Hypertension and Diabetes: Understanding the Goals

Case

A 44-year-old Caucasian male with a 1-year history of type 2 diabetes mellitus (DM) comes to the clinic for follow-up. Recent laboratory findings include an A1c level of 6.9% (American Diabetes Association [ADA] goal, lower than 7%); all other laboratory results are within normal range. Current medications include metformin, 1000 mg twice daily, and atorvastatin, 80 mg/d. Vitals today include a blood pressure of 146/84 mm Hg (average of 2 readings). Blood pressure at the most recent visit was 158/94 mm Hg (average of 2 readings). The patient states that he has been checking his blood pressure at home for the last month (average reading, 154/96 mm Hg) and wants to know his blood pressure goal.

Discussion

Hypertension is a common comorbidity of DM, and both DM and hypertension are considered major risk factors for the development of cardiovascular (CV) and microvascular complications. Patients with both DM and hypertension are at about twice the risk for CV disease and are at increased risk for DM complications, such as nephropathy.

Lowering blood pressure in patients with DM clearly has a benefit in reducing renal complications, CV events, and death.¹ Because hypertension occurs in the majority of patients with DM, lowering patients’ blood pressure is vital to their care and should remain a priority in the overall prevention and treatment of CV and microvascular complications.

Understanding the goals for the management of hypertension in patients with DM is an important first step. Although this may sound simple, the release of multiple guidelines in recent years has somewhat complicated the picture. The Eighth Joint National Committee (JNC 8) and the American Society of Hypertension (ASH) guidelines, both released late in 2013, agree on a goal blood pressure. However, a difference is noted with the European Society of Hypertension/European Society of Cardiology (ESH/ESC) guideline from 2013 and with the 2014 American Diabetes Association’s Standards of Care.^2-5 These blood pressure goals are summarized as follows:

• JNC 8: 140/90 mm Hg

• ASH: 140/90 mm Hg

• ESH/ESC: 140/85 mm Hg

• ADA: 140/80 mm Hg

Previous guidelines, such as JNC 7, identified a lower blood pressure goal of 130/80 mm Hg in patients with DM, supporting the “lower is better” notion in these patients with diagnoses of both DM and hypertension.⁶ In 2009, the ESH guidelines suggested that this goal was unsupported by prospective clinical trial data and adjusted the systolic goal to lower than 140 mm Hg.⁷ More recent guidelines have followed with further analysis of the data and further adjustments in blood pressure goals.^2-5

Current guidelines agree on the systolic blood pressure goal and recommend that the systolic blood pressure be managed to a goal of lower than 140 mm Hg.^2-5 As noted above, previous systolic blood pressure goals were lower than 130 mm Hg; however, it has been determined that evidence for these lower goals is limited.

The most notable trial used in considering systolic blood pressure goals is the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.⁸ This study examined the cardioprotective benefits of intensive blood pressure lowering (lower than 120 mm Hg SBP) as compared with standard therapy (SBP goal, 130 to 139 mm Hg) in high-risk patients with type 2 DM.

Although a small yet statistically significant benefit was seen with the secondary end point of stroke reduction in the intensive group, no difference was seen for the primary end point of nonfatal myocardial infarction, nonfatal stroke, and CVD death. Serious adverse events were significantly higher in the intensive group, and no changes were seen with regard to renal function or other microvascular complications, although albuminuria was reduced significantly.⁸

Because there was a lack of evidence of benefit of a lower systolic blood pressure goal, the guidelines consistently recommend a systolic blood pressure goal of lower than 140 mm Hg, although it is unclear whether a somewhat lower goal (lower than 135 mm Hg) may be more beneficial, especially in younger patients or those with renal disease, or whether intensive therapy should be a target for those at high risk for stroke.

