European Journal of Psychotraumatology (Sep 2012)

Serum leptin concentrations and telomere length in MDD and in controls

  • Owen M. Wolkowitz,
  • Jodie Bryk,
  • Synthia H. Mellon,
  • Elissa S. Epel,
  • Elizabeth H. Blackburn,
  • Jue Lin,
  • Robert H. Lustig,
  • Peter J. Havel,
  • Victor I. Reus,
  • Heather M. Burke,
  • Rebecca Rosser,
  • John Coetzee,
  • Laura Mahan,
  • Michelle Coy,
  • Steven P. Hamilton,
  • Craig J. Nelson

DOI
https://doi.org/10.3402/ejpt.v3i0.19374
Journal volume & issue
Vol. 3, no. 0
pp. 1 – 1

Abstract

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Obesity and the metabolic syndrome (MetS) predispose to multiple diseases and to accelerated cell aging as indexed by accelerated shortening of telomeres in peripheral blood mononuclear cells (PBMC's). Major depressive disorder (MDD) is often associated with MetS and is also associated with increased disease risk and PBMC telomere shortening. A potential role of leptin in telomere shortening has been suggested, but prior results have been inconsistent and no study has yet assessed this relationship in MDD. The goal of this study was to assess the relationship between serum leptin concentrations and PBMC telomere length in MDD and in controls and to assess whether this relationship is mediated by body-mass index (BMI) or the homeostatic model assessment of insulin resistance (HOMA-IR), two principal components of the MetS.Eighteen medication-free MDD subjects (11 female, 7 male, mean age 37.1 + 2.7 years) and 17 healthy controls (11 female, 6 male, mean age 37.8 + 3.0 years) had blood drawn for assay of fasting morning levels of leptin, glucose, and insulin and PBMC telomere length. The groups did not differ on BMI (24.66 + 3.72 vs. 24.77 + 4.29, respectively, n.s.). Analyses were co-varied for age and sex, with and without BMI.In the combined group, serum leptin concentrations were inversely correlated with telomere length (r= − 0.33, p<0.02), with and without co-varying for BMI. This relationship remained significant in the MDD group alone (r= − 0.54, p<0.04) but missed significance in the controls (r= − 0.23, ns). Hierarchical linear regression, entering BMI and HOMA-IR prior to leptin (with telomere length the dependent variable) showed that BMI and HOMA-IR were not significantly correlated with telomere length (t=1.04, p>0.30, and t=1.49, p>0.10, respectively), but leptin concentrations remained significantly correlated with telomere length (t= − 2.88, p=0.007).Relatively high leptin concentrations, in the presence or absence of increased BMI and insulin resistance, may be a risk factor for telomere shortening. While this was demonstrated here in individuals with MDD, a similar relationship in non-depressed individuals cannot be ruled out because of the small sample size.

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