RESUMEN
BACKGROUND/OBJECTIVES: To compare body fat mass at the same stage of pubertal maturation, genital stage 2 (G2), in a Spanish and in a Mexican sample of boys. SUBJECTS/METHODS: Data from Spain (n=177) were from a previous longitudinal clinical follow-up and data from Mexico (n=91) from a cross-sectional study. Subjects were grouped according to the presence of G2 at similar ages. Spanish sample was divided into boys with G2 at age 12 (n=60), 13 (n=74) and 14 (n=43). In Mexican sample, 23 boys were at G2 at 12 years, 38 at age 13 and 30 at 14 years. Height, weight, upper arm circumference and four skinfold thicknesses were recorded. Genital development was assessed (Tanner scale). Sum of four skinfolds (SUM), body mass index (BMI), percentage of body fat (%BF) and extremity/trunk skinfold ratio (ETR=(triceps+biceps)/(subscapular+suprailiac)) was calculated. RESULTS: When comparing subjects with different ages at G2 from the same country, or with the same age at G2 from different countries, no significant differences were found in adiposity variables (%BF, SUM), nor in BMI. Nevertheless, there were differences in body fat distribution: ETR was higher in Spanish boys (P<0.001), because of their greater triceps skinfold thickness (P=0.013), and due to the greater trunk fat stores in Mexican boys (P<0.01, subscapular and suprailiac skinfolds). CONCLUSIONS: There is a subcutaneous fat mass store characteristic of G2 in boys, which is not only independent of age, but is also observable in two different populations.
Asunto(s)
Tejido Adiposo , Distribución de la Grasa Corporal , Pubertad , Adolescente , Antropometría , Tamaño Corporal , Niño , Humanos , Masculino , México , Grosor de los Pliegues Cutáneos , EspañaRESUMEN
This paper analyzed the intensity and duration of height growth during puberty in boys and girls in relation to rhythm of maturation. A longitudinal clinical follow-up between ages of 10 and 20 years, was carried out in a sample of 251 children grouped according to age at pubertal onset: boys (genital stage 2) at the ages of 11 (n = 28), 12 (n = 38), 13 (n = 42), and 14 (n = 27); and girls (breast stage 2) at the ages of 10 (n = 37), 11 (n = 47), 12 (n = 19), and 13 (n = 13). Height was measured annually. Testicular volume and genital development were assessed in boys, and breast development was assessed in girls. There were significant differences (P < 0.001) in height at the age of pubertal onset among maturity groups. Late maturers were taller than early maturers (r = 0.49, P < 0.001 for girls; r = 0.38, P < 0.001 for boys). However, final heights did not differ according to age of onset in either sex. In boys, later onset of puberty was associated with a smaller pubertal height gain (r = -0.60, P < 0.001) and a shorter period of pubertal growth (r = -0.61, P < 0.001). Equally in girls, earlier onset of puberty was associated with a greater pubertal height gain (r = -0.68, P < 0.001) and a longer period of pubertal growth (r = -0.59, P < 0.001). In conclusion, age of pubertal onset does not affect final height attained in both sexes, since there is an inverse compensatory phenomenon in both sexes between height at pubertal onset and the intensity and duration of pubertal growth.
Asunto(s)
Estatura/fisiología , Crecimiento/fisiología , Pubertad/fisiología , Adolescente , Adulto , Factores de Edad , Análisis de Varianza , Antropometría , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Valor Predictivo de las Pruebas , Valores de Referencia , Caracteres Sexuales , Factores de TiempoRESUMEN
OBJECTIVE: To observe the time lapse between the start of puberty and the advent of menarche in groups of girls maturing at different ages. SUBJECTS: A sample of 163 girls subgrouped by pubertal onset at 9 (n = 22), 10 (n = 53), 11 (n = 54), 12 (n = 27), and 13 (n = 7) years of age. DESIGN: Clinical follow-up from 10 to 17 years of age. METHODS: Onset of puberty was defined by the combined observation of mammary development on the Tanner scale and the height curve. The date of menarche was recorded (month and year), and the time lapse was expressed as a function of the date of birth. RESULTS: In the overall study sample, the duration of puberty was 1.96 +/- 0.06 years. For the subgroups of girls starting puberty at 9, 10, 11, 12, and 13 years of age, the time lapse to menarche was 2.77 +/- 0.16, 2.27 +/- 0.16, 1.78 +/- 0.08, 1.44 +/- 0.10, and 0.65 +/- 0.09 years, respectively (p < 0.001). The correlation coefficient (r) between the onset of puberty and its duration was r = -0.62 (p < 0.001), and that of age of pubertal onset versus age of menarche was r = 0.66 (p < 0.001). CONCLUSION: The duration of puberty in girls depends on the timing of its onset; the earlier the onset of puberty the longer its duration.
Asunto(s)
Menarquia/fisiología , Adolescente , Factores de Edad , Niño , Femenino , Estudios de Seguimiento , Humanos , Factores de TiempoRESUMEN
Seventeen constitutionally short boys were studied throughout puberty. Nine received oxandrolone (0.1 mg/kg/day). Treatment was started before onset of puberty. Eight boys served as control subjects. No significant increase in linear growth or skeletal maturation was observed in the treated group. Likewise the peak height velocity was unchanged. Pubic hair developed similarly in both groups in relation to chronologic and skeletal age. The only significant difference was a diminution in testicular volume index during treatment after bone age of 12 years and until bone age of 14 6/12 years.