Diabetes and Endocrinology

What we do

We provide comprehensive clinical care for endocrine disorders and diabetes.

Our department actively conducts specialized diagnostic and therapeutic procedures, including:

Isotope Treatment (Radioactive Iodine Therapy) for Graves' Disease
Endocrine Dynamic Function Tests (Load Tests) for Pituitary and Adrenal Diseases
Adrenal Vein Sampling (AVS) for Primary Aldosteronism

For details, please refer to the section on Target Conditions.

(Updated: October 6, 2022)

Conditions we handle

Metabolic & Thyroid Disorders: Diabetes Mellitus, Graves' Disease, Subacute Thyroiditis, Hypothyroidism, Obesity.

Adrenal Disorders: Hypercortisolism (Cushing's Syndrome), Pheochromocytoma, Primary Aldosteronism, Adrenal Insufficiency, Adrenal Incidentaloma.

Pituitary & Parathyroid Disorders: Acromegaly, Prolactinoma (Prolactin-Secreting Pituitary Adenoma), Hyperparathyroidism, and related conditions.

Medical Information & Patient Guidance

What are Endocrine Disorders?

Endocrine disorders are diseases related to hormones secreted within the body.

Major Conditions Include:

Insulin-Related Disorders: Diabetes Mellitus, etc.
Thyroid Hormone-Related Disorders: Graves' Disease, Subacute Thyroiditis, Hypothyroidism, etc.
Adrenal Hormone-Related Disorders: Hypercortisolism (Cushing's Syndrome), Pheochromocytoma, Primary Aldosteronism, Adrenal Insufficiency, Adrenal Incidentaloma, etc.
Pituitary Hormone-Related Disorders: Acromegaly, Prolactinoma, etc.
Parathyroid Hormone-Related Disorders: Hyperparathyroidism, etc.

What Kind of Disease is Graves' Disease?

Graves' disease is a condition in which the thyroid gland (located at the front of the neck) produces excessive amounts of thyroid hormone—the hormone responsible for stimulating metabolic activity.

Even when resting, the body feels as though it is in a "full-sprint state."

Common Symptoms of the "Full-Sprint State" Include:

Rapid pulse and heart palpitations
Shortness of breath and excessive sweating
Weight loss despite a strong appetite
Irritability and hand/foot tremors
Tendency toward diarrhea/loose stools

If you experience these symptoms, please consult your primary care physician (or a local clinic) to have your thyroid function checked via blood tests measuring Free T4 and TSH. High Free T4 combined with low TSH levels suggests the possibility of Graves' disease. Please discuss with your doctor about seeking a specialized evaluation at our hospital or another medical center.

Detailed Evaluation for Graves' Disease

It is crucial to determine the precise underlying cause of elevated thyroid hormones, as treatment strategies vary significantly depending on the etiology.

We take a detailed clinical history, perform a physical examination, and select the necessary diagnostic tests. Diagnostic tools include blood tests, thyroid ultrasonography, and thyroid scintigraphy.

In particular, thyroid scintigraphy is a specialized diagnostic imaging modality available only at select medical facilities, including our hospital. It serves as the single most critical exam for confirming the exact cause of elevated thyroid hormones.

Treatment Options for Graves' Disease

There are two main treatment pathways:

1.Pharmacotherapy: Using antithyroid medications to suppress thyroid hormone production.
2.Definitive Therapy: Reducing thyroid tissue volume through surgery or radioactive isotope therapy.

Treatment choice depends on individual clinical status and is finalized through shared decision-making.

Note: Patients who have been on medication for at least two years, or those planning a future pregnancy, are strongly recommended to consider non-pharmacological treatment options.

What is Isotope Treatment? (Radioactive Iodine Therapy)

Isotope therapy reduces thyroid gland volume using radioactive substances (radioisotopes).

Although "radioactive" may sound intimidating, the procedure simply involves swallowing a single small capsule on an outpatient basis. No external radiation beam is applied to your body.

Once swallowed, the capsule is absorbed through the intestines and concentrates specifically in the thyroid gland, reducing its size and resolving Graves' disease. It does not cause hair loss, cancer, or leukemia, nor does it affect future offspring. The physical burden is low, making it suitable even for patients with severe heart or lung conditions. In the United States, it is widely utilized as a standard, safe first-line treatment.

