Effects of an equol-containing supplement on advanced glycation end products, visceral fat and climacteric symptoms in postmenopausal women: A randomized controlled trial

Introduction Equol, an isoflavone derivative whose chemical structure is similar to estrogen, is considered a potentially effective agent for relieving climacteric symptoms, for the prevention of lifestyle-related diseases, and for aging care in postmenopausal women. We investigated the effect of an equol-containing supplement on metabolism and aging and climacteric symptoms with respect to internally produced equol in postmenopausal women. Methods A single-center, randomized controlled trial (registration number: UMIN000030975) on 57 postmenopausal Japanese women (mean age: 56±5.37 years) was conducted. Twenty-seven women received the equol supplement, while the remaining received control. Metabolic and aging-related biomarkers were compared before and after the 3-month intervention. Climacteric symptoms were assessed every month using a validated self-administered questionnaire in Japanese postmenopausal women. Results Three months post-intervention, the treatment group showed significant improvement in climacteric symptoms compared to the control group (81% vs. 53%, respectively, p = 0.045). We did not observe any beneficial effect on metabolic and aging-related biomarkers in the intervention group. However, in certain populations, significant improvement in skin autofluorescence, which is a measurement of AGE skin products, and visceral fat area was observed, especially among equol producers. Conclusion Women receiving equol supplementation showed improved climacteric symptoms. This study offered a new hypothesis that there may be a synergy between supplemented equol and endogenously produced equol to improve skin aging and visceral fat in certain populations.


Objective
To investigate the relationship between dietary status, type of intestinal bacteria, and equol-producing ability.
To examine the effects of ingestion of "equol + lactobionic acid" on various parameters of lifestyle-related disease risk such as arteriosclerosis and visceral fat area including the relationship with the above background factors.

Research population
Postmenopausal women who undergo medical examinations at the Sendai General Health Screening Clinic.

Methods
Subjects: Healthy postmenopausal women aged 50 years or older who undergo a medical examination at the above facility and who have consented to this study.

Research Objective and Background
Equol is an active metabolite in which daidzein, a type of soy isoflavone, is metabolized by intestinal bacteria. Its structure is similar to that of the female hormone estrogen, and it has an estrogen-like action, which alleviates menopausal symptoms. , Suppression of bone loss, improvement of lipid metabolism and arteriosclerosis, etc. have been reported, and are expected to be effective for a wide range of women's health care.
On the other hand, the number of people who can produce equol in the body is as small as about 50% in Japan, and it is said that the eating habits, living environment, and intestinal bacteria, which are equol-producing bacteria, are involved in the equol-producing ability.
In this clinical study, it is considered meaningful to investigate and clarify the relationship between dietary habits and the types of intestinal bacteria regarding equol-producing ability.
In addition, we investigated the effects of ingestion of "equol + lactobionic acid" on lifestyle-related disease parameters such as vascular system, visceral fat area, and AGEs (advanced glycation end products) in the above subjects, and investigated the effects of equol production ability and intestinal bacteria It is important to clarify the relationship with the background factors of equol in order to further build evidence on the action of equol.

1) Target person
Those who have recruited subjects from postmenopausal* healthy women aged 50 years or older who wish to undergo a medical examination at the Sendai General Medical Examination Clinic and have obtained their consent to participate in this study. * Menopause is spontaneous menopause, excluding menopause due to invasion such as surgery.
2) Selection, exclusion, discontinuation criteria ①Selection criteria Those who meet all of the following selection criteria and have the ability to consent are eligible. ・Japanese healthy postmenopausal women over 50 years old ・Persons undergoing medical examination at Sendai General Clinic ・Persons who can undergo interviews or examinations at the start of the examination and every month at the Sendai General Clinic (8 minutes on foot from JR Sendai Station) ・Person who can take the recommended quantity of supplement and record daily life diary during the implementation period (12 weeks) ②Exclusion criteria Persons with a history of allergies to soy foods, dairy products, and brewer's yeast. ・Persons who have started taking medicines or health foods that may have an effect during the test period.
・Those who are receiving HRT or who are taking drugs that may act on hormones.
・Others that the investigating doctor deems inappropriate.

③Cancellation criteria
Clinical research will be discontinued if any of the following applies. ・ During the test period, the subject develops serious symptoms and the safety of the supplement becomes questionable. ・ When it becomes clear that the subject was affected by continuously consuming the supplement.
3) Registration ・The principal investigator will register the candidate as a subject after confirming that she meets the eligibility criteria and does not meet any of the exclusion criteria.
Before and after ingestion of supplement: height / weight / body composition, blood test (TG, HDL-C, LDL-C, T-CL, uric acid, HbA1C), baPWV, visceral fat CT test (fat scan), AGE measurement by AGE reader, and climacteric system assessments.

