Towards a Better Understanding of Diabetes Distress, Depression and Poor Glycaemic Control (DIA-LINK Study)
Condition: Diabetes Mellitus, Type 1; Depressive Symptoms; Stress, Psychological; Glucose, High Blood
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 1; Depression; Stress, Psychological
Study type: Observational

Summary: 
      The DIA-LINK Study is a prospective observational study analysing longitudinal associations
      and mediating links between diabetes distress (DD), depressive symptoms (DS) and glycaemic
      outcomes in people with type 1 diabetes (T1DM). A total of 200 people with T1DM with
      different levels of DD and DS are to be enrolled.

      At baseline, all participants are assessed for DD and DS, psychological and stress-related
      variables, self-reported self-management, HbA1c and inflammatory markers.

      This is followed by a 4-week ambulatory assessment period including continuous glucose
      monitoring (CGM), continuous activity tracking and daily event sampling regarding sleep,
      stress levels, mood and diabetes-related issues; additionally, cortisol levels are assessed
      on four days within this period.

      Three months after baseline, a follow-up assessment covers DD and DS levels, stress-related
      variables, self-reported self-management, HbA1c and final CGM assessment.

      The analyses aim to establish risk factors/protective factors regarding DD and DS, their
      relative impact on glycaemic outcomes and potential mediation of the associations by
      behavioural (e.g. self-management, physical activity), physical (e.g. heart rate variability,
      inflammatory activity) and mental variables (subjective stress level) in T1DM.
    

Detailed description: 
      The DIA-LINK Study is a prospective observational study analysing longitudinal associations
      between diabetes distress (DD), depressive symptoms (DS) and glycaemic outcomes in people
      with type 1 diabetes (T1DM). A variety of behavioural, physical and mental variables are
      assessed to analyse the mediating links between DD, DS and glycaemia.

      A total of 200 people with T1DM are enrolled according to DD (PAID ≥ / < 40) and DS (CES-D ≥
      / < 22) scores so that four groups (n = 50 persons each) with varying levels of DD and DS are
      established: 1. PAID < 40 and CES-D < 22 (no DD, no DS); 2. PAID ≥ 40 and CES-D < 22 (DD, no
      DS); 3. PAID < 40 and CES-D ≥ 22 (DS, no DD); 4. PAID ≥ 40 and CES-D ≥ 22 (DD and DS).

      At baseline, all participants are assessed for relevant psychological and stress-related
      variables (daily hassles, life events, diabetes-related problems and fears, coping styles,
      resilience, diabetes acceptance, depression) as well as self-reported diabetes
      self-management using validated self-report scales and interviews; HbA1c and selected markers
      of inflammation (hsCRP, IL-6, IL-18, IL1Ra) are analysed from venous blood samples.

      This is followed by a 4-week ambulatory assessment period including continuous glucose
      monitoring (CGM) (to establish time in range, glucose variability and times in
      hypo/hyperglycaemia), continuous activity tracking regarding general activity, movement,
      sleep and heart rate using a wristband as well as event sampling regarding sleep quality,
      stress levels, mood and diabetes-related issues four times daily using a smartphone app.
      Additionally, salivary cortisol levels are estimated on four consecutive days (each including
      a morning, afternoon and night time sample) within this period.

      Three months after baseline, a follow-up assessment is performed which includes self-report
      measures of DD and DS, stress-related variables and diabetes self-management, HbA1c
      estimation from venous blood samples and final CGM assessment over 14 days.

      The collected data are used to analyse risk factors/protective factors regarding DD and DS,
      their relative impact on glycaemic outcomes and potential mediation of the associations by
      behavioural (e.g. self-management, physical activity), physical (e.g. heart rate variability,
      inflammatory activity) and mental variables (subjective stress level) in T1DM.

      The findings shall be used to develop personalised interventions for people with diabetes and
      comorbid mental conditions (DD and DS).
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        People with T1DM with different levels of diabetes distress (DD) and/or depressive symptoms
        (DS): Four groups of n = 50 persons each reporting 1. "no DD/no DS" vs. 2. "DD/no DS" vs.
        3. "DS/no DD" vs. "DD and DS".
      
Biospecimen description: 
      HbA1c; Cortisol; Markers of inflammation (hsCRP, IL-6, IL-1Ra, IL-18)