Pubertal development in Danish children: Comparison of recent European and US data

Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Denmark.
International Journal of Andrology (Impact Factor: 3.7). 02/2006; 29(1):247-55; discussion 286-90. DOI: 10.1111/j.1365-2605.2005.00556.x
Source: PubMed


Two recent epidemiological studies (PROS and NHANES III) from the USA noted earlier sexual maturation in girls, leading to increased attention internationally to the age at onset of puberty. We studied the timing of puberty in a large cohort of healthy Danish children in order to evaluate differences between USA and Denmark, as well as to look for possible secular trends in pubertal development. Healthy Caucasian children from public schools in Denmark participated in the study which was carried out in 1991-1993. A total number of 826 boys and 1,100 girls (aged 6.0-19.9 years) were included, and pubertal stages were assessed by clinical examination according to methods of Tanner. In boys testicular volume was determined using an orchidometer. We found that age at breast development 2 (B2) was 10.88 years, and mean menarcheal age was 13.42 years. Girls with body mass index (BMI) above the median had significantly earlier puberty (age at B2 10.42 years) compared with girls with BMI below the median (age at B2 11.24 years, p < 0.0001). Similarly, menarcheal age was significantly lower in girls with BMI above the median compared with girls with BMI below the median (13.12 vs. 13.70 years, p = 0.0012). In Danish boys we found that age at genital stage 2 (G2) was 11.83 years. Both sexes were significantly taller compared with data from 1964, but timing of pubertal maturation seemed unaltered. Finally, puberty occurred much later in Denmark compared with recent data from USA. We could not detect any downwards secular trend in the timing of puberty in Denmark between 1964 and 1991-1993 as seen in the US. Obesity certainly plays a role in the timing of puberty, but the marked differences between Denmark and USA cannot be attributed exclusively to differences in BMI. A possible role of other factors like genetic polymorphisms, nutrition, physical activity or endocrine disrupting chemicals must therefore also be considered. Therefore, we believe it is crucial to monitor the pubertal development closely in Denmark in the coming decades.

