肥満心筋症に閉塞型睡眠時無呼吸を合併した1例

A Case of Extreme Obesity Complicated by Cardiomyopathy of Obesity and Obstructive Sleep Apnea

要旨

　高度肥満男性に発症した肥満心筋症，閉塞型睡眠時無呼吸症候群に対し，減量，薬物，nCPAP療法で良好な経過が得られた1例を経験した．患者は33歳，男性．身長174cm，体重157kg，BMI51.9kg/m²．安静時の呼吸苦を自覚，NYHAⅢ度の状態で当院を受診した．心エコー図所見は，LVDd89mm，LVDs80mm，%FS11.2%と全周性の壁運動低下および左室拡大を呈し，拡張型心筋症類似の病態に合致した．右心カテーテル検査では，肺動脈楔入圧の上昇と高心拍出量が特徴的であった．1日1,200kcalの食事療法下で，利尿薬，ACE阻害薬，ピモベンダンの投与，さらに，β-bloker療法を行った．一方，夜間のいびきがひどく，ポリソムノグラフィーを行ったところ，重度の閉塞型睡眠時無呼吸(apnea hypopnea index 63.4/hr)と判明，nCPAP療法を開始した．約5カ月の経過で，体重は120kg前後に減量し，心エコー図所見もLVDd73mm，LVDs58mm，%FS20.5%と改善を認めた．

Summary

　A 33-year-old obese man was admitted to our hospital because of dyspnea. He was 174cm in height and 157kg in weight. Body mass index was 51.9kg/m². He was diagnosed as having dilated cardiomyopathy, because echocardiography showed a diffusely hypokinetic and enlarged left ventricle(left ventricular end-diastolic diameter: LVDd 89mm, left ventricular end-systolic diameter: LVDs 80mm, and %fractional shortening: %FS 11.2%). With a 1,200-Calorie diet, he was administered diuretics and an angiotensin converting enzyme inhibitor. After two weeks of treatment, right heart catheterization demonstrated that pulmonary capillary wedge pressure was 31mmHg and cardiac outputwas 6.7l/min. These hemodynamic data were compatible with cardiomyopathy of obesity in that left ventricular filling pressure was elevated with maintenance of a high output state. Pimobendan was additionally administered, and β-blocker therapy was subsequently initiated. On the other hand, the patient was noticed to have snoring and apnea during sleep. The polysomnography disclosed that he suffered from obstructive sleep apnea. The apnea hypopnea index was 63.4/hour, the maximum duration of apnea was 57 seconds, and the minimum nocturnal oxygen saturation was 67%. He underwent continuous nasal positive airway pressure(nCPAP)therapy at a pressure of 9.6cmH2O. The polysomnography under nCPAP demonstrated improvement of the sleep parameters: the apnea hypopnea index decreased to 3.0/hour, the maximum duration of apnea decreased to 34 seconds, and the minimum nocturnal oxygen saturation increased to 87%. The patient was relieved of symptoms after 5 months' treatment with diet, medication and nCPAP. His body weight was maintained around 120kg, and echocardiography revealed improvement in cardiac function(LVDd 73mm, LVDs 58mm, and % FS 20.5%). Extreme obesity complicated by cardiomyopathy of obesityand obstructive sleepapneaisrarein Japan. β-blocker therapy along with diet and nCPAP was effective in this case.