May/June 2016

Hyperkyphosis: A New Geriatric Syndrome
By Diane L. Schneider, MD, MSc
Today's Geriatric Medicine
Vol. 9 No. 3 P. 16

Geriatrician and epidemiologist Diane L. Schneider, MD, MSc, gathers information and insight on hyperkyphosis from Deborah Kado, MD, MS, who has focused 20 years of research on the thoracic spine curvature that often goes undiagnosed and untreated.

Kyphosis is the normal concave curvature of the thoracic spine. Although kyphosis is commonly the term used for the pathologic condition of forward stooped posture or "dowager's hump," hyperkyphosis is the correct description.

Geriatric syndrome is a problem that usually has more than one cause and involves many parts of the body. The term "geriatric syndrome" is used to capture those clinical conditions in older individuals that do not fit into discrete disease categories. Many of the most common conditions cared for by geriatricians, such as delirium, falls, and frailty, are classified as geriatric syndromes.

Deborah Kado, MD, MS, a geriatrician, director of the osteoporosis clinic at the University of California, San Diego (UCSD) Hospitals, and a professor of medicine at UCSD, is one of the few researchers who study hyperkyphosis. For 20 years, hyperkyphosis has been the focus of her research activities. She recently sat down with Today's Geriatric Medicine's Editorial Board Advisor Diane L. Schneider, MD, MSc, to provide insights on why clinicians should recognize, document, and treat hyperkyphosis.

DS: How do you define hyperkyphosis?
DK: Hyperkyphosis is increased thoracic curvature of the spine greater than a 40° angle. Usually poor outcomes are observed with angles greater than 50°. With angles greater than 40°, a patient is at greater risk of progression of hyperkyphosis.

DS: How did you become interested in this area?
DK: In 1996, I started my fellowship at the University of California, San Francisco (UCSF) with Steve Cummings, MD, FACP. I knew nothing about bone, but I had written on my application that I was interested in the effects of Diet Coke on bone density. Soon after I arrived at UCSF, Dr. Cummings gave the fellows an introductory lecture on osteoporosis. My first fellowship question was: What is the risk of mortality in women with vertebral fractures that do not come to clinical attention? Using the Study of Osteoporotic Fractures data, I found that women over the age of 65 with vertebral fractures were more likely to die over the next eight years. Mortality increased with a greater number of vertebral fractures.

Then the question became: Why are these women with vertebral fractures dying? One of the hypotheses was that death occurred from becoming hunched over. So that's how my investigation started, and here I am 20 years later still studying the same thing.

DS: Why do you think hyperkyphosis is underreported and not a diagnosis included on the problem list?
DK: Until recently, hyperkyphosis or excessive thoracic curvature that is seen commonly with aging has been assumed to be a consequence of the aging process, like graying of the hair. Currently there are no standardized diagnosis criteria or treatments. So clinicians have not identified it as a problem because they had nothing to offer. But it's one of those diagnoses that when you see it, it is obvious, especially if it is moderate to severe.

DS: Why is it important to identify hyperkyphosis in patients?
DK: Since hyperkyphosis progresses, it's important to prevent progression and the future risk of associated poor health outcomes.

For our patients, hyperkyphosis is bothersome. They don't like becoming progressively hunched over. In our osteoporosis clinic, we see many women who seek medical advice because they don't want the condition to worsen as they get older. So fracture prevention is one important aspect.

Some women come in because they saw their mothers get hunched over, and they don't want the same thing to happen to them. Therefore, screening for low bone density in patients with family history is important.

Height loss and progressive postural slumping might provide clues to underlying vertebral fractures and trigger the clinician to do an osteoporosis work-up that includes bone density assessment by DXA [dual-energy X-ray absorptiometry] and radiographic imaging of the spine. If the patient has vertebral fractures or low bone density, treatment for osteoporosis is indicated. Studies in the last five years have demonstrated that women and men with low bone density and vertebral fractures are much more likely to experience kyphosis progression.

However, only about one-third of patients with hyperkyphosis have underlying vertebral fractures.

DS: What's accounting for the two-thirds of patients with hyperkyphosis who don't have vertebral fractures?
DK: Epidemiological studies have demonstrated apart from just vertebral fractures and low bone density, bone density loss, low body weight, degenerative disc disease—particularly in men—and a family history of dowager's hump are all predictors of hyperkyphosis. We have also found that older women who undergo weight loss have progression of thoracic kyphosis. Therefore, weight loss is not a desirable thing in women over the age of 65, whether intentional or unintentional. Being thin is not better for overall survival or osteoporosis. A BMI [body mass index] of 25 to 30 is considered ideal for older individuals because it provides "insurance" in case of an acute illness and hospitalization.

