Background
The prognostic importance of hemoglobin is controversial. We investigated the prognostic importance of baseline and in-treatment hemoglobin in the LIFE study.
Methods
Eight thousand one hundred ninety-four LIFE patients with hypertension and left ventricular hypertrophy with available baseline hemoglobin measurements were randomized to losartan- or atenolol-based treatment and followed for 4.8 years for end points of all-cause mortality and composite of cardiovascular death, nonfatal stroke, or nonfatal myocardial infarction.
Results
U-shaped relations were observed between deciles of baseline hemoglobin and all-cause mortality and the composite end point. In univariate Cox models, baseline hemoglobin in the lowest gender-specific decile (women/men: <12.5/13.4 g/dL) was associated with all-cause mortality (hazard ratio [HR] 2.01, 95 % CI 1.64-2.64) and the composite end point (HR 1.53, 95 % CI 1.27-1.85, both P < .001), whereas hemoglobin in the highest gender-specific decile (women/men: ≥15.0/16.2 g/dL) was not. The decrease in hemoglobin was higher (P < .001) in patients allocated to losartan- (14.3-13.8 g/dL) versus atenolol-based treatment (14.3-14.0 g/dL). In Cox models with the same gender-specific definitions for high and low hemoglobin as time-varying covariates with adjustment for treatment allocation and established risk factors and diseases, hemoglobin in the lowest decile was associated with higher rates of all-cause mortality (HR 3.03, 95 % CI 1.89-4.85, P < .001) and the composite end point (HR 1.36, 95 % CI 1.08-1.71, P < .01), whereas hemoglobin in the highest decile was not.
Conclusions
After adjusting for other risk factors, relatively low, but not high, hemoglobin during antihypertensive treatment was associated with higher incidence of all-cause mortality and the composite end point.
