UMIN-ICDS Clinical Trial

Public title

A Prospective Observational Study of Diabetic Neuropathy in Patients with Diabetes at Our Hospital

Acronym

A Prospective Observational Study of Diabetic Neuropathy in Patients with Diabetes at Our Hospital

Scientific Title

A Prospective Observational Study of Diabetic Neuropathy in Patients with Diabetes at Our Hospital

Scientific Title:Acronym

A Prospective Observational Study of Diabetic Neuropathy in Patients with Diabetes at Our Hospital

Region

Japan

Condition

Diabetes

Classification by specialty

Endocrinology and Metabolism

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

This study aims to determine the prevalence of diabetic neuropathy among patients with diabetes who are regularly followed in our department, based on screening examinations for diabetic neuropathy performed as part of routine clinical practice. We will also classify the severity of diabetic neuropathy and clarify the distribution of patients across different severity categories. Furthermore, plantar sensory function, which is particularly susceptible to impairment in diabetes, will be evaluated according to neuropathy severity using the current perception threshold as an objective measure.

In routine diabetes care, diabetic polyneuropathy is often diagnosed using simplified diagnostic criteria because of practical limitations such as restricted consultation time. These criteria consist of the presence of subjective symptoms such as numbness or pain, absence or reduction of the Achilles tendon reflex, and impaired vibratory sensation at the medial malleolus. However, reduced cutaneous sensation is not directly incorporated into these simplified diagnostic criteria.

Loss of protective sensation is an important clinical concern because sensory impairment has been reported to be associated with an increased risk of diabetic foot lesions, foot ulceration, and lower-extremity amputation. Therefore, clarifying the prevalence and severity of sensory impairment in patients with diabetes, particularly in relation to the severity of diabetic neuropathy, may provide clinically meaningful information for the prevention and early detection of diabetic foot complications.

Basic objectives2

Efficacy

Basic objectives -Others

Trial characteristics_1

Trial characteristics_2

Developmental phase

Primary outcomes

Primary endpoint:
To determine the association between the presence or absence of diabetic neuropathy and current perception threshold in the study participants. Diabetic neuropathy will be diagnosed according to the Simplified Diagnostic Criteria for Diabetic Polyneuropathy, partially revised in 2019 by the Study Group on Diabetic Neuropathy.

The prevalence of diabetic neuropathy will be calculated using descriptive statistics. Current perception thresholds at the bilateral great toes and bilateral Achilles tendon regions will be summarized separately for participants with and without diabetic neuropathy using JMP statistical software. The distributions will be described using the mean, median, and interquartile range, as appropriate. Between-group comparisons will be performed using Student's t-test or the Mann-Whitney U test, depending on the distribution of the data.

Key secondary outcomes

Secondary endpoint:
The severity of diabetic polyneuropathy will be classified into five categories according to Baba's classification: grade 0 (no abnormality), grade 1 (subclinical), grade 2 (mild), grade 3 (moderate), and grade 4 (severe). The distribution of current perception thresholds at the skin of the bilateral great toes and bilateral Achilles tendon regions will be determined for each severity group.

Neuropathy severity will be assessed using the nerve conduction study-based severity classification for diabetic polyneuropathy, version 4, commonly referred to as Baba's classification. Severity will be summarized as a categorical variable according to Baba's classification. Current perception thresholds at the bilateral great toes and bilateral Achilles tendon regions will be summarized for each severity category using JMP statistical software, with the mean, median, and interquartile range reported as appropriate. Between-group comparisons will be performed using one-way analysis of variance or the Kruskal-Wallis test, depending on the distribution of the data. Multiple comparison procedures will be performed as appropriate.

Exploratory endpoint:
Among participants who do not meet the Simplified Diagnostic Criteria for Diabetic Polyneuropathy, show no evidence of sensory impairment on qualitative sensory testing, and have a coefficient of variation of R-R intervals (CVR-R) within the normal range, the characteristics of participants with elevated current perception thresholds will be explored.

Study type

Observational

Basic design

Randomization

Randomization unit

Blinding

Control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

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

Age-lower limit

18

years-old

<=

Age-upper limit

Not applicable

Gender

Male and Female

Key inclusion criteria

Patients who meet all of the following criteria will be eligible for inclusion:
1. Age 18 years or older at the time of obtaining informed consent.
2. Either sex.
3. Participants who have received an explanation regarding participation in the study and have provided written informed consent.
4. Participants who meet the diagnostic criteria for diabetes mellitus.

