A few days ago, Kerri posed this question on Twitter:
— Kerri / Diabetes (@sixuntilme) March 4, 2015
I was struck by Jess’ response:
I was always under the impression that it could– stress increases hormones like cortisol and epinephrine, which raises blood glucose– so why would a licensed physician say no?
Well, perhaps he is devoted to evidence-based medicine, I thought, and the data are not strong enough to support that hypothesis.
So I enlisted the help of my friends– Dr. Google, MD and Dr. Google, PhD– to investigate what the experimental data say.
Like much of science, the evidence is….tricky!
Some studies indicate yes:
- An active stressor (e.g. a timed arithmetic test) led to a significant BG response in insulin-dependent subjects, but passive stressors (like watching a tense film clip) did not. (Gonder-Frederick et al.)
- One T1 girl prone to frequent and debilitating DKA experienced a rise in glucose and fatty chain acid levels after a stress interview. (The experiment was in regard to beta adrenergic blockade, which blocked these physiological responses after a subsequent stress interview.) (Baker, et al.)
- Rats with lab-induced diabetes showed a rise in BG when exposed to a cat, with different patterns of spike and drop between Type 1 and Type 2 diabetes. (Chang, et al.)
More studies seem to indicate nope:
- Subjects with normal BGs, with high BGs, and without diabetes all experienced increase in heart rate and blood pressure during stress, but no rise in blood glucose and other stress hormones. (Kemmer, et al.)
- Type 2 diabetics only experienced a BG rise after receiving norepinephrine injections, not while playing a stressful competitive computer game. (Bruce, et al.)
- Growth hormone increased in Type 1 subjects after a stress interview compared to normal subjects, but neither group experienced a significant increase in blood glucose. Interestingly, depressed diabetics had a cortisol spike compared to non-depressed diabetics. (Sachs et al.)
- Type 1 diabetics fitted with CGMs were found to have no glucose spikes after a stressful interview. They only had a delayed return to normal if a meal preceded the stress interview. (Wiesli, et al.)
- Adolescent T1’s did not show metabolic or hormonal changes after three stressful lab tasks. (Delamater, et al.)
The data showing hyperglycemia in physical stress (like stroke or heart attack) is more robust (McCowan, Malhotra, and Bisitrian). So, too, is the link between chronic stress and diabetes. High A1Cs are associated with both life hassles (Cox, et al.) and psychiatric illness. (Lustman, et al.)
But I’m just not convinced by the data regarding acute emotional stress and high blood sugars. One study involved rats. One involved two subjects. The only one that involved a decent sample concluded that “Subjects’ BG response to the active stressor was idiosyncratic,” even if it was statistically significant over time.
On the other hand….the relationships between blood glucose, stress hormones, and emotions are really complicated. Anxiety increases oxidative stress in mice, linked to cardiovascular disease and cancer (Bouayed, et al.) But in people without diabetes, epinephrine can increase blood glucose, which thereby may feed the brain and enhance memory of emotionally strong events (Blake, Varnhagen, and Parent). Oh, and watch out if you’re depressed, because you have a 37% higher risk of developing Type 2 diabetes than adults without depression. (Knol, et al.)
As the scientists conclude in one baller study that measured endocrine response while subjects went skydiving, “Even in a very homogenous group of subjects and under well-controlled conditions, endocrine responses to acute psychological stress show considerable variations.”
And that’s without diabetes in the picture!
Sometimes my blood sugar drops like this!
Medicine is a science. I can understand why Jess’ endo would take the evidence-based route and say that stress does not affect BGs. However….medicine is also art. What if this guy listened patiently? What if he took a moment to stop charting “pt is non-compliant, warned of complications of uncontrolled glucose” and took 2 minutes for open-ended questions?
How does stress affect your diabetes management? What can we do today to make it better?
Until more experiments can enter the annals of medicine, let’s see what happens when n=1.