From Heartwire
Should You Start a Statin in a Newly Diagnosed Diabetic?
September 15, 2011 (Lisbon, Portugal) — Mounting evidence supporting a link between statins and new-onset diabetes should give clinicians pause for thought when initiating drug therapy in people with prediabetes or even a new diabetes diagnosis. That’s one of the messages to emerge from sessions here at the European Association for the Study of Diabetes (EASD) 2011 Meeting.
Dr Naveed Sattar
The risk/benefit balance is particularly important given the ongoing debate over whether diabetes itself is a cardiovascular disease (CVD) ”risk equivalent,” experts say.
”At the point of diagnosis, many physicians are considering diabetes as a CVD risk equivalent, which is part of the case for commencing statins, with the presumption that once a patient has moved to the threshold of diagnosis, that is the same as if they had already had a heart attack,” Dr Naveed Sattar (University of Glasgow, Scotland) told heartwire . ”But clearly a number of individuals who are at the threshold of a diabetes diagnosis are at very low vascular risk. And if we start a statin, we will gain little benefit and in fact, we may push that individual over and above the threshold for diabetes.”
The Mounting Data
Speaking in a Thursday morning session, Dr David Preiss (University of Glasgow) summarized the evidence linking statins and diabetes risk, citing the 25% increase seen in JUPITER, as well as the 12% increased risk seen for high-dose statins in a meta-analysis published earlier this summer. Also reported by heartwire , an earlier meta-analysis had also found a dose-dependent increase in risk in three trials of atorvastatin.
Dr David Preiss
Citing numbers from the June meta-analysis, on which he was a coauthor, Preiss pointed out that while 498 patients would have to be treated to get one case of diabetes, only 155 patients would need to be treated to prevent one major cardiovascular event–a risk/benefit balance that led the authors of the study to conclude that net benefit favored statin use.
But Preiss also noted that that CV-event rate was driven largely by coronary revascularizations; the number needed to treat to prevent one nonfatal MI was a number much closer to the number needed for new-onset diabetes, at 578.
”I’m not suggesting that new-onset diabetes is equivalent to MI, but it gives something for physicians to think about,” Preiss said.
Dr Kausik Ray
But Dr Kausik Ray (St George’s University of London, UK), another author on the meta-analysis who also spoke during today’s session, steered clear of saying that statins played a causal role in new-onset diabetes, instead focusing on the link with what he termed ”dysglycemia.”
In an interview with heartwire , Ray explained: ”I was trying to differentiate between dysglycemia and diabetes, because the two are definitely not the same thing. I think that what cardiologists should be doing is screening people over time and following up to see what kind of effects the statin has on glucose and what the consequences are of developing dysglycemia.”
Ray continued: ”The problem is, if someone develops dysglycemia on a statin, you don’t know if they would have developed it anyway, or true diabetes anyway, or whether the statin made them dysglycemic. You are never going to be able to tease that out.”
Parallels in the Blood-Pressure Field
There’s also the possibility that the blood-sugar increases being seen are not ”true diabetes,” said Ray.
In another talk summarizing the effects of different blood-pressure drugs on development of diabetes, Dr Neil Poulter (Imperial College London, UK) reviewed the now-well-accepted evidence that thiazide diuretics and beta-blockers adversely affect glucose metabolism and risk of new-onset diabetes, mediated by drug dose.
During his talk, Poulter showed data indicating that glucose levels that climbed in patients taking a thiazide diuretic dropped again when the drug was stopped, even after years of use.
That was ”intriguing,” Ray told heartwire . ”If you can normalize this [effect on blood glucose], even so much later on, then it would suggest that it is affecting something downstream, and it’s not ’diabetes’ in the same way. If you are just affecting glucose levels because you are affecting insulin levels downstream, that’s a different story.”
Ray, as he did when his meta-analysis was published, came down in favor of statin therapy, saying the benefits outweighed the risks. But he left open the possibility that long-term effects may shift perspectives. ”We don’t know the long-term consequences, and while I’ve talked about macrovascular disease, we don’t know about microvascular disease, and that’s why I think we probably need long-term follow-up registries for medications that we prescribe lifelong.”
Diabetes as a CVD Risk Equivalent?
Sattar believes that diabetes ”clearly is not a CVD risk equivalent,” at least within the first five years postdiagnosis, but many physicians still feel compelled to hedge their bets and start newly diagnosed patients on a statin.
And while that may be appropriate in older patients who are clearly at higher vascular risk, ”the push to earlier and earlier pharmacotherapy in diabetes patients is not necessarily a good idea. For someone who is 25, who has developed diabetes, who has a high [body-mass index] BMI, there may be other routes to go down first to try to offset their diabetes risk.”
Even in people with prediabetes, he continued, ”If we put people too quickly on statins, they may progress to diabetes and may in some individuals cause muscle ache, and that may counteract any lifestyle interventions. We can always revisit the statin question in two, three, or five years. We haven’t done our patients a disservice by not starting them on a statin.”
Is Diabetes a CVD Risk Equivalent or Not?
Researchers are still trying to tease out just what degree of CV risk diabetes conveys, and at what time point. Most data suggest that people with established diabetes face an increased risk of cardiovascular events that increases with diabetes duration, although what that risk is and when it kicks in are subject to debate.
Dr Silvia Canivell
Spanish researchers are tackling the question in a prospective cohort study of over 2500 patients with and without diabetes and with and without a previous cardiovascular event.
Presenting baseline data during an EASD poster session, Dr Silvia Canivell (Hospital Clinic, Barcelona, Spain) showed that in patients with both diabetes and previous cardiovascular disease, the death rate at one year was double that of patients with CVD and no diabetes (27.3% vs 14.4%, p=0.02). Moreover, cardiovascular death rates were very similar in patients with cardiovascular disease and no diabetes (14.4%) to what they were in patients with diabetes but no previous CVD (16.7% p=0.7). Of note, mean diabetes duration in the diabetic patients was seven years.
Speaking with heartwire , Canivell stressed that one-year data are not sufficient to answer the question of whether a diabetes diagnosis is equivalent to a CVD risk factor, but she and her colleagues will continue to track their cohort out to five years.
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Publicerad: |2011-09-22|