Hypertension May Be Linked to Bone Aging, Study Suggests

A study recently presented at the American Heart Association's Hypertension Scientific Session 2022 conference found that young mice which high blood pressure showed bone loss and osteoporosis-associated bone damage akin to older mice.

As indicated in a SciTechDaily report, high blood pressure and osteoporosis are common disorders, "and individuals may have both conditions simultaneously.

Investigators of this study examined inflammation associated with high blood pressure in mice and found it could be related to osteoporosis.

According to Elizabeth Maria Hennen, the study's lead author and a Ph.D. candidate in biomedical engineering at Vanderbilt University in Nashville, Tennessee, bone marrow is a location where both new bone and new immune cells are produced.

She said they suspect the more pro-inflammatory immune cells in the bone marrow may result in bone damage and weakening it.

Link Between Bone Aging and Hypertension

The lead author also explained that by understanding how hypertension contributes to osteoporosis, they might be able to lessen the risk of osteoporosis and better shield people later in life from having fragility fractures and low quality of life.

In order to investigate the possible link between bone aging and hypertension, the study investigators compared young mice with artificially induced hypertension to older mice that don't have hypertension.

Hennen explained that in their study published in the Hypertension journal, the human age equivalents of mice ranged from 47 and 56 years for the older mice and between 20 and 30 years for the younger mice.

Twelve young mice aged four months old were administered angiotensin II, a hormone that causes elevated blood pressure.

Mice's Bones Studied

For six weeks during the study, researchers used micro-computer tomography, an advanced imaging approach to analyze the mice's bones from all four groups.

Bone strength and density were used to identify both density and strength were used to determine bone health. Mathematical algorithms were employed to examine the possible effects of hypertension and aging on mice's microstructure and strength of bone.

The young mice with induced hypertension, when compared to the young mice without high blood pressure, had a significant 24-percent reduction in bone volume fraction, an 18-percent reduction in the thickness of the sponge-like trabecular bone found at the end of long bones like femurs and the spinal column, and a 34-percent decrease in approximated failure force, which is the bones' ability to withstand different force types.

Failure force is translated into weaker bones. Bone weakness in the spine can result in vertebral fractures later in life, explained Hennen.

Inflammation on Mice's Bone Health Examined

On the contrary, the older mice who were given the angiotensin-II infusion did not show similar bone loss. During the research, though, the old mice, with or without hypertension, showed a reduced bone quality akin to that of the young hypertensive mice.

In these mouse models, having high blood pressure at a younger age essentially aged bones as if there were 15 to 25 human years older, explained Hennen.

To examine the effect of inflammation on the mice's bone health, researchers examined the bone marrow using flow cytometry, a related ScienceDaily report specified.

This tool enabled researchers to determine individual cells to sort specific immune cells out. The young mice with hypertension discovered a rise in the number of inflammatory signaling molecules, specifying a rise in inflammation in the bones compared to the young mice that were not given angiotensin II.

A report about the link between hypertension and bone aging is shown on Medical Diaogue's YouTube video below:

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