40020787616

拡張期心不全を起こす要因には，年齢や高血圧，糖尿病など様々な要因がある．糖尿病は高血圧を合併することで心筋のパフォーマンスが落ちることが知られている．糖尿病患者における拡張期心不全は，糖尿病性心不全の前駆症状としても重要だと考えられている．本研究の目的は，糖尿病性心筋症の発症リスクを糖尿病患者および高血圧を併発している糖尿病患者において左室拡張機能指標から評価・検討することである．213名のII型糖尿病患者を96名のDM群と117名のDM-HT群の2群に分けて検討を行った．また，糖尿病も高血圧もない健常68名をコントロール群とした．さらに，これらの3群を年齢別に4つの階層に分け，年齢別の検討も行った．LVEFやLV mass indexはDM群，DM-HT群においてもコントロール群と比較して有意な違いは認められなかった．拡張機能指標であるE/Aは加齢に伴い低下し，さらに各年齢層で比較してもコントロール群と比べDM群，DM-HT群ともに有意な低下が認められた．また，弛緩機能指標であるE’は3群ともに加齢に伴い低下し，さらにどの年齢層においてもDM群，DM-HT群に比べコントロール群において有意に高値であった．重回帰分析を行ったところ，DM-HT群のE’に対する独立規定因子は，年齢と心筋重量であった．これらの結果から，II型糖尿病は弛緩機能が有意に障害されることが示されたが，高血圧と糖尿病を合併している場合，年齢に関係なく弛緩機能が低下することが認められた．収縮機能や他の拡張機能指標の低下が認められてなくても，弛緩機能が低下することは糖尿病性心筋症になる可能性が高いことが考えられる．

Various factors such as age, hypertension, diabetes mellitus (DM) are possible cause of diastolic heart failure (HF). Hypertension appears to consist of impaired active relaxation remains of passive compliance. The presence of a diabetic cardiomyopathy is findings the association of diabetes with LV dysfunction independent of hypertension, coronary artery disease, and other heart disease. First of all, diabetic cardiomyopathy appears to consist of only diastolic dysfunction with normal systolic function. Echocardiographic examination can measure to detect any abnormalities in LV diastolic dysfunction before its clinical appearance. The purpose of this study was to investigate the impact of diastolic dysfunction in the diabetic patients without ischemic heart disease, including hypertension.We studied 213 patients with type II DM, and divided into two groups. The subjects were selected 96 DM patients (DM group; HbA1c 10.2±2.5, LVEF 67±7%, age 20-83) and 117 subjects were diabetic patients with hypertension (DM-HT group; HbA1c 9.4±2.0, LVEF 68±8%, age 22-84). Sixty-eight normal cases were also enrolled as control subjects (control group; LVEF 66±5%, age range 18-79). We classified the subjects according to age in quarters (stage1; 18-45yr, stage2; 46-59, stage3; 60-69, stage 4; 70-84) in each group. The noninvasive assessment of diastolic dysfunction mainly depended on Doppler studies.Neither DM group nor DM-HT group had significant difference with control group regarding LV ejection fraction (EF) and LV mass index. The ratio of early (E) and late (A) diastolic transmitral flow velocity (E/A) was decreased with age in all groups (P < 0.01). E/A in DM group and DM-HT group were significantly lower than control group in every stage of age (P < 0.05). E’, as the index of LV relaxation, was decreased with age (P< 0.01), and it was significantly higher in control group than that of other groups in every stage of age (P <0.05). The index of LV filling pressure such as E/E’ in DM and DM-HT group was not significantly different between stage 1 and other stages. In multiple linear regression analysis, LV mass index and age were selected as independent determinants of E’ in DM-HT group (P < 0.05).We concluded that type II DM is associated with predominant LV diastolic dysfunction. Impaired relaxation was induced by increased LV mass in diabetic patients with hypertension. Diabetic patients had impaired relaxation independent of age.