UMIN-CTR Clinical Trial
| Unique ID issued by UMIN | UMIN000062525 |
|---|---|
| Receipt number | R000071572 |
| Scientific Title | Recorded COVID-19 and Change in Measured Glycemia From Before to After Infection Among Older Adults in Japan: A Risk-Set-Matched Difference-in-Differences Study |
| Date of disclosure of the study information | 2026/08/09 |
| Last modified on | 2026/08/09 14:29:48 |
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Basic information
Public title
A study of whether, among older adults, recorded COVID-19 is associated with a sustained change in a measured glycemic marker (HbA1c) from before to after infection, compared with people without recorded COVID-19, using health check-up and claims measurements
Acronym
COVID-19 and Glycemia Change Study in Older Adults (JMDC)
Scientific Title
Recorded COVID-19 and Change in Measured Glycemia From Before to After Infection Among Older Adults in Japan: A Risk-Set-Matched Difference-in-Differences Study
Scientific Title:Acronym
COVID-19 Glycemia DiD Study (Late-Elderly)
Region
| Japan |
Condition
Condition
COVID-19 (exposure) and change in glycemia (HbA1c) / incident diabetes (outcome), among late-elderly adults without pre-existing diabetes.
Classification by specialty
| Endocrinology and Metabolism | Infectious disease | Geriatrics |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
Using linked data from Japan Late-Stage Elderly Medical Care System (enrollment, claims, dispensing, care-related, and health check-up records through March 2025), to estimate whether recorded COVID-19 is associated with the change in HbA1c from before (about 12 months before index) to after (about 12 months after index) infection, among adults aged 65 years or older without pre-existing diabetes and with baseline HbA1c below 6.5%, within a risk-set-matched difference-in-differences framework, compared with matched controls without recorded COVID-19. Death, disenrollment, and observation are handled explicitly using observation weighting (IPOW/AIPW).
Basic objectives2
Others
Basic objectives -Others
Observational study evaluating an exposure-outcome association: an epidemiological study assessing whether COVID-19 is associated with a sustained change in glycemia among older adults.
Trial characteristics_1
Exploratory
Trial characteristics_2
Pragmatic
Developmental phase
Not applicable
Assessment
Primary outcomes
The primary outcome is post-index minus pre-index HbA1c (percentage points). The laboratory outcome is evaluated only among those with no recorded death and continuous enrollment through month 15 (death is derived from the enrollment-end reason and cannot be observed after non-death exit). Using exposure-group-specific observation models (IPOW/AIPW), the between-group difference in HbA1c change is estimated in the matching-weighted population (95% CI).
Key secondary outcomes
Secondary: the proportion with follow-up HbA1c of at least 6.5%, upper-tail change, subgroups by calendar era (before and after the May 2023 reclassification), baseline HbA1c, BMI, prior steroid use, and hospitalization, initiation of glucose-lowering medication, newly recorded diabetes diagnosis, and mortality (matching-weighted Kaplan-Meier). Nonfatal outcomes use matching-weighted Aalen-Johansen estimates. Contamination scenarios for unrecorded infection and overlap-restricted analyses are also examined.
Base
Study type
Observational
Study design
Basic design
Randomization
Randomization unit
Blinding
Control
Stratification
Dynamic allocation
Institution consideration
Blocking
Concealment
Intervention
No. of arms
Purpose of intervention
Type of intervention
Interventions/Control_1
Interventions/Control_2
Interventions/Control_3
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 65 | years-old | <= |
Age-upper limit
| Not applicable |
Gender
Male and Female
Key inclusion criteria
(1) Adults aged 65 years or older in linked data from the Japan Late-Stage Elderly Medical Care System (enrollment, medical/dispensing/care-related claims, and health check-up records through March 2025). (2) At least 24 months of continuous enrollment. (3) A baseline HbA1c measured 9 to 15 months before index and below 6.5%. (4) No recorded diabetes diagnosis or glucose-lowering medication in the prior 24 months. The source extract was selected for respiratory-related medical contact or systemic anti-infective treatment, and the primary cohort required that extract-entry evidence to precede index. The exposure group is first recorded COVID-19 (confirmed nonsuspected diagnosis plus SARS-CoV-2 testing, COVID-19 hospitalization, diagnosis plus an eligible antiviral, or an eligible antiviral alone; eligible antivirals were molnupiravir, ensitrelvir, and nirmatrelvir/ritonavir). Controls had no recorded COVID-19 by the matched index date. Frozen exact-index-month matched sets were restricted to index dates through December 2023.