For clear explanations, refer to the Japan Thyroid Association Guide or visit harecoco.net for detailed medical explanations.

What Kind of Disease is Subacute Thyroiditis?

Subacute thyroiditis is an inflammatory condition of the thyroid gland that causes pain in the front of the neck accompanied by fever.

Characteristic Manifestations Include:

Severe tenderness when pressing the front lower surface of the neck (thyroid area)
Pain shifting from the right side to the left side (or vice versa)
Persistent fever

Because common viral colds can present similarly, if you experience these symptoms, consult your primary care physician to consider a referral to a specialist center. Pain and fever caused by this condition are managed effectively with analgesics or corticosteroids.

What Kind of Disease is Hypercortisolism (Cushing's Syndrome)?

Cushing's syndrome is a disease characterized by the overproduction of cortisol (a steroid hormone) in the body.

Excessive Steroid Hormone Levels May Lead To:

Rounded "moon face" and facial flushing
Fragile skin and unexplained bruising / subcutaneous hemorrhage
Refractory diabetes mellitus that is difficult to control
Vertebral compression fractures
Rapid weight gain without increased food intake

Similar features can occur in patients taking steroid medications for other medical conditions. If you exhibit these symptoms, please consult your primary care physician to arrange a evaluation at a specialized medical facility. If diabetes or hypertension stems from this condition, surgical removal of the hormone-producing lesion can lead to significant clinical improvement.

What Kind of Disease is Acromegaly?

Acromegaly is caused by the excessive production of growth hormone (the hormone that stimulates body growth).

Excessive Growth Hormone May Cause:

Thickening of skin on hands and feet; enlargement of the nose and jaw (These changes progress very slowly over years, making them hard for family members to notice)
Profuse sweating and persistent, severe headaches
Hand numbness / tingling (Carpal Tunnel Syndrome caused by thickened tissue compressing nerves)
Loud snoring and sleep apnea (due to airway narrowing)
Development of diabetes mellitus and hypertension

If these symptoms apply to you, consult your physician to order a blood test measuring IGF-1 (Insulin-like Growth Factor 1 / Somatomedin C). Normal IGF-1 ranges vary by age; if levels are elevated, further diagnostic workup at a specialized center is warranted.

When diagnosed, surgical removal of the growth-hormone-secreting tumor can reverse physical changes and resolve diabetes, hypertension, carpal tunnel syndrome, and sleep apnea.

Successful treatment of acromegaly is estimated to extend life expectancy by approximately 10 years.

What Kind of Disease is Prolactinoma?

A prolactinoma is a tumor that overproduces prolactin (the hormone responsible for stimulating breast milk production).

Excessive Prolactin Levels May Lead To:

Galactorrhea (breast milk secretion unrelated to pregnancy)
Amenorrhea (cessation of menstrual periods)
Male infertility

Because elevated prolactin can also stem from medication side effects or gynecological conditions, consult your doctor to evaluate whether a specialist visit is indicated. Pharmacotherapy to suppress prolactin secretion typically resolves galactorrhea and restores normal menstruation.

What Kind of Disease is Hyperparathyroidism?

Hyperparathyroidism occurs when parathyroid hormone (which elevates blood calcium levels) is overproduced.

It is frequently detected incidentally as high blood calcium levels during routine blood tests, often without noticeable symptoms. However, it can cause urinary tract stones (kidney stones), osteoporosis, and renal impairment.

As hypercalcemia can also result from medications (such as vitamin D supplements), consult your physician first. If hyperparathyroidism is identified as the underlying cause of kidney stones or osteoporosis, surgical removal of the overactive parathyroid tissue can resolve the condition.

(Medical Information Section Updated: February 25, 2022)

Number of cases

Total Outpatient Consultations: 32,842 patients
Total Inpatient Patient Days / Admissions: 403 patient days (or admissions)

(FY2024 Track Record)

The majority of outpatients are for diabetic and hyperlipidemia and thyroid diseases in our departemtn. Most of the inpatients have diabetes, who are engaged in diabetes education, blood glucose control, evaluation and treatment of diabetic complications, and many referrals from neighboring medical institutions.

In addition, the following medical treatments are also provided.

1) Support fro diabetic patient
One session is 30 minites which conducted by a nurse for patients with lifestyle-related diseases, if there is a request by a doctor. The nurse in charge uses behavioral medical techniques to support the patient's self-care behavior and provide mental care regarding medical treatment.