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    • "This difference could be because of racial, nutritional and environmental varieties. The mean age of menarche in UK and Denmark studies were 12.9 and 13.13 years, respectively [4, 7]. It can be concluded that our subjects experience earlier menarcheal age than European girls. "
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    ABSTRACT: Puberty is a critical time between childhood and adulthood. Many studies have reported that the mean age of breast development is decreasing. The aim of this study was to provide updated data on the pubertal development of girls and to evaluate precocious puberty in our population. This cross sectional study was conducted in 6 to 16 year old school girls during 2009-2010 in Qazvin. 2240 healthy girls from all geographical regions with every socioeconomic status were selected by a stratified multistage cluster design to obtain representative sample of population. A questionnaire including demographic data, anthropometric measurements, secondary sexual characteristics, menarche status and its onset was filled out for every participant. Secondary sexual characteristics including breast development (B(1-5)) and pubic hair (PH(1-5)) were evaluated according to Marshal and Tanner recommendation. The mean±SD of height, weight, and BMI of participants was 139.7±14.5, 36.1±12.9 and 17.9±3.7 respectively. The mean age (10th - 90th percentile) of B(2) and PH(2) were 9.71(7.67-11.4) and 9.82 years (7.84-11.42) respectively. Mean age of menstruation was 12.52 years. The mean BMI was significantly higher in pubertal females comparing to prepubertal girls (P<0.001). Average duration of puberty (the time from initiation of puberty to menarche) was 2.81 years. The mean age of pubertal onset in girls living in Qazvin is 9.71 years. Menarche occurs at mean age of 12.52 and onset of puberty earlier than 6.24 years will be precocious. We found that girls in Qazvin had a slightly earlier age of initiation of puberty and of menarche in comparison with other studies in Iran.
    Iranian Journal of Pediatrics 09/2012; 22(3):392-8. · 0.52 Impact Factor
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    • "Therefore, the relationship between malocclusion and skeletal maturation can be retrospectively investigated by comparing the menarcheal age, which is an indicator of skeletal maturation, among different malocclusion groups. However, the clinical application of this indicator to a given population would warrant the reassessment of pubertal stages in the population because secular trends in sexual maturation, including menarcheal age, have been observed in many countries.7,8 "
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    ABSTRACT: This study aimed to evaluate the mean age of menarche, its secular trend in Korean women, and the relationship between malocclusion and the rate of skeletal maturation, as defined by menarcheal age. We retrospectively collected data on menarcheal age from 931 Korean women born during 1961 - 1997. Subjects were divided by the malocclusion type and birth-year decade into 3 and 4 groups, respectively. The mean menarcheal age for each group was determined, and one-way ANOVA was performed for intergroup comparison (p = 0.05). Two-way ANOVA was also performed to compare all the 12 subgroups (p = 0.05). The mean age of menarche was 12.82 years for Korean women born during 1961 - 1997. A distinct downward secular trend of menarcheal age was noticed (p < 0.05). For the birth-year decade 1961 - 1970, the Class III malocclusion group showed earlier onset of menarche than the other malocclusion groups (p < 0.05), but the other birth-year groups did not show any significant difference in the type of malocclusion (p > 0.05). A positive secular trend towards earlier menarche exists among Korean women. Malocclusion does not show any significant relationship with the rate of skeletal maturation, as defined by menarcheal age.
    Korean Journal of Orthodontics 02/2012; 42(1):11-6. DOI:10.4041/kjod.2012.42.1.11 · 1.17 Impact Factor
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    • "Interestingly, rapid growth between 11 and 13 years of age in boys and between 9 and 11 years of age in girls showed the strongest association with increased CHD risk. These ages closely coincide with the timing of puberty in the Danish population both measured as sexual maturation [19] and as the onset of pubertal growth spurt [20]. In this same cohort, the average age at the onset of pubertal growth spurt was 12.2 years in boys born from 1930 to 1940 and decreased to 11.8 years in those born from 1965 to 1970 whereas in girls the ages were 10.4 and 10.2 years, respectively [20]. "
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    ABSTRACT: Adult height is inversely associated with the risk of coronary heart disease (CHD), but it is still unknown which phase of the human growth period is critical for the formation of this association. We investigated the association between growth in height from 7 to 13 years of age and the risk of CHD in adulthood. The heights of almost all children born 1930 through 1976 who attended school in the Copenhagen municipality (232,063 children) were measured annually from 7 to 13 years of age. Birth weight data were available since 1936. Fatal and non-fatal CHD events were ascertained by register linkage until 2008 (25,214 cases). Hazard ratios (HR) with 95% confidence intervals (CI) were estimated by Cox proportional hazards regression for height z-scores (standard deviation units) and change in height z-scores. Height z-scores were inversely related to the risk of CHD. The association was strongest at 7 years of age (HR = 0.91, CI 0.90-0.92 in boys and 0.88, CI 0.86-0.90 in girls) and steadily weakened thereafter, yet it still remained at 13 years of age (HR = 0.95, CI 0.94-0.97 and 0.91, CI 0.89-0.93, boys and girls respectively). The associations were not modified by birth weight. Independent of the age-specific risk, rapid growth was associated with an increased CHD risk, most pronounced between 9 and 11 years in girls (HR = 1.22, CI 1.14-1.31) and between 11 and 13 years in boys (HR = 1.28, CI 1.22-1.33) per unit increase in z-score. Adjustment for body mass index somewhat strengthened the associations of CHD risk with height and weakened the association with growth. Risk of CHD in adulthood is inversely related to height at ages 7 through 13 years, but strongest in the youngest, and, independently hereof, the risk increased by growth velocity.
    PLoS ONE 01/2012; 7(1):e30476. DOI:10.1371/journal.pone.0030476 · 3.23 Impact Factor
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