From the CEO: October 2025
CAC results, shifting focus to glucose health, and the fitness gadget I can't live without.
Four things on my mind this month
1. Coronary artery calcification (CAC) test
I recently got a coronary artery calcification (CAC) test. It measures calcium in your arteries, a signal that plaque has already built up and hardened. These hard plaques aren't the major risk for heart attack, but they form from soft plaques, which are the real risk. If you have hard plaque, you must have had or have soft plaque—indicating risk of heart attack is non-zero.
My CAC was 0—no calcium—which is good news! However, a recent paper points out that in younger people (I'm 36), high LDL levels still represent elevated risk even with CAC=0. Soft, dangerous plaques can still be present; CAC=0 just tells me none has been present long enough to harden or "calcify" yet.
For this reason, CAC should be used as a risk "floor"—your risk is probably no lower than your CAC score, but it can certainly be higher. It's an incredibly important screening tool with this lens, and everyone should get one starting in their 30s.
2. My next program: Glucose Health
I started Levels after using a CGM to discover I had Impaired Glucose Tolerance caused by lifestyle (and probably some predisposition). My insulin sensitivity is fairly good now, and my fasting insulin sits around 2.3 μIU/mL. However, between Feb and May of this year, my fasting glucose jumped from mid-90s mg/dL to 101 and has stayed there (over 100 is prediabetes range).
I'm not surprised: in March, my son arrived and I entered a new era of disrupted sleep, which I've been battling with more coffee throughout the day. I know from research that poor sleep directly affects cortisol, insulin, and glucose dynamics, as does caffeine, but sometimes something has to give. Now that I've hit my ApoB goal, I'm going to shift my attention to improving fasting glucose.
While I may not be able to do much about sleep, I'll use the in-app Glucose Health program to focus on exercise, protein intake, and timing and quality of carbohydrates—alongside cortisol management efforts like reduced caffeine hours and (hopefully) some sauna and breath work. Life and work are not giving me much quarter right now but I find the challenge motivating.
3. The fitness gadget I can't live without
I was sleeping poorly at 5,000ft elevation in Montana this past weekend and was reminded how much I love my Garmin smartwatch. This thing is truly an awesome product: it tracks my sleep, exercise (including maps and workout routines), and stress markers in a super functional form factor and with a battery that, three years in, still lasts 10+ days.
What I find myself referencing most: Overnight resting heart rate and heart rate variability—these metrics track the quality of my sleep incredibly well. Resting heart rate overnight is the single best correlate with how rested I feel in the morning. And Body Battery, a metric Garmin developed that I think is brilliant. It's just what it sounds like—you're the battery, and this score aligns with your "recharge and depletion" cycles. It charges up during restful sleep and depletes from exertion through the day. Sleeping deeply and long enough to hit 100 on the Body Battery is a difficult challenge and requires a lot of healthy habits to come together. Over the course of 4 nights (Fri-Mon), I was fascinated to watch these markers as my recovery started to improve (despite HR and HRV remaining pretty off).
I think sleep/exercise wearables are massively underrated for their health benefits. The sensor quality is really great for the price these days and they can be powerful motivational/accountability tools.
4. Recommendations
Since I mentioned sleep struggles, I've been deep in resources on sleep apnea. This guide on PAP therapy has been incredibly helpful as I navigate my mild sleep apnea with an infant at home.
Follow me on X here. Other than Levels, I have no affiliation with any of the products mentioned or linked above—I'm just a satisfied customer.
—Josh
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