Recent changes in pubertal timing in healthy Danish boys: associations with body mass index.

CONTEXT In the 1990s, the American population-based study NHANES III renewed the focus on possible secular trends in male puberty. However, no conclusions could be made on pubertal onset due to the lack of compatible data. OBJECTIVE The aim of the study was to evaluate secular trends in pubertal onset during the recent 15 yr and their relation to body mass index (BMI) in boys. DESIGN AND SETTING We conducted a cross-sectional study in 1991-1993 and a combined cross-sectional and longitudinal study in 2006-2008 (The Copenhagen Puberty Study) at a tertiary center for pediatric endocrinology. PARTICIPANTS A total of 1528 boys aged 5.8 to 19.9 yr participated (n = 824 in 1991-1993, and n = 704 in 2006-2008). Genital and pubic hair stages as well as testicular volume by orchidometry were evaluated. Blood samples were analyzed for LH, FSH, testosterone, and SHBG. MAIN OUTCOME MEASURES We measured age at onset of pubertal markers. RESULTS Onset of puberty, defined as age at attainment of testicular volume above 3 ml, occurred significantly earlier in 2006-2008 [11.66 yr (11.49-11.82); mean (95% confidence interval)] than in 1991-1993 [11.92 yr (11.76-12.08); P = 0.025]. Significantly higher LH, but not testosterone, levels were found in the 11- to 16-yr-old boys from 2006-2008 compared to 1991-1993 (P = 0.020). BMI Z-score increased significantly from 1991-1993 [0.044 (-0.016 to 0.104)] to 2006-2008 [0.290 (0.219-0.361); P < 0.001]. Interestingly, pubertal onset and LH levels were no longer significantly different between study periods after adjustment for BMI. CONCLUSIONS Estimated mean age at onset of puberty has declined significantly during the recent 15 yr. This decline was associated with the coincident increase in BMI.

[1]  A. Rogol,et al.  Consensus Statement on the Use of Gonadotropin-Releasing Hormone Analogs in Children , 2009, Pediatrics.

[2]  R. Lipton,et al.  Thelarche, Pubarche, and Menarche Attainment in Children With Normal and Elevated Body Mass Index , 2009, Pediatrics.

[3]  P. Kaplowitz.  Link Between Body Fat and the Timing of Puberty , 2008, Pediatrics.

[4]  S. Swan,et al.  Examination of US Puberty-Timing Data from 1940 to 1994 for Secular Trends: Panel Findings , 2008, Pediatrics.

[5]  Anders Juul,et al.  Age at voice break in Danish boys: effects of pre-pubertal body mass index and secular trend. , 2007, International journal of andrology.

[6]  L. Lönn,et al.  Pubertal Timing Is an Independent Predictor of Central Adiposity in Young Adult Males , 2006, Diabetes.

[7]  F. Pralong,et al.  Control of GnRH neuronal activity by metabolic factors: The role of leptin and insulin , 2006, Molecular and Cellular Endocrinology.

[8]  A. Slyper.  The pubertal timing controversy in the USA, and a review of possible causative factors for the advance in timing of onset of puberty , 2006, Clinical endocrinology.

[9]  M. Herman-Giddens.  Recent data on pubertal milestones in United States children: the secular trend toward earlier development. , 2006, International journal of andrology.

[10]  E. M. Laursen,et al.  Pubertal development in Danish children: comparison of recent European and US data. , 2006, International journal of andrology.

[11]  J. Duarte,et al.  Association between overweight and early sexual maturation in Portuguese boys and girls , 2006, Annals of human biology.

[12]  T. K. Jensen,et al.  Prevalence and Incidence of Precocious Pubertal Development in Denmark: An Epidemiologic Study Based on National Registries , 2005, Pediatrics.

[13]  Shumei S. Sun,et al.  Is sexual maturity occurring earlier among U.S. children? , 2005, The Journal of adolescent health : official publication of the Society for Adolescent Medicine.

[14]  T. Çaşkurlu,et al.  Measurement of pediatric testicular volume with Prader orchidometer: comparison of different hands , 2005, Pediatric Surgery International.

[15]  F. Ebling.  The neuroendocrine timing of puberty. , 2005, Reproduction.

[16]  D. Elahi,et al.  Increasing insulin resistance is associated with a decrease in Leydig cell testosterone secretion in men. , 2005, The Journal of clinical endocrinology and metabolism.

