With an increased incidence of pediatric type 1 diabetes (T1D) and a decrease in age at
diagnosis, children are exposed to complications such as renal impairment at a very young
age.
The current biomarker used to diagnose renal impairment is microalbuminuria, but it's a late
marker. Early screening is a major issue to reduce T1D consequences.
Early glomerular hyperfiltration (GHF) could participate in the development and progression
of nephropathy. Hyperfiltration has also been associated with a systemic endothelial
dysfunction and with changes in arterial stiffness, suggesting, at least to a certain extent,
a state of generalized vascular dysfunction.
Diabetes is responsible for very early neurovascular dysfunctions, detectable with techniques
to evaluate cutaneous neurovascular interaction. Those should help bringing to light very
early microcirculation impairment, particularly precocious endothelial dysfunction (ED).
No study about correlation between GHF and ED is currently available. The hypothesis assessed
is those of a strong correlation between ED and GHF in children and adolescent with a story
of T1D for at least 10 years.
This pilot study should allow assessing ED's and GHF's proportions in our population, in
order to conduct a larger study to prove, in a prospective way, the prognostic value of ED in
the apparition of nephropathy, taking into count other factors such as diabetes duration or
stability.
This measure could be included in the global evaluation of microangiopathy risk in children
and then take action to prevent negative outcomes.
The second aspect of this study is the assessment of other functions and metabolisms possibly
impaired in T1D: osseous microarchitecture, vitamin D status and precocious evaluation of
macro angiopathy through intima media thickness measurement.
Long term diabetes in children is associated with shorter and leaner bones, despite a correct
mineralization, a reduced bone density and a fracture risk increased six fold. Bone status in
the population will be evaluated through the study of bones microarchitecture via HR-pQCT
(High Resolution peripheral Quantitative Computed Tomography) on both tibia and radius,
dual-energy X-ray absorptiometry (DXA), and bone turn over biochemical markers.
Results on bone microarchitecture in a preexisting cohort of healthy children and adolescents
will be used to compare results.