Key exclusion criteria
(1) A recorded diabetes diagnosis or glucose-lowering medication in the prior 24 months. (2) A baseline HbA1c not measured 9 to 15 months before index, or 6.5% or higher. (3) Less than 24 months of continuous enrollment. (4) An index date after December 2023.
Target sample size
68820
Research contact person
Name of lead principal investigator
| 1st name | Satoshi |
| Middle name | |
| Last name | Kutsuna |
Organization
The University of Osaka, Graduate School of Medicine Faculty of Medicine
Division name
Department of Infection Prevention and Control
Zip code
565-0871
Address
2-2, Yamadaoka, Suita city
TEL
0836-6879-5111
kutsuna@hp-infect.med.osaka-u.ac.jp
Public contact
Name of contact person
| 1st name | Satoshi |
| Middle name | |
| Last name | Kutsuna |
Organization
The University of Osaka, Graduate School of Medicine Faculty of Medicine
Division name
Department of Infection Prevention and Control
Zip code
565-0871
Address
2-2, Yamadaoka, Suita city
TEL
0836-6879-5111
Homepage URL
kutsuna@hp-infect.med.osaka-u.ac.jp
Sponsor or person
Institute
The University of Osaka, Graduate School of Medicine Faculty of Medicine
Institute
Department
Personal name
Funding Source
Organization
The University of Osaka
Organization
Division
Category of Funding Organization
Self funding
Nationality of Funding Organization
Japan
Other related organizations
Co-sponsor
None
Name of secondary funder(s)
None
IRB Contact (For public release)
Organization
The University of Osaka Hospital, Ethical Review Board
Address
2-15, Yamadaoka, Suita city
Tel
0836-6879-5111
rinri@hp-crc.med.osaka-u.ac.jp
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
大阪大学大学院医学系研究科 感染制御学 / The University of Osaka, Graduate School of Medicine
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 08 | Month | 09 | Day |
Related information
URL releasing protocol
Publication of results
Unpublished
Result
URL related to results and publications
Number of participants that the trial has enrolled
68820
Results
Results date posted
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Participant flow
Adverse events
Outcome measures
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Completed
Date of protocol fixation
| 2026 | Year | 04 | Month | 14 | Day |
Date of IRB
| 2026 | Year | 04 | Month | 14 | Day |
Anticipated trial start date
| 2026 | Year | 04 | Month | 14 | Day |
Last follow-up date
| 2026 | Year | 08 | Month | 09 | Day |
Date of closure to data entry
| 2026 | Year | 08 | Month | 09 | Day |
Date trial data considered complete
| 2026 | Year | 08 | Month | 09 | Day |
Date analysis concluded
| 2026 | Year | 08 | Month | 09 | Day |
Other
Other related information
This is a retrospective risk-set-matched difference-in-differences study using linked data from the Japan Late-Stage Elderly Medical Care System (enrollment, claims, dispensing, care-related, and health check-up records through March 2025; index dates through December 2023). Among adults aged 65 years or older without pre-existing diabetes and with baseline HbA1c below 6.5%, the association between recorded COVID-19 and change in HbA1c from before to after infection was estimated compared with matched controls. Existing anonymized data were analysed after institutional review board approval.
Management information
Registered date
| 2026 | Year | 08 | Month | 09 | Day |
Last modified on
| 2026 | Year | 08 | Month | 09 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071572
