population-level TC distributions changed after adjusting for age, sex, and body mass index (BMI). Methods Three randomly selected cohorts from the first stage of the Slovenian universal screening programme (coverage >90%) were analysed. The cohorts included 4,810 children screened in 2009, 3,538 in 2014, and 4,169 in 2023. Age, sex, height, weight, and TC were extracted from routine records; BMI was calculated. Between-year differences were analysed using appropriate parametric and non-parametric tests. Adjusted comparisons were obtained using linear regression (TC ~ year + age + BMI + sex). Results Cohort characteristics differed modestly (age increasing from 5.0 ± 0.1 to 5.6 ± 0.5 years), while BMI remained stable (15.8–15.6 kg/m²). Sex distribution was consistent (≈50% male). Unadjusted TC means were similar: 4.13 ± 0.71 mmol/L (2009), 4.16 ± 0.67 (2014), 4.08 ± 0.68 (2023). Percentile bands (5th–95th and 10th–90th) were nearly overlapping across all three years, indicating stable population distributions (Figure 1). Global tests showed statistically significant between-year variation (p<0.01), but post hoc comparisons demonstrated only small absolute differences: 2009 vs 2014: +0.03 mmol/L (p=0.10); 2009 vs 2023: –0.05 mmol/L (p<0.01); 2014 vs 2023: –0.08 mmol/L (p<0.01). In multivariable models (Figure 2), 2014 had slightly higher TC than 2009 (+0.04 mmol/L, p<0.01), whereas 2023 did not differ from 2009 (p=0.62). Using calendar year as a continuous predictor showed no linear trend over time (p=0.65). Conclusion Total cholesterol levels in Slovenian pre-school children remained highly stable over 15 years, with only minimal adjusted differences between cohorts. Despite societal changes in childhood lifestyle, early-life lipid profiles did not show upward drift. These findings confirm the robustness of universal childhood cholesterol screening for detecting genetically mediated hypercholesterolemia.