More than 29 million Americans have diabetes, and each year another 1.7 million are given the diagnosis.1 Prediabetes is even more common; over one-third of US adults ages 20 years and older, and more than half of those who are ages 65 and older, have attained this precursor status, representing another 86 million Americans.1
Because the evidence base for the management of diabetes is rapidly expanding, the American Diabetes Association’s (ADA) Professional Practice Committee updates its Standards of Medical Care in Diabetes annually to incorporate new evidence into its recommendations. The 2017 Standards of Care are available at: professional.diabetes.org/jfp.2
Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality for people with diabetes, and is the largest contributor to the direct and indirect costs of the disease.2 As a result, all patients with diabetes should have cardiovascular (CV) risk factors, including dyslipidemia, hypertension, smoking, a family history of premature coronary disease, and the presence of albuminuria, assessed at least annually.2 Numerous studies have demonstrated the efficacy of controlling individual CV risk factors in preventing or slowing ASCVD in people with diabetes. Even larger benefits, including reduced ASCVD morbidity and mortality, can be achieved when multiple risk factors are addressed simultaneously.3
To hone your management of CV risks in patients with diabetes, we’ve put together this Q&A pointing out the elements of the ADA’s 2017 Standards of Care that are most relevant to the management of patients at risk for, or with established, ASCVD.
Since ASCVD so commonly co-occurs with diabetes, should I routinely screen asymptomatic patients with diabetes for heart disease?
No. The current evidence suggests that outcomes are NOT improved by screening people before they develop symptoms of ASCVD,4 and widespread ASCVD screening has not been shown to be cost-effective. Cardiac testing should be reserved for those with typical or atypical symptoms or those with an abnormal resting electrocardiogram (EKG).
What are the benefits of lifestyle interventions?
The benefits include not only lost pounds, but improved mobility, physical and sexual functioning, and health-related quality of life. Recommend that all overweight patients with diabetes take advantage of intensive lifestyle interventions focusing on weight loss through decreased caloric intake and increased physical activity as per the Look AHEAD (Action for Health in Diabetes) trial.5 Although the intensive lifestyle intervention in the Look AHEAD trial did not decrease CV outcomes over 10 years of follow-up, it did improve control of CV risk factors and led to people in the intervention group taking fewer glucose-, blood pressure (BP)-, and lipid-lowering medications than those in the standard care group.
There is no one diet that is recommended for all people with diabetes. Weight reduction often requires intensive intervention. In order for weight loss diets to be sustainable, they must include patient preferences.
People with diabetes should be encouraged to receive individualized medical nutrition therapy (MNT), preferably from a registered dietitian who is well versed in nutritional management for diabetes. Such MNT is associated with a 0.5% to 2% decrease in A1c levels for people with type 2 diabetes.6-9 Specific healthy diets include the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and plant-based diets.
A new lifestyle recommendation in this year’s ADA Standards is that periods of prolonged sitting should be interrupted every 30 minutes with a period of physical activity. This appears to have glycemic benefits.2
When should I initiate hypertension treatment in patients with diabetes?
Nonpharmacologic therapy is reasonable in people with diabetes and mildly elevated BP (>120/80 mm Hg). If systolic blood pressure (SBP) is confirmed to be >140 mm Hg and/or diastolic blood pressure (DBP) is confirmed to be >90 mm Hg, the ADA recommends initiating pharmacologic therapy along with nonpharmacologic strategies. For patients with confirmed office-based BP >160/100 mm Hg, the ADA advises initiating lifestyle modifications as well as 2 pharmacologic medications (or a single pill combination of agents).2
What is the recommended BP target for patients with diabetes and hypertension?
These patients should be treated with a combination of measures, including lifestyle modification and pharmacologic therapy, to a target BP of <140/90 mm Hg. Randomized controlled trials (RCTs) have shown benefits with this target in terms of a reduction in the incidence of coronary heart disease (CHD) events, stroke, and diabetic kidney disease.10,11
A 2012 meta-analysis of randomized trials involving adults with type 2 diabetes mellitus (T2DM) and comparing intensive BP targets (≤130 mm Hg SBP and ≤80 mm Hg DBP) with standard targets (≤140-160 mm Hg SBP and ≤85-100 mm Hg DBP) found no significant reduction in mortality or nonfatal MIs associated with more intense BP control. There was a statistically significant 35% relative risk (RR) reduction in stroke with intensive targets, but lower BP was also associated with an increased risk of hypotension and syncope.12
The 2010 Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial,13 which randomized 5518 patients with T2DM at high risk for ASCVD to either a target SBP of <120 mm Hg or 130 to 140 mm Hg, found that the patients with the lower SBP target did not benefit in the primary end point (a composite of nonfatal MI, nonfatal stroke, and CV death), but did benefit from nominally significant lower rates of total stroke and nonfatal stroke.
Based on these data, the ADA Standards of Care suggest that, “more intensive BP control may be reasonable in certain motivated, ACCORD-like patients (40-79 years of age with prior evidence of CVD or multiple CV risk factors) who have been educated about the added treatment burden, side effects, and costs of more intensive BP control and for patients who prefer to lower their risk of stroke beyond what can be achieved with usual care.”
Another major study, the 2015 Systolic Blood Pressure Intervention Trial (SPRINT) trial,14 demonstrated that treating patients with hypertension to a target SBP <120 mm Hg compared to the usual target of <140 mm Hg resulted in a 25% lower RR of the primary outcome (a composite of MI, other acute coronary syndromes, stroke, heart failure, or death from CV causes) and about a 25% reduction in all-cause mortality; however, people with diabetes were not included in the trial, so the applicability of the results to decisions about BP management in patients with diabetes is not known.
A 2015 systematic review and meta-analysis of over 100,000 participants looked at SBP lowering in adults with T2DM and found that each 10-mm Hg reduction in SBP was associated with a significantly lower risk of morbidity, CV events, CHD, stroke, albuminuria, and retinopathy.10 When trials were stratified by mean baseline SBP (<140 mm Hg or ≥140 mm Hg), RRs for outcomes other than stroke, retinopathy, and renal failure were lower in studies with greater baseline SBP.
The latest ADA Standards of Care recommend that a lower BP target of 130/80 mm Hg may be appropriate for patients at high risk of CVD if this target can be achieved without undue treatment burden. A DBP of <80 mm Hg may also be appropriate in certain patients including those with a long life expectancy, CKD, elevated urinary albumin excretion, and those with evidence of CVD or associated risk factors.15 Of note, treating older adults with diabetes to an SBP target of <130 mm Hg has not been shown to improve cardiovascular outcomes,16 and treating to a diastolic target of <70 mm Hg has been associated with a greater risk of mortality.17
What are the current recommended treatment options?
Treatment for hypertension in adults with diabetes without albuminuria should include any of the classes of medications demonstrated to reduce CV events in patients with diabetes, such as:
- angiotensin-converting enzyme (ACE) inhibitors,
- angiotensin receptor blockers (ARBs),
- thiazide-like diuretics, and
- dihydropyridine calcium channel blockers.