Men with chronic heart failure (HF) who have low levels of estrogen are four times more likely to die than men with normal levels of the hormone, a Polish study has found.
But, conversely, having high levels of estrogen also appears to pose an increase risk of death.
For the study, researchers examined the relationship between concentrations of estrogen, in the form of estradiol, in the blood and the rate of death in men with chronic heart failure and reduced left ventricular ejection fraction.
A total of 508 men, with an average age of 58, were recruited for the study between 2002 and 2006.
Venous blood samples were taken from all the men before they were divided into five groups, based on the levels of estradiol in their blood.
Hospital records were examined to identify how many of the patients died over the three-year follow-up period. Overall, a total of 171 men died during the study.
When the researchers focused on estradiol, they found that men with the lowest levels, on average 8.6 pg/ml, were four times more likely to die than men with normal levels, 26.8 pg/ml.
Those with the highest estradiol levels, 44.5 pg/ml, were twice as likely to die as men with normal levels.
The research team, led by Dr Ewa Jankowska, from the centre for heart disease at the Military Hospital in Wroclaw, concluded that low and high concentrations of circulating estradiol 'are significant predictors of a poor prognosis'.
However, the researchers are unsure whether estradiol concentrations are related to critical body changes in the progression of heart failure or are merely markers of that progression.
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