Exploratory CSII Trial on Erectile Dysfunction in T2DM Patients

Effects of Continuous Subcutaneous Insulin Infusion (CSII) on Erectile Dysfunction in T2DM Patients: A Prospective, Exploratory, Controlled Trial

Erectile dysfunction (ED) is a common form of organic sexual dysfunction in males with diabetes, with estimated incidence rates between 35 and 75%. Fifty percent of men with diabetes are afflicted with ED within 10 years of their diagnosis. Long-term poor glycemic control increases the risk ED. Although comparatively costly, advantages of CSII over other modes of insulin delivery include better glycemic control, fewer hypoglycemic episodes, and improved quality of life. In a previously published study, on CSII in T2DM, in our center, 83% of men reported an improvement in sexual function as a secondary endpoint. The current study is planned to further explore this finding.

Background Erectile dysfunction (ED) is a common form of organic sexual dysfunction in males with diabetes, with estimated incidence rates between 35 and 75%. Fifty percent of men with diabetes are afflicted with ED within 10 years of their diagnosis. Long-term poor glycemic control increases the risk ED. Neuropathy is a major contributor to diabetic ED. Other causes of ED in diabetes include vascular disease, metabolic control, nutrition, endocrine disorders, psychogenic factors, and drugs.

Continuous Sub-cutaneous Insulin Infusion The Continuous Subcutaneous Insulin Infusion (CSII) Pump (insulin pump for short) is a pager-sized device which can be connected to the body through an infusion set so as to deliver insulin continuously. It consists of a disposable reservoir for insulin, a disposable infusion set, including a cannula for subcutaneous insertion and a tubing system which connects the insulin reservoir to the cannula. Insulin pump therapy by itself is not a new therapy for diabetes mellitus. It is an alternative delivery mechanism for administration of insulin and is found to be superior to ordinary syringes and insulin pens. Insulin pumps were popularly used in T1DM but nowadays insulin pumps are commonly used in T2DM patients as well.

A guideline for use of insulin pumps in India has been recently published in Diabetes Technology and Therapeutics journal, which included participation from Jothydev's Diabetes Center.

Although comparatively costly, advantages of CSII over other modes of insulin delivery include better glycemic control, fewer hypoglycemic episodes, and improved quality of life. Our own center has reported a significant reduction in HbA1c when subjects in multiple daily insulin switched to CSII.

Relevant Clinical Data In the aforementioned study of CSII in Type 2 diabetes patients in our study, 83% of men reported an improvement in sexual function when queried after 6 months on CSII. The mode of improvement and magnitude of this effect is not known, and needs to be ascertained in prospective trials. The present study proposal is to corroborate the findings, and obtain clarification of effect size.

Potential Benefits & Risks The following improvements can be expected following initiation of insulin pump therapy.

• Improvement in HbA1c
• Reduction in blood sugar fluctuations
• Reduction in major and minor hypoglycemic episodes
• Reduction in total daily dose of insulin
• Improvement in QOL

The following are some risks/disadvantages of using insulin pump therapy

• Cost of pumps and consumables is higher than other modes of insulin delivery
• There is a risk of infection if the cannula is not changed once in every three days.
• Improper use of insulin pump boluses can lead to insulin stacking and low sugars.

Proper patient education and monitoring will be part of the study to overcome the risks of insulin pump therapy.

Inclusion Criteria:

• Male T2DM patients with HbA1c < 9%
• Mild ED to Moderate ED as defined by International Index of Erectile Function (IIEF) questionnaire
• Able and willing to use insulin pumps for at least the duration of the study

Exclusion Criteria:

• Severe dysfunction in IIEF Score or duration of ED more than 3 years
• Heart failure (class II - IV) or unstable cardiovascular disease; poorly controlled blood pressure (systolic > 170 or < 90 mmHg or diastolic > 100 or < 50 mmHg) or orthostatic hypotension
• Medications: Substance abuse, anticancer and steroid therapy
• Sexual dysfunction in partner, lack of stable relationship.
• History of radical prostatectomy or pelvic surgery, significant penile deformities, penile implants, or history of stroke or spinal-cord trauma.