2) Diabetes support class
An "Open Diabetes Seminar" is held every two months for outpatients. In addition, for inpatients, doctors, nurses, other profession will educate through video almost every day in the ward.

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List of Doctors

Director

Masahiro MASUZAWA

Subspeciality
General Internal Medicine / Endocrine Disorders
Conditions for Referral
Pituitary disorders / Adrenal disorders / Thyroid disorders

Department name	Diabetes and Endocrinology
Medical School	Hamamatsu University School of Medicine
Special Qualifications	Board Certified and Certified Specialist of Japanese Society of Internal Medicine. Board Certified Specialist of The Japan Endocrine Society Board Advanced Certified Specialist of Japan Diabetes Society. Board Certified Specialist of The Japanese Society for Dialysis Therapy
Education & Career	1992.Mar. Graduated from Hamamatsu University School of Medicine 1992.Jun. Resident of Hamamatsu University Hospital 1993.Apr. Resident of Haibara Hospital 1994.Apr. Internal Medicine， Haibara Hospital 1999.Jun. Assistant Chief of Internal Medicine， Kameda Medical Center 2003.Jan. Assistant Chief of Internal Medicine and Connective Tissue Disorders， Kameda Medical Center 1998: Endocrinology， Kameda Medical Center 2009.Jan. Vice Chief of Endocrinology 2011.Apr. Chief of Endocrinology

Director

Masaki MIURA

Subspeciality
Obesity Medicine / Diabetes Mellitus
Conditions for Referral
Obesity / Diabetes Mellitus

Department name	Diabetes and Endocrinology
Medical School	Juntendo University
Special Qualifications	Diabetes Specialist & Instructor (Japan Diabetes Society) Completed Ministry of Health, Labour and Welfare Clinical Training Instructor Course Completed Palliative Care Training Program for Physicians Involved in Cancer Care
Education & Career	2007 – Graduated from Juntendo University School of Medicine 2007 – Oji Co-op Hospital 2009 – Department of Diabetology, Tachikawa Sougo Hospital 2012 – Department of Diabetes & Endocrinology, Juntendo University 2013 – Entered Graduate School, Juntendo University 2017 – Graduated from Graduate School, Juntendo University 2017 – Assistant, Department of Diabetes & Endocrinology, Juntendo University 2018 – Assistant Professor, Department of Diabetes & Endocrinology, Juntendo University 2018 – Assistant Professor, Juntendo University Shizuoka Hospital Apr 2020 – Deputy Director, Department of Diabetes & Endocrinology, Kameda Medical Center Apr 2020 – Part-time Assistant Professor, Department of Diabetes & Endocrinology, Juntendo University Apr 2021 – Director, Department of Diabetes & Endocrinology

Deputy Director

Nobuhiro NAKATAKE

Subspeciality
Endocrine Disorders

Department name	Diabetes and Endocrinology
Medical School	University of the Ryukyus School of Medicine
Special Qualifications	Endocrinology Specialist, Instructor & Councilor (Japan Endocrine Society) Thyroid Specialist (Japan Thyroid Association) General Internal Medicine Specialist (Japan)
Education & Career	1999 – Graduated from University of the Ryukyus School of Medicine 1999 – Intern & Internal Medicine Resident, Okinawa Chubu Hospital 2001 – Staff Physician, Division of Endocrinology (Second Department of Internal Medicine), University of the Ryukyus 2003 – Clinical Scientist, RSR Limited, United Kingdom 2003 – Research Fellow, Cardiff University School of Medicine, United Kingdom 2004 – Clinical Attachment, Endocrinology & General Internal Medicine, Caerphilly District Miners' Hospital, United Kingdom 2007 – Staff Physician, Noguchi Thyroid Hospital, Beppu 2010 – Vice Director, Tajiri Thyroid Clinic, Kumamoto 2013 – Director, Department of General Medicine, Saiseikai Fukuoka General Hospital 2017 – Director, Department of Endocrinology, Fukuoka Tokushukai Hospital May 2021 – Appointed Deputy Director, Department of Diabetes & Endocrinology, Kameda Medical Center

Chief Physician

Asako TSUNEMI

Subspeciality
Diabetes Mellitus, Endocrine Disorders, Type 1 Diabetes, Continuous Glucose Monitoring (CGM) & Insulin Pump Therapy, Patient Support Programs

Department name	Diabetes and Endocrinology
Medical School	Juntendo University School of Medicine
Special Qualifications	Certified Internist (Japan) Diabetes Specialist (Japan Diabetes Society) Endocrinology Specialist (Japan Endocrine Society) Training Supervisor, Endocrinology, Metabolism & Diabetology Completed Palliative Care Training Program CTI Certified Professional Co-Active Coach (USA)
Education & Career	Mar 2010 – Graduated from Juntendo University School of Medicine Apr 2010 – Junior Residency, Juntendo University Shizuoka Hospital Apr 2012 – Clinical Fellow, Department of Metabolism & Endocrinology, Juntendo University Jul 2014 – Assistant, Department of Diabetes & Endocrinology, Juntendo University Urayasu Hospital Jan 2017 – Assistant, Department of Metabolism & Endocrinology, Juntendo University Apr 2018 – Graduate School of Medicine, Department of Metabolism & Endocrinology, Juntendo University Apr 2022 – Part-time Assistant Professor, Department of Metabolism & Endocrinology, Juntendo University Jul 2022 – Appointed Chief Physician, Department of Diabetes & Endocrinology, Kameda Medical Center

Vice Chairman, Tetsusho-kai Medical Corporation; Hospital Director, Kameda Medical Center; Chief Executive, Medical Management Division; Director, Cancer Center Promotion Center; Concurrently serving in Diabetes & Endocrinology

Toshiaki KAMEDA

Department name	Diabetes and Endocrinology
Medical School	Kawasaki Medical School
Special Qualifications	Certified Internist (Japan) Completed Ministry of Health, Labour and Welfare Clinical Training Instructor Course Completed Ministry of Health, Labour and Welfare Online Medical Care Training Program
Education & Career	Apr 2008 – Graduated from Kawasaki Medical School Apr 2008 – Resident, Tokyo Medical and Dental University (currently Institute of Science Tokyo) Apr 2009 – Resident, JA Toride Medical Center Apr 2010 – Joined the Department of Metabolism & Endocrinology, Juntendo University Hospital Jan 2013 – Shioda Memorial Hospital Apr 2013 – Department of Internal Medicine, Ito Hospital Apr 2015 – Department of Diabetes & Endocrinology, Kameda Medical Center Feb 2016 – International Administration Fellow, Beaumont Hospital Royal Oak Jan 2017 – International Administration Student, Khoo Teck Puat Hospital Apr 2017 – Department of Diabetes & Endocrinology, Kameda Medical Center Jul 2018 – Vice Director, Kameda Medical Center; Deputy Chief Executive, Medical Management Division; Concurre

Chief of Endocrinology

Osamu OGAWA

Subspeciality
Diabetes， Obesity

Department name	Diabetes and Endocrinology
Medical School	Juntendo University Faculty of Medicine
Special Qualifications	Board Certified Physician of The Japanese Society of Internal Medicine Board Certified Specialist and Advanced Certified Specialist of The Japan Diabetes Society Board Certified Specialist of Japanese Society of Anti-Aging Medicine Board Certified Physician of Japan Medical Association
Education & Career	1994.Mar. Graduated from Juntendo University 1994.Jun. Resident of Ohta Nishinouchi Hospital 1996.Apr. Fukushima Medical University Hospital 1997.Apr. Onomachi Hospital 1998.Apr. Juntendo University Faculty of Medicine 1998.Sep. Takayanagi Hospital 2006.Oct. Midorigaoka Ekimae Clinic 2010.Sep. Endocrinology， Kameda Medical Center 2010.Oct. Vice Chief of Endocrinology， Kameda Medical Center 2011.Apr. Chief of Endocrinology， Kameda Medical Center

Internal Medicine Resident

Yusuke MINAKATA

Subspeciality
Diabetes Mellitus / Endocrinology

Department name	Diabetes and Endocrinology
Medical School	Juntendo University School of Medicine
Education & Career	Mar 2022 – Graduated from Juntendo University School of Medicine Apr 2022 – Kameda Medical Center Apr 2024 – Juntendo University Urayasu Hospital Apr 2025 – Department of Diabetes & Endocrinology, Kameda Medical Center