title: Increasing incidence of premature thelarche in the Central Region of Denmark - Challenges in differentiating girls less than 7 years of age with premature thelarche from girls with precocious puberty in real-life practice.
abstract: BACKGROUND
  Premature thelarche (PT) seems to be increasing and it is difficult to differentiate its early stages from precocious puberty (PP). Clinical and biochemical parameters are warranted to differentiate the two diagnoses.
  
  
  METHODS
  One hundred ninety-one girls aged 0.5-7 years were included. Diagnoses were validated and the girls were categorized to the groups PP (n = 27) and PT (n = 164). Anthropometry, Tanner stages, ethnicity, bone age, and biochemistry, were recorded. Conventional variables for diagnosing PP were compared between the groups at time of referral to identify parameters predictive for the diagnosis.
  
  
  RESULTS
  The referral rate of PT increased from 1998-2013. Girls with PT and PP differed with regards to age at referral, body mass index standard deviation scores (BMISDS), ethnicity, bone age advancement, basal luteinizing hormone (LH), gonadotropin releasing hormone (GnRH) stimulated LH and follicle stimulating hormone (FSH), basal and stimulated LH/FSH ratio, and sex-hormone binding globulin (SHBG). Apart from SHBG there was considerable overlap of the variables between the PT and the PP groups.
  
  
  CONCLUSIONS
  First, the incidence of PT appears to increase. Second, SHBG was the variable which best discriminated PT from PP. Third, stimulated LH in 1-3 years old girls with PT is similar to stimulated LH in 5-7 years old girls with PP. Age, BMISDS, ethnicity, bone age, stimulated gonadotropins and LH/FSH and SHBG are all useful variables for differentiating PP from PT. However normative data for stimulated LH and FSH in the age group 0.5-7 years are warranted.
authors.affiliation: Department of Pediatrics, Aarhus University Hospital, Skejby, Palle Juul Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
authors.forename: Mia Elbek
authors.initials: ME
authors.lastname: Sømod
authors.affiliation: Medical Research Laboratory, Aarhus University, Nørrebrogade 44 building 3B, DK-8000 Aarhus C, Denmark.|Department of Pediatrics, Randers Regional Hospital, DK-8930 Randers, Denmark.
authors.forename: Esben Thyssen
authors.initials: ET
authors.lastname: Vestergaard
authors.affiliation: Department of Pediatrics, Aarhus University Hospital, Skejby, Palle Juul Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
authors.forename: Kurt
authors.initials: K
authors.lastname: Kristensen
authors.affiliation: Department of Pediatrics, Aarhus University Hospital, Skejby, Palle Juul Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
authors.forename: Niels Holtum
authors.initials: NH
authors.lastname: Birkebæk
keywords: Gonadotropins; Incidence; Precocious puberty; Premature thelarche; Sex hormone binding globulin