DS: Besides evaluating for osteoporosis, why should clinicians be concerned?
DK: Overall hyperkyphosis portends worse health outcomes. Multiple studies have shown that being hyperkyphotic is associated with worse physical function, both self-reported and performance-based, such as greater difficulty getting up from a chair. Some studies found difficulty with balance, lower grip strength, slower gait speed, and a greater likelihood of falls. The incidence of falls has escalated to a significant epidemic in the older population. Patients with hyperkyphosis are two times more likely to fall than their counterparts of the same age without hyperkyphosis. Therefore, if clinicians identify the condition and treat it, the trajectory and outcomes can likely be improved.

DS: What are the consequences of hyperkyphosis?
DK: The presence of cervico-thoracic or midthoracic kyphosis is a strong predictor for mortality. Women with hyperkyphosis who had underlying vertebral fractures fared the worst for longevity.

Both men and women showed evidence of declining lung function over time. The presence of vertebral fractures predicted future nonspine fractures. And severe hyperkyphosis is associated with gastrointestinal problems, including [gastroesophageal reflux disorder] and dysphagia.

DS: What can be done to improve hyperkyphosis?
DK: Referral to physical therapy for extensor spinal strength will likely be shown to be effective. An uncontrolled exercise pilot study targeting spinal muscle strength among older women with hyperkyphosis resulted in a significant improvement in kyphosis, spinal muscle strength, and physical performance. Based on those results, the Study of Hyperkyphosis, Exercise and Function Protocol was designed as a randomized control intervention. The intervention group received physical therapy three times per week for six months compared with the education-only control group. During one-hour physical therapy sessions, groups of 10 subjects participated in training that targeted spinal extensor muscles, spinal mobility, and postural alignment. Wendy Katzman, PT, DPTSc, OCS, will present the results at the fall meeting of the American Society for Bone and Mineral Research.

Fall prevention is another expected treatment outcome but has not been formally studied yet in randomized controlled trials.

Treating osteoporosis, if it exists, is important to decrease the risk of vertebral fractures. Once one vertebral fracture has occurred, the risk of subsequent vertebral fractures is high.

DS: Is there a difference between genders in hyperkyphosis?
DK: It depends on the method used to measure the angle. The "Blocks Method" that measures the cervical and upper thoracic spine by placing blocks under the subject's head shows a greater angle in men than women. However, using the "Cobb Method," which is based on a lateral radiograph and a measure of the midthoracic area, women have worse angles of curvature. In general, hyperkyphosis is more common in women.

Evaluation of sex hormones has shown some interesting results. In an analysis of the Study of Osteoporotic Fractures, over a 15-year period, estrogen users, current or past, had more upright posture and less hyperkyphosis than never users. In the MrOS [The Osteoporotic Fractures in Men] study, men with lower estradiol levels had the highest angles of kyphosis. Higher [sex hormone-binding globulin] levels were also predictive of a higher degree of curvature.

These findings suggest that estrogen is somehow a factor. The role of sex hormones in the underlying etiology is under investigation. In a small study published in the Journal of Bone and Mineral Research in November 2015, estrogen and marrow fat changes in vertebral bodies suggested that estradiol regulates bone marrow fat independent of bone mass. Perhaps estrogen has a direct effect to prevent gradual anterior vertebral wedging.

DS: How can clinicians evaluate their patients for hyperkyphosis?
DK: An easy test for clinicians is to determine whether the patient can lie flat on the exam table. If he or she cannot do so without one or two pillows, then some type of kyphotic posture is present. Cervico-thoracic kyphosis involving the neck is more head-forward posture.

The easiest way to quantitate kyphosis is to have a patient stand against the wall. Measure the occiput-to-wall distance. Because of fall risk, I also assess balance with tandem and semitandem stand.

DS: What do you recommend to your patients with hyperkyphosis?
DK: I teach my patients diaphragmatic breathing to engage the core musculature. It's a safe exercise in older individuals and shouldn't cause any injury. The breathing helps them to be aware of their posture so they can be self-correcting.

There are some new high-tech postural reminder devices, but these may not be readily adopted by older patients. I consider referral to physical therapy. And I counsel patients on avoiding extreme spinal flexion and twisting.

Despite significant findings regarding its adverse effects on measures of health and quality of life, hyperkyphosis is only beginning to be recognized by clinicians as a major health concern.

 — Diane L. Schneider, MD, MSc, is a geriatrician and epidemiologist, a former associate professor of medicine, the author of The Complete Book of Bone Health, and cofounder of 4BoneHealth.