Clinical trial NCT04682457: Defining the Decline in Endogenous Insulin Secretion in Type 1 Diabetes Diagnosed After 30 Years of Age.
Official title: Defining the Decline in Endogenous Insulin Secretion in Type 1 Diabetes Diagnosed After 30 Years of Age.
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Diabetes Mellitus, Type 1
Progression
Lead sponsor: Royal Devon and Exeter NHS Foundation Trust
Sponsor class: OTHER
First posted: 2020-12-23
Enrollment: 130
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Recent clinical diagnosis of type 1 diabetes

Brief summary: The study aims is to find out if people with type 1 diabetes diagnosed in later life (after age 30) have the same rapid loss of insulin secretion (measured using C-peptide) that occurs in younger adults with type 1 diabetes. The investigators will recruit 135 participants aged over 30 years with a clinical diagnosis of type 1 diabetes and diabetes duration ≤100 days. The investigators will also recruit a comparison group of 61 participants aged 18-30 with a clinical diagnosis of type 1 diabetes and diabetes duration ≤100 days. C-peptide will be measured during mixed meal tolerance tests (MMTT) performed at baseline, 6 months and a year.

This study also aims to test a new more practical way of monitoring insulin secretion at home using a finger prick 'blood spot' rather than time consuming tests in a hospital. Finger-prick C-peptide samples will be collected after the MMTT and by the participants at home throughout the year.

Detailed description: The study aims to evaluate progression of type 1 diabetes. Primary analysis will be conducted on those with \>=1 diabetes autoantibody positive (GAD, IA2 ZNT8). Sensitivity analysis will be performed by repeating all analysis defining T1D as a) double antibody positivity and b) single antibody positivity combined with a high genetic risk score for T1D (T1DGRS\>5th centile of a control population).

Further aims will be to evaluate the utility of dried blood spot testing to detect change in C-peptide and the utility of home test results as a marker of hypoglycaemia and glucose variability.

Eligibility criteria: Inclusion Criteria:

* Adults with a clinical diagnosis of Type 1 diabetes within the previous 100 days.
* Aged \>30 at the time of Type 1 diabetes diagnosis OR (additional early onset Type 1 diabetes cohort) aged ≥18 and ≤30 at the time of Type 1 diabetes diagnosis.
* Insulin treated at the time of recruitment
* Able and willing to provide informed consent.

Exclusion criteria

* Pregnancy
* Known monogenic diabetes
* Known secondary diabetes (diabetes considered likely due to medication, cystic fibrosis, pancreatitis, pancreatic cancer, pancreatic surgery, hemochromatosis or Cushing's syndrome).

Primary outcomes:
measure: C-peptide value at a year
timeFrame: 12 months
measure: Change in C-peptide over a year
timeFrame: 12 months
Secondary outcomes:
measure: C-peptide value at 12 months
timeFrame: 12 months
measure: Glucose variability & hypoglycemia
timeFrame: 12 months
measure: Change in dried blood spot C-peptide
timeFrame: 12 months
Other outcomes:
Locations:
city: Exeter
country: United Kingdom
facility: Royal Devon & Exeter NHS Foundation Trust
state: Devon
Study officials:
affiliation: NIHR Exeter Clinical Research Facility
name: Angus Jones, MBBS MRCP
role: STUDY_DIRECTOR
affiliation: NIHR Exeter Clinical Research Facility
name: Nicholas Thomas, MRCP
role: PRINCIPAL_INVESTIGATOR
References:
citation: Thomas NJ, Lynam AL, Hill AV, Weedon MN, Shields BM, Oram RA, McDonald TJ, Hattersley AT, Jones AG. Type 1 diabetes defined by severe insulin deficiency occurs after 30 years of age and is commonly treated as type 2 diabetes. Diabetologia. 2019 Jul;62(7):1167-1172. doi: 10.1007/s00125-019-4863-8. Epub 2019 Apr 10.