Background Studies have shown that serum low-density lipoprotein (LDL-C) and non-high-density lipoprotein (non-HDL-C) have recently declined in the USA among adult and child populations despite high obesity prevalence rates. The purpose of this study was to assess whether there was a significant linear decrease in LDL-C and non-HDL-C, but not Body Mass Index (BMI) percentile among a cross-sectional, large, homogenous cohort with consistent methodology over the past decade.
Methods A total of 47 198 children, mostly between 10 and 11 years old, participating between 2002 and 2012 were examined to assess trends in serum lipid concentration and BMI percentile.
Results For LDL-C, year of screening was significant (p<0.0001) even with the inclusion of gender, age and BMI (all p<0.0001). For non-HDL-C, year of screening was also significant (p<0.0001), even with the inclusion of gender (p=0.0445), age (p<0.0001), BMI (p<0.0001) and systolic blood pressure (p=0.0021). Although some non-linear trends were also significant (eg, a quartic trend, p<0.001), the linear trend provided the best fit for both cholesterol models. By comparison, we noted general maintenance of BMI percentile over time.
Conclusions Between 2002 and 2012, among 5th grade Appalachian children, there was a consistent linear decrease in LDL-C and non-HDL-C despite continued high prevalence rates of obesity, diabetes and hypertension. The improvement in LDL-C and non-HDL-C could be due to multifactorial causes.