Multiple prior studies have shown that diabetics have a lower risk of heart attack and stroke if they take a statin, even those with no history of heart problems, said senior study author Dr. Salim Virani, a cardiologist at the Michael E. DeBakey VA Medical Center in Houston.
"That's not debatable at this point," said Virani, who is also an associate professor at Baylor College of Medicine. "They should all be on statins."
But analysis of data from 204 cardiology practices across the United States revealed that 38 percent of middle-aged diabetics have not been prescribed statins.
The American College of Cardiology, the American Heart Association and the American Diabetes Association have issued recommendations that anyone aged 40 and older with diabetes be prescribed statins.
Dr. Robert Eckel, past president of the American Heart Association, said the statin treatment gap uncovered by Virani and colleagues is "more dramatic than I expected."
"I perhaps thought 15 or 20 percent of patients with diabetes would not be on statin therapy," said Eckel, who is chair of atherosclerosis for the University of Colorado School of Medicine. "This is almost 40 percent. That's unacceptable."
Worse, there appears to be a great deal of randomness in who gets prescribed a statin, the study found.
The researchers discovered a 57 percent variation in statin prescribing practices, even after accounting for individual patient factors such as age, gender, race, high blood pressure, high cholesterol, tobacco use and insurance coverage.
In other words, if you take two identical patients receiving care at two different cardiology practices, one is 57 percent more likely to be prescribed statins than the other.
By comparison, an earlier analysis of statin use among similar patients within the VA health care system showed only 20 percent variation in prescriptions. Virani said that's likely because VA doctors have uniform protocols and shared electronic health records, which produces more consistent care compared to individual cardiology practices.
For this study, researchers analyzed records of 215,193 patients with diabetes but no overt heart disease who visited a cardiologist between May 2008 and October 2013. They were aged 40 to 75.
The researchers found that only about 62 percent of middle-aged diabetics were prescribed a statin.
Those prescribed statins were more likely to have risk factors that endangered their heart health, the study reports. Further, they also were more likely to receive non-statin cholesterol-lowering therapy (28 percent versus 13 percent for people not receiving a statin) and had lower mean LDL "bad" cholesterol readings (90 mg/dL versus 103 mg/dL).
There are some patients who aren't prescribed statins due to side effects like muscle aches and pains, Virani said. Anticipating this, the researchers removed 5,722 patients from their analysis who had documented statin intolerance in their medical records.
Undocumented statin intolerance might account for some of the patients who did not receive a statin in the final analysis, but not many or most, Virani said.
Statin side effects can be handled without taking a patient off the drug completely, Virani added.
"A lot of these patients can be switched over to a different statin, especially if a health-care provider can have a discussion about the benefits of taking it," he said.
Many of these patients likely don't get the statin prescription they need because their busy doctor is focused solely on the medical issue that brought the two together that day, Virani said.
"We have to take the time to close the loop and make sure we're not just treating them for the current problem, but also what we can do to reduce their risk of heart attack or stroke in the future," he said.
There's one bit of good news from this study, Eckel noted -- the percentage of diabetics on statins is growing gradually.
"The good news is the trend is increasing, but it's not as exponential as we'd like to see it," Eckel said. "It's a gradual upward slope, in terms of patients receiving statins."
The study, which was funded through an American Medical Association Foundation seed grant, was published online Sept. 12 in the Journal of the American College of Cardiology.
For more on statin use among diabetics, visit the American Diabetes Association.
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