Early menopause, smoking increase risk of heart failure

A new study by Swedish researchers has found that women who experience an early menopause are at increased risk for heart failure. In addition, smoking increases that risk. The study was published online on May 12 in the journal Menopause.

The investigators conducted a study to determine whether younger age at natural menopause carries a risk of heart failure. They also evaluated whether smoking modified that risk. They used data from the Swedish Mammography Cohort, which comprised 22,256 postmenopausal women. Age of natural menopause was noted and the women were followed from 1997 through 2011. The women’s first episode of heart failure was determined through the Swedish National Patient Register and the Cause of Death Register. The data was subjected to statistical analysis to determine the risk of heart failure.

The investigators found that during an average follow-up of 13 years, 2,532 first events of heart failure hospitalizations and deaths occurred. The average age at menopause was 51 years. Early natural menopause (40-45 years), compared to menopause at ages 50 to 54 years, was significantly associated with heart failure (1.40-fold increased risk). When the data was analyzed in regard to smoking status, a similar increased risk was found among women who did not experience an early menopause and smoked. In addition, women who smoked were more likely to experience an early menopause. The investigators found a significant interaction between age at natural menopause and smoking.

The authors concluded that their study found that women who experience an early natural menopause are at increased risk for developing heart failure. In addition, smoking can modify the association by increasing the risk even among women who enter menopause from ages 46 to 49 years.

This study is in agreement with a study published September 18, 2011 in the journal Menopause. Study author Dr. Volodymyr Dvornyk, from the University of Hong Kong, noted that women “should be aware of this effect and possible health consequences” of smoking, in addition to its other known risks. He and his research team conducted a meta-analysis, which pooled data from six studies of approximately 6,000 women in the U.S., Poland, Turkey, and Iran. It revealed that women who smoke may enter menopause about a year earlier than nonsmokers. On average, non-smokers reached the menopause between age 46 and 51, depending on the study population. In all but two of the studies, smokers were younger: between age 43 and 50. The researchers also reviewed five other studies that used a cut-off age of 50 or 51 to stratify women into “early” and “late” menopause groups. Among the more than 43,000 women in that analysis, smokers were 43% more likely than nonsmokers to have early menopause. They wrote, “Our results give further evidence that smoking is significantly associated with earlier [age at menopause] and provide yet another justification for women to avoid this habit.”

One in five women in Los Angeles smoke, according to the Los Angeles County Department of Public Health. These women are at significantly increased for cardiovascular disease, chronic obstructive pulmonary disease (COPD), lung cancer, and other cancers.