title: Circulating PCSK9 levels correlate with the serum LDL cholesterol level in newborn infants.
abstract: OBJECTIVE
  Protein convertase subtilisin/Kexin type-9 (PCSK9) is a substantial player in lipoprotein metabolism. This study was designed to elucidate the role of PCSK9 in the regulation of lipoprotein during the fetal period.
  
  
  METHODS
  This study was a cross-sectional study. Eighty-one neonates (45 males, 36 females) who were admitted to the neonatal intensive care unit were enrolled in the study. The median age in gestational weeks and weight at birth were 37.1 weeks and 2493 g, respectively. There were no gender differences, but the proportion of infants who were small-for-gestational age (SGA) was significantly higher among females than males. The prefed serum PCSK9 level was assayed with ELISA kits.
  
  
  RESULTS
  The median PCSK9 concentration in male newborns was significantly lower than that in females (148.2 ng/ml vs. 171.4 ng/ml, respectively, p<0.001). Circulating serum PCSK9 levels were positively correlated with total cholesterol (r=0.281, p<0.05) and low-density lipoprotein cholesterol (LDL-C; r=0.272, p<0.05). However, there were no correlations between PCSK9 levels and birth weight, gestational age or SGA. Multivariate forward stepwise linear regression analysis revealed that gestational age and circulating PCSK9 levels were independent predictors of the serum LDL-C levels in newborn infants.
  
  
  CONCLUSIONS
  Our first quantitative analysis of neonatal serum PCSK9 levels at birth showed that circulating PCSK9 levels show gender-based differences and are significantly correlated with LDL-C. These results suggest that PCSK9 could play an important role in regulating LDL-C levels during the fetal period.
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan; Center of Maternal, Fetal and Neonatal Medicine, University of Occupational and Environmental Health Hospital, Kitakyushu, Japan. Electronic address: arashun@med.uoeh-u.ac.jp.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Araki
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan; Center of Maternal, Fetal and Neonatal Medicine, University of Occupational and Environmental Health Hospital, Kitakyushu, Japan.
authors.forename: Shutaro
authors.initials: S
authors.lastname: Suga
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan; Center of Maternal, Fetal and Neonatal Medicine, University of Occupational and Environmental Health Hospital, Kitakyushu, Japan.
authors.forename: Fuyu
authors.initials: F
authors.lastname: Miyake
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan; Center of Maternal, Fetal and Neonatal Medicine, University of Occupational and Environmental Health Hospital, Kitakyushu, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Ichikawa
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan; Center of Maternal, Fetal and Neonatal Medicine, University of Occupational and Environmental Health Hospital, Kitakyushu, Japan.
authors.forename: Tadamune
authors.initials: T
authors.lastname: Kinjo
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Yukiyo
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kusuhara
mesh_terms: D001724:Birth Weight; D008078:Cholesterol, LDL / Q000097:blood*; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases / Q000097:blood*; D012697:Serine Endopeptidases / Q000097:blood*; D012737:Sex Factors; D018709:Statistics, Nonparametric
chemical_list: D008078:Cholesterol, LDL; C472125:PCSK9 protein, human; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D012697:Serine Endopeptidases
keywords: LDL-C; PCSK9; metabolic syndrome; newborn infants; small-for-gestational age