Psychological predictors and consequences of nocturnal hypo- and hyperglycemia in adults with type 1 diabetes and their main relative: the DiaN8 study

Optimal glycemic management of type 1 diabetes requires limiting the time spent
in hyperglycemia, while avoiding hypoglycemia. Overnight glycemic management is
particularly complex. The psychological aspects related to nocturnal hypo- and
hyperglycemia are under-researched, as are the consequences of these overnight
glucose excursions for sleep and aspects of daytime functioning.

The primary objective of the DiaN8 study is to examine which health beliefs and
emotions are associated with behavior with likely hypoglycemic or hyperglycemic
impact during the night in adults with type 1 diabetes and their main relative
(partner or parent). Secondary objectives are to (a) determine the relation of
nighttime glucose levels with sleep and next day mood, fatigue, and cognitive
functioning in these groups, and (b) explore the merit of providing tailored
change strategy suggestions in case of potentially unhelpful beliefs, emotions,
or behaviors.

This multi-method exploratory observational study with pilot intervention
includes: (a) a study visit with an interview, the completion of
questionnaires, and a brief training in the use of ambulatory equipment; (b)
subsequent real-life ambulatory measurements over seven days (continuous
glucose monitor, accelerometer, ecological momentary assessment app, optional
sleep wearable); and (c) the provision of written feedback to all participants
based on study data, and change strategy suggestions for participants with
potentially unhelpful beliefs, emotions or behaviors (followed by a brief
follow-up telephone call and an optional second week of ambulatory measurements
after three months to evaluate any changes in the main study parameters).

In general, participants will not benefit directly from participation. However,
the study may expand our knowledge in this area and highlight avenues for
intervention. For a subgroup, there is a potential direct benefit as tailored
change strategy suggestions are provided based on their study data. Indirect
individual benefits include written feedback about the main study parameters
(with the option to share data with the diabetes care team) and financial
incentive. At the end of the study all participants receive a summary of the
most important study results at the group level.
The risks associated with participation can be considered negligible. The
burden of participation is limited to an estimated time investment of 2 to 2,5
hours for the baseline study visit, 7 x 30 minutes (divided over five
measurements per day) for the ambulatory assessments, and 15 minutes for the
follow-up telephone call. For each app invitation, participants are given the
option to skip the assessment. Investing further time by implementing change
strategy suggestions and participating in a second week of ambulatory
assessment is optional. Wearing of the ambulatory devices is of negligible
burden and risk. The diagnostic glucose monitoring device is also used in
standard care; when following the user instructions, it can usually be inserted
and worn without difficulties. As the sensor is inserted in the body, insurance
is arranged for participation of the person with type 1 diabetes. The project
team requests the Medical Research Ethics Committee Arnhem-Nijmegen to provide
dispensation from the statutory obligation to provide insurance for the
participating main relative as he/she does not have to wear the diagnostic
sensor.