First study to analyze the association between genetic determinants of puberty timing and measurements of bone mineral density.
- People with the genetic factors responsible for delaying the average age of puberty are at an increased risk for low bone density.
- Low density bones make people more susceptible to diseases like osteoporosis and also recurrent bone fractures.
- Bone mineral density was found to be the lowest in the lower back and hip bones.
Adolescence-the peak period of bone development
Adolescence is a period of peak bone development. It is crucial as majority of bone growth and development occurs during puberty. Since the spine is rich in trabecular bone it may be particularly affected by late puberty effects. Therefore, when puberty is delayed so is bone development leading to conditions like osteoporosis and bone fractures later in life.Study Overview
The study was carried out to determine the association of the genetics that leads to delayed puberty on bone density. Bone and growth measurements were taken over a period of 7 years from over 2,000 healthy children, adolescents and young adults for the Bone Mineral Density in Childhood Study at CHOP. The study used two different approaches to study delayed puberty and bone density. The first was a genetic risk score that performed the association analysis of puberty-delaying effect estimates. The second is the Mendelian Randomization which determined the causal inference analysis.Another analysis called the Mendelian Randomization was used to determine that delayed puberty caused lower bone density in adults. A strong causal effect was also detected in young adolescent girls that reiterates that in fact delayed puberty does cause lower bone density. The causal effect was however not evident in the case of young adolescent boys.
"If an individual is genetically programmed for later puberty, we found that he or she tends to have lower bone mineral density during childhood as well as in adulthood," said geneticist Struan F. A. Grant, PhD, co-author of the study.
References:
- Cousminer, D. L., Mitchell, J. A., Chesi, A., Roy, S. M., Kalkwarf, H. J., Lappe, J. M., Gilsanz, V.,Oberfield, S. E., Shepherd, J. A., Kelly, A., McCormack, S. E., Voight, B. F., Zemel, B. S. and Grant, S. F. (2017), GeneticallyDetermined Later Puberty Impacts Lowered Bone Mineral Density in Childhood and Adulthood. J Bone Miner Res. doi: 10.1002/jbmr.3320