title: The reciprocal links between synaptophysin serum levels and the prevalence of metabolic syndrome according to selected low-grade inflammation indices and age-related androgen serum level changes in men.
abstract: The correlations between synaptophysin (SYP) plasma levels and the brain neurotransmission activity are still not strictly identified. However, the efficiency of neurotransmission depends, inter alia, on the age, hormonal status, and coexistence of a low-grade systemic inflammation (LGSI) which is regarded as a pathogenic link with obesity and insulin resistance, atherogenesis and aging per se.
  
  
  OBJECTIVE
  The aim of this study was to investigate the associations between synaptophysin serum levels and age, LGSI indices, homocysteine and selected hormonal parameters (dehydroepiandrosterone and its sulfate, free-testosterone, SHBG) and the prevalence of metabolic syndrome (MS) in men over the age of 40.
  
  
  METHODS
  After randomization, 157 male volunteers aged 40-80 years were included in a retrospective study. MS was diagnosed according to the International Diabetes Federation criteria. For the diagnosis of late-onset hypogonadism (LOH) we adopted the criteria proposed by the European Male Aging Study (EMAS).
  
  
  RESULTS
  Synaptophysin plasma concentrations in respondents decreased with age, but only between the ages of 40 to 70 years. There were no differences in SYP plasma concentrations in men suffering from MS compared to healthy subjects (p=0.845). Men suffering from MS demonstrated while higher hs-CRP (high sensitive C - reactive protein) levels than healthy (p=0.019), contrary to the α1-antichymotrypsin and transferrin. A positive monotonic correlation between synaptophysin and hs-CRP was demonstrated (r=0.235; p=0.003). No statistically significant relationships between SYP and homocysteine plasma levels were presented (r=0.047; p=0.562), although in men diagnosed with MS higher homocysteine levels compared to healthy subjects were demonstrated. No correlations between synaptophysin and free testosterone (r=-0.036; p=0.651), DHEA (r=-0.122; p=0.128) and its sulphate (r=-0.024; p=0.764) as well as SHBG (r=-0.088; p=0.288) were demonstrated.
  
  
  CONCLUSIONS
  Although the correlations between synaptophysin plasma levels and age as well as strong LGSI indicator (hs-CRP) have been demonstrated, the usefulness of determining SYP serum concentration as a marker of age-related studied diseases (MS, LOH) seems to be significantly limited.
authors.affiliation: Outpatients Unit of Endocrine Diseases, Wschowa, Poznan, Poland.
authors.forename: Waldemar Adam
authors.initials: WA
authors.lastname: Herman
authors.affiliation: Department of Clinical Neuroimmunology, University of Medical Sciences, Poznan, Poland.
authors.forename: Marlena
authors.initials: M
authors.lastname: Wójcicka
authors.affiliation: Department of Computer Science and Statistics, University of Medical Sciences, Poznan, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Kołodziejczak
authors.affiliation: Department of Clinical Neuroimmunology, University of Medical Sciences, Poznan, Poland; Neuroimmunological Unit Mossakowski Medical Research Centre Polish Academy of Sciences, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Losy
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, University of Medical Sciences, Poznan, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Łącka
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D000728:Androgens / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood*; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D011044:Poland; D011897:Random Allocation; D012189:Retrospective Studies; D016708:Synaptophysin / Q000097:blood*
chemical_list: D000728:Androgens; D015415:Biomarkers; D016708:Synaptophysin
keywords: aging men; late-onset hypogonadism; low-grade systemic inflammation; metabolic syndrome; synaptophysin