People with unhealthy blood cholesterol levels are more likely to have tendon pain or altered tendon structure, according to a new review.
Cholestrol is essential for life, but too much in the blood increases the risk for cardiovascular disease and may also be linked to musculoskeletal problems, such as tendon injuries, said coauthor James E. Gaida of the University of Canberra and Monash University in Australia.
"Tendons connect muscle to bone, and tendinopathy is condition where a person feels pain when using their tendons," he said. It can affect any tendon including the Achilles tendon in the heel or the rotator cuff tendon in the shoulder, he noted.
"The most interesting finding was that the pattern of cholesterol changes seen with tendinopathy was similar to that which increases cardiovascular disease risk," Gaida told Reuters Health by email. "It seems that what is bad for your heart is bad for your tendons."
Gaida and his coauthor reviewed 17 studies that described cholesterol levels or use of cholesterol lowering drugs and participants' tendon structure or pain. Altogether the studies involved more than 2,000 people.
"Cholesterol is deposited within the tendon matrix when its level in