Hypertension is a major global public health concern and continues to be the leading cause of premature cardiovascular morbidity and death. In the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline update for hypertension, the threshold for defining hypertension was lowered, meaning many more people meet the threshold which now defines hypertension. “Patients with diabetes have high cardiovascular risk and frequently have hypertension,” says Matthew J. Singleton, MD, MBE, MHS, MSc. “Understanding how we can keep patients with diabetes as healthy as possible and decrease their risk of hypertension is especially important to reducing the morbidity and mortality associated with diabetes.”

Although the link between heavy alcohol consumption and hypertension has been well established, recent studies have suggested that light and moderate alcohol consumption may improve cardiovascular outcomes in patients with heart disease. However, research is lacking on the effects of alcohol as a risk factor for hypertension in patients with type 2 diabetes. Given the disease burden of both hypertension and type 2 diabetes, it is important to better understand if relatively simple but meaningful interventions, such as moderating alcohol consumption, can be of benefit to patients.

Addressing an Unmet Need

Dr. Singleton and colleagues had a study published in the Journal of the American Heart Association that sought to describe the association of alcohol consumption with prevalent hypertension in participants in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial. “Our goal was to explore the relationship between various levels of alcohol consumption and the risk of hypertension in patients with diabetes,” Dr. Singleton says.

For the analysis, alcohol consumption was defined as none, light drinking (1 to 7 drinks per week), moderate drinking (8 to 14 drinks per week), and heavy drinking (15 or more drinks per week). Blood pressure was categorized using the 2017 ACC/AHA guidelines as normal, elevated blood pressure, stage 1 hypertension, and stage 2 hypertension. In total, the investigators analyzed data on 10,200 participants.

Results from the study demonstrated that light alcohol consumption was not associated with elevated blood pressure (Table) or any stage hypertension. Conversely, moderate and heavy alcohol consumption were associated with elevated blood pressure, stage 1, and stage 2 hypertension. “In addition to the known relationship between heavy alcohol consumption and hypertension, our study indicated that even moderate alcohol consumption was associated with increased odds of hypertension in patients with diabetes and elevated cardiovascular risk,” Dr. Singleton says.

Examining the Implications

Although numerous studies in recent years have suggested that light and moderate alcohol consumption may have beneficial effects on cardiovascular health, the study by Dr. Singleton and colleagues supports that consumption of more than 7 drinks per week may be associated with elevated blood pressure and stage 1 and stage 2 hypertension in those with type 2 diabetes, especially those with elevated cardiovascular risk. “In light of our findings, discussions with patients about how their alcohol consumption interacts with their blood pressure are important, even in those who are only moderate drinkers,” says Dr. Singleton.

The study team noted that since the mechanisms behind the potential cardioprotective effects of alcohol are complex, caution should be used when broaching the subject with patients. Miscalculating the benefits of alcohol consumption on cardiovascular disease may inhibit the use of low risk interventions—such as alcohol cessation counseling—for this easily modifiable risk factor. It is possible that simple lifestyle modifications to temper alcohol consumption may lead to health benefits by decreasing rates of hypertension, which in turn could have a positive impact on the substantial morbidity and mortality associated with diabetes.

While the study adds to a growing body of literature questioning the previously reported beneficial effects of alcohol on hypertension and cardiovascular health in patients with type 2 diabetes, Dr. Singleton says more research into these associations would be valuable. “Further research is needed to establish the cause-and-effect relationship between alcohol consumption and hypertension,” he says. “A clinical trial comparing blood pressure levels between patients with type 2 diabetes who are advised to decrease their alcohol consumption and those who are not advised to lower their consumption would be helpful.”