Defining the Decline in Endogenous Insulin Secretion in Type 1 Diabetes Diagnosed After 30 Years of Age. (DROPLeT)

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Diabetes Mellitus, Type 1; Progression

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.

• Study Type: Observational
• Enrollment (Actual): 130

Contacts and Locations

• Study Contact: Name: Anita Hill; Phone Number: 01392408184; Email: Anita.Hill2@nhs.net
• Study Contact Backup: Name: Peter Tippett; Phone Number: 01392408184; Email: rde-tr.DiabetesResearch@nhs.net

Study Locations

• United Kingdom
  • Devon
    • Exeter, Devon, United Kingdom, EX2 5DW
      • Royal Devon & Exeter NHS Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Recent clinical diagnosis of type 1 diabetes

Description

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).

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Late Onset; Participants diagnosed with Type 1 diabetes at over 30 years of age.
18 to 30; Participants diagnosed with Type 1 diabetes between 18 and 30 years of age

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
C-peptide value at a year	12 month (Mixed Meal Tolerance Test) MMTT area under the curve (AUC) C-peptide.	12 months
Change in C-peptide over a year	Rate of change of MMTT AUC C-peptide over 12 months assessed at regular study visits	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
C-peptide value at 12 months	Mean C-peptide at 12 months assessed using MMTT and home blood samples	12 months
Glucose variability & hypoglycemia	Glucose variability & hypoglycemia as measured by continuous glucose monitoring (CGM)	12 months
Change in dried blood spot C-peptide	Rate of change in home dried blood spot C-peptide over 12 months	12 months

Collaborators and Investigators

• Sponsor: Royal Devon and Exeter NHS Foundation Trust
• Investigators: Study Director: Angus Jones, MBBS MRCP, NIHR Exeter Clinical Research Facility; Principal Investigator: Nicholas Thomas, MRCP, NIHR Exeter Clinical Research Facility

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2019
• Primary Completion (Estimated): September 1, 2023
• Study Completion (Estimated): December 1, 2023

Study Registration Dates

• First Submitted: December 15, 2020
• First Submitted That Met QC Criteria: December 22, 2020
• First Posted (Actual): December 23, 2020

Study Record Updates

• Last Update Posted (Actual): September 6, 2023
• Last Update Submitted That Met QC Criteria: September 4, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Immune System Diseases; Autoimmune Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 1
• Other Study ID Numbers: 2003962

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No