Diabetes Mellitus

Medical Problem

Diabetes mellitus is a group of metabolic diseases characterized by high blood sugar (glucose) levels, which result from defects in insulin secretion, or action, or both. There are two major types of diabetes, called type 1 and type 2. Most people with type 2 diabetes are failing to achieve optimal blood glucose control, leading to disease progression and the onset of debilitating and expensive complications, including heart disease, amputations, blindness and kidney failure. To achieve adequate blood glucose control, all patients with type 1 diabetes need exogenous insulin, and most with type 2 diabetes will also eventually require insulin replacement therapy. Fear of needles and the burden associated with multiple daily injections remain among the most significant barriers to initiating and maintaining insulin therapy.

New Discovery

EXUBERA (insulin human [rDNA origin]) Inhalation Powder is a prescription medication that contains rapid-acting, dry powder human insulin that is inhaled normally through the mouth into the lungs, using the handheld Exubera Inhaler. EXUBERA helps control high blood sugar.

Hypothesis

In patients with type 1 diabetes, glycemic control can be achieved as effectively with an inhaled insulin regimen, comprising preprandial inhaled intrapulmonary insulin plus a bedtime ultralente injection, as with a conventional subcutaneous insulin regimen involving two to three injections per day. My objective was to compare patient satisfaction between inhaled insulin and subcutaneous insulin.

Research Design and Methods

The trial was a 12-week randomized open-label trial. It consisted of a 4-week baseline lead-in phase, in which subjects continued their usual injected insulin regimen (two to three injections daily) and received instruction on a weight-maintaining diet and blood glucose monitoring, followed by randomization to either an inhaled insulin regimen or a conventional subcutaneous insulin regimen for 12 weeks. The inhaled insulin regimen consisted of rapid-onset inhaled insulin administered immediately before meals using a dry powder aerosol delivery plus bedtime subcutaneous ultralente insulin. The subcutaneous insulin regimen involved the subject's usual split/mixed insulin regimen given two or three times per day. Administration of insulin, inhaled or injected, was preceded by a blood glucose measurement. Patients were followed weekly for review of blood glucose monitoring and adjustment of insulin dosage, if required.

A total of 70 subjects with type 1 diabetes were enrolled in the trial. Subjects were aged 18Ð'-55 years and were following a stable insulin administration schedule (for at least 2 months) involving two to three injections daily. Screening and prerandomization HbA1c values were between 7.0 and 11.9%, with fasting plasma C-peptide 0.2 pmol/ml. Body weight of each subject was 80Ð'-130% of ideal. Subjects were nonsmokers (for at least 6 months), gave normal results on a chest x-ray and pulmonary function tests, and had an electrocardiogram showing normal sinus rhythm. All subjects performed blood glucose monitoring four times daily: before breakfast, before lunch, before supper, and at bedtime.

Results

A 15-item self-administered patient satisfaction questionnaire, the Patient Satisfaction with Insulin Therapy (PSIT) Questionnaire, was completed by each subject at baseline and week 12. The PSIT measures global (overall) satisfaction and two domains (subscales): convenience/ease of use and social comfort. The questionnaire asks subjects to rate statements such as "I find it easy to take insulin the way I take it now," "I have no discomfort taking insulin," "I find it convenient to take insulin," and "I am self-conscious about taking insulin away from home."