Diabetes mellitus is defined as meeting at least one of the following criteria:
1. HbA1c of 6.5% or higher.
2. Fasting plasma glucose of 126 mg/dL or higher, or random plasma glucose of 200 mg/dL or higher.
3. Currently receiving pharmacological treatment for diabetes mellitus.

Participants must meet at least one of criteria 1 through 3 above.

Key exclusion criteria

Patients who meet any of the following criteria will be excluded from the study:
1. Patients with an implanted cardiac pacemaker.
2. Patients with an identifiable cause of polyneuropathy other than diabetes mellitus, including vitamin B12 deficiency, chronic inflammatory demyelinating polyneuropathy (CIDP), a history of heavy alcohol consumption, a history of chemotherapy, or uremic neuropathy due to renal failure.
3. Patients receiving dialysis, to exclude the possibility of uremic neuropathy.
4. Patients with a history of lower limb amputation or severe orthopedic disease that prevents appropriate positioning for the examinations.
5. Patients who are unable to understand examination instructions because of cognitive impairment.
6. Patients with trauma, ulceration, or infection of the plantar surface of the foot. Patients may be included after these conditions have healed.
7. Patients considered unsuitable for participation in the study by the principal investigator.

Target sample size

200

Name of lead principal investigator

1st name	Yudai
Middle name
Last name	Kumagai

Organization

Tohoku Medical and Pharmaceutical University

Division name

Division of Diabetes, Metabolism and Endocrinology, Faculty of Medicine

Zip code

983-8536

Address

1-15-1 Fukumuro, Miyagino-ku, Sendai, Miyagi

TEL

022-259-1221

Email

kumagai.yudai@tohoku-mpu.ac.jp

Name of contact person

1st name	Yudai
Middle name
Last name	Kumagai

Organization

Tohoku Medical and Pharmaceutical University

Division name

Division of Diabetes, Metabolism and Endocrinology, Faculty of Medicine

Zip code

983-8536

Address

1-15-1 Fukumuro, Miyagino-ku, Sendai, Miyagi

TEL

022-259-1221

Homepage URL

Email

kumagai.yudai@tohoku-mpu.ac.jp

Institute

Tohoku Medical and Pharmaceutical University

Institute

Department

Personal name

Organization

none

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization

Co-sponsor

Name of secondary funder(s)

Organization

Tohoku Medical and Pharmaceutical University

Address

1-15-1 Fukumuro, Miyagino-ku, Sendai, Miyagi

Tel

022-259-1221

Email

kumagai.yudai@tohoku-mpu.ac.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

Date of disclosure of the study information

2026

Year

10

Month

01

Day

URL releasing protocol

Publication of results

Unpublished

URL related to results and publications

Number of participants that the trial has enrolled

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

Recruitment status

Enrolling by invitation

Date of protocol fixation

2026

Year

05

Month

27

Day

Date of IRB

2026

Year

07

Month

01

Day

Anticipated trial start date

2026

Year

07

Month

01

Day

Last follow-up date

2028

Year

06

Month

30

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

Observation items

1. Participant characteristics
Age, sex, medical history, history of present illness, medication history, alcohol consumption history, smoking history, and duration of diabetes mellitus.

2. General physical findings
Height, body weight, and blood pressure.

3. Laboratory tests
Biochemical and laboratory parameters: C-reactive protein (CRP), AST, ALT, gamma-GTP, platelet count, FIB-4 index, BUN, creatinine, eGFR, uric acid, urinary albumin, blood glucose, HbA1c, insulin, C-peptide, triglycerides (TG), total cholesterol (T-Cho), HDL-C, and LDL-C.

4. Parameters related to diabetic neuropathy
Subjective symptoms considered to be attributable to diabetic neuropathy.
Bilateral Achilles tendon reflexes.
Bilateral vibration perception at the medial malleoli using a C128 tuning fork.
Qualitative sensory testing of both feet.
Current perception thresholds at the skin of the bilateral great toes and bilateral Achilles tendon regions.
Nerve conduction parameters of the right tibial and sural nerves.
Coefficient of variation of R-R intervals (CVR-R) as an index of cardiac autonomic function.

Registered date

2026

Year

09

Month

30

Day

Last modified on

2026

Year

09

Month

30

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072251