Changes in calcium kinetics associated with menarche

To evaluate the consequences of puberty on calcium (Ca) metabolism, we measured Ca kinetic parameters in 43 healthy girls at 1-60 months post menarche. There was a close relationship between the logarithmic transform of the number of months post menarche and the bone Ca deposition rate (V-0+) (r = -0.90, P < 0.001). Using multiple regression analysis with the logarithmic transforms of chronological age and months pc,st menarche as independent parameters, we found that the number of months post menarche was more significantly correlated with V-0+ (t = -7.4, P < 0.0001) than with chronological age (t = -3.1, P = 0.003). A longitudinal study of 17 girls demonstrated a peak V-0+ approximately 8 months before menarche, with a decrease in V-0+ after menarche. These studies indicate that the peak time for bone Ca deposition is in the premenarcheal and perimenarcheal time period. The close correlation between V-0+ and months post menarche demonstrates the importance of puberty in consideration of bone Ca metabolism in girls.