Studying the Effectiveness of Non-Invasive Glucose Sensors in Patients With Diabetes: The SENSOR Study

Self-monitoring of blood glucose (SMBG) can both facilitate and hinder adherence in patients
with diabetes mellitus (DM). Readings provide real-time information on hypoglycemic and
hyperglycemic excursions. These data are crucial to successfully managing this disease, as
SMBG can help guide decisions on titrating medications, and can potentially encourage patient
engagement. There are drawbacks. Piercing the skin to check glucose up to several times a day
can be uncomfortable and obtrusive for a patient with DM. SMBG offers only a snapshot of the
patient's glucose at the time of testing.

Continuous glucose monitoring (CGM) can reveal glucose trends. A subcutaneous sensor
transmits interstitial glucose readings approximately every five minutes. Yet, sensor
insertion requires a needle. Patients still must test SMBG about 4 times per day to calibrate
the CGM sensor. This modality is less accurate with low or rapidly rising glucose. CGM is
also not widely available, due to cost and insurance issues. A non-invasive glucose monitor,
the GlucoWatch, was discontinued due to problems with accuracy and tolerability.

Compounding these challenges is the surging number of individuals with DM. Every 19 seconds,
an American 20 years of age or older is diagnosed with DM. If current trends continue, 1 in 3
Americans could have DM by 2050.

There is thus an unmet need for a non-invasive glucose monitoring device. UCSD nanoengineers
developed a flexible, ultra-thin sensor adherent to the skin, similar to a temporary tattoo.
Preliminary data from seven individuals without DM demonstrated correlation between glucose
measurements from this sensor and a glucometer. Evaluating this sensor in patients with DM
will be critical: while hour-to-hour blood glucose fluctuates approximately 50% throughout
the day in those without DM, it may vary up to 10-fold in patients with DM. This study would
be the first to examine this sensor in individuals with DM. The investigators hypothesize
that compared with a glucometer, a tattoo sensor can accurately measure glucose in patients
with DM.

Inclusion Criteria:

1. An existing diagnosis of diabetes mellitus, either T1DM or T2DM

2. Absence of cognitive impairment, as demonstrated by a Montreal Cognitive Assessment
(MOCA) score greater than 26; those individuals with questionable cognitive ability
will be screened with this instrument.

3. Ability to provide informed consent for participation.

Exclusion Criteria:

1. Individuals without diabetes

2. Those who have a MOCA score of 26 or less

3. Those who cannot speak or read English. The investigators are limiting participation
to those who read and speak English, as this is a pilot study of a small number of
participants, that will very unlikely offer the prospect of direct benefit from
participating.

4. Individuals who have a cardiac, respiratory, or other condition that would preclude
safely exercising at a moderate pace. Along with a medical history and physical
examination by the PI, prospective participants will complete the Physical Activity
Readiness Questionnaire (PAR-Q) to help determine those who may safely exercise for
this study. One or more "yes" responses does not necessarily exclude an individual
from participating.

5. Individuals who have frequent hypoglycemia, hypoglycemia unawareness, or who are at
high risk for hypoglycemia.