<u>Background</u>
<p>There is substantial evidence that adults
with type 1 diabetes have reduced bone mineral density (BMD), however findings in
youth are inconsistent.</p>
<p><u>Purpose</u></p>
<p>Systematic review and meta-analysis of BMD in
youth with type 1 diabetes using multiple modalities: dual energy X-ray
absorptiometry (DXA), peripheral quantitative computed tomography (pQCT) and/or
quantitative ultrasound (QUS).</p>
<p><u>Data Sources</u></p>
<p>PubMed, Embase, Scopus and Web of Science from
01/01/1990 to 31/12/2020, limited to humans, without language restriction.</p>
<p><u>Study Selection</u></p>
<p>Inclusion criteria: cross sectional or cohort
studies that included BMD measured either by DXA, pQCT and/or QUS in youth (age
<20 years) with type 1 diabetes and matched controls. </p>
<p><u>Data extraction</u></p>
<p>Total body (TB), lumbar spine (LS) and femoral
BMD (DXA); tibia, radius and lumbar spine (pQCT); and phalanx and calcaneum
(QUS). Weighted mean difference (WMD) or standardized mean difference (SMD)
were estimated and meta-regression was performed using age, diabetes duration
and HbA1c as covariates.</p>
<p><u>Data Synthesis </u></p>
<p>We identified 1300 non-duplicate studies; 46 met the inclusion
criteria, including 2617 cases and 3851 controls. Mean age was 12.6 ± 2.3 years. Youth with type 1 diabetes had lower BMD: TB
(WMD -0.04 g/cm<sup>2</sup>, 95% CI -0.06 to -0.02, <i>P</i>=0.0006); LS (-0.02 g/cm<sup>2</sup>, -0.03 to -0.0, <i>P = 0.01</i>); femur (-0.04 g/cm<sup>2</sup>,
-0.05 to -0.03, <i>P</i><0.00001); tibial
trabecular (-11.32 g/cm<sup>3</sup>,-17.33 to -5.30, <i>P</i>=0.0002), radial trabecular (-0.91, -1.55 to -0.27, <i>P=0.005</i>); phalangeal (-0.32, -0.38 to
-0.25, <i>P</i><0.00001) and calcaneal (SMD
-0.69, -1.11 to -0.26, <i>P</i>=0.001). Using meta-regression TB BMD was associated
with older age (coefficient -0.0063, -0.0095 to -0.0031, <i>P</i>=0.002), but not longer diabetes duration or HbA1c.</p>
<p><u>Limitations</u></p>
<p>Meta-analysis was limited by the small number of studies
using QUS and pQCT and lack of use BMD z-scores in all studies. </p>
<p><u>Conclusions</u></p>
<p>Bone development is abnormal in youth with type 1
diabetes, assessed by multiple modalities. Routine assessment of BMD should be
considered in all youth with type 1 diabetes.</p>