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Testosterone, estradiol levels could help predict sudden cardiac arrest
Assessing sex hormone levels could help identify people who are at an increased risk for sudden cardiac arrest, according to research published in Heart Rhythm.
Lower testosterone levels were observed in men who experienced sudden cardiac arrest and higher levels of estradiol increased likelihood in both men and women, researchers at Cedars-Sinai Heart Institute discovered.
“Because [sudden cardiac arrest] is usually fatal, we are constantly looking for ways to predict which patients are susceptible so we can concentrate on prevention,” Sumeet Chugh, MD, said in a press release. “If we wait until someone has a [sudden cardiac arrest], it is usually too late for treatment.”
Kumar Narayanan, MD, along with Chugh and colleagues, looked at patients from the ongoing Oregon Sudden Unexpected Death Study. The team identified 149 patients (median age, 64.1 years; 73.2% male) who experienced sudden cardiac arrest and matched them with controls (median age, 64.2 years; 72.5% male).
Kumar Narayanan
The researchers evaluated testosterone and estradiol levels based on blood samples, drawn at the time of sudden cardiac arrest in cases of an event or during a routine medical visit.
Median testosterone levels were significantly lower in men (4.4 ng/mL vs. 5.4 ng/mL; P=.01) in cases of sudden cardiac arrest vs. controls. Median estradiol levels were increased in men (68 pg/mL vs. 52 pg/mL; P<.001) and women (54 pg/mL vs. 36 pg/mL; P<.001) who had sudden cardiac arrest.
Higher testosterone levels were associated with lower sudden cardiac arrest risk in men only (OR=0.75; 95% CI, 0.58-0.96), based on multivariate analysis. Higher estradiol levels were associated with increased risk for sudden cardiac arrest in men (OR=2; 95% CI, 1.5-2.6) and women (OR=3.5; 95% CI, 1.9-6.4). In men, higher testosterone-to-estrogen ratio was associated with a lower likelihood of sudden cardiac arrest (OR=0.5; 95% CI, 0.4-0.7).
“This is the first time it has been reported that there is an association between sex hormone levels and [sudden cardiac arrest],” Chugh said. “While these findings need to be confirmed by other studies, they suggest that higher testosterone levels in men may offer protection from sudden cardiac arrest and lower levels of estrogen may protect both men and women.”
Disclosure: The work was supported by grants from National Heart, Lung, and Blood Institute.