Switching to E-Cigarettes After Type 2 Diabetes Diagnosis and Health Outcomes (E-cig-DM)

February 10, 2026 updated by: Ki Hong Choi, Samsung Medical Center

Clinical Outcomes Associated With Switching From Combustible Cigarettes to Electronic Cigarettes Among Adults With Newly Diagnosed Type 2 Diabetes: A Nationwide Retrospective Cohort Study

Individuals with T2DM who smoke have higher risks of cardiovascular disease and other complications. Many people consider e-cigarette as a "harm-reduction" alternatives to combustible cigarettes, but it is not clear whether switching to e-cigarettes improves health outcomes in patients with diabetes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Use of electronic cigarettes has increased, partly driven by the perception that they may serve as a "harm-reduction" alternative to combustible cigarettes. Evidence cited in prior work includes higher cessation rates versus nicotine replacement therapy in a randomized trial and reductions in biomarkers of potential harm after switching from combustible cigarettes to e-cigarettes; observational data in high-risk PCI populations have also suggested lower MACCE risk after switching. However, constituents such as nicotine and heavy metals may adversely affect diabetes management, and most prior studies have emphasized potential harms of e-cigarette use itself. As a result, whether switching from combustible cigarettes to e-cigarettes confers a harm-reduction benefit in patients with diabetes remains uncertain. In this regards, the current study evaluated clinical outcomes associated with switching from combustible cigarettes to e-cigarettes in patients with diabetes and to assess whether the degree of switching (partial vs full transition) modifies the risk of adverse clinical events.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
133320

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • South Korea
    • Gannam-gu
      • Seoul, Gannam-gu, South Korea, 06351
        • Samsung Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients diagnosed with diabetes from 2018 onward who reported being a "current smoker" at a health examination within the 4 years prior to the diabetes diagnosis, and who could be classified after diagnosis as either continued combustible cigarette smoking ("Current") or e-cigarette use (partial or full transition).

Description

Inclusion Criteria:

  • Patients diagnosed with diabetes who reported being a "current smoker" at a health examination within the 4 years prior to the diabetes diagnosis.

Exclusion Criteria:

  • age <40 years or ≥75 years
  • Pre-existing AMI before diabetes diagnosis
  • Pre-existing Revascularization before diabetes diagnosis
  • Pre-existing diabetes complications before diabetes diagnosis
  • Pre-existing cancer before diabetes diagnosis
  • Death within 6 months of the first health examination after diabetes diagnosis
  • Cancer within 6 months of the first health examination after diabetes diagnosis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Continued combustible cigarette use
Continued combustible cigarette users after diagnosed DM
Partial Switching to E-cigarette
partial switching to E-cigarette users after diagnosed DM
Behavioral: Switching to E-cigarette
Switching to E-cigarette
Full switching to E-cigarette
fully switching to E-cigarette users after diagnosed DM
Behavioral: Switching to E-cigarette
Switching to E-cigarette

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Rates of MACE
Time Frame: Up to 5 years
MACE was defined as the composite of all-cause death, MI, and repeat revascularization. The diagnosis of MI was made if patients were hospitalized with primary diagnostic codes related to MI (ICD-10 I21, I22) during follow-up period. In a previous validation study, the accuracy of diagnosis of MI in NHIS data was 93%.16 Unplanned revascularization was defined as presence of procedure codes for percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) after index date.
Up to 5 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Rates of Diabetic complications
Time Frame: Up to 5 years
Diabetic complications were defined as presence of diabetic neuropathy (ICD-10: E10.4, E11.4, E12.4, E13.4, E14.4, G59.0, G63.2, and G99.0), diabetic foot without amputation (ICD-10: E10.5, E10.7, E11.5, E11.7, E12.5, E12.7, E13.5, E13.7, E14.5, and E14.7), diabetic foot with amputation (ICD-10: E10.5, E10.7, E11.5, E11.7, E12.5, E12.7, E13.5, E13.7, E14.5, and E14.7; procedure codes: N0572-0575), and diabetic retinopathy, including non-proliferative (ICD-10: H360) and proliferative (ICD-10: H360; procedure codes: S5160 and S516) forms.
Up to 5 years
Rates of All-cause death
Time Frame: Up to 5 years
the individual components of MACE
Up to 5 years
Rates of Myocardial infarction
Time Frame: Up to 5 years
the individual components of MACE. The diagnosis of MI was made if patients were hospitalized with primary diagnostic codes related to MI (ICD-10 I21, I22) during follow-up period.
Up to 5 years
Rates of Unplanned Revascularization
Time Frame: Up to 5 years
Unplanned revascularization was defined as presence of procedure codes for percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) after index date.
Up to 5 years
Rates of Ischemic stroke
Time Frame: Up to 5 years
Stroke was defined based on ICD codes for ischemic stroke (ICD-10 I63, I64) or intracranial hemorrhage (ICD-10 I60-62), combined with the codes for hospitalization.
Up to 5 years
Rates of Hemorrhage stroke
Time Frame: Up to 5 years
Hemorrhage stroke was defined based on ICD codes for intracranial hemorrhage (ICD-10 I60-62), combined with the codes for hospitalization.
Up to 5 years
Rates of Mild pulmonary disease
Time Frame: Up to 5 years
Mild pulmonary disease were identified using validated ICD-10 codes.
Up to 5 years
Rates of Severe exacerbation of Pulmonary disease
Time Frame: Up to 5 years
Hospitalization for exacerbation in patients with a documented pulmonary disease code.
Up to 5 years
Rates of Cancer
Time Frame: Up to 5 years
Cancer was defined as the presence of cancer-specific insurance claim code (V193 code) with a C code which was an ICD-10 code for cancer.
Up to 5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Samsung Medical Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ki Hong Choi, MD, PhD, Samsung Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 22, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 17, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • DM_E-cigarette

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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