[Follow-up study on effects of height velocity and puberty onset on biochemical markers of bone turnover].
In order to clarify the factors which affect bone metabolism at a young age, we investigated the relationships among the change of biochemical markers of bone turnover, the height velocity (HV) and puberty onset in healthy Japanese children. One hundred and twelve children (61 boys and 51 girls) were recruited at the fourth grade level in the elementary school (9 years old) and followed for 6 years. Serum bone specific alkaline phosphatase (B-ALP), serum tartrate-resistant acid phosphatase (TR-ACP), urine hydroxyproline (Hyp) and urine calcium (Ca) were measured as the biochemical markers of bone turnover. Bone mineral density of calcaneus was also measured by ultrasound method at the first grade (12 years old) and the third grade (14 years old) of junior high school. Heights and weights of all subjects were measured every April and the HV were calculated between each year. Puberty onset was defined as the time when pubic hair appeared in boys and as the time when menarche started in girls by self-administered questionnaire. All the biochemical markers of bone metabolism except for urine Ca had a significant positive relationship with HV. The values of the markers were highest of the time when the HV was maximum. In girls, the values of the biochemical markers remained high before menarche and then decreased significantly within three years after menarche, suggesting that bone turnover changed rapidly from high turnover type to low turnover type after menarche. On the other hand, in boys, high turnover type remained for a few years after puberty onset. Bone mineral density of calcaneus by ultrasound method increased significantly in boys between the two years in junior high school, but the increase was unclear except for broadband ultrasound attenuation (BUA) in girls in the same period.
Nishino
H
H
Department of Environmental Health, Toyama Institute of Health.
Horii
Y
Y
Tanaka
T
T
Yamagami
T
T
Matsukura
T
T
Kagamimori
S
S
D000135:Acid Phosphatase / Q000097:blood; D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D044466:Asian People; D015415:Biomarkers / Q000032:analysis*; D001827:Body Height; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000652:urine; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006909:Hydroxyproline / Q000652:urine; D007564:Japan; D008297:Male; D008572:Menarche / Q000502:physiology; D011627:Puberty / Q000502:physiology*
D015415:Biomarkers; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D006909:Hydroxyproline; D002118:Calcium