Development of a youth-report measure of DPN symptoms: Conceptualization and content validation.

AIMS: To develop a content valid youth-report measure of diabetic peripheral neuropathy (DPN) symptoms. METHODS: Semi-structured interviews with 5 clinicians and 15 youth aged 8-17 with diabetes were conducted to elicit and clarify youth's DPN experiences. A systematic review of existing adult-report DPN symptom measures was conducted to identify item concepts representative of each experience. The concepts were transformed into items that were iteratively revised based on cognitive interviews (n = 13 youth aged 8-17) and readability analyses. RESULTS: Clinician and youth interviews supported a tripartite conceptual framework of youth DPN symptoms: paresthesia, pain, and anesthesia. Forty-eight youth-report items were generated to represent DPN symptoms identified through the semi-structured interviews and a systematic review of 13 symptom questionnaires for adults. Of these, 23 were eliminated and 3 were revised based on cognitive interviews conducted with youth. The remaining 25 items were on average, written at a 3rd grade reading level. CONCLUSIONS: This study is the first to generate a content valid self-report measure of youth's lived experiences with DPN that uses developmentally appropriate terminology. With further psychometric testing, the measure could be used to advance research on pediatric DPN and enhance clinicians' capacity to identify the condition in childhood.

Racial disparities in screening for diabetic retinopathy in youth with type 1 diabetes.

Of 1112 children with type 1 diabetes, dilated eye exams were performed in 717 (64%). Children were less likely to be screened for diabetic retinopathy (DR) if they were black (OR=1.6; p=0.005) or had poorer diabetes control (p=0.002). Those at greatest risk for DR were least likely to be screened.

The evaluation of peripheral neuropathy in youth with type 1 diabetes.

Of 151 youth with type 1 diabetes who were screened for peripheral neuropathy, and received nerve conduction studies, 11% were diagnosed with Diabetic Peripheral Neuropathy (DPN). DPN can occur in young children, with short diabetes duration, and good diabetes control. National guidelines for screening children for DPN should be developed.

Extremes of clinical and enzymatic phenotypes in children with hyperinsulinism caused by glucokinase activating mutations.

OBJECTIVE: Heterozygous activating mutations of glucokinase have been reported to cause hypoglycemia attributable to hyperinsulinism in a limited number of families. We report three children with de novo glucokinase hyperinsulinism mutations who displayed a spectrum of clinical phenotypes corresponding to marked differences in enzyme kinetics. RESEARCH DESIGN AND METHODS: Mutations were directly sequenced, and mutants were expressed as glutathionyl S-transferase-glucokinase fusion proteins. Kinetic analysis of the enzymes included determinations of stability, activity index, the response to glucokinase activator drug, and the effect of glucokinase regulatory protein. RESULTS: Child 1 had an ins454A mutation, child 2 a W99L mutation, and child 3 an M197I mutation. Diazoxide treatment was effective in child 3 but ineffective in child 1 and only partially effective in child 2. Expression of the mutant glucokinase ins454A, W99L, and M197I enzymes revealed a continuum of high relative activity indexes in the three children (26, 8.9, and 3.1, respectively; wild type = 1.0). Allosteric responses to inhibition by glucokinase regulatory protein and activation by the drug RO0281675 were impaired by the ins454A but unaffected by the M197I mutation. Estimated thresholds for glucose-stimulated insulin release were more severely reduced by the ins454A than the M197I mutation and intermediate in the W99L mutation (1.1, 3.5, and 2.2 mmol/l, respectively; wild type = 5.0 mmol/l). CONCLUSIONS: These results confirm the potency of glucokinase as the pancreatic beta-cell glucose sensor, and they demonstrate that responsiveness to diazoxide varies with genotype in glucokinase hyperinsulinism resulting in hypoglycemia, which can be more difficult to control than previously believed.

Operating expenses for the diagnosis and treatment of peripheral vascular disease in an academic interventional radiology department: cost calculations according to a microeconomic method.

PURPOSE: A correct understanding of the true costs of a procedure is necessary to make informed decisions in cost-effectiveness analyses. The actual comprehensive costs of performing cardiovascular and interventional radiology (CVIR) procedures were analyzed in the present study, as opposed to charges or ratios of costs to charges (RCCs), as often used in the literature. MATERIALS AND METHODS: Costs included labor, equipment, administration, facility establishment and maintenance, overhead, and consumable supplies. Cost identification was initially performed with use of an hourly rate that reflected the cost of operating the CVIR section. This was then combined with the costs of the consumable supplies used during each type of procedure. Eight types of vascular procedures were studied in 235 consecutive patients to determine mean procedure duration and supplies consumption. Costs were then compared with charges and RCCs of these procedures. RESULTS: The hourly rate for operating one angiography suite was 690 dollars. Average cost by procedure, including hourly rate plus consumable supplies, were: aortic arteriogram, 1,442 dollars; aortobifemoral arteriogram, 1,554 dollars; unilateral limb arteriogram, 1,307 dollars; simple iliac or femoropopliteal angioplasty, 2,119 dollars; arterial stent placement, 2,780 dollars; percutaneous thrombectomy, 1,998 dollars; arterial in situ thrombolysis, 3,133 dollars; and arteriogram after thrombolysis, 926 dollars. RCCs calculated for each procedure ranged from 0.39 (thrombectomy) to 1.92 (control arteriography during or after thrombolysis) and were lower than expected based on previous reports. CONCLUSIONS: The average actual costs of several common diagnostic and therapeutic procedures for peripheral vascular occlusive disease were established, allowing determination of the relative importance of different cost components. This methodology may serve as a template for future cost analyses.