CLINICAL CHARACTERISTICS AND CIRCULATING COLLAGEN AND LAMININ METABOLITES IN INSULIN-DEPENDENT DIABETIC CHILDREN WITH JOINT AND SKIN MANIFESTATIONS

One hundred seventy-four children and adolescents with insulin-depende nt diabetes mellitus were examined for joint contractures and skin man ifestations in their hands. Joint contractures were found in 52 (29.8% ) and skin manifestations in 29 (16.6%) patients. To eliminate the pos sible confounding effects of age and duration of diabetes on the varia bles to be studied, patients younger than 7 y and with a duration of d iabetes shorter than 3 y were excluded from the subsequent analyses. O f the remaining 108 children, those with joint contractures had lower serum concentrations of the 7-S domain of type IV collagen and the P1 fragment of laminin than the other patients (p = 0.033) but higher mea n glycated Hb levels (p = 0.048). A clear association was noted betwee n the occurrence of joint contractures and skin changes (p = 0.007). B ackground retinopathy was found in six patients (5.6%), three of whom had stage II joint contractures (p = 0.064). The children with skin ch anges and those with combined joint and skin manifestations more often had insulin-dependent diabetes mellitus in their first-degree relativ es (p = 0.038 and p = 0.043, respectively). No difference in relative height was found between the groups. No association could be seen betw een disease susceptibility antigens in the HLA-D locus and joint or sk in manifestations. The lower levels of circulating collagen and lamini n metabolites in the diabetic children with joint contractures suggest that these patients are characterized by a reduced turnover of baseme nt membranes in tissues. In addition, our data suggest that the develo pment of joint contractures is associated with impaired metabolic cont rol but not necessarily with growth retardation.