Excess Bodyweight and Our Hearts
A Retrospective, a Prospective
October is a funny month for me.
Like everyone, I enjoy the change of seasons, how Halloween is the first act of the three acts of the holidays: Halloween, Thanksgiving, and Christmas. (We can call New Years the opening credits of the story that’s next year.)
I enjoy the cooler weather, some of the fall sports, the seasonal treats that start appearing, and how the community feels like it’s kind of relaxing.
October, though, also seems to have tentpole life events for me.
Several friends and family members have birthdays this month.
At the other end, 15 years ago, one of my best friends departed in October. A couple of years ago, it was my wife’s grandmother. Last year, it was my brother-in-law.
So, when October comes, it’s A Tale of Two Cities—the best of times and the worst of times.
Each of these deaths was essentially due to the same cause—heart failure, not the chronic condition but the literal stopping—which is ultimately the cause of every death, but some deaths have issues that lead up to failure of the heart, but these deaths were caused by issues with the heart itself.
In my friend’s case, it was a congenital issue. He was 28, unmarried, no kids.
In my wife’s grandmother’s, it was aging. She was over 100, with a long line to survive her, even having known a few of her great-great-grandchildren.
Then, in my brother-in-law’s case, it was a lifetime of overweight that caused excess work and strain on his heart. He was 50, married, with three kids.
Dr. Peter Atia often talks about our last decade of life, what he calls the marginal decade, which is categorized by frailty, weakness, disability, disease, and cognitive decline. (Check out his book Outlive.)
Though my wife’s grandma had a long life, I’d argue she’d have had quite a robust marginal decade had she strengthened her heart through exercise, and I seriously doubt that my friend and brother-in-law knew they were in their marginal decade.
It’s easy to dismiss these cases of overweight leading to heart attacks—but in the US, almost 70% of adults are overweight or obese [1], and as one out of five kids are overweight or obese [2], they’re heading right for that bullseye, so it’s a problem that most of us are looking at.
Why is this the case though? Not these obesity stats—that’s multifactorial: social, cultural, environmental—but why is it that overweight places so much stress and strain on our hearts?
First is the issue of hypertension, the increase in blood pressure, which measures the pressure of the blood against the artery walls but really reflects how hard the heart must work to pump out a given volume of blood.
Imagine wearing a weighted vest, like police armor under your shirt. It literally adds load to the body, compressing it, even compressing the veins and arteries it sits on. This load sandwiches and narrows the blood vessels. It’s like any roadway that narrows. The traffic levels remain the same but now have to cram into fewer lanes. This is our baseline arterial situation with any level of overweight, and the pressure increases with each excess ounce we gain.
When we gain weight, we tend to notice it deposit disproportionately in certain places, typically the stomach area for the gents—the beer bellies and spare tires—and the hips and thighs (and later the back of the upper arms) for the ladies. That’s purely our genetics.
We also will store and accumulate excess weight in places that we can’t see, that we don’t even think of, including the spaces around our organs, further limiting the already-limited spaces for blood vessels, and we will even add excess weight to the inside of our throat and even our very tongue.
Sometimes, the muscles in our jaw and throat can relax when we sleep, narrowing the airways, but when they are basically oversized and overweight, this muscular relaxation becomes problematic. Like the excess weight narrowing and compressing our blood vessels, our airways narrow to the point that they sometimes become temporarily but completely occluded—that is, blocked—resulting in an inability to breathe. When this air blockage occurs while sleeping, it’s called obstructive sleep apnea.
You don’t need a serious clinical diagnosis before you experience sleep apnea. It ramps up in proportion with the amount of weight gained. These stoppages of breathing at night have insipid effects on us. Obviously, blood oxygen levels decrease while blood carbon dioxide levels increase. Again, that means our heart has to beat harder and faster to get the diminishing oxygen to the brain. In order to combat this, the brain in turn will send out pulses of adrenaline to wake us up, spiking blood pressure even more, so we can wake up and get some air in our lungs and head.
You may have experienced this outright or something similar. For me, when I’ve had upper respiratory infections or hard colds, the thing I hate most is that postnasal drip for the very reason that the nasal congestion drips back into the airway during sleep. I stop breathing for a moment, and I experience something similar to apnea, the adrenaline surge spiking my blood pressure and jolting my heart. It’s exhausting. And frustrating.
