title: Gender and the active smoking and high-sensitivity C-reactive protein relation in late adolescence.
abstract: C-reactive protein (CRP), smoking, and oral contraceptive (OC) use are associated with CVD risk in adults. This study examines the effect of smoking on high-sensitivity CRP (hs-CRP) levels, and the interactive effects of sex and OC use on this relationship in an adolescent cohort. A total of 1,050 adolescents (mean age 17 ± 0.25 years) from the Western Australian Pregnancy Cohort (Raine) Study had anthropometric, lifestyle, and metabolic measures recorded. The association between smoking status and log-transformed hs-CRP was analyzed using multivariable Tobit linear regression models, with adjustment for adiposity, lifestyle, and early-life confounders. A three-level variable (girls not using OCs, girls using OCs, and boys) was employed to assess the interactive effects of sex, OC use, and smoking. Smoking associated with higher hs-CRP levels in girls not using OCs (b = 0.571; P = 0.001), but not in girls using OCs (b = -0.117; P = 0.598) or in boys (b = 0.183; P = 0.2). OC use in nonsmoking girls was the strongest factor associated with higher hs-CRP levels (b = 1.189; P < 0.001). This study has demonstrated a more robust effect of smoking on hs-CRP levels in girls not using OCs compared with boys. The findings may explain why CVD risk conferred by smoking is higher in women than in men.
authors.affiliation: Royal Perth Hospital Unit, School of Medicine and Pharmacology, University of Western Australia, Perth, Australia.
authors.forename: Chi
authors.initials: C
authors.lastname: Le-Ha
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Beilin
authors.forename: Sally
authors.initials: S
authors.lastname: Burrows
authors.forename: Wendy H
authors.initials: WH
authors.lastname: Oddy
authors.forename: Beth
authors.initials: B
authors.lastname: Hands
authors.forename: Trevor A
authors.initials: TA
authors.lastname: Mori
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000097:blood / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000209:etiology; D003276:Contraceptives, Oral / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects / Q000097:blood / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D003276:Contraceptives, Oral; D002097:C-Reactive Protein
keywords: adolescent smoking; cardiovascular risk factors; oral contraceptives; sex differences