title: Circulating Prostate-Specific Antigen and Telomere Length in a Nationally Representative Sample of Men Without History of Prostate Cancer.
abstract: We investigated the association of prostate-specific antigen (PSA) with leukocyte telomere length, which may be altered in preclinical prostate malignancies.
  
  
  
  This study was based on the 2001-2002 U.S. National Health and Nutrition Examination Survey (NHANES). A subsample of 1,127 men aged 40-85 years without prior history of prostate cancer who provided informed consent and blood samples were selected. Leukocyte telomere length (LTL) relative to standard DNA reference (T/S ratio) was quantified by polymerase chain reaction (PCR). Survey-weighted multivariable linear regression was performed to examine T/S ratio across quintiles of total and free PSA and free-to-total PSA ratio (%fPSA). A sensitivity analysis was performed by excluding men dying from prostate cancer during follow-up through to December 31, 2006. Stratification analyses were carried out to assess any effect modification by age group, race, body mass index (BMI), and levels of C-reactive protein (CRP), a marker of inflammation.
  
  
  
  Higher total PSA levels were associated to longer LTL, with approximately 8% increase in log-transformed T/S ratio (95% confidence interval [CI]: 2-13%) among men in the highest quintile of total PSA compared to the lowest in the fully adjusted model (Ptrend= 0.01). No significant association was found for free PSA or %fPSA, although nonlinearity between all PSA measures and T/S ratio was indicated. Similar results were found after excluding men who died from prostate cancer during follow-up. We also found the associations between total PSA and T/S ratio to be strongest among non-Hispanic blacks, non-obese men (BMI <30 kg/m2), and those with low CRP. However, a significant interaction was only found between total PSA and race/ethnicity (Pinteraction= 0.01).
  
  
  
  Total PSA levels were strongly associated to LTL, particularly among non-Hispanic blacks. Our findings support a potential link between PSA and specific mechanisms contributing to prostate cancer development. Prostate 77:22-32, 2017. © 2016 Wiley Periodicals, Inc.
authors: MRC Unit for Lifelong Health and Ageing, University College London, London, United Kingdom.|Division of Haematology/Oncology, Faculty of Medicine, Gadjah Mada University, Yogyakarta, Indonesia.|PILAR Research and Education, Cambridge, United Kingdom.
authors: Wahyu
authors: W
authors: Wulaningsih
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.|Department of Obstetrics/Gynaecology, Faculty of Medicine, Gadjah Mada University, Yogyakarta, Indonesia.
authors: Yuliana
authors: Y
authors: Astuti
authors: Department of Biochemistry and Biophysics, University of California, Driver Group, L.L.C., San Francisco, California.
authors: Tetsuya
authors: T
authors: Matsuguchi
authors: Division of Haematology/Oncology, Faculty of Medicine, Gadjah Mada University, Yogyakarta, Indonesia.
authors: Putri
authors: P
authors: Anggrandariyanny
authors: PILAR Research and Education, Cambridge, United Kingdom.|Institute for Mathematical and Molecular Biomedicine, King's College London, London, United Kingdom.
authors: Johnathan
authors: J
authors: Watkins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000379:methods; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000453:epidemiology; D016615:Telomere / Q000378:metabolism*; D059505:Telomere Homeostasis / Q000502:physiology*
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
keywords: prostate cancer; prostate-specific antigen; telomere; telomere length