title: Interactive associations of physical activity, adiposity, and oral contraceptive use on C-reactive protein levels in young women.
abstract: Oral contraceptives (OCs) are the most frequently used type of birth control among young women. OC-users have higher C-reactive protein (CRP) values, an indicator of systemic inflammation, than do non-OC-users. In addition, adiposity (percent fat) is positively associated with CRP, and physical activity (PA) is inversely associated with CRP. The present study determined the interactive associations of PA, percent fat, and OC-use with CRP. Data were collected during 2012-2015 at the University of Georgia. Objective PA was measured via pedometers. Percent fat was measured via dual X-ray absorptiometry. The current OC-use was self-reported. High-sensitivity (hs) CRP was determined using venipuncture. Multivariate linear regression determined the interactive associations of percent fat, OC-use, and PA with hs-CRP. Participants (n = 247; mean age 18.9 ± 1.4 years, 60.7 percent white) accumulated a mean of 10,075.7 ± 3,593.4 steps/day. One-third of participants were categorized as overweight/obese by BMI (mean = 24.5 ± 4.8 kg/m2, mean percent fat = 35.2 ± 6.8). The current OC-use was reported by 26.2 percent of the sample (n = 61). A significant three-way interaction (β = 0.01, p = .03) indicated that higher PA was associated with lower hs-CRP in non-OC-users with higher percent fat, but not among OC-users with higher percent fat. These results highlight the need to measure and account for the current OC-use in studies examining the relationship between PA and CRP.
authors.affiliation: a Department of Kinesiology , The University of Alabama , Tuscaloosa , Alabama , USA.|b Department of Kinesiology , The University of Georgia , Athens , Georgia , USA.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Fedewa
authors.affiliation: a Department of Kinesiology , The University of Alabama , Tuscaloosa , Alabama , USA.|e University of Tennessee at Chattanooga , Chattanooga , Tennessee , USA.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Hathaway
authors.affiliation: b Department of Kinesiology , The University of Georgia , Athens , Georgia , USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Higgins
authors.affiliation: b Department of Kinesiology , The University of Georgia , Athens , Georgia , USA.|c Department of Kinesiology , East Carolina University , Greenville , North Carolina , USA.
authors.forename: Bhibha M
authors.initials: BM
authors.lastname: Das
authors.affiliation: d University Health Center, The University of Georgia , Athens , Georgia , USA.
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Forehand
authors.affiliation: b Department of Kinesiology , The University of Georgia , Athens , Georgia , USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Schmidt
authors.affiliation: b Department of Kinesiology , The University of Georgia , Athens , Georgia , USA.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Evans
mesh_terms: D050154:Adiposity; D000293:Adolescent; D000328:Adult; D002097:C-Reactive Protein / Q000032:analysis / Q000378:metabolism*; D016022:Case-Control Studies; D003276:Contraceptives, Oral / Q000008:administration & dosage / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007249:Inflammation; D009765:Obesity; D012307:Risk Factors; D055815:Young Adult
chemical_list: D003276:Contraceptives, Oral; D002097:C-Reactive Protein
keywords: Body composition; inflammation; oral contraceptives; physical activity