In addition to the reduced oxygen availability, the spikes in blood pressure, the increased workload of the heart, and the adrenaline pulses that wake us up, “The many [other] health consequences of OSA [obstructive sleep apnea] include daytime sleepiness, reduced quality of life, decreased learning skills, and importantly, neurocognitive impairments that include impaired episodic memory, executive function, attention and visuospatial cognitive functions” [3].
So far, excess weight has increased our hearts’ baseline work requirements through the added pressure and literal extra load of excess weight that compresses our blood vessels as well as the increased work the heart must crank out if we experience any level of apnea—which on its own has many other downstream negative consequences to healthy living.
Excess weight also has metabolic effects. As we are often in an energy surplus, we have more nutrients and energy floating around in our blood, which means that our fasting blood sugar and triglycerides are elevated. One of the problems here is that our blood becomes more viscous, thicker. It goes from something like apple juice to something like chocolate milk. The former is much easier to pump than the latter, again, making our hearts do more work just to deliver oxygen to our brain and tissues.
When we’re eating more food, we’re eating more of everything. Including sodium. There’s a pocket of rabid sodium proponents out there that say that we don’t have to worry about sodium intake; some even say we should lean into it.
However, the American Heart Association recommends keeping sodium intake between 1,500 to 2,300 mgs a day [4], and if you’re already hypertensive, you want to try and get under that low end of that recommendation. (The WHO recommends keeping it under 2,000 mgs [5].) One reason thought to explain sodium’s increase in blood pressure is that it increases blood volume by drawing water into the blood from the surrounding tissues.
Whatever the mechanisms:
“Available evidence suggests a direct relationship between sodium intake and blood pressure (BP) values. Excessive sodium consumption (defined by the World Health Organization as >5 g sodium per day) has been shown to produce a significant increase in BP and has been linked with onset of hypertension and its cardiovascular complications. Conversely, reduction in sodium intake not only decreases BP levels and hypertension incidence, but is also associated with a reduction in cardiovascular morbidity and mortality.” [6]
So, excess weight contributes to increased blood pressure and thereby more strain on the heart through several ways: compressive forces on the blood vessels, possible episodes of sleep apnea, more viscous blood, and increased blood volume through higher salt intake (which, to be fair, can also occur at any bodyweight).
On top of all this, let’s add inactivity and sedentariness into the mix. When we are inactive for prolonged periods, our muscles atrophy, a simple result of disuse. The atrophy isn’t limited to skeletal muscles. Exercise keeps our heart, lungs, and brains active, trained, and strong. If we’re inactive and letting our hearts get unconditioned to hard work while simultaneously asking it to do more baseline work on a constant basis, it’s like we’re asked to do more work with fewer resources at our jobs. It’s stressful. We’re inevitably going to fall behind. At some point, it’ll catch up to us; in the heart’s case, oxygen deprivation leads to death of the heart cells, infarction, and possibly death.
Now, imagine that we do this for years and years—the strain we put on our poor hearts, which are muscles, obviously, that can only handle so much work over a given period.
For the first quarter of this year, I did something of a hard bulk (intentional weight gain to support and maximize muscle growth). I gained about 20 lbs. overall in less than 4 months (which was way too much). At the top end of that bodyweight range, the mid-180s, I had a noticeable increase in effort with any cardio work. It’s kind of wild. It’s like my cardiopulmonary fitness had regressed.
In June, I started a bit of a cut and have shed about 15 lbs. of that excess weight, and even a few pounds in, my cardio fitness improved significantly and without doing anything differently in my training. At the end of the bulk, jogging a mile was getting tough. Now, two miles is easily doable.
One of the best things we can do for our hearts is maintain a healthy bodyweight, which will lighten the loads and compressive forces on the blood vessels and reduce the likelihood that we’ll experience sleep apnea. We’ll keep our blood more aqueous than viscous, making it easier to pump. Additionally, some low-hanging fruit is to keep an eye on sodium intake and do some regular exercise activity to keep all our muscles and systems tip top.
Taking care of ourselves is not just an ego-centric pursuit or a manifestation of vanity. It is a sure way to keep ourselves better, keep ourselves here for longer, and, really, is an extension of our love for those we care about.
We want to create more of the best of times, experience more of these great seasons, and stave off the worst of times.
As imperfect as we may sometimes feel, we often don’t realize how perfect we are to those that love us.
And we owe it to them to try our best to stick around.
