For a study published in the Journal of the American Heart Association, researchers assessed the kind of effect anemia and levels of hemoglobin in the blood had on death risks for adults a year after suffering a stroke, examining data from more than 8,000 patients who were diagnosed with acute stroke upon admission in the hospital from 2003 to 2015 and with the average age of 77.
Based on their findings, the researchers saw that some 25 percent of the study participants had anemia at the time of their admission and that the condition was associated with higher risks of death up to a year following either a hemorrhagic stroke, where a blood vessel ruptures, or an ischemic stroke, where a blood vessel clots.
Low hemoglobin levels are usually the problem, but the researchers have discovered that high hemoglobin levels can also be troublesome, as they have also been associated with higher risks of death and poorer outcomes on the overall a month after the stroke.
According to Phyo Myint, senior author for the study, those who suffered hemorrhagic strokes have about a 1.5 higher chance of death, while ischemic stroke survivors are twice as likely to die if they have anemia compared with their counterparts with normal hemoglobin levels.
In addition to using data from the U.K. Regional Stroke Registry, the researchers also reviewed relevant studies, pooling together 20 earlier works to create a larger study that compiled data across countries. This bumped up the number of patients studied to 29,943, which allowed for results to be better quantified and generalized.
The researchers believe their work highlights the effects of hemoglobin levels on outcomes for stroke patients and the need to increase interventions and awareness in stroke patients who also have anemia.
"As the study has convincingly demonstrated, anemia does worsen the outcome of stroke, so it is very important that we identify at-risk patients and optimize the management [of their health]," said Raphae Barlas, a co-author of the study.
According to the National Center for Health Statistics, 9.6 percent of residents in assisted living and other residential care facilities have been diagnosed with anemia.
In addition to Myint and Barlas, Katie Honney, John Potter, Mamas Mamas, Yoon Loke, Anthony Metcalf, Stephen McCall, Kristian Bowles, Joao Bettencourt-Silva and Allan Clark also contributed to the study, which received funding support from the Norfolk and Norwich University Hospital (NNUH) Research and Development Department and the NNUH NHS Foundation Trust Stroke Services.