Lipoprotein‐subclass particle numbers in children with abdominal obesity

Abstract

Background The lipoprotein particle number (PN) profile may be a better marker of cardiovascular risks than standard serum lipid measurements. The aim of this study was to analyze the lipoprotein PNs in Japanese children with abdominal obesity and to determine the subclass profile. Methods The participants included 164 Japanese children (79 boys and 85 girls) aged 9–13 years. We obtained waist‐to‐height ratios (WHtR) and serum lipids for all participants. The lipoprotein PNs in 12 subclasses were analyzed using high performance liquid chromatography (HPLC). Results Both boys and girls with abdominal obesity (WHtR ≧ 0.5) had significantly higher triglyceride (TG), very‐low‐density lipoprotein (VLDL)‐PN, and all VLDL‐subclass PNs compared to those without abdominal obesity. In boys with abdominal obesity, low‐density lipoprotein (LDL)‐PN was higher, but lipoprotein cholesterol (LDL‐C) was not, and high‐density lipoprotein cholesterol (HDL‐C) was lower, but HDL‐PN was not compared to those without abdominal obesity. In girls with abdominal obesity, LDL‐C and LDL‐PN were not significantly different and both HDL‐C and HDL‐PN were lower compared to those without abdominal obesity. Subclass analyses demonstrated that boys and girls with abdominal obesity had significantly lower very large and large HDL‐PNs than those without abdominal obesity. In addition, medium, small, and very small LDL‐PNs were higher in boys with abdominal obesity than those without abdominal obesity. Conclusions This study found that Japanese children with abdominal obesity are affected by the lipoprotein‐subclass PN profile, with sex differences in the LDL‐ and HDL‐subclasses, which is different from results obtained by standard serum lipid measurements.

Best practices to promote rigor and reproducibility in the era of sex-inclusive research

“…But, although the DISS approach is biased toward false positive findings ( Bland and Altman, 2011 ; George et al, 2016 ), it can also produce false negatives – that is, it can cause investigators to miss real sex differences (left panel of Figure 2B ). For example, in a recent study of abdominal obesity in children (AO), the authors missed a large sex difference in the association between AO and a measure of lipoprotein particle number because their within-sex p-values showed non-significant associations in both girls and boys ( Akiyama et al, 2022 ). In fact, the interaction between sex and AO was highly significant ( P =0.001); the association in girls was positive and among boys, negative ( Vorland et al, 2023 ).…”

Determination of sex differences requires formal test for differences: Comment on “lipoprotein‐subclass particle numbers in children with abdominal obesity”

“…We read with interest the paper by Akiyama et al 1 describing differences in lipoprotein subclasses and particle numbers in children with and without abdominal obesity. We commend the authors for including both boys and girls, which improves the generalizability of the findings, 2 and for disaggregating data by sex, which is becoming standard practice in the USA as well as Japan.…”

“…See TableS1for p-values. Note that CIs may not match nominal significance because our figures do not account for multiple comparisons within outcome, whereas table 1 in Akiyama et al1 adjusted for multiple comparisons. (b) Correlations between waist: height ratio (WHtR) or HOMA-IR and outcomes.…”