Again and again, this is why people should actually read the references and not get caught up in “medicine 3.0” hype over listening to “sciency” blogs. I’ll pick it apart this time, but the broader theme here is it’s easy to hold illusory confidence for anyone (including physicians btw) that they “know something” and makes them feel they are special because they know something beyond what the scientific/medical community knows.
CGMs aren’t proven to be useful in nondiabetics - there is negligible evidence. I am quite familiar with the literature Attia has cited and have deeply considered it. None of the cutoffs Attia uses is supported by any evidence he cited - it appears to be arbitrary.
If you read his assertions in the article and pick apart the references - which almost nobody does - what he is claiming is clearly without evidence. The 2018 study he cites suggests that glycemic dysregulation is not fully captured by traditional metrics - but it does NOT suggest that the classification of excursions above 140 mg/dL provides more than traditional metrics - it might or it might not. Some people have highly variable individual glucose levels.
The study he cites does not confirm any evidence of glycemic variability readings with outcomes. Even if it did, there is no justification for using CGMs in patients broadly for more than 2 weeks as a short diagnostic. Glycemic variability may be only indicative of poor health rather than causal.
If you read his citation: Postprandial Hyperglycemia and Glycemic Variability | Diabetes Care | American Diabetes Association
“The biggest gap still is the missing evidence as derived from randomized prospective intervention studies targeting postprandial hyperglycemia and seeking to reduce hard CV end points. In fact, there has been some stark disappointment recently in this context. As this evidence by intervention is, however, key for the ultimate approval of a treatment concept that it is mandatory to care for postprandial hyperglycemia and glucose variability beyond achieving appropriate glycemic control as assessed by HbA1c, the current net balance of attained evidence is not favorable that we should care.”
If you read further in your cited blog post:
" Prospective studies show that higher glucose variability in nondiabetics is associated with an increased risk of cardiovascular disease, frailty, cardiovascular death, cancer death, and death from any cause compared to lower glucose variability."
Look at the actual citation for AD and it only says hyperinsulinemia.
Look at the citation for frality and it only says HOMA-IR.
And so on…
Nowhere does it say glucose variability or mention any cutoff of 140 mg/dL. None of them use CGMs. They use either OGTT or HOMA-IR.
There are a lot more flaws in the article. I’m not going to pick through all of them.
That being said, I do use a CGM for data gathering purposes (there is no proven use for this - the data might end up being mostly useless), but it is NOT for prevention because it’s NOT a cost-effective approach and there is no real evidence for wide use. I would not recommend one for non-diabetics if they are seeking preventatives until there is real evidence.
It is quite possible CGMs could provide biofeedback that could increase adherence to lifestyle interventions for nondiabetics, but that is not demonstrated in a randomized clinical trial. It’s far easier to go beyond the evidence to recruit patients to pay 6 figures a year - CGM is a big part of that - especially if you understand his background and track record of going far beyond the evidence on NuSI which he quietly withdrew from when it burned into the ground so far that he had to jump ship as soon as there was smoke.
He has been a huge proponent of LC diets, despite the lack of evidence, and despite the NuSI debactacle. So it’s not particularly surprising he is going after glucose variability, but he neglects mentioning common confounders - postprandial triglycerides as an independent risk factor for early atherosclerosis, which also affects downstream dementia risks. Even if he is right about glucose variability - it is quite plausible trading carbs for fat is just trading one issue for another. He does not even mention that once. He is making assertions without evidence, including completely arbitrary ones.
Let’s illustrate it in a simple hypothetical example: if one has a twin brother with almost identical metrics and lifestyle - then one trades eating blueberries for say sausage because sugar levels go slightly over 140 mg/dL - are you sure that glycemic variability matters (assuming it turns out to be later supported to some degree)? Eating more sausage (or processed meats in general) has suggestive evidence for early atherosclerosis and dementia, as well as cancer. Unprocessed red meats may also be the case, perhaps beyond a certain rough threshold of intake, but we are not certain. So would one still keep eating sausages instead of blueberries based on glycemic variability with evidence showing (1) the other twin is not getting diabetes/glucose intolerance with blueberries (2) the first twin brother is having early atherosclerosis with carotid ultrasound/CAC? Probably not. There are plenty of other variables not captured.
So again, I suggest you avoid “influencer” blogs and social media to sway against facts - it’s easy to get caught up - I originally thought maybe Sinclair’s resveratrol claims could have merit until I actually read through the citations and other papers very, very carefully - then I realized he is going way overboard as a business strategy with high certainty. Historically, proposed longevity interventions are fraught with hyperbole for so many decades, so we should be particularly wary of the need to be vigilant and meticulous. Attia has a few guests I admire such as Dr. Matt K and Dr. Miller who recognize hyperbole is detrimental to their reputation in their scientific career for their peers and the “aging” field that is already fraught with hyperbole in general. Again, Attia is not a reliable source and he has a track record of doing that with incentives to do so - leaping beyond the evidence significantly - although I suppose he learned a bit from his first excursion with NuSI to temper that to a lower amount. Attia’s voice is amplified by other mini “influencers” on social media, despite clearly a severe lack of evidence and you end up with groupthink. I hope you can see the real issues here and I suggest you actually dive deeper than blogs/podcasts/the like.
