Adults born with low birth weight face higher risk for osteopenia, osteoporosis

Adults born with very low birth weight or who were small for gestational age showed a higher risk for osteopenia and osteoporosis, according to recently published findings from researchers in Norway.

“Between 8% to 26% of infants are born with low birth weight, depending on geographical region,” Chandima Balasuriya, MD, MBBS, a PhD candidate in the department of cancer research and molecular medicine at the Norwegian University of Science and Technology, and colleagues wrote. “The survival rate has increased gradually over the past three decades, and the first to receive advanced neonatal care have now entered adulthood. Growing evidence suggests that low birth weight is associated with subnormal peak bone mass.”

The researchers performed a follow-up cohort study of 186 white patients aged between 25 and 28 years who were born preterm with very low birth weight (n = 52) or born at full term but small for gestational age (n = 59), as well as a control cohort born at term with normal birth weight (n = 75). The main outcome was patients’ bone mineral density (BMD) as measured by DXA; secondary outcomes were bone mineral content, serum bone markers and trabecular bone score.

Patients born with very low birth weight had lower BMD and bone mineral content compared with controls, the researchers wrote, with lower BMD z scores (mean differences, 0.6 [P = .003] for femoral neck; 0.4 [P = .01] for total hip; 0.5 [P = .007] for whole body; 0.3 [P = .213] for lumbar spine), the researchers reported. The researchers reported lower spine bone mineral content and whole-body BMD z scores among patients in the small-for-gestational-age group; however, this difference did not hold true after adjustment.  

There were no overall differences in adult height, weight or BMI. When stratified by sex, however, men in the very-low-birth-weight and small-for-gestational-age groups were shorter than men in the control group (mean difference, 5.5 cm and 5.1 cm, respectively; P = .006 and P = .007), while women who were born small for gestational age were shorter than women in the control group (mean difference 4.3 cm; P = .036).

Both the small-for-gestational-age and very-low-birth-weight groups faced a higher risk for osteopenia or osteoporosis (adjusted OR = 2.0 for small-for-gestational-age adults; adjusted OR = 2.4 for very-low-birth-weight adults), Balasuriya and colleagues wrote.

“Our data highlight the importance of follow-up of infants born with low birth weight to ensure optimal accrual of bone mass from birth to adulthood,” the researchers wrote. “Bone health must become a concern starting prenatally, focusing on optimizing maternal health.” – by Andy Polhamus

Disclosure: The researchers report no relevant financial disclosures.