Impaired skin microcirculation in paediatric patients with type 1 diabetes mellitus.
OBJECTIVE
We used Laser Doppler Fluximetry (LDF) to define "normal" endothelial function in a large cohort of healthy children and adolescents and to evaluate skin microcirculation in paediatric patients with type 1 diabetes mellitus.


METHODS
LDF was performed in 102 healthy children (12.8 ± 3.3 years of age; 48 male) and 68 patients (12.9 ± 3.3 years of age; 33 male). Duration of disease was 5.0 ± 3.97 years. Each participant sequentially underwent three stimulation protocols (localized thermal hyperaemia with localized warming to maximum 40°C, iontophoretic delivery of pilocarpine hydrochloride (PCH) and sodium nitroprusside (SNP)). The maximum relative increase in skin blood flow and the total relative response, i.e. the area under the curve (AUC) to each stimulus (AUCheat, AUCPCH, AUCSNP) was determined. In addition, the area of a right-angled triangle summarizing the time to and the amplitude of the first peak, which represents the axon reflex mediated neurogenic vasodilation (ARR) was calculated.


RESULTS
In healthy controls, AUCheat, AUCPCH, AUCSNP, and ARR turned out to be independent of sex, age, and anthropometric values. Per parameter the 10th percentile generated from data of healthy controls was used as the lower threshold to define normal endothelial function. Diabetic patients showed significantly reduced vasodilatative response to either physical or pharmacological stimulation with SNP, whereas the response to PCH was comparable in both cohorts. In patients compared to controls i) a significantly higher frequency of impaired vasodilatation in response to heat and SNP was noted and ii) vascular response was classified as pathological in more than one of the parameters with significantly higher frequency.


CONCLUSIONS
Skin microvascular endothelial dysfunction is already present in about 25% of paediatric type 1 diabetic patients suffering from type 1 diabetes for at least one year. Future studies are needed to assess the predictive value of endothelial dysfunction in the development of long-term (cardio)vascular comorbidity in these patients.
Department of Paediatrics, University Hospital Rostock, Germany. dagmar-christiane.fischer@med.uni-rostock.de
Mirjam
M
Heimhalt-El Hamriti
Corinna
C
Schreiver
Anja
A
Noerenberg
Julia
J
Scheffler
Ulrike
U
Jacoby
Dieter
D
Haffner
Dagmar-C
DC
Fischer
D000293:Adolescent; D019540:Area Under Curve; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000000981:diagnostic imaging; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology*; D018721:Muscarinic Agonists / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010862:Pilocarpine / Q000494:pharmacology; D012016:Reference Values; D012867:Skin / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000187:drug effects; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology; D055815:Young Adult
D018721:Muscarinic Agonists; D014665:Vasodilator Agents; D010862:Pilocarpine; D009599:Nitroprusside