The goal for diastolic blood pressure is less clear according to those guidelines referenced above; both ESH/ESC and the ADA recommend a lower diastolic blood pressure goal than JNC 8 and ASH.^2-5

The most frequently cited studies used in considering diastolic blood pressure goals in patients with DM are the Hypertension Optimal Treatment (HOT) and UK Prospective Diabetes Study (UKPDS) trials. The HOT trial targeted diastolic blood pressure goals of lower than 90 mm Hg, lower than 85 mm Hg, and lower than 80 mm Hg. Investigators found a benefit with more intensive therapy, specifically a diastolic blood pressure of lower than 85 mm Hg. The treatment effects were small and the event rates were low, probably because of the profound decrease in blood pressure in all patients from baseline and the very effective blood pressure control achieved with only 8.5% of patients having a diastolic blood pressure of higher than 90 mm Hg. JNC 8 specifically graded the evidence from this trial as low quality because the information in patients with DM came from a post hoc analysis of a small subgroup.⁹

The UKPDS study compared tight blood pressure control (lower than 150/85 mm Hg) to less tight blood pressure control (lower than 180/105 mm Hg) in patients with DM. The tight blood pressure control group achieved a mean blood pressure of 144/82 mm Hg, decreased from 159/94 mm Hg at baseline. The rates of stroke, heart failure, DM-related end points, and deaths related to DM were significantly lower in this group; however, because the diastolic blood pressure of lower than 85 mm Hg was compared with the goal of lower than 105 mm Hg and because the study targeted both systolic and diastolic blood pressure goals, JNC 8 did not conclude this to support the lower diastolic blood pressure goal.¹⁰

Regardless of the diastolic blood pressure goal chosen, evidence clearly shows that lowering blood pressure in patients with DM can decrease both CV and microvascular outcomes. Therefore, clinicians should place a priority on identifying patients with elevated blood pressure and treating these patients. They often require 2 or more antihypertensives to control their blood pressure, and clinicians should initiate treatment and frequently titrate medications.

The multidisciplinary team can assist with closely monitoring and adjusting therapy to achieve a goal of at least lower than 140/90 mm Hg while also educating patients and making sure they understand the need for and benefits obtained from adherence to life-long treatment. Once treatment has been initiated, the team can focus on identification of selected patients who may be more likely to benefit from a more intensive blood pressure goal, such as those with a long life expectancy, chronic kidney disease, and albuminuria as well as those at high-risk for stroke.

In the case above, a 1- or 2-drug regimen should be initiated and the patient should be monitored closely to titrate medications to the blood pressure goal. Because of this patient’s young age, he may be less susceptible to adverse effects associated with more intensive therapy and may benefit from a tighter blood pressure goal. However, the priority should be placed on initiating therapy, educating the patient, and treating to a blood pressure goal of at least lower than 140/90 mm Hg.

References:

1. Lopez-Jaramillo P, Lopez-Lopez J, Lopez-Lopez C, Rodriguez-Alvarez MI. The goal of blood pressure in the hypertensive patient with diabetes is defined: now the challenge is go from recommendations to practice. Diabetol Metab Syndr. 2014;6:31.

2. James PA, Oparil S, Cater BL, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: Report from the panel members appointed to the Eighth Joint National Committee (JNC 8). [Erratum in JAMA. 2014;311:1809.] JAMA. 2014;311:507-520.

3. Weber MA, Schiffrin EL, White WB, et al. Clinical practice guidelines for the management of hypertension in the community: A statement by the American Society of Hypertension and the International Society of Hypertension. J Hypertens. 2014;32:3-15.

4. Mancia G, Fagard R, Narkiewicz K, et al. 2013 ESH/ESC Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society ofHypertension (ESH) and of the European Society of Cardiology (ESC). J Hypertens. 31:1281-1357.

5. American Diabetes Association. Standards of medical care in diabetes-2014. Diabetes Care. 2014;37(Suppl 1):S14-S80.

6. 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.

7. Mancia G, Laurent S, Agabiti-Rosei E, et al. Reappraisal of European guidelines on hypertension management: a European Society of Hypertension Task Force document. J Hypertens. 2009;27:2121-2158.

8. Cushman WC, Evans GW, Byington RP, et al; the ACCORD Study Group. Effects of intensive blood-pressure control in type 2 diabetes mellitus. N Engl J Med. 2010;362:1575-1585.

9. Hansson L, Zanchetti A, Carruthers SG, et al; the HOT Study Group. Effects of intensive blood-pressure lowering and low-dose aspirin in patients with hypertension: principal results of the Hypertension Optimal Treatment (HOT) randomised trial. Lancet. 1998;351:1755-1762.

10. UK Prospective Diabetes Study Group. Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes: UKPDS 38. [Erratum in BMJ. 1999;318:29.] BMJ. 1998;317:703-713.