Impaired microvascular hyperaemic response in children with diabetes mellitus.

Clinically detectable microvascular complications of diabetes are uncommon in children with diabetes especially in the prepubertal group. It is unclear whether subtle functional abnormalities of the microcirculation occur in children without evidence of clinical microangiopathy and in particular whether abnormalities can be demonstrated in children before puberty. The maximum hyperaemic response to direct local heating (44 degrees C) of the foot skin was measured by laser Doppler fluximetry in 50 diabetic and 50 non-diabetic children. An impaired hyperaemic response occurred in the diabetic children compared with control children (diabetic 1.25 (95% CI 1.13-1.37) V; control 1.74 (1.60-1.88) V; p less than 0.001) and was significantly related to duration of diabetes but not to long-term blood glucose control. The impaired response was also present in prepubertal diabetic children (diabetic 1.37 (1.16-1.58) V; control 1.89 (1.67-2.12) V; p less than 0.001). Systolic and diastolic blood pressure were significantly raised in the prepubertal diabetic children. These data suggest that a functional abnormality of the microcirculation occurs in children with diabetes in the absence of clinically detectable microangiopathy, and even before puberty.