Healthy lifestyle linked to lower risk of sudden cardiac death in women

Women who don’t smoke, have a body mass index (BMI) lower than 25, exercise at least 30 minutes a day, and adhere to a Mediterranean-style diet have a significantly lower risk of sudden cardiac death (SCD), a new study published in JAMA (2011;306[1]:62-69) finds.

The prospective cohort study followed 81,722 women in the Nurses’ Cohort Study from 1984 to 2010, assessing lifestyle variables by questionnaire every 2 to 4 years. The researchers defined a low-risk lifestyle as maintaining a BMI below 25, exercising 30 minutes or more a day, not smoking, and having a Mediterranean diet score in the top 40% of the cohort (ie, high intake of fruits, vegetables, nuts, whole grains, and fish and moderate alcohol consumption).

During the 26-year follow-up period, 321 women suffered SCD (death within 1 hour of symptom onset without evidence of circulatory collapse) at a mean age of 72 years. The study found an independent and inverse association between all 4 low-risk lifestyle variables and a lower risk of SCD. Compared with women who had no low-risk factors, women with 1 low-risk factor had a multivariable relative risk of 0.54; women with 2 factors, 0.41; women with 3 factors, 0.33; and women with 4 factors, 0.08.

Women at low risk for all 4 lifestyle factors had a 92% lower risk of SCD than women at low risk for none of the factors, the authors observe. “If these associations are causal, 81% of SCD within this cohort may have been prevented if all women adhered to a low-risk lifestyle,” they write. The study didn’t assess how long women adhered to the healthy lifestyle factors, nor did it prove a causal connection between lifestyle and lower risk of SCD.