Influence of differences in birth weight on bones in adult women

Items that came to light based on a pilot study

Abstract

The purpose of this study was to confirm whether there was a difference in the factors related to bone development and bone mass when individuals witha low weight at birth (low birth weight infants: LBWI) and those with a normal weight at birth (normal birth weight infants: NBWI) reached adulthood, then examine the future risk of developing bone joint diseases. Among female college students who were born in the period when Japan saw a rapid rise in LBWIs and who are currently in adulthood asa statistical population, an LBWI group (six subjects) and an NBWI group (six subjects) were extracted. In addition to taking measurements of bone mass area ratio, bone mineral content,lower leg length ratio, and weight, the subjects were asked regarding their time spent exercising during school age and puberty, after which the data was compared between the two groups. As a result, it was found that there was no significant difference in the bone mass area ratio between both groups. However, the LBWI group indicated a significantly lower value in the lower leg length ratio (p<0.05). Therefore, it was suggested that while a difference in birth weight does not affect bone density in adulthood, LBWIs may inhibit the postnatal growth of the bone, in the form of shortening the lower leg length ratio. Moreover, it remains necessary to elucidate the mechanism that causes an inhibition of postnatal growth of the bone and to also follow up the effects of LBWI on bone in old age.