3.3 Hypertension, Dyslipidemia & Peripheral Artery Disease

Hypertension, dyslipidemia, and peripheral artery disease (PAD) are closely linked through shared vascular pathophysiology and frequently coexist with coronary disease in the same patient.

Hypertension: Classification and Pathophysiology

The 2017 ACC/AHA guideline defines blood-pressure categories as follows:

Chronic hypertension develops through several interacting mechanisms: sustained increases in peripheral vascular resistance, overactivation of the renin-angiotensin-aldosterone system (RAAS) promoting sodium/water retention and vasoconstriction, endothelial dysfunction reducing nitric-oxide-mediated vasodilation, and progressive arterial stiffness from vascular remodeling. Over time, sustained afterload elevation drives left ventricular hypertrophy and increases risk for CAD, stroke, heart failure, and chronic kidney disease.

Exercise Blood-Pressure Responses

Hypertensive patients often show an exaggerated systolic blood-pressure response to exercise — a rise disproportionate to the workload performed — reflecting the same arterial stiffness and endothelial dysfunction that drives resting hypertension, and it independently predicts future hypertension and cardiovascular events even in currently normotensive individuals. Conversely, regular aerobic training produces post-exercise hypotension, a transient reduction in blood pressure below pre-exercise baseline lasting several hours, mediated by peripheral vasodilation and reduced sympathetic outflow; this is a genuine therapeutic benefit of exercise, not an adverse finding, though patients should be monitored for symptomatic hypotension immediately post-exercise.

During graded exercise testing, an exercise-induced hypertensive response is an established indication to terminate the test: guidelines commonly cite SBP >250 mmHg or DBP >115 mmHg as an absolute or relative termination threshold, and the CEP must recognize this value in real time rather than waiting for symptoms.

Dyslipidemia

Dyslipidemia refers to abnormal levels of LDL cholesterol (atherogenic, promotes plaque formation), HDL cholesterol (protective, mediates reverse cholesterol transport), and triglycerides (elevated levels associated with insulin resistance and metabolic syndrome). Elevated LDL is the primary driver of the atherosclerotic cascade described for CAD — oxidized LDL infiltrates the arterial wall, is engulfed by macrophages, and forms the lipid core of atherosclerotic plaque. Because this same process underlies both coronary and peripheral arterial disease, dyslipidemia management (lifestyle plus statin or other lipid-lowering therapy) is central to secondary prevention across every vascular bed. Regular aerobic exercise modestly raises HDL and lowers triglycerides, and combined with resistance training contributes to a more favorable lipid profile, though LDL reduction depends more heavily on diet and pharmacotherapy.

Peripheral Artery Disease: Pathophysiology and Diagnosis

PAD results from atherosclerotic narrowing of the arteries supplying the lower extremities, most often at the aortoiliac, femoropopliteal, or tibial segments. As a stenosis progresses, blood flow becomes inadequate to meet the metabolic demand of exercising limb muscle, producing intermittent claudication — reproducible, exertional ischemic pain (commonly calf, thigh, or buttock) that resolves promptly with rest. In advanced disease, critical limb ischemia can produce rest pain, non-healing ulcers, or gangrene.

The ankle-brachial index (ABI) is the primary diagnostic and severity tool:

• 1.00-1.40: normal
• 0.91-0.99: borderline
• 0.41-0.90: mild-to-moderate PAD
• <=0.40: severe PAD
• >1.40: non-compressible/calcified vessels (also abnormal, requires further testing)

Exercise as PAD Therapy and Safety Considerations

Supervised, claudication-limited walking exercise is a first-line, evidence-based therapy for PAD: patients walk to a moderate-to-near-maximal claudication pain level, rest until the pain subsides, and repeat, progressively increasing total walking time. This intermittent protocol improves collateral circulation, walking distance, and functional capacity over a typical 12-week supervised program. Safety considerations include recognizing that claudication pain is expected and therapeutic within this protocol (distinct from resting pain or non-healing wounds, which require urgent referral), monitoring for the exercise-induced hypertensive response described above (common given the frequent HTN-PAD overlap), and inspecting the feet regularly for ischemic ulcers, especially in patients with concurrent diabetes.

Exercise Prescription Notes Across This Cluster

Because hypertension, dyslipidemia, and PAD frequently coexist in the same patient with underlying atherosclerosis, exercise programming typically layers moderate-intensity aerobic exercise (the primary driver of post-exercise hypotension and favorable lipid shifts) with resistance training performed at moderate loads and controlled breathing to avoid excessive pressor response from breath-holding (Valsalva maneuver). Isometric handgrip training has also gained recognition as an effective adjunct for lowering resting blood pressure in hypertensive patients, though it should be introduced cautiously and is not appropriate as a substitute for aerobic exercise. Across all three conditions, blood pressure should be checked periodically during sessions, not only at intake, since medication changes and disease progression can shift a patient's exercise blood-pressure response between visits.