BIOLOGIC MATERIAL IN NEEDLES AND CARTRIDGES AFTER INSULIN INJECTION WITH A PEN IN DIABETIC-PATIENTS

OBJECTlVE - To evaluate the frequency of non-inert material, including cells, in needles and cartridges after insulin injection with pen-lik e devices in diabetic patients. RESEARCH DESIGN AND METHODS - A prospe ctive study was conducted in 120 insulin-treated diabetic patients who used pen-like devices. The patients, 46 women and 74 men, were 20-77 years old; 60% had type 1 diabetes, and 38% were overweight. Duration of diabetes ranged from 1 month to 40 years, and insulin therapy range d from 1 month to 30 years. Insulin injection was performed by a train ed nurse, using the patient's usual pen and cartridge. A cytopathologi cal examination was performed on the material obtained from the needle and found in the cartridge after centrifugation. All slides were read by a single investigator.RESULTS - In 62% of the patients, non-inert material was found, including squamous (32%) and epithelial (58%) cell s. Biologic material was found in 30% of the needles and 58% of the ca rtridges, and in both needle and cartridge in 25% of the population. B iologic material was found more frequently in patients who had a longe r duration of diabetes, who were treated with insulin for a longer tim e, and who performed injection in the thighs or upper arms (P < 0.05). In multivariate analysis, the presence of biologic material was assoc iated with the duration of diabetes (R-2 = 0.09; P < 0.01). CONCLUSION S - Our data suggest that biologic material can be trapped in the deli very system, including the cartridge, after an insulin injection with a pen-like device. Our results emphasize the strict need for individua l use of insulin delivery systems, including cartridges and nonrefilla ble pens, especially in clinics and hospitals.