Dong XinQi, Mendes de Leon Carlos, Artz Andrew, Tang YuXiao, Shah Raj, Evans Denis
Rush University Medical Center, 710 South Paulina Street, Chicago, IL 60612, USA.
J Gerontol A Biol Sci Med Sci. 2008 Aug;63(8):873-8. doi: 10.1093/gerona/63.8.873.
Anemia is associated with increased mortality risk. The impact of mildly low hemoglobin concentration (Hb) on risk for mortality remains unclear, especially among blacks. We examined the racial differences between Hb and mortality.
This was a population-based study conducted from 1993 through 2006, in a geographically defined community of Chicago, Illinois. A stratified, random sample of 1806 participants 65 years old or older and 50% black, who were participating in the Chicago Health Aging Project and underwent clinical evaluation. Mortality was ascertained using the National Death Index. Cox proportional hazard models were used to assess the independent relation of Hb to mortality risk.
The proportion of participants with anemia by World Health Organization (WHO) criteria (Hb < 13.0 g/dL for men and < 12.0 g/dL for women) was 39% among blacks, and 17% among whites. Blacks had lower mean Hb (12.6 +/- 1.5 g/dL) than did whites (13.5 +/- 1.5 g/dL). In multivariable analysis, anemia was associated with increased mortality risk in blacks (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.43-2.53) and in whites (HR, 1.85; 95% CI, 1.32-2.59). Among blacks, Hb 0-0.9 g/dL below the anemia threshold is associated with increased mortality risk compared to Hb 0-0.9 g/dL above the anemia cutoff (HR, 1.84; 95% CI, 1.21-2.79), Hb 1.1-2.0 g/dL above the anemia cutoff (HR, 1.35; 95% CI, 0.88-2.05) and Hb 2.1-3.0 g/dL above the anemia cutoff (HR, 2.24; 95% CI, 1.12-4.47). The terms for interaction between black ethnicity/race and anemia suggested that blacks did not have a statistically significant difference in mortality risk compared to whites. Subgroup analyses of interaction terms suggested that Hb 0.1-1.0 g/dL above anemia cutoff group, blacks may have lower mortality risk compared to whites in the mildly low normal ranges of Hb (p =.02).
Both anemia by WHO criteria and mild reductions in Hb were related to increased risk of mortality in older blacks and whites.
贫血与死亡风险增加相关。轻度低血红蛋白浓度（Hb）对死亡风险的影响仍不明确，尤其是在黑人中。我们研究了Hb与死亡率之间的种族差异。
这是一项基于人群的研究，于1993年至2006年在伊利诺伊州芝加哥一个地理区域界定的社区进行。从参与芝加哥健康老龄化项目并接受临床评估的1806名65岁及以上且50%为黑人的参与者中进行分层随机抽样。使用国家死亡指数确定死亡率。采用Cox比例风险模型评估Hb与死亡风险的独立关系。
根据世界卫生组织（WHO）标准（男性Hb<13.0 g/dL，女性Hb<12.0 g/dL），黑人中贫血参与者的比例为39%，白人中为17%。黑人的平均Hb（12.6±1.5 g/dL）低于白人（13.5±1.5 g/dL）。在多变量分析中，贫血与黑人（风险比[HR]，1.90；95%置信区间[CI]，1.43 - 2.53）和白人（HR，1.85；95%CI，1.32 - 2.59）的死亡风险增加相关。在黑人中，与高于贫血临界值0 - 0.9 g/dL的Hb相比，低于贫血临界值0 - 0.9 g/dL的Hb与死亡风险增加相关（HR，1.84；95%CI，1.21 - 2.79），高于贫血临界值1.1 - 2.0 g/dL的Hb（HR，1.35；95%CI，0.88 - 2.05）以及高于贫血临界值2.1 - 3.0 g/dL的Hb（HR，2.24；95%CI，1.12 - 4.47）。黑人种族/民族与贫血之间的交互项表明，与白人相比，黑人在死亡风险方面没有统计学上的显著差异。交互项的亚组分析表明，在高于贫血临界值0.1 - 1.0 g/dL组中，在轻度低正常范围的Hb水平下，黑人的死亡风险可能低于白人（p = 0.02）。
根据WHO标准的贫血以及Hb的轻度降低均与老年黑人和白人的死亡风险增加相关。
