Lower bone mineral density in preterm born adults, compared to term-born siblings

Young adults born preterm with a very low birth weight (<1500 grams) have lower bone mineral density than their term-born siblings, according to a recently published study. 

As a departure from previous studies, the study used the preterm born individuals’ term-born siblings as the control group. By comparing siblings, the researchers could account for potential genetic, and/or shared early life environmental confounding factors. 

Previous studies have demonstrated that individuals born preterm with a very low birth weight have lower bone mineral density in adulthood, compared to unrelated controls born at term. The current study revealed similar differences in the sibling setting, but these differences were smaller than those previously observed. 

-    Our findings indicate that genetic and environmental factors might explain a part, but not all, of the differences in bone mineral density previous studies have found between adults born preterm and those born at term, notes postdoctoral researcher at the Finnish Institute for Health and Welfare (THL), Samuel Sandboge.

A decreased bone mineral density is associated with a higher risk of osteoporotic fractures later in life. The current study, however, did not examine bone fractures in individuals born preterm with a very low birth weight, and the findings of a lower bone mineral density do not automatically translate to a higher risk of fractures in this group. Further studies are needed to explore if this is the case. Factors that improve bone mineral density include a sufficient intake of calcium and vitamin D, adequate physical activity, and not smoking.

The study was performed in collaboration between researchers at the Finnish Institute for Health and Welfare (THL), the University of Helsinki, Helsinki University Hospital, and the University of Oulu. 77 individuals born preterm with very low birth weight and 70 term-born siblings took part in the study. 

Publication

“Bone mineral density in very low birthweight individuals – a sibling study” was been published in Paediatric and Perinatal Epidemiology.

 Additional information 

Samuel Sandboge, MD, PhD, [email protected], +358 40 040 5299
Juho Kuula, MD, PhD student, [email protected], +358 40 836 9567