The Associations Between Blood Neutrophils, Lymphocytes, and Monocytes with Changes in Percent Body Fat (BF%) are Distinctly Modified by Pubertal Stage in Overweight Latino Adolescents

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 690-701-Obesity Pathophysiology
Translational
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-693
Brandon D Kayser*1, Claudia M Toledo-Corral2, Tanya L Alderete3, Marc Weigensberg3 and Michael I Goran4
1Univ of Southern CA, Los Angeles, CA, 2University of Southern Californi, Los Angeles, CA, 3University of Southern California, 4Univ of Southern California, Los Angeles, CA
Obesity is associated with white adipose tissue inflammation, whereby the secretion of inflammatory adipocytokines can activate and recruit circulating leukocytes. The relationship between obesity and inflammation during puberty is poorly understood, although several cross-sectional studies in children and adolescents have shown positive associations between BMI or abdominal obesity and total blood leukocyte counts (WBC)1-3 and neutrophils (NEUT)2,4. We performed a longitudinal analysis of %BF and blood leukocytes in order to elucidate the temporal relationships between increasing body composition and leukocyte subtypes across puberty.

Subjects consisted of 165 (90 male) from a longitudinal cohort of overweight/obese Latino adolescents who had at least 2 annual visits (median 3, maximum 7). The mean age was 11.2 years and mean BMI z-score was 2.04 at baseline. %BF was determined by DEXA. Total leukocyte (WBC), and absolute (NEUT), lymphocytes (LYMPH), and monocytes (MONO) were measured by routine blood leukocyte counts. Separate marginal models were built for each leukocyte measurement and were estimated by GEE. The cross-sectional and longitudinal effects of time-varying %BF were disaggregated as %BF at baseline (%BFBase) and change-from-baseline (%BFChange). Time-in-study, sex, and baseline Tanner were included as a priori covariates.

After adjusting for covariates and including significant interactions, WBC (β=.07, p<0.05) and NEUT (β=.05, p<0.05) at baseline were positively associated with %BFBase. On average, all leukocyte counts remained stable across puberty (Tanner main effect, p>0.05), although WBC increased across Tanner with increasing %BFBase (β=0.02, p<0.05). The distinct nature of the interactions between %BFChange and linear trend over Tanner (NEUT, β=-0.03, p<0.001; LYMPH, β =0.01, p<0.01; MONO, β =0.01, p<0.05), and quadratic trend over Tanner (MONO, β =-0.002, p<0.05) indicate that the positive associations between %BFChange and NEUT, MONO, and LYMPH is greatest at early, middle, and later Tanner stages, respectively.

Higher %BFBase predicts increasing WBC across puberty, whereas the strength of the positive association between %BFChange and leukocyte subtypes changes distinctly across time. These data are consistent with an inflammatory condition in obese adolescents, and that stages of adolescent development can modify the relationship between changing body composition and blood leukocytes.

(1) Visser M, Bouter LM, McQuillan GM, Wener MH, Harris TB. Low-Grade Systemic Inflammation in Overweight Children. PEDIATRICS. 2001;107 (1):e13-e13. (2) Kim JA, Park HS. White blood cell count and abdominal fat distribution in female obese adolescents. Metabolism. 2008;57 (10):1375-1379. (3) Pirkola J, Vaarasmaki M, Ala-Korpela M et al. Low-grade, systemic inflammation in adolescents: association with early-life factors, gender, and lifestyle. Am J Epidemiol. 2010;171 (1):72-82. (4)  Skinner AC, Steiner MJ, Henderson FW, Perrin EM. Multiple markers of inflammation and weight status: cross-sectional analyses throughout childhood. Pediatrics. 2010;125 (4):e801-9.

Nothing to Disclose: BDK, CMT, TLA, MW, MIG

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: National Institute of Diabetes And Digestive And Kidney Diseases of the National Institutes of Health R01DK059211.