How do high blood glucose levels (BGLs) raise blood pressure?
TL;DR: High blood glucose levels (BGLs) cause vascular muscle cells to change their biochemistry and create “stress” (metabolic imbalance) that stiffens the vessels and raises blood pressure. (about 5 min read)
Metabolic tips for reducing blood pressure by stabilizing BGLs:
Eat foods with refined carbs around the time you’ll be moving around. Movement = your muscles can pull glucose out of the blood & bring BGLs down.
Moving throughout the day can improve circulation by physically pushing your blood around.
Your blood is pumped mostly by the elasticity of your blood vessels. Your heart “pumps” your blood in the sense that it is the obvious pacemaker but most of the pressure that keeps your blood moving around your body comes from the elasticity of your blood vessels. If your blood vessels didn’t need to be elastic, it wouldn’t be a problem if they got stiff. And it is a problem, or else your doctor would never talk about hardening arteries being a risk factor for heart attacks.
High blood glucose levels make your blood vessels less elastic*. Excess glucose in the blood causes biochemical changes in the vascular smooth muscle cells that line our blood vessels. A particularly detrimental change is that the vascular smooth muscle cells do not produce the metabolite nitric oxide correctly; this leads to less elasticity and stiffer blood vessels. Stiffer blood vessels = higher blood pressure.
Stiffer blood vessels lead to poor circulation. Your heart can pump harder to overcome some of the extra resistance of inelastic, stiff blood vessels, but the increased force cannot completely compensate for the loss of elasticity. This is a more serious problem for smaller blood vessels - the ones that actually feed your cells nutrients and oxygen, and take away wastes like uric acid and carbon dioxide (CO2). Stiffer blood vessels mean that it is harder to get nutrients to all the cells of your body, further increasing metabolic stress. Which increases cortisol and inflammation, which increases blood vessel stiffness if they are persistent.
Stressed-out blood vessels are stiffer AND weaker*. Since high glucose levels cause metabolic stress inside vascular smooth muscle cells, those cells will also make signals that ask the immune system for “help” - basically, they release chemicals that tell certain cells of your immune system that there’s trouble and it needs to be cleaned up. The cells in your body use the set of “help” signals when they are under metabolic stress as they do when they are under attack from a pathogen; in both cases, immune cells show up to fight the Good Fight and throw down in a pretty gnarly way that tries to eliminate the threat. This makes sense when cells are stressed because of a virus or bacteria infection which can be eliminated by an immune ambush, but it’s not such a great response when the threat is a metabolic threat from too many refined carbs in someone’s breakfast combo before their first business meeting.
Inflammation of blood vessels contributes to the risk of cardiovascular disease. In your immune system’s very noble attempt to fight off the “threat” that is stressing out the vascular cells, your immune system ends up doing more damage since the call is coming from inside the house - the stress is a metabolic stress from frequently and/or sustained elevated BGLs. Stress is metabolic imbalance: if the stress is going to be constant, then the inflammation is also going to be constant. Inflammation of blood vessels leads to the progression of atherosclerotic plaques and an increased risk of cardiovascular disease.
Increasing movement can help with circulation. Muscle contraction can help offset some of the negative consequences of stiffer blood vessels, even before metabolic balance is restored. This is because moving around squeezes your muscles and all the blood (and other fluids) in the muscles. Muscles also help take glucose out of the bloodstream without insulin - this helps lower BGLs without your pancreas having to put out more insulin and is important for maintaining (or restoring!) insulin sensitivity. Keep blood flowing properly by staying hydrated and moving throughout the day to help your heart out.
Metabolic tips for reducing blood pressure by stabilizing BGLs:
Eat foods with refined carbs around the time you’ll be moving around. Movement = your muscles can pull glucose out of the blood & bring BGLs down.
Moving throughout the day can improve circulation by physically pushing your blood around.
*Many studies have shown that increased sugar intake leads to increased blood pressure.
Dokken, BB. (2008) The Pathophysiology of Cardiovascular Disease and Diabetes: beyond blood pressure and lipids. Diabetes Specrt.
Malik, et al., (2014) Impact of Sugar-Sweetened Beverages on Blood Pressure. Am J of Cardiology.
