Can uncontrolled Diabetes Mellitus (DM) cause uncontrolled Hypertension (HTN)?

From the Guidelines

Yes, uncontrolled diabetes mellitus can contribute to uncontrolled hypertension. The relationship between these two conditions is complex and bidirectional. When diabetes is poorly managed, high blood glucose levels damage blood vessels, causing them to become stiff and less elastic. This arterial stiffening increases peripheral resistance, forcing the heart to work harder and raising blood pressure. Additionally, diabetes affects kidney function through diabetic nephropathy, impairing the kidneys' ability to regulate blood pressure. Insulin resistance, common in type 2 diabetes, activates the sympathetic nervous system and increases sodium retention, both of which elevate blood pressure. Diabetes also causes endothelial dysfunction, reducing nitric oxide production that normally helps blood vessels dilate.

Key Points to Consider

• Managing diabetes effectively through medications (such as metformin, SGLT2 inhibitors, or insulin), regular blood glucose monitoring, diet, exercise, and weight management can help improve blood pressure control.
• Treating hypertension in diabetic patients often requires multiple medications, with ACE inhibitors or ARBs typically preferred as first-line agents due to their renoprotective effects, as supported by recent guidelines 1.
• The goal for blood pressure management in patients with diabetes is to achieve a systolic blood pressure of less than 130 mmHg, as recommended by the 2019 ESC guidelines on diabetes, pre-diabetes, and cardiovascular diseases 1.
• Lifestyle modifications, including weight loss and physical activity, are central to the prevention and management of both diabetes and hypertension, as emphasized in the guideline-driven management of hypertension 1.

Evidence-Based Recommendations

The most recent and highest quality evidence supports the use of ACE inhibitors or ARBs as first-line agents for treating hypertension in diabetic patients, due to their renoprotective effects 1. Additionally, the evidence suggests that achieving a systolic blood pressure of less than 130 mmHg is a reasonable goal for patients with diabetes, as it can help reduce the risk of micro- and macrovascular complications 1.

Clinical Implications

In clinical practice, managing diabetes and hypertension requires a comprehensive approach that includes lifestyle modifications, regular monitoring, and pharmacological interventions. By prioritizing the management of diabetes and hypertension, healthcare providers can help reduce the risk of cardiovascular complications and improve patient outcomes, as supported by the evidence 1.

From the Research

Relationship Between Uncontrolled Diabetes Mellitus (DM) and Uncontrolled Hypertension (HTN)

• Uncontrolled DM is associated with high cardiovascular morbidity and mortality, and the coexistence of hypertension and DM multiplies the diabetic complications manifold 2.
• The combination of diabetes and hypertension provides additive increases in the risk of life-threatening cardiovascular events 3.
• High blood pressure substantially increases the risk of both macro and micro vascular complications in patients with diabetes, doubling the risk of all-cause mortality and stroke, tripling the risk of coronary heart disease, and significantly hastening the progression of diabetic nephropathy, retinopathy, and neuropathy 4.

Impact of Uncontrolled DM on Blood Pressure Control

• Earlier studies have shown that lowering blood glucose, blood pressure, or both decreases the diabetic complications 2.
• However, recent clinical outcomes trials have demonstrated that lowering glycosylated hemoglobin to <7.0% and BP to <130/80 mm Hg does not add any additional benefit to patients with DM and hypertension and may be detrimental to their health 2.
• The consensus of scientific opinion at present is that BP should be reduced to 130 to 139/70 to 80 mm Hg in patients with DM with increased cardiovascular risk 2.

Management of Hypertension in Patients with DM

• All classes of antihypertensive agents are effective in reducing blood pressure in diabetic subjects, and all show evidence of a concomitant reduction in cardiovascular risk 3.
• Antihypertensive drugs can also significantly influence the probability that otherwise healthy individuals will develop metabolic syndrome or type 2 diabetes 3.
• The method by which to control hypertension, whether pharmacological or non-pharmacological, is also a matter of debate and has been extensively studied in the literature 5.
• New medications have been introduced for the treatment of DM, some of which also affect BP, and the clinician treating hypertensive and diabetic patients should be familiar with these medications and their effect on BP 5.