今日の糖尿病診療—心血管合併症の予防と診断

Recent Medical Treatment of Diabetes Mellitus : Prevention and Cardiovascular Complications

はじめに

　糖尿病患者は世界中で増加しており，我が国においても，生活習慣の変化に伴い2007年では890万人になっている．血糖コントロールが不良な状態が持続すると，細小血管障害や大血管障害といった合併症が生じ，生活の質（QOL）を著しく低下させる．3大合併症といわれる腎症，網膜症，神経障害の細小血管合併症は糖尿病発症から10年近い病期を経て発症することが知られているのに対し，冠動脈疾患を含む大血管合併症は糖尿病の前段階である耐糖能異常の時点から発症リスクの上昇が認められる．したがって，糖尿病と診断された早期の時点で，動脈硬化が既に発症している可能性が示されている．また，心不全発症も糖尿病患者では多く，そのリスクは非糖尿病患者と比べ3〜5倍高いことが知られている．したがって，糖尿病患者のQOLの維持や寿命の確保のためには，心血管合併症の予防と早期発見，治療が重要である．

Abstract : Type 2 diabetes mellitus (DM) doubles the risk of major cardiovascular complications in both patients with and those without established cardiovascular disease (CVD), and the majority of patients with DM die of CVD. Therefore, prevention and early diagnosis for CVD are important for the improvement of quality of life and prognosis of patients with DM. Exercise stress tests, such as a treadmill test, are needed to detect myocardial ischemia, but such stress testing should be done by cardiologists. On the other hand, measurement of ankle brachial index (ABI) is quick and easy and has been used successfully to diagnose peripheral artery disease. Since ABI is known to be a good predictor of the risk of recurrent CV events and death, I strongly recommend that ABI be measured in all DM patients. Dipeptidyl peptidase 4 (DPP-4) inhibitors are oral agents with little risk of hypoglycemia and thus used widely. In 2013, two clinical studies (EXAMINE and SAVOR-TIMI53) showed that DPP-4 inhibitors were generally safe and well-tolerated but did not decrease or increase the rate of CV events in patients with high risk for CV. Although the study periods were short (1.5-2.0 years), it was shown that a reduction of CV events in DM patients with CV risk is difficult with glycemic control alone. Results of the Steno-2 study showed that optimal treatment of hypertension and dyslipidemia in addition to glycemic control are needed to reduce CV events.