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-dependent diabetes mellitus were examined for joint contractures and skin manifestations in their hands. Joint contractures were found in 52 (29.8%) and skin manifestations in 29 (16.6%) patients. To eliminate the possible confounding effects of age and duration of diabetes on the variables to be studied, patients younger than 7 y and with a duration of diabetes shorter than 3 y were excluded from the subsequent analyses. Of 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 mean glycated Hb levels (p = 0.048). A clear association was noted between the occurrence of joint contractures and skin changes (p = 0.007). Background retinopathy was found in six patients (5.6%), three of whom had stage II joint contractures (p = 0.064). The children with skin changes and those with combined joint and skin manifestations more often had insulin-dependent diabetes mellitus in their first-degree relatives (p = 0.038 and p = 0.043, respectively). No difference in relative height was found between the groups. No association could be seen between disease susceptibility antigens in the HLA-D locus and joint or skin manifestations. The lower levels of circulating collagen and laminin metabolites in the diabetic children with joint contractures suggest that these patients are characterized by a reduced turnover of basement membranes in tissues.