['To determine if the use of indwelling catheters for insulin injections affects the long- and short-term metabolic control of insulin-dependent diabetes mellitus (IDDM).', 'Sixteen children and adolescents 9-20 years of age were included in a randomized 10-week crossover study using indwelling catheters (Insuflon, Pharma-Plast, Lynge, Denmark; CHRONIMED, Minnetonka, Minnesota) for insulin injections. Their diabetes duration was 7.5 +/- 3.3 years (range 2-14), and they used multiple injection therapy with 4-5 doses/day. C-peptide was < or = 0.15 nM fasting and < or = 0.30 nM postprandial.', 'We found no significant difference between those with and without Insuflon in degree of metabolic control reflected by HbA1c (with Insuflon, 7.3 +/- 2.6%; without, 7.1 +/- 2.2%), 24-h profiles of blood glucose and free insulin, 24-h samples of glucosuria, or ketonuria. Weight, insulin doses per kilogram per 24 h, and insulin antibodies were all the same in the two groups.'] Is metabolic control altered when using indwelling catheters for insulin injections?