A Medscape Medical News article began, “As part of a BMJ series on overdiagnosis, which looked at the risks and harms to patients of expanding disease definitions, Yudkin and Montori analyzed the concept of prediabetes.” The lead author of the essay was John S. Yudkin, emeritus professor of medicine, University College, London.
This is not the legendary John Ludkin, founding professor of the department of nutrition at Queen Elizabeth College, London, who advocated for a low-carb dietary and lobbied against sugar in the 60’s and 70s. That John Yudkin retired in 1971, published “Pure, White and Deadly” in 1972, and was promptly ostracized by academicians and ridiculed like Atkins in the U.S. He died in 1995. Neither is this John S. Yudkin a son of the famed MD; he’s probably a nephew.
The arguments in the BMJ piece read like the “con” side of an Oxford debate. The Medscape author concluded, “The existential question of whether prediabetes is a useful concept or should be abandoned is largely philosophical.” In this I agree, but the arguments presented by Yudkin and Montori do raise several issues that deserve consideration.
The first is that “prediabetes is a heterogeneous concept,” e.g., definitions “overlap” and from the start create confusion. The original concept of “intermediate hyperglycemia,” Medscape points out, was termed “impaired glucose tolerance” and was “based on the oral glucose tolerance test (OGTT).” While used today and still the “gold standard,” this procedure is time consuming and expensive. When I was tested back in the 80’s, it was as a hospital outpatient.
That procedure was supplanted in 1997 by simply drawing blood and sending it to a lab. This new “intermediate hyperglycemia” procedure was called “Impaired Fasting Glucose.” It was revised in 2003 when the diagnosis of diabetes was dropped from 140 to 126mg/dL and the new category of “prediabetes” created (100 to 125mg/dl).
“Only recently,” in 2010, Medscape continues, “a nameless intermediate category based on A1c was designated.” It is “nameless,” I suspect, to allow for the dust to settle. Since 2010 the medical profession, through disciplinary rivalries, has engaged in internecine battles on guidance to clinicians treating a likewise “heterogeneous” patient population. It allows clinicians to treat some elderly or intractable patients to an A1c of 8.0%. Prior to 1997 the ADA defined DM as an A1c ≥7.0% (est. Aver. Glucose: 154mg/dl), then in 2003 ≥6.5% (eAG: 140mg/dL), then, in 2010, an upstart group suggested a more aggressive standard: ≥6.0% (eAG:125mg/dL). The ADA, however, as well as the WHO/IDF, now still define T2DM as an A1c of ≥6.5% and A1c’s of 5.7% - 6.4% as “intermediate hyperglycemia” and thus “prediabetes.”
The second issue that should be recognized in “the case against considering elevated but sub-diagnostic levels of glycemia a disease unto itself that deserves intervention” is whether such a diagnosis “can provide benefit by precisely identifying those who will develop diabetes…” That was a key question examined by the authors, Medscape says, and the surprising answer, Yudkin and Montori say, regardless of how pre-diabetes is defined, is “no.” “Less than one half of all such people develop diabetes within 10 years.” I knew it was less than 100%, but “Less than half…” surprised me.
“Another important question is whether treatment for prediabetes can prevent diabetes onset,” Both Medscape and the BMJ say “yes,” the “diabetes risk among high-risk individuals can indeed be reduced, but “…only among a subset of the intervention groups.” This last sentence is critically important for my readers. YOU want to be a member of that subset that not only delays the onset of diabetes but REVERSES PREDIABETES. This exclusive club is a subset-of-the-subset exception, and you CAN be a member, really. BUT YOU HAVE TO CHANGE YOUR DIET. Stop eating the carbohydrate foods (sugars and starches) that raise your blood sugar. You have to recognize that your glucose metabolism is broken. If you’re “prediabetic,” YOU ARE INSULIN RESISTANT, ergo CARBOHYDRATE INTOLERANT.Afterword: The best part of this hyperbolic debate over the “risks and harms” of overtreatment were the “comments” in the BMJ. The first two were academic essays in themselves and, while good, got just one or two “likes.” The 9th down was from a practicing doctor who argued the “pro” prediabetes case. His short comment got 50 “likes” at last count (including mine). I hope the editors and readers of the BMJ take note. And besides, even if you never become diabetic, your heart disease and dementia risk are related to your glucose levels. Takeaway: Control your blood sugar!