The relationship between diabetes and high blood pressure is, no doubt, an important but complicated one. On the one hand, high blood pressure, insulin resistance, obesity, and abnormalities in blood cholesterol and triglyceride levels commonly coexist, a condition called metabolic syndrome. And as we noted in a post last fall here at Diabetes Flashpoints, nighttime blood pressure levels may have a dramatic impact on a person’s risk of developing Type 2 diabetes.
But on the other hand, according to a recent study, people with diabetes may be worse off when they take medications to lower (or further lower, if they already take another blood pressure medication) moderately high blood pressure.
The study, published late last month by The BMJ (formerly British Medical Journal), looked at 49 different, previously conducted trials of blood pressure treatments in people with diabetes, involving a total of almost 74,000 participants (most of whom had Type 2 diabetes). Specifically, the researchers wanted to look at the effect of starting a blood pressure medication — regardless of whether it’s the only medication someone is taking, or a drug being added to a previous treatment — at different levels of high blood pressure.
According to an article on the study at MedPage Today, the researchers found that in participants whose systolic (the top number) blood pressure was lower than 140 mm Hg before starting on their blood pressure medication, treatment increased the risk of death from cardiovascular causes by an average of 15%. The risk of death from all causes was also slightly higher in this group, but this difference was not statistically significant.
In participants whose systolic blood pressure was between 140 and 150 when they began treatment, there was a small, statistically insignificant drop in the risk of death from cardiovascular causes, as well as a 13% drop in the risk of death from all causes. There was also a 16% drop in the risk of heart attack and a 20% drop in the risk of developing heart failure.
In participants whose systolic blood pressure was above 150 at the start of their treatment, the risk of death from all causes dropped by 11%, while the risk of death from cardiovascular causes dropped by 25%. They also experienced lower risks of heart attack (by 26%), stroke (23%), and advanced kidney disease (18%).
Based on this study, the benefits of taking blood-pressure-lowering drugs are clear when a person’s systolic blood pressure is above 140, with the benefits even stronger if the number is above 150. But for people whose blood pressure was below 140, trying to lower blood pressure any further by taking a drug led only to worse outcomes. Despite this result, a leading doctor quoted in the MedPage Today article — who wasn’t involved with the study — was dismissive of its findings and said that most doctors still believed that lower blood pressure is better. He noted that treatment guidelines are unlikely to change as a result of this study or others like it.
What’s your reaction to this study — are you worried that your treatment for high blood pressure might be too aggressive? If your blood pressure is elevated but below 140 systolic, have you or your doctor considered adding a drug treatment to lower it? Do you think doctors should give greater weight to the possible risks of taking blood-pressure-lowering drugs, in addition to their benefits? Or does the high rate and potential complications of high blood pressure mean that doctors should be even more aggressive? Leave a comment below!