[17]  Youfa Wang.  Is obesity associated with early sexual maturation? A comparison of the association in American boys versus girls. , 2002, Pediatrics.

[18]  Shumei S. Sun,et al.  National estimates of the timing of sexual maturation and racial differences among US children. , 2002, Pediatrics.

[19]  R. Troiano,et al.  Stature and pubertal stage assessment in American boys: the 1988-1994 Third National Health and Nutrition Examination Survey. , 2002, The Journal of adolescent health : official publication of the Society for Adolescent Medicine.

[20]  G. Koch,et al.  Secondary sexual characteristics in boys: estimates from the national health and nutrition examination survey III, 1988-1994. , 2001, Archives of pediatrics & adolescent medicine.

[21]  R. Wasserman,et al.  Earlier onset of puberty in girls: relation to increased body mass index and race. , 2001, Pediatrics.

[22]  A. Giwercman,et al.  Inter-observer variation in the results of the clinical andrological examination including estimation of testicular size. , 2000, International journal of andrology.

[23]  P. Kaplowitz,et al.  Reexamination of the Age Limit for Defining When Puberty Is Precocious in Girls in the United States: Implications for Evaluation and Treatment , 1999, Pediatrics.

[24]  A. Isidori,et al.  Leptin and androgens in male obesity: evidence for leptin contribution to reduced androgen levels. , 1999, The Journal of clinical endocrinology and metabolism.

[25]  K. Flegal,et al.  Overweight children and adolescents: description, epidemiology, and demographics. , 1998, Pediatrics.

[26]  L. Dunkel,et al.  Twenty-four-hour profiles of luteinizing hormone, follicle-stimulating hormone, testosterone, and estradiol levels: a semilongitudinal study throughout puberty in healthy boys. , 1997, The Journal of clinical endocrinology and metabolism.

[27]  G. Lindgren.  Pubertal stages 1980 of Stockholm schoolchildren , 1996, Acta paediatrica.

[28]  G. Huster,et al.  Pubertal staging in boys. , 1995, The Journal of pediatrics.

[29]  N. Skakkebaek,et al.  Serum insulin-like growth factor-I in 1030 healthy children, adolescents, and adults: relation to age, sex, stage of puberty, testicular size, and body mass index. , 1994, The Journal of clinical endocrinology and metabolism.

[30]  R. Largo,et al.  Pubertal development in Swiss boys. , 1983, Helvetica paediatrica acta.

[31]  P. Leaverton,et al.  Secondary sex characteristics of girls 12 to 17 years of age: the U.S. Health Examination Survey. , 1979, The Journal of pediatrics.

[32]  T. Thelle,et al.  [Measurement of testicular volume with Prader's orchiometer in 1,389 boys 5--15 1/2 years old]. , 1979, Ugeskrift for laeger.

[33]  G. Berenson,et al.  Anthropometric and maturation measurements of children, ages 5 to 14 years, in a biracial community--the Bogalusa Heart Study. , 1977, The American journal of clinical nutrition.

[34]  A. Prader,et al.  Testicular volume during adolescence. Cross-sectional and longitudinal studies. , 1974, Helvetica paediatrica acta.

[35]  J M Tanner,et al.  Variations in the Pattern of Pubertal Changes in Boys , 1970, Archives of disease in childhood.

[36]  L. Leslie,et al.  Residency Review and Redesign in Pediatrics Committee. Linking Process to Outcome : Are We Training Pediatricians to Meet Evolving Health Care Needs? , 2009 .

[37]  Y. Ogawa,et al.  Testicular volume measurement: comparison of ultrasonography, orchidometry, and water displacement. , 2007, Urology.

[38]  Lester R Curtin,et al.  Centers for Disease Control and Prevention 2000 growth charts for the United States: improvements to the 1977 National Center for Health Statistics version. , 2002, Pediatrics.

[39]  Stef van Buuren,et al.  Pubertal Development in The Netherlands 1965–1997 , 2001, Pediatric Research.

[40]  Y. Makita,et al.  Diurnal rhythms of luteinizing hormone, follicle-stimulating hormone, and testosterone secretion before the onset of male puberty. , 1999, The Journal of clinical endocrinology and metabolism.

[41]  N. Skakkebaek,et al.  Urinary growth hormone excretion in 657 healthy children and adults: normal values, inter- and intraindividual variations. , 1991, Hormone research.