Hypertension, a chronic elevation of blood pressure, is a significant burden on the world’s population, affecting approximately one billion people. We’ve known hypertension leads to an increased risk for cardiovascular disease for many years. However, it is becoming increasingly evident that hypertension plays a role in other disorders as well.
Recent Research on Hypertension Comorbidities
Hypertension and Metabolic Syndrome
It is estimated that one in three people suffer from metabolic syndrome (MetS) in the United States, and hypertension commonly develops in association with MetS and obesity.2 Although it’s clear these disorders are connected, there is little understanding of how.
Jonathan Nizar and team from Stanford University performed a study to understand how the epithelial Na+ channel (ENaC) might play a role in development of hypertension in MetS. Their study evaluated the role of diet on sodium excretion and used DSI’s PA-C10 telemetry implant to assess blood pressure levels. The results indicated that high fat feeding weakened sodium excretion, increased blood pressure, and caused obesity and insulin resistance.3
Hypertension and Dementia
There is still a lack of diagnostic tools available to physicians, preventing them from identifying the onset of dementia before neurodegeneration begins. As a result, treatment typically begins after symptoms have surfaced. Unfortunately, we are learning that by the time symptoms are experienced, it’s often too late to reverse damage.4
Researchers from Istituto di Ricovero e Cura a Carattere Scientifico Neuromed studied patients 40-65 years of age and performed an MRI scan to examine damage to the brain.4 Specifically, they were interested in any alterations in white matter of hypertensive patients’ brains and looked for a connection with weakened cognitive abilities.
The researchers found alterations in three white matter fiber-tracts of those with hypertension. They also had significantly lower scores on cognitive tests than non-hypertensive patients including executive functions, processing speed, memory, and other learning tasks.4
Hypertension and Air Pollution
Research recently published from Johns Hopkins University showed that fetal exposure to air pollution in the third trimester causes the child to experience high blood pressure from ages three to nine.5 The researchers evaluated air pollution exposure levels in 1,293 women by tracking pollution readings near their homes. Specifically, they looked at levels of particles so tiny, they can get into the lungs and bloodstream and therefore reach the fetus.6 When a child experiences elevated blood pressure, the issue is likely to follow them into adulthood.6
Hypertension and Pregnancy
Published in JAMA Psychiatry, new research indicates hypertension in pregnant mothers could lead to neurodevelopmental disorders, such as autism. Although a conclusive link has yet to be identified, the topic is high-priority with increasing instances of obesity, metabolic syndrome, and advanced maternal age.7 The team searched through databases to examine previous publications assessing this link and found that children of hypertensive mothers had a 35% higher risk of developing autism and 30% higher risk of ADHD.7 The research team recommended additional study of the link between hypertension and neurodevelopmental disorders to fully understand the mechanism causing it.
Animal Models
The preferred animal model for studying hypertension is the spontaneously hypertensive rat as they quickly and easily develop hypertension.8,9 Other animal models used are mice, primates, and swine. High-sodium and high-fructose diets are often used to produce hypertension. Breeding also plays a large role in developing models of hypertension. The spontaneously hypertensive rat is a Wistar rat specifically bred for hypertension research.9 In addition to hypertension, it is used to evaluate cardiovascular disease, metabolic diseases, renal disorders, insulin resistance, hypertriglyceridemia, hyperinsulinemia, hypercholesterolemia, stroke, nephropathy, and osteoporosis.9 There are also genetically engineered animals models of hypertension, transgenic and knock-out.
DSI Solutions
DSI has provided solutions to cardiovascular researchers for over 30 years and our PhysioTel™ telemetry has been cited in over 3,000 hypertension publications. The PhysioTel™ telemetry platform is designed to monitor physiologic signals in conscious, freely moving animals ranging in size from mouse to primate. DSI offers the widest range of physiologic signal monitoring options, providing the flexibility needed to study hypertension in combination with comorbidities. The ability to measure various pressures (arterial, left ventricular, ocular, bladder, and intra-cranial), ECG, temperature, and activity is key in cardiovascular studies. Metabolic studies benefit from the ability to collect second-to-second measurements of blood glucose. Those interested in neuroscience endpoints have access to biopotentials including EEG, EMG, and EOG as well as sympathetic nerve activity. Studies requiring respiratory endpoints can utilize telemetry or the Buxco line of respiratory and inhalation solutions.
To learn more about the solutions we offer, visit our Hypertension Solutions page.
References
1CDC. (2017). “Hypertension Prevalence and Control Among Adults: United States, 2015–2016. https://www.cdc.gov/nchs/products/databriefs/db289.htm
2Ecelbarger CM. (2016). “Metabolic syndrome, hypertension, and the frontier between”. https://www.physiology.org/doi/10.1152/ajprenal.00095.2016
3Nizar JM, Dong W, McClellan RB, Labarca M, Zhou Y, Wong J, Goens DG, Zhao M, Velarde N, Bernstein D, Pellizzon M, Satlin LM, Bhall V. (2016). “Na+-sensitive elevation in blood pressure is ENaC independent in diet-induced obesity and insulin resistance”. Renal Physiology. https://doi.org/10.1152/ajprenal.00265.2015
4Science Daily. (2018). “Dementia can be caused by hypertension”. https://www.sciencedaily.com/releases/2018/06/180613101925.htm
5Zhang M, Mueller NT, Wang H, Hong X, Appel LJ, Wang X. (2018). “Maternal Exposure to Ambient Particulate Matter ≤2.5 µm During Pregnancy and the Risk for High Blood Pressure in Childhood”. Hypertension. 72:194-201. https://doi.org/10.1161/HYPERTENSIONAHA.117.10944
6New York Times. (2018). “Hypertension in kids linked to air pollution exposure in womb”. Honolulu Star Advertiser. http://www.staradvertiser.com/2018/06/11/features/hypertension-in-kids-linked-to-air-pollution-exposure-in-womb/
7Maher GM, et al. (2018). “Hypertension in pregnancy may increase child’s risk for autism, ADHD”. JAMA Psychiatry. https://www.healio.com/psychiatry/autism-spectrum-disorders/news/online/%7B19cb5a79-acc1-4ddc-9b58-016425105117%7D/hypertension-in-pregnancy-may-increase-childs-risk-for-autism-adhd
8Leong X, Ng C, Jaarin K. (2015). “Animal Models in Cardiovascular Research: Hypertension and Atherosclerosis”. BioMed Research International. http://dx.doi.org/10.1155/2015/528757
9Razny K, Bednarski M, Sapa J, Gdula-Argasinska J, Tyszka-Czochara M, Librowski T, Salat K. (2014). “Animal Models for Hypertension Research”. ACTA Biologica Cracoviensia. Series Zoologia. 55/56: 124-129. https://www.researchgate.net/publication/272484711_ANIMAL_MODELS_FOR_HYPERTENSION_RESEARCH