Focus on ‘fracture syndrome,’ not osteoporosis, to prevent osteoporosis-related fractures
AUSTIN, Texas — The key to preventing osteoporosis-related fractures does not lie in treating osteoporosis in a vacuum, but rather in viewing the condition as one component of a larger syndrome that warrants a more holistic approach, including nutritional assessment and fall prevention, Neil C. Binkley, MD, said during a presentation.
“We should consider osteoporosis as part of a syndrome, not the sole disease, leading to fracture,” Binkley, professor of medicine and director of the Osteoporosis Clinical Center and research program at University of Wisconsin, Madison, told Endocrine Today. “This syndrome might be called dysmobility syndrome — but the name is unimportant — and includes low bone mass and quality (osteoporosis) and low muscle mass and quality (sarcopenia), but also includes diabetes and other disorders that predispose older adults to falls and fractures.”
This syndrome, Binkley said, is analogous to conditions like metabolic syndrome and requires comprehensive consideration, including a focus on nutrition and muscle loss.
The nutrition field today is in “chaos;” conflicting studies have left both patients and providers confused regarding the targets for various nutrients, and the best ways to achieve those targets via supplementation and diet, Binkley said during the presentation at the American Association of Clinical Endocrinologists Annual Scientific and Clinical Congress. There is still much to learn, he said, regarding both nutritional and bone health.
“My bottom-line recommendation is that your grandmother had it right, and that is to eat a well-balanced diet,” Binkley said.
The goal of treating osteoporosis is obvious, Binkley said: clinicians need to prevent fractures. However, many patients at risk for fracture are not being treated.
“I would suggest to you that, on our watch, we have failed,” Binkley said. “We need to be doing something different.”
Data have suggested that, when focusing on T-score alone, clinicians identify less than half of women and one in five men who are going to sustain an osteoporosis-related fracture, Binkley said. These data are often used to ask how to better identify patients with osteopenia.
“What is often neglected are people who have osteoporosis-related fractures and normal bone mineral density,” Binkley said. “Roughly 18% of men and roughly 12% of women sustained an osteoporosis-related fracture with normal BMD. Now, we call that ‘osteoporosis.’ But is it, really?”
Roughly nine in 10 hip fractures are caused by falls, Binkley said. Clinicians should think about what can lead to falls — namely, decreases in muscle function and physical performance. Age-related muscle loss, Binkley said, along with poor physical function will often predict who is most likely to sustain an osteoporosis-related fracture, and both must be targeted.
“Treating osteoporosis as we’ve been doing, without considering other parts of the syndrome that cause fractures, is much like treating hyperlipidemia and ignoring hypertension and diabetes in patients who have metabolic syndrome,” Binkley said. “As a gross over-simplification, I think the reason that our bone drugs only reduce nonvertebral fractures by 30% to 50% is because the bones are only responsible for 30% to 50% of what we’re calling osteoporosis-related fractures.”
Treating ‘fracture syndrome’
Treatment of what Binkley called “fracture syndrome” also requires a thorough nutritional assessment. Despite the obesity epidemic, older patients are commonly malnourished, and 40% of hip fracture patients have energy/protein malnutrition. Inadequate protein intake reduces muscle synthesis, he said.
“We need to think about providing nutritional, caloric, protein supplements,” Binkley said. “Almost half of us are not meeting the current [recommended daily allowance] of 0.8 g per kilogram [of body weight] for protein. Many of the expert groups on sarcopenia are thinking we need at least 1.2 g and perhaps 1.5 g of protein. That is a lot of protein.”
But confusion continues regarding what nutrients should be targeted for bone health and what levels are considered “normal,” making it difficult to define what is considered “low” for any given nutrient, Binkley said. Standardizing clinical studies using physiological criteria can help better answer those questions, Binkley said, and inclusion criteria for studies must define who is “low” in a nutrient.
“I would suggest that if we designed a study to look at the effect of iron on anemia and we didn’t demand [included] people to be low in iron, we would conclude that iron is not important for hemoglobin synthesis,” he said. “That’s what we’ve been doing, and that is part of the reason we’re confused with regard to nutrients.”
In addition, the response to a fixed dose of any nutrient likely differs from patient to patient, according to Binkley. Large clinical trials have ignored that possibility, he said.
“None of our [randomized controlled trials] have used the treat-to-target strategy,” Binkley said. “[It is a] big shock that we hear diverging study reports that lead to confusion among our patients and among ourselves.”
The commonsense approach is to realize that genetics haven’t changed, Binkley said, and optimal human nutrition should be what it was for humans that lived 100,000 years ago.
Nutrients to target
Researching possible, individual nutrients that could be important for bone health leads to a list that runs from A to Z, Binkley said. Studies have suggested benefits for everything from vitamin A, boron and phosphorus to vitamin K, magnesium and strontium, among many others.
“Nutrition is clearly important for various aspects of this syndrome, importantly osteoporosis and sarcopenia,” Binkley said in an interview. “Despite ongoing controversy, there is reasonable clinical consensus regarding appropriate calcium, vitamin D and protein status needed for older adults.”
While many studies of both calcium and vitamin D have substantial flaws, both the AACE and National Osteoporosis Foundation recommendations are reasonable given what he called the “current state of ignorance,” Binkley said. The best research recommends 1,000 to 1,200 mg per day of calcium for most patients, ideally through diet, but also through supplementation if necessary, Binkley said. Despite “passionate arguments,” Binkley said the right target for 25-hydroxyvitamin D remains unknown; however, the current recommendation stands at 800 to 1,000 IU daily for most adults. He noted that human physiology expects daily vitamin D input, and he cautioned against very large bolus doses of vitamin D.
Some patients with osteoporosis may also have a phosphorus deficiency, particularly women aged 60 years and older; for these patients Binkley recommended a calcium/phosphate supplement.
Other nutrients, such as magnesium, have been understudied, whereas some, like strontium, might be toxic and are not advised, he said. Recent reviews do not support using vitamin K for bone health, and it remains unclear if vitamin A is useful.
Most importantly, Binkley said, is for adults to consume a balanced diet rich in low-fat dairy products, fruits and vegetables.
“I’d suggest to you that maybe we’re not much smarter than Hippocrates,” he said. “Hippocrates said ‘Let thy food be thy medicine and thy medicine be thy food,’ over 2,300 years ago.” – by Regina Schaffer
Binkley N. Nutritional Impact on Bone Health. Presented at: Presented at: AACE Annual Scientific and Clinical Congress; May 3-7, 2017; Austin, Texas.
Disclosures: Binkley reports receiving research support from Amgen, Eli Lilly, GE Healthcare, Merck and Novartis and serving on advisory boards for Amgen and Radius Health.