Hormone therapy is well known for treating the symptoms of menopause, but does it have benefits for knees, too?
A new study says maybe.
Results from a large-scale study in Korea show that women who received hormone therapy (HT) had significantly less risk of developing symptomatic knee arthritis than women who did not receive hormone treatments.
The results of the study can be found online in Menopause, the journal of the North American Menopause Society.
Osteoarthritis is a common musculoskeletal condition. It affects more than 31 million Americans and is the leading cause of joint pain and physical disability in seniors.
Osteoarthritis develops when the cartilage found in the joints begins to degrade.
"Cartilage breaks down over time as a result of aging and use," said Dr. Mona Alqulali, a Bettendorf, Iowa, OB-GYN and cosmetic surgeon.
When cartilage begins to degenerate, bone slides against bone when the joint is in use. The result is pain, inflammation, stiffness and, in many cases, a decreased range of motion.
Conventional treatments for osteoarthritis include joint-replacement surgery, which carries the risk of complications such as infection, as well as pain relievers and nonsteroidal anti-inflammatory drugs, which can cause gastrointestinal disorders.
There is an additional negative to joint-replacement surgery, too.
"Artificial joints only have a shelf life of 10 to 15 years," said Alqulali.
This means potentially having more than one knee replacement on the same leg in your lifetime.
Osteoarthritis typically affects the knees and hips, but can also develop in the back, hands and feet. Women have a higher risk than men of developing osteoarthritis because of the hormonal changes of menopause.
Why Menopause Matters
"When women go into menopause, hormones fluctuate," Alqulali said.
Menopause is the end of a woman's reproductive years and typically begins between the ages of 45 and 50.
During menopause, women experience hot flashes, insomnia, weight gain and changes to hair and skin. These changes occur because the body's production of estrogen decreases.
"When estrogen decreases, everything - not just the reproductive system - goes haywire," Alqulali said. "Estrogen is the primary female sex hormone and helps to regulate the female reproductive system and menstruation. It also helps to reduce inflammation at high concentrations."
When estrogen levels are depleted during menopause, inflammation - and osteoarthritis - spikes.
Since the knee is one of the most commonly affected joints, osteoarthritis of the knee has been the focus of several studies related to the effectiveness of HT for joint damage.
During the Korea study, data was collected from nearly 4,800 postmenopausal women. The researchers found the prevalence of knee osteoarthritis was much lower in the women using HT than in those not taking hormones.
While the initial finding shows the potential for a connection between a reduced occurrence of knee osteoarthritis and HT, other variables must be taken into consideration such as age, weight, body mass index and genetics.
"While age does contribute to the development of knee osteoarthritis, other factors do, too, such as weight and traumatic injuries," Alqulali said.
Other smaller studies have also shown some connection between hormone therapy during menopause and a reduced risk for osteoarthritis.
"Reducing the impact of osteoarthritis on the joints could mean the chance of staying active into later years," Alqulali said.
Staying active during menopause has additional health benefits, including protecting heart health, lowering cholesterol and reducing the chances of developing diabetes - three things that can also happen as a result of changes in estrogen levels.
"If joints do not hurt with movement, that means people tend to move more," Alqulali said.
The North American Menopause Society (NAMS). "Hormone therapy may be best defense against knee osteoarthritis." ScienceDaily. ScienceDaily, 8 January 2019.