The Relative Prevalence and Severity of Autonomic Nervous System Dysfunction

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to measure the prevalence and severity of cardiac autonomic neuropathy (CAN), diabetic autonomic neuropathy (DAN) which in non-diabetics is termed advanced nervous system (ANS) dysfunction, and autonomic dysfunction as well as the overall sympathovagal balance (SB) in the CEFH population of diabetic patients versus non-diabetic patients undergoing elective vitreoretinal surgery.

Detailed Description
-----------------
The purpose of this study is to measure the prevalence and severity of cardiac autonomic neuropathy (CAN), diabetic autonomic neuropathy (DAN) which in non-diabetics is termed advanced nervous system (ANS) dysfunction, and autonomic dysfunction as well as the overall sympathovagal balance (SB) in the CEFH population of diabetic patients versus non-diabetic patients undergoing elective vitreoretinal surgery.

Official Title
-----------------
The Relative Prevalence and Severity of Autonomic Nervous System Dysfunction in Diabetic Patients Undergoing Retinal Surgery

Conditions
-----------------
Cardiovascular Autonomic Neuropathy, Diabetic Autonomic Neuropathy, Autonomic Dysfunction

Intervention / Treatment
-----------------
* Other: ANSAR ANX 3.0 Software


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Type I and Type II Diabetic patients 19 or older who are scheduled for elective surgery to improve vision impaired by diabetic retinopathy Patients scheduled during the same time period without diabetes for retinal surgery will serve as an age and gender matched reference group to undergo the non-invasive ANS testing on the day of surgery Exclusion Criteria: Inability to stand will only do baseline, deep breathing and Valsalva portions (A-D) of the testing as described in section 8.1 Patients with syncope on standing will only do portions A-D of the test Inability to cooperate with deep breathing and Valsalva Tracheoscopy or otherwise not able to perform a Valsalva Not desiring to participate after informed consent Known history of idiopathic dysautonomia Pulmonary difficulties associated with hyperventilation, including acute URI Pacemaker dependent Persistently high intraocular pressure despite treatment Atrial fibrillation Ventricular arrhythmias greater than 10 beats per minute Taking MAO inhibitors

Ages Eligible for Study
-----------------
Minimum Age: 19 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: ANSAR ANX 3.0 Software|Three values are calculated by the ANSAR ANX 3.0® software of the spectral analysis of HRV and respiration: RFa an indicator of parasympathetic function with normal values between 0.5 and 10 bpm2; LFa an indicator of sympathetic function also with normal values between 0.5 and 10 bpm2; SB or the ratio of LFa/RFa with normal reference values of 0.4 to 3.0. The ANSAR ANX 3.0® software defines three different levels of autonomic neuropathy (autonomic dysfunction) as follows (see Figure 1): Cardiovascular Autonomic Neuropathy (CAN): resting parasympathetic insufficiency (not enough parasympathetic protection for the heart) or RFa < 0.1 bpm2. Diabetic Autonomic Neuropathy (DAN), or advanced autonomic dysfunction in non-diabetics, is defined as low autonomics: LFa < 0.5 bpm2 or 0.1 < RFa < 0.5 bpm2. Autonomic Dysfunction: normal resting LFa and RFa, but low LFa response to Valsalva or low RFa response to deep breathing.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary outcome will be to quantify, using the ANSR ANX 3.0 technology, the prevalence of cardiac autonomic neuropathy (CAN), diabetic autonomic neuropathy (DAN),referred to as advanced autonomic nervous system dysfunction in non-diabetic patients. |  | 15 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The strength of various comorbidities as predictors of autonomic dysfunction in both diabetics and non-diabetics will be evaluated. The differential effect of these various comorbidities in Type I versus Type II diabetes on ANS dysfunction and neuropathy |  | 15 minutes | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Cardiovascular Autonomic Neuropathy, Diabetic Autonomic Neuropathy, Autonomic Dysfunction