Early Manifestation of Type 1 Diabetes in Children is a Risk Factor for Changed Bone Geometry: Data Using Peripheral Quantitative Computed Tomography

Objective: Normal to severely decreased bone mineral density has been reported in children with type 1 diabetes. To detect possible abnormalities in bone mineralization, geometry, and muscle bone unit, we measured selective parameters in children with type 1 diabetes using peripheral quantitative computed tomography.

Methods: Measurements of the radius by peripheral quantitative computed tomography were made to assess cortical and trabecular bone characteristics as well as muscle mass in 88 patients (42 girls, 46 boys) at a mean age of 11.7 +/- 3.0 years, a mean disease duration of 5.6 +/- 3.7 years, and a mean manifestation age of type 1 diabetes of 6.1 +/- 3.5 years. Height, weight, Tanner stage, insulin regimen, and glycosylated hemoglobin values were recorded. Bone metabolism was studied by measurement of bone formation and bone resorption parameters. Dynamic muscle force was measured using a grip strength device.

Results: Overall, cortical, trabecular, and total bone mineral density were within the reference range. Total and cortical bone cross-sectional area and muscle mass were low in prepubertal patients, and total cross-sectional area was low in early puberty. Adolescent patients showed normal bone and muscle parameters. Grip strength and recreational physical activity were normal in all in relation to a healthy reference population. In a subgroup of 18 patients, early manifestation of type 1 diabetes was detected as a risk factor for altered bone development with significantly reduced cortical bone mineral density and total, cortical, and muscle cross-sectional area (-0.9 +/- 1.3 SD, -2.1 +/- 1.3 SD, -1.6 +/- 0.7 SD, and -1.0 +/- 0.7 SD, respectively). Bone characteristics were not influenced by metabolic control, disease duration, or insulin regimen.

Conclusions: Manifestation of type 1 diabetes at an early age may impair bone development. Longitudinal data are needed to determine whether this impairment persists into adolescence and adulthood.