title: Variations in leptin and insulin levels within one swimming season in non-obese female cold water swimmers.
abstract: OBJECTIVE
  We examined whether cold water swimming for seven consecutive months changes basal leptin and insulin concentrations and insulin sensitivity in healthy non-obese women.
  
  
  METHODS
  Fourteen recreational female swimmers aged 45 ± 8.7 years, regularly swimming outdoors during winter months were exposed to cold water at least twice a week. Fasting blood samples were collected in October, January and April. Serum leptin, insulin and glucose concentrations were tested and insulin sensitivity was calculated using updated model HOMA2.
  
  
  RESULTS
  Repeated cold water baths significantly increased insulin sensitivity and decreased insulin and leptin concentrations (p = 0.006, p = 0.032, p = 0.042, respectively). Leptin concentration positively correlated with body-mass index (BMI) and insulin level (r = 0.412, r = 0.868, respectively). Insulin level inversely correlated with insulin sensitivity and positively with glucose (r = -0.893, r = 0.166, respectively). No associations between leptin and insulin sensitivity were found.
  
  
  CONCLUSIONS
  Regular cold water swimming may stimulate metabolic changes suggesting that leptin and insulin participate in adaptive metabolic mechanisms triggered by repeated cold exposure accompanied by mild exercise in healthy non-obese women.
authors.affiliation: a Department of Physiology , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Magdalena
authors.initials: M
authors.lastname: Gibas-Dorna
authors.affiliation: a Department of Physiology , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Zuzanna
authors.initials: Z
authors.lastname: Checinska
authors.affiliation: a Department of Physiology , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Emilia
authors.initials: E
authors.lastname: Korek
authors.affiliation: a Department of Physiology , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Justyna
authors.initials: J
authors.lastname: Kupsz
authors.affiliation: b Department of Informatics and Statistics , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Anna
authors.initials: A
authors.lastname: Sowinska
authors.affiliation: c Mother and Child Health, Poznan University of Medical Sciences , Poznan , Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Wojciechowska
authors.affiliation: a Department of Physiology , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Hanna
authors.initials: H
authors.lastname: Krauss
authors.affiliation: a Department of Physiology , Poznan University of Medical Sciences , Poznan , Poland ;
authors.forename: Jacek
authors.initials: J
authors.lastname: Piątek
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose; D015992:Body Mass Index; D003080:Cold Temperature; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D012621:Seasons; D013550:Swimming
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D020738:Leptin
keywords: Cold water swimming; insulin; insulin sensitivity; leptin