In comparison with the traditional long-acting insulins, i.e., NPH and Ultralente (1–3), insulin glargine, a novel insulin analogue has been documented to decrease the number of hypoglycemic episodes while achieving an adequate glycemic control. The decline in hypoglycemic events, especially nocturnal, is attributed to the ability of insulin glargine to attain a steady-state plasma insulin concentration without a peak for ∼24 h on a subcutaneous (SC) administration of a single dose (4). Therefore, insulin glargine may achieve an effect similar to that obtained by continuous intravenous (IV) or SC infusion of regular insulin in subjects requiring continuous enteral or parenteral alimentation. However, documentation of the use of glargine in similar circumstances is lacking. In this article, we studied a subject in whom insulin glargine monotherapy attained and maintained desirable glycemic control while receiving continuous enteral feeding.
R.A., a 60-year-old white man with type 2 diabetes of 2 years’ duration, underwent radical surgery and was receiving radiation therapy for management of a squammous cell carcinoma of the oral cavity. Postoperatively, he manifested recurrent aspiration on several attempts at oral feeding and therefore was being administered continuous enteral tube feeding. His HbA1c before surgery was 7.5% with capillary blood glucose recordings between 180 and 250 mg/dl (10–14 mmol/l). It was determined that the subject would require enteral nutritional support for a prolonged period of time, even after discharge from the hospital within a week after surgery. Therefore, due to ease of administration, SC insulin glargine was initiated with 24 units at 9:00 p.m. instead of continuous IV or SC infusion administration. The dose of insulin glargine was gradually increased by 2–4 units at intervals of 3 days (even at home via telephone counseling) to attain blood sugars between 100 and 140 mg/dl (5.6–7.8 mmol/l) determined at 6-h intervals. Within 3 weeks, the optimal glycemic control, between 80 and 140 mg/dl, as reflected by most home blood glucose readings, was achieved with 45 units insulin glargine. There was not a single hypoglycemic event during the period. The same insulin dose continued for the next 3 months while monitoring blood glucose levels. The maintenance of optimal glycemic control was further confirmed by an HbA1c concentration of 6.1% at 6 months.
This case study illustrates that SC administration of insulin glargine is able to attain and maintain desirable glycemic control in subjects who require continuous enteral (or parenteral) alimentation without inducement of hypoglycemia. This beneficial effect could be attributed to its unique profile of achieving steady, peakless insulin concentrations. Therefore, it could replace IV or SC continuous infusion of regular insulin during hospitalization, especially on the general ward, and at home because of its ease of administration and convenience.
References
Address correspondence to Udaya M. Kabadi, Professor of Medicine, Division of Endocrinology, University of Iowa Hospitals and Clinics, 6W27 VAMC, 601 U.S. Highway 6, Iowa City, IA 52246. E-mail: [email protected].
