title: Prolactin is associated with metabolic risk and cortisol in 1007 women with polycystic ovary syndrome.
abstract: OBJECTIVE
  Is there an association between prolactin and markers of metabolic risk in polycystic ovary syndrome (PCOS)?
  
  
  CONCLUSIONS
  Low serum prolactin was a metabolic risk marker in PCOS.
  
  
  BACKGROUND
  Prolactin is routinely measured to exclude endocrine diseases in PCOS. Recent studies have suggested that prolactin can be used as a marker for metabolic and cardiovascular risk.
  
  
  METHODS
  Retrospective cross-sectional study in an academic tertiary-care medical center. Data were collected during 1997-2012. Premenopausal women (n = 1007) with hirsutism and/or PCOS and 116 healthy, age-matched controls were included. Prolactin levels were measured in blood samples taken in the morning after a minimum of 2 h awakening time. Macroprolactinemia was excluded by the precipitation of serum with polyethylene glycol in patients with increased prolactin levels.
  
  
  METHODS
  Serum prolactin levels were measured along with a clinical evaluation (Ferriman-Gallwey score, BMI, waist circumference, blood pressure) plus hormone analyses (sex hormones, fasting lipids, insulin, glucose), transvaginal ultrasound, and oral glucose tolerance (n = 234) and adrenocorticotrophic hormone tests (n = 201). All patients had prolactin levels below the upper reference limit (23 µg/l).
  
  
  RESULTS
  Prolactin levels were significantly lower in patients versus controls; median (quartiles) prolactin levels 7 (5-10) versus 9 (7-13) µg/l (P < 0.001). In the patient population prolactin levels were inversely associated with age, smoking status, waist circumference, total cholesterol, triglyceride and low-density lipoprotein (LDL) and positively associated with high-density lipoprotein, estradiol, total testosterone, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone and cortisol levels. In multiple regression analyses, prolactin was inversely associated with LDL and positively associated with estradiol, 17-hydroxyprogesterone and cortisol after correcting for age, BMI and smoking status in patients with PCOS.
  
  
  CONCLUSIONS
  The study design was cross-sectional and prospective studies are needed to further determine the impact of prolactin levels on cardiovascular outcomes. Patients included in the study were relatively lean and only 20 had diabetes, which could have affected our findings. In addition, the collection of blood samples when estrogen levels were low (follicular phase) could be related to the lower levels of prolactin. Furthermore, as prolactin is secreted in a pulsatile manner, several measures of prolactin may be needed to further investigate associations between prolactin and metabolic risk.
  
  
  CONCLUSIONS
  Our findings of inverse associations between prolactin levels and metabolic risk markers are supported by studies in populations of women without PCOS. The association between prolactin and adrenal activity should be evaluated in future studies.
  
  
  BACKGROUND
  This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector. There are no conflicts of interest to declare.
authors.affiliation: Department of Endocrinology and Metabolism, Odense University Hospital, 5000 Odense C, Denmark dorte.glintborg@rsyd.dk.
authors.forename: Dorte
authors.initials: D
authors.lastname: Glintborg
authors.affiliation: Department of Endocrinology and Metabolism, Odense University Hospital, 5000 Odense C, Denmark.
authors.forename: Magda
authors.initials: M
authors.lastname: Altinok
authors.affiliation: Department of Endocrinology and Metabolism, Odense University Hospital, 5000 Odense C, Denmark.
authors.forename: Hanne
authors.initials: H
authors.lastname: Mumm
authors.affiliation: Department of Endocrinology and Metabolism, Odense University Hospital, 5000 Odense C, Denmark.
authors.forename: Kristian
authors.initials: K
authors.lastname: Buch
authors.affiliation: Department of Gynecology and Obstetrics, Odense University Hospital, 5000 Odense C, Denmark.
authors.forename: Pernille
authors.initials: P
authors.lastname: Ravn
authors.affiliation: Department of Endocrinology and Metabolism, Odense University Hospital, 5000 Odense C, Denmark.
authors.forename: Marianne
authors.initials: M
authors.lastname: Andersen
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D004958:Estradiol / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008659:Metabolic Diseases / Q000150:complications / Q000175:diagnosis*; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000150:complications; D011388:Prolactin / Q000097:blood*; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D013739:Testosterone / Q000097:blood; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D015415:Biomarkers; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D013739:Testosterone; D004958:Estradiol; D019314:Dehydroepiandrosterone Sulfate; D019326:17-alpha-Hydroxyprogesterone; D011388:Prolactin; D002784:Cholesterol; D006854:Hydrocortisone
keywords: diabetes; insulin resistance; metabolic risk; polycystic ovary syndrome; prolactin