Research has shown that most patients with type 2 diabetes also have comorbid hypertension, with the prevalence depending on other factors, such as cardiovascular disease (CVD), microvascular and macrovascular complications, age, obesity, and ethnicity. “Some studies have estimated that as many as 60% to 70% of people with diabetes also suffer from high blood pressure (BP),” says Carol H. Wysham, MD. “In type 2 diabetes, hypertension usually coexists with other cardiometabolic risk factors. The risk for macrovascular complications in patients with diabetes who have hypertension is doubled. Both hypertension and diabetes affect the same major target organs.”
According to the American Diabetes Association’s Standards of Medical Care in Diabetes-2011, lowering BP to less than 130/80 mm Hg is the primary goal in the management for most hypertensive patients with diabetes (Table 1). “This cut-off for a diagnosis of hypertension is lower in people with diabetes than in those without diabetes—for whom the recommended BP is 140/90 mm Hg— because of the clear synergistic risks of hypertension and diabetes,” says Dr. Wysham. Randomized clinical trials have demonstrated the benefits of lowering BP, including reductions in CVD events, stroke, and nephropathy.
Treatment Goals to Reduce Blood Pressure
Recent data from landmark clinical investigations have had mixed results with regard to using various BP thresholds for patients with diabetes. These studies indicate that systolic BP targets may vary for individual patients based on responses to therapy, medication tolerance, and individual characteristics. “It’s important for clinicians to keep in mind that most of these analyses have suggested that outcomes are worse if the systolic BP is greater than 140 mm Hg,” Dr. Wysham says. “Whereas, in the ACCORD trial, lowering systolic BP below 120 mm Hg did not lower risk for total cardiovascular events, the risk for stroke was significantly reduced. This suggests that patients with diabetes and hypertension should receive individualized treatment goals to optimize outcomes.”
Non-Pharmacologic & Pharmacologic Strategies
Lifestyle changes are important in the management of hypertension in people with diabetes (Table 2). These include reducing sodium intake, decreasing excess body weight, and increasing consumption of fruits, vegetables, and low-fat dairy products. Avoiding excessive alcohol consumption and increasing activity levels are other important non-pharmacologic strategies. These approaches may also positively affect glycemic control and improve cholesterol levels. “The key for clinicians is to start patients slowly on lifestyle modifications and to give concrete examples on what they can do to change their habits,” says Dr. Wysham. “It’s important to be prepared with handouts for patients and to explain to them why these modifications matter.”
An initial trial of non-pharmacologic therapy may be reasonable in people with diabetes who have mild hypertension (systolic BP 130-139 mm Hg or diastolic BP 80-89 mm Hg). If systolic BP is 140 mm Hg or higher and/or diastolic BP is 90 mm Hg or higher at the time of diagnosis, pharmacologic therapy should be initiated along with non-pharmacologic therapy. “Antihypertensive medications include a variety of drug classes, such as ACE inhibitors, ARBs, β-blockers, diuretics, and calcium channel blockers,” Dr. Wysham says. “These agents have been effective in reducing cardiovascular events, especially when used in combination with lifestyle interventions. Clinicians need to tailor treatment regimens to ensure that risk factors are addressed with selected therapies. Certain classes of drugs may be more beneficial for patients depending on their total cardiovascular risk, as well as their risk for subsequent microvascular complications.”
An important caveat, according to Dr. Wysham, is that most patients with hypertension require multi-drug therapy to reach treatment goals, especially patients with diabetes. “People with diabetes have lower BP targets, so it’s likely that they’ll require multiple drugs to reach their target BP goals.” If BP is refractory to optimal doses of at least three antihypertensive agents of different classifications (one of which should be a diuretic), clinicians should consider evaluating patients for secondary forms of hypertension or referring them to hypertension specialists.
Be Proactive When Managing Diabetes
When managing patients with diabetes, it is crucial to assess the entire cardiometabolic spectrum on an individual basis. This information will guide clinicians in selecting treatments to enhance outcomes, says Dr. Wysham. “Clinicians should look beyond glycemic control and assess BP, as well other CVD-related conditions, at each patient visit. We have made significant strides in our understanding of hypertension and in the development of treatments to lower BP, but the key is to ensure that patients receive these interventions appropriately and as early as possible. Being proactive about cardiovascular health will help patients with diabetes live longer, healthier lives.”
Readings & Resources (click to view)
American Diabetes Association. Standards of Medical Care in Diabetes—2011. Diabetes Care. 2011;34:S11-S61. Available at: http://care.diabetesjournals.org/content/34/Supplement_1/S11.full.
Chobanian AV, Bakris GL, Black HR, et al. National Heart, Lung, and Blood Institute Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, National High Blood Pressure Education Program Coordinating Committee. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003;289:2560-2572.
UKPDS: Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes: UKPDS 38. UK Prospective Diabetes Study Group. BMJ. 1998;317:703-713.
Adler AI, Stratton IM, Neil HA, et al. Association of systolic blood pressure with macrovascular and microvascular complications of type 2 diabetes (UKPDS 36): prospective observational study. BMJ. 2000;321:412-419.