More people with diffuse idiopathic skeletal hyperostosis (DISH) develop cardiovascular disease (CVD) than is predicted by the Framingham Risk Score, results of an observational study have shown.
Atherosclerosis. 2019;287:24-9 (CC BY 4.0)
A 68-year-old male shows thoracic DISH (upper panel, white arrow) and calcifications in left anterior descending coronary artery (LAD). Lower left panel shows a 3D reconstruction of the spine showing DISH and lower right, LAD calcification quantification.
Notably, a higher rate of myocardial infarction (MI) was seen in those with DISH than in those without DISH over the 10-year follow-up period (24.4% vs. 4.3%; P = .0055).
“We propose more scrutiny is warranted in evaluating CV risk in these patients, more demanding treatment target goals should be established, and as a result, earlier and more aggressive preventive medical interventions instituted,” corresponding author Reuven Mader, MD, and associates wrote in Arthritis Research & Therapy.
“What Mader’s study is pointing out is that it’s worth the radiologist reporting [DISH],” Elizabeth A. Regan, MD, PhD, from the National Jewish Health Center in Denver, said in an interview.
DISH on a chest x-ray or CT scan should be another “red flag to be even more attentive to cardiovascular risk,” she added, particularly because studies have shown that people with DISH tend to be obese, have metabolic syndrome, or diabetes – all of which independently increase their risk for cardiovascular disease.
An old condition often found by accident
Physicians have known about DISH for many years, Dr. Mader of Ha’Emek Medical Center in Afula, Israel, observed in an interview. Historical evidence suggests it was present more than a thousand years ago, but it wasn’t until the 1950s that it gained scientific interest. Originally coined Forestier’s disease, it was renamed DISH in the late 1960s following the realization that it was not limited to the spine.
“It is a condition which is characterized by new bone formation,” Dr. Mader explained. This new bone formation has some predilection for the entheses – the tendons, ligaments, or joint capsules, that attach to the bone.
“Diagnosis of the disease is based mainly on radiographs, especially of the thoracic spine, and it requires the formation of bridges that connect at least four contiguous vertebra,” he continued.
“The bridges are usually right-sided and usually the intervertebral spaces are spared. Classically there is no involvement of the sacroiliac joints, although there are some changes that might involve the sacroiliac joints but in a different manner than in inflammatory sacroiliitis.”
DISH was originally thought to be a pain syndrome, which has “not played out,” Dr. Regan noted in her interview. While there may be people who experience pain as a result of DISH, most cases are asymptomatic and usually picked up incidentally on a chest x-ray or CT scan.
“It’s something that’s not obvious,” she said. One of the main problems it can cause is stiffness and lack of mobility in the spine and this can lead to quite severe fractures in some cases, such as during a car accident. Hence spinal surgeons and other orthopedic specialists, such as Dr. Regan, have also taken an interest in the condition.
“Apart from the thoracic spine, DISH may also involve the cervical spine; there have been many reports about difficulty in swallowing, breathing, and in the lumbar spine, spinal stenosis and so forth,” Dr. Mader said. The differential diagnosis includes ankylosing spondylitis, although there is some evidence that the two can coexist.
“The diagnosis depends on the alertness of the examining physician,” he added, noting that rheumatologists and other specialists would be “very aware of this condition” and “sensitive to changes that we see when we examine these patients.”