Related Experiment Video
Updated: Sep 29, 2025
Scanning Skeletal Remains for Bone Mineral Density in Forensic Contexts
Published on: January 29, 2018
Bone mineral density in very low birthweight adults-A sibling study
Samuel Sandboge1,2, Juho Kuula1,3, Johan Björkqvist1
1Population Health Unit, Finnish Institute for Health and Welfare, Helsinki and Oulu, Finland.
Insights
Adults born very low birthweight (VLBW) have lower bone mineral density and content than term-born siblings. These differences, partly due to smaller body size, suggest shared factors influence bone health in VLBW individuals.
Area of Science:
- Pediatrics
- Bone Health
- Perinatal Medicine
Background:
- Individuals born very low birthweight (VLBW) exhibit reduced bone mineral density (BMD) and bone mineral content (BMC) compared to term-born peers.
- The precise causal factors linking VLBW to diminished bone health remain unclear.
Purpose of the Study:
- To investigate BMD and BMC in adults born VLBW using a sibling comparison design.
- To control for shared genetic and environmental influences confounding the VLBW-bone health association.
Main Methods:
- A cohort study involving 77 VLBW adults and 70 same-sex term-born siblings (mean age 29 years).
- Dual-energy X-ray absorptiometry (DXA) was used to measure BMD Z-scores and BMC at the femoral neck, lumbar spine, and whole body.
- Linear mixed-effects models were employed for data analysis.
Main Results:
- VLBW adults had significantly lower femoral neck BMD Z-scores (0.25 units) and BMC (0.35 grams) compared to siblings, adjusted for sex, age, and maternal smoking.
- Lower bone mineral content was observed across all measured sites (lumbar spine, whole body) in the VLBW group.
- Adjustment for adult body size partially attenuated these differences.
Conclusions:
- Adults born VLBW demonstrate reduced bone mineral content and femoral neck BMD compared to their term-born siblings.
- Smaller adult body size partially explains these bone deficits, but does not fully account for the observed differences.
- Shared genetic or environmental factors play a role, but do not exclusively determine the association between preterm VLBW birth and adult bone mineralization.
Background:
Children and adults born very low birthweight (VLBW, <1500 g) at preterm gestations have lower bone mineral density (BMD) and/or bone mineral content (BMC) than those born at term, but causality remains unknown.
Objectives:
Our aim was to assess BMD and BMC in adults born at VLBW in a sibling comparison setting to account for shared genetic and environmental confounders.
Methods:
We conducted a cohort study of 77 adults born VLBW and 70 same-sex term-born siblings at mean age of 29 years. The primary outcome variables were BMD Z-scores, and BMC, of the femoral neck, lumbar spine, and whole body, measured using dual-energy X-ray absorptiometry. We analysed data by linear mixed models.
Results:
The VLBW adults had a 0.25 (95% CI 0.02, 0.47) Z-score unit lower femoral neck BMD, and 0.35 (95% CI 0.16, 0.54) grams lower femoral neck BMC than their term-born siblings, after adjustment for sex, age, and maternal smoking. Additional adjustment for adult body size attenuated the results. Lumbar spine, and whole body BMC were also lower in the VLBW group.
Conclusions:
Individuals born at VLBW had lower BMC values at all three measurement sites, as well as lower femoral neck BMD Z-scores, compared to term-born siblings, partly explained by their smaller adult body size, but the differences were smaller than those reported previously with unrelated controls. This suggests that genetic or environmental confounders explain partly, but not exclusively, the association between preterm VLBW birth and adult bone mineralisation.
Related Concept Videos
01:29Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
01:09Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
01:31Essential Minerals for Bone Health
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
01:09Spongy Bone
Spongy bone is more porous, and less dense compared to compact bone. It is composed of concentric lamellae that are arranged irregularly to form the trabecular network. In some bones, the spaces between trabeculae contain red marrow, where...
01:18The Bone Matrix
01:21Skeleton and Calcium Homeostasis