Analysis
For the primary measures, perform chi-squared test and t test for comparison between groups and before and after the study period. For secondary outcomes, anonymized data are entered into the database and the correlation is analyzed. Drop out cases and missing values are not included in the analysis. Other questionnaire surveys will be conducted according to the evaluation criteria of each questionnaire. The visceral fat CT examination and baPWV measurement at the start of the test and at 12 weeks will be performed at the same site in order to eliminate measurement errors.

Expected adverse events
In rare cases, allergic symptoms to supplement may appear.

1) Symptoms or disease
Any unfavorable or unintended signs, symptoms or disease that develops during the study is treated as an adverse event. However, worsening of biomedical parameters in the study will not be treated as an adverse event.

2) Objective findings
If abnormalities or deterioration (normal → abnormal / worse, abnormal / worse → more abnormal / worser) are detected after the study period compared to before the study, it is treated as an adverse event.
Regardless of the items specified or unspecified in this protocol, those considered to be adverse events need to be recorded in the case report, describing the onset, time of maximum severity, outcome, and relevance.

3) Recording and investigation of adverse events
If an adverse event occurs, its symptoms or disease, content of objective findings, date of onset, degree, severity, presence or absence of treatment and its content, outcome and date of diagnosis, relevance to this clinical study and the underlying reason are to be recorded in the adverse event section of the case report. When the name of the disease is described, the symptom associated with the disease is not recorded as an adverse event.
If an adverse event is observed in the symptoms, diseases, or objective findings observed during the treatment period, it will be followed up until the condition become normalized or improved up to a level that could not be regarded as an adverse event, regardless of whether it has a causal relationship with this clinical study. However, this does not apply if the investigator determines that the patient has recovered.
In that case, the grounds for determining recovery shall be stated in the case report form. If irreversible adverse events are observed due to organic disorders (cerebral infarction, myocardial infarction, etc.), follow-up will be conducted until the symptoms stabilize or improve.

4) Classification of adverse events
The degree of adverse events is classified according to the following criteria. Regarding adverse events, items ①to ③) are those whose relevance to this clinical study cannot be ruled out, and item ④is regarded as an adverse event whose relevance to this clinical study is denied.

6) Serious adverse events
If a serious adverse event occurs during the study period, whether or not it has a causal relationship with this clinical study, the investigator will immediately give an appropriate treatment to the subject.

7) Providing new information
When new information on the safety of this clinical study is obtained, the explanatory document and consent document will be revised promptly as necessary.

Medical expenses and compensation
1) Medical expenses ・ The cost of the first regular medical examination will be borne by the patient, and if it is clear that it is related to this clinicaltrial, the patient will not be liable for the cost. If it is unclear, it will be decided through consultation. ・ If medical expenses are incurred, the research implementation facility, Sendai General Health Examination Clinic, and Advanced Medical Care Co., Ltd., the sponsor company, will deal with them upon discussion.

2) Compensation
If the subject is liable for compensation as a result of health damage due to this clinical study, the investigator and the sponsor company will discuss and decide how to handle it.

1) Compliance with ethical guidelines for clinical research
This clinical study will be conducted in compliance with the ethical principles based on the "Ethical Guidelines for Clinical Research" (Ministry of Health, Labor and Welfare) and this protocol.

2) Ethics Committee
The ethical issues and validity of this proposal will be discussed in the Prior to the start of this clinical study, the principal investigator will explain the following matters to the subject based on the explanatory document, and then obtain the written consent of the subject based on his / her free will.
The following items should be described in the explanatory document.

4) Providing information to subjects
When the investigator obtains information that may affect the subject's will regarding the continuation of participation in the clinical study, the investigator promptly informs the subject or his / her substitute to participate in the clinical study, and check if the subject wants to continue. In addition, this process will be recorded in the medical record.

5) Protection of personal information
Protect the personal information of subjects when conducting clinical trials.
In protecting personal information, all data related to this protocol should be anonymized (coded) and handled. Information that can be identifiable personally will be stored and managed in a place where it can be locked under the strict control of the person in-charge of personal information management at the Sendai General Medical Examination Clinic. When it is no longer needed, dispose of it in an irreproducible form such as incineration or dissolution. In the unlikely event that personal information is leaked, the following measures will be taken promptly.