The Gap in Male/Female Life Expectancy Keeps Growing

Can physiological and societal differences help explain the reasons?

My wife sometimes reminds me, when we get on the topic, that she has a feeling I will pass away before her. Thanks for the confidence, honey.

I get her point, though. Generally speaking, women outlive men. But the gap in terms of years continues to grow even as the US overall life expectancy drops much faster than comparable developed countries.

According to the Kaiser Family Foundation:

U.S. life expectancy at birth fell by 2.4 years between 2019 and 2021 — from 78.8 to 76.4. In comparable countries, the average life expectancy fell only 0.3 years — from 82.6 to 82.3. Meanwhile, U.S. healthcare spending per person remains the highest and was nearly double that of similarly large and wealthy nations in 2021.

But it is the gap between men and women that is interesting. A new JAMA research letter released yesterday confirms a worsening gap that is bigger than it has been in almost 20 years.

The life expectancy gap between sexes increased 0.23 years from 2010 to 2019 and 0.70 years from 2019 to 2021. So, a much larger jump has been seen in the last few years compared to the decade prior. From 2010–2019, the biggest contributor to the gap was from unintentional injuries.

From 2019–2021, COVID-19 took over as the main contributor to the gap. Unintentional injuries came in a close second, and the authors postulate that this is likely mostly from drug overdose deaths.

So, the data is essentially saying COVID had a disproportionately higher toll on men than women. The likelihood of this has to do with the overall reasons why men die at younger ages compared to women. COVID accelerated that decline, it seems.

Men experienced higher COVID-19 death rates for likely multifactorial reasons, including higher burden of comorbidities and differences in health behaviors and socioeconomic factors, such as labor force participation, incarceration, and homelessness.

This partially explains more COVID deaths in men, but there are many reasons postulated as to why there is a gap at all. I want to touch on three key factors that make a real difference in the growth of this gap between sexes.

1 — Men are inclined to risky behavior.

Dr. Perminder Sachdev, a professor of neuropsychiatry at the University of New South Wales, says, “Men are more likely to smoke, drink excessively and be overweight,”

Dr Sachdev says. “They are also less likely to seek medical help early, and, if diagnosed with a disease, they are more likely to be non-adherent to treatment.” On top of all that, he says, “Men are more likely to take life-threatening risks and to die in car accidents, brawls, or gun fights.”

This theory of risk-taking comes from biology and brain development. The brain's frontal lobe, which controls judgment and consideration of an action’s consequences, develops more slowly in boys and young men than in their female counterparts.

This is why accidents tend to be higher among men. This also may contribute to detrimental lifestyle decisions among young men, such as smoking or drinking to excess.

2 — Hormones play an important role.

Things like smoking and drinking contribute to the number one cause of death, heart disease. Women are semi-protected by estrogen, which seems to have a benefit in the development of early heart disease.

In the same way that estrogen is protective, testosterone has been shown to be a contributor to riskier decisions.

Taking anabolic steroids, which are structurally related to testosterone, has been associated with a number of high-risk health behaviors, including drug use, aggressive violence, and high-risk sexual behavior.

Social dominance and aggression, which can jeopardize interpersonal relationships and physical well-being, are also generally associated with testosterone in men. If this leads to social isolation, then we are already aware that it contributes to higher mortality rates.

However, things are never this simple. Other studies show that testosterone can help reduce the risk of coronary artery disease or decrease its effect on mortality when higher levels are present.

So, the answers are not entirely clear, but theories do exist. But another question to ask is why COVID-19 had such a larger impact on the life expectancies of men compared to women.

3 — The pandemic exposed gaps and inequality.

Given that the data that exists, backed by physiology, shows that men partake in riskier behaviors, it would make sense that they would have a higher mortality from COVID-19, especially early on in the pandemic. But the data is not so clear.

Early on in the pandemic, the gap was clearer. A study from March 1, 2020, and November 30, 2020, conducted in the US showed:

Compared to females, males with COVID-19 had a higher rate of in-hospital mortality (13.8% vs 10.2%), a higher rate of respiratory intubation (21.4% vs 14.6%), and a longer length of hospital stay (9.5 ± 12.5 days vs. 7.8 ± 9.8 days).

But another study showed that in some countries like India, the numbers were closer together. The study states, “These findings are surprising since global data have indicated that both biological factors (stronger immune responses) and behavioral risk factors (e.g., smoking and other lifestyle habits) place men at a greater risk for health complications and death as a consequence of COVID-19.”

It could be due to a younger overall population in India, which can skew the numbers. It may also have to do with poor surveillance. However, inequality between men and women cannot be dismissed.

Previous research from India indicates marked sex differences in access to health services, with women being less likely to be admitted to hospital than men. So, the women who were admitted were likely sicker, and therefore, the data would show increased in-hospital mortality.

This is hypothetical, as the data is hard to come by, but you can postulate that a similar pattern is likely in many places where women have fewer rights than men. COVID mortality rates are likely more similar between sexes. But on the flip side, data collection to prove the point is not a priority in these types of places.

Conclusions

I found the data in the new JAMA letter interesting because of the widening gap between sexes when it comes to mortality here in the US.

The decline in life expectancy itself is concerning enough, but when we have large gaps like this between any groups, it means there is something more to explore.

Hopefully, future studies will take into account the reasons for these gaps in order to make more robust conclusions. For now, we are heading in the wrong direction for both men and women when it comes to mortality in the United States.