By Billy Hammond (Copyright AELS)

November 15, 2021

Diabetes and HbA1c

Every now and then there’s talk in the media about how measuring the HbA1c levels in the blood can determine whether or not someone has diabetes or not. There’s usually little mention of what it is in the advertising or discussion that follows.

The “Hb” stands for hemoglobin, the oxygen transport component in your blood. The HbA refers to adult hemoglobin (there are other types, such as fetal hemoglobin). 4 minor components result from the nonezymatic glycosylation of its amino acid protein residues: (HbA1a1, HbA1a2, HbA1b1, and HbA1c). In the HbA1c, the glycosylation occurs on an N-terminal valine.*

It is a reaction that is dependent on glucose levels, so as glucose levels increase the HbA1C levels also rise. Normal levels of HbA1c are between 4-6% of total hemoglobin and those greater than 6.5% are indicative of diabetes mellitis. It is an indicator that is assumed valid for the past two months because red blood cells live for about 120 days.

It alone isn’t sufficient to warrant a diabetes diagnosis (random plasma glucose with symptoms, fasting plasma glucose and a 2-hour post oral plasma glucose over two days are needed as well), but it is enough to urge a person to see their doctor for the follow-up tests.**

*Lieberman, Michael A.; Marks, Allan; Peet, Alisa. Marks’ Basic Medical Biochemistry (Lieberman, Marks’s Basic Medical Biochemistry) . Lippincot (Wolters Kluwer Health).

**O’Connell, Theodore X.; Pedigo, Ryan A.; Blair, Thomas E.. Crush Step 1 E-Book: The Ultimate USMLE Step 1 Review . Elsevier Health Sciences. Kindle Edition.

糖尿病とHbA1c

テレビなどでよくHbA1cを調べれば糖尿病が発見できると聞く。HbAは成人ヘモグロビン(胎児ヘモグロビンの他のヘモグロビンの種類もある)を表す。ヘモグロビンは血液内の酸素を運ぶ成分である。ヘモグロビンのアミノ酸残留の非酵素的なグリコシル化から4つの成分ができる( HbA1a1, HbA1a2, HbA1b1, and HbA1c)。HbA1cの場合、そのグリコシル化はN末端部位バリンで起きる。*

その反応はグルコース濃度に依存しているのでグロコース値が上がるとHbA1cレベルも上がる。正常値は総合グルコースの46%で、糖尿病を疑うレベルは6.5%以上。赤血球は約120日の存続期間 があるのでその半分の過去2ヶ月間としての記録としてみなす。

但し、HbA1cだけでは糖尿病診断はできない。症状の伴ったランダム血漿検査、空腹時血漿グルコース及び2日間に渡ったの2時間後の経口グルコース負荷試験も必要)**但し、高い値の場合は出来るだけ早くかかりつけ医との相談が必要。

*Lieberman, Michael A.; Marks, Allan; Peet, Alisa. Marks’ Basic Medical Biochemistry (Lieberman, Marks’s Basic Medical Biochemistry) . Lippincot (Wolters Kluwer Health).

**O’Connell, Theodore X.; Pedigo, Ryan A.; Blair, Thomas E.. Crush Step 1 E-Book: The Ultimate USMLE Step 1 Review . Elsevier Health Sciences. Kindle Edition.

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English novels by Billy Hammond published by AELS

(AELS出版英語書籍リスト)

 

I. Majoh Gakuin and Hikari Juku – Japanese Witch Schools Trilogy

1. Majoh Gakuin & Hikari Juku – Japanese Witch Schools

2. Lost Witch (The second book)

3. Fate & Magic (The final book in the trilogy)

II. Brindle – Scryer Extraordinaire Trilogy

1. Brindle – Scryer Extraordinaire

2. Brindle – Scryer Extraordinaire – Returns

3. Brindle – Scryer Extraordinaire – Challenges (The final book in the trilogy)

III. Fantasy fiction set in Japan

1. 21st Century Ninja

2. Regressed

3. Japanese Woman

IV. Fantasy fiction set outside of Japan

1. Dimension Jumpers

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