What Constitutes Normal Hemoglobin Concentrations in Community-Dwelling Older Adults?

To assess the relationship between hemoglobin concentration and cause-specific mortality.

Cohort study.

Data from the government-sponsored Annual Geriatric Health Examination Program.

Community-dwelling Taipei citizens aged 65 and older followed up between 2006 and 2010 (N = 77,532).

Mortality was determined by matching participants' medical records with national death files. Cox proportional hazards regression models were used to evaluate the relationship between hemoglobin concentration (World Health Organization (WHO)-defined anemia and 7 hemoglobin concentrations) and cause-specific mortality.

The mortality risk of WHO-defined anemia increased substantially in both sexes for all-cause and cancer mortalities (men, hazard ratio (HR) = 1.86, 95% confidence interval (CI) = 1.71-2.02 for all-cause mortality; HR = 1.94, 95% CI = 1.69-2.22 for cancer mortality; for women, HR = 1.63, 95% CI = 1.43-1.86 for all-cause mortality; HR = 1.74, 95% CI = 1.38-2.19 for cancer mortality). Men with hemoglobin concentrations of 15.0 to 15.9 g/dL and women with hemoglobin concentrations of 13.0 to 13.9 g/dL had the lowest risks of all-cause, cardiovascular, and cancer mortality. Risks of all-cause and cancer mortality increased significantly when hemoglobin concentrations were less than 14 g/dL in men and less than 12 g/dL in women. Even mild anemia (11.0-11.9 g/dL) was associated with greater mortality risk. Stratification according to age, body mass index, estimated glomerular filtration rate, and presence of comorbidities did not lead to any substantial changes.

Hemoglobin concentrations associated with optimal survival in older adults were identified and additional data provided regarding the relationship between hemoglobin concentrations and cause-specific mortality risks in older adults.