High blood pressure is a significant contributor to cardiovascular disease and a health risk that increases with age in both men and women. The causes of cardiovascular disease are complex and every year we learn more about the impact of a person’s total health and wellness on their blood pressure and risks of hypertension.
Insulin is a metabolic hormone that is responsible for managing glucose (sugar) levels in the body. Recent years have focused on the other impacts that insulin has on the body, especially when it is chronically elevated. When patients have years of high insulin (which is released when we eat carbohydrates and food in general) their bodies develop a resistance to the action of insulin, meaning that it does not control blood sugar levels as effectively and cells become less responsive to insulin’s action.
Insulin does more in the body than regulate blood sugar, and patients are often surprised that high insulin can lead to fatigue, hormone imbalance, water retention and high blood pressure. The link between high blood pressure and insulin is so strong, that we may actually be able to predict future hypertension in younger patients by tracking their insulin over time.
Insulin can be checked with a simple blood test and compared against glucose levels to create a score of insulin resistance. How insulin changes blood pressure is complex, but it’s involved with salt retention in the kidney, increasing the sympathetic nervous system and causing oxidative stress1.
An interesting finding about insulin is that it is often elevated years before a patient would ever be considered to be diabetic and elevated levels above optimal causes hypertension even in patients who have not been flagged as a risk for diabetes2. The impact of insulin on blood pressure is also independent of a patient’s weight (although the impact is amplified when a person’s sits above their ideal BMI)3.
One particular study tracked thousands of non-diabetic patients for 4 years, and watched their insulin levels with respect to their blood pressure. The patients who had their insulin levels increase over the four years of the study had double the risk of developing hypertension than patients who had their insulin levels stable over the same time period. None of the patients were diabetic at the beginning of the study (although a few went on to become diabetic during the study)4.
If you are concerned about your family history or your personal risk of high blood pressure, or if you have been diagnosed with high blood pressure at a young age, these are the take-away messages regarding insulin:
- Insulin levels when above ideal, increase blood pressure, even in patients who are not diabetic.
- By controlling your insulin levels over a 4 year period, you can decrease your risk of developing high blood pressure.
- Insulin is not typically tested at your physical exam (fasting glucose is) and is an inexpensive predictive test for future high blood pressure.
- Diet and lifestyle measures to control insulin levels can also help reduce your blood pressure.
The Naturopathic Doctors at our office are experienced at testing and treating elevated insulin and blood pressure in patients who are newly diagnosed, or who need more support beyond their medication. Reaching out to our office is the first step to supporting your cardiovascular health and future and we are happy to offer a complimentary 15 minute consultation if you require more information about the role we can play in your long term health.
1. Tiwari, S., Riazi, S. & Ecelbarger, C. A. Insulin’s impact on renal sodium transport and blood pressure in health, obesity, and diabetes. Am. J. Physiol.-Ren. Physiol. 293, F974–F984 (2007).
2. Fournier, A. M., Gadia, M. T., Kubrusly, D. B., Skyler, J. S. & Sosenko, J. M. Blood pressure, insulin, and glycemia in nondiabetic subjects. Am. J. Med. 80, 861–864 (1986).
3. El-Atat, F. A., Stas, S. N., McFarlane, S. I. & Sowers, J. R. The relationship between hyperinsulinemia, hypertension and progressive renal disease. J. Am. Soc. Nephrol. JASN 15, 2816–2827 (2004).
4. Park, S. E. et al. Impact of hyperinsulinemia on the development of hypertension in normotensive, nondiabetic adults: a 4-year follow-up study. Metabolism. 62, 532–538 (2013).
5. Costantino, D., Minozzi, G., Minozzi, E. & Guaraldi, C. Metabolic and hormonal effects of myo-inositol in women with polycystic ovary syndrome: a double-blind trial. Eur. Rev. Med. Pharmacol. Sci. 13, 105–110 (2009).
6. Heise, T., Magnusson, K., Heinemann, L. & Sawicki, P. T. Insulin resistance and the effect of insulin on blood pressure in essential hypertension. Hypertens. Dallas Tex 1979 32, 243–248 (1998).
7. Haffner, S. M., Miettinen, H., Gaskill, S. P. & Stern, M. P. Metabolic Precursors of Hypertension: The San Antonio Heart Study. Arch. Intern. Med. 156, 1994–2001 (1996).