糖尿病を合併する慢性心不全ではObesity Paradoxを認めない

今日はDMを合併する慢性心不全患者ではObesity Paradoxを認めないという論文を紹介します。

Chris Adamopoulos et al: Absence of obesity paradox in patients with chronic heart failure and diabetes mellitus: a propensity-matched study. Eur J Heart Fail (2010)
doi: 10.1093/eurjhf/hfq159 First published online: October 7, 2010

慢性心不全やCOPDでは、肥満患者ほど生命予後がよいObesity Paradoxを認めるという報告がされています。今回、糖尿病のあるCHF患者とないCHF患者でマッチングして、肥満群と非肥満群の予後を調べました。

その結果、DMのCHF患者では死亡率が肥満群38％、非肥満群39％、ハザード比0.99で有意差なしでした。一方、DMでないCHF患者では死亡率が肥満群23％、非肥満群27％、ハザード比0.77で統計学的有意差がありました。

以上より、糖尿病を有する慢性心不全患者ではDMコントロールの問題などで、Obesity Paradoxを認めない可能性があります。ただ、減量すれば生命予後がよくなるかどうかはわかりません。少なくとも糖尿病を有する慢性心不全患者の場合、体重増加を勧める必要はなさそうです。一方、DMのないCHF患者では体重増加を勧めたほうがよいかもしれません。

Abstract

Aims Obesity is paradoxically associated with survival benefit in patients with chronic heart failure (HF). However, obesity complicates the management of diabetes mellitus (DM), which is common in HF. Yet, little is known about the impact of obesity in HF patients with DM. Therefore, we examined the association between obesity and outcomes in propensity-matched cohorts of HF patient with and without DM.

Methods and results Of the 7788 participants with chronic mild to moderate HF in the Digitalis Investigation Group trial, 7379 were non-cachectic [body mass index (BMI) ≥20 kg/m2] at baseline. Of these, 2153 (29%) had DM, of whom 798 (37%) were obese (BMI ≥30 kg/m2). Of the 5226 patients without DM, 1162 (22%) were obese. Propensity scores for obesity were used to separately assemble 636 pairs of obese and non-obese patients with DM and 770 pairs of obese and non-obese patients without DM, who were balanced on 32 baseline characteristics. Among matched patients with DM, all-cause mortality occurred in 38 and 39% of obese and non-obese patients, respectively [hazard ratio (HR) when obesity was compared with no obesity 0.99; 95% confidence interval (CI) 0.80–1.22; P = 0.915]. Among matched patients without DM, all-cause mortality occurred in 23 and 27% obese and non-obese patients, respectively (HR associated with obesity 0.77; 95% CI 0.61–0.97; P = 0.025).

Conclusion In patients with chronic mild to moderate HF and DM, obesity confers no paradoxical survival benefit. Whether intentional weight loss may improve outcomes in these patients needs to be investigated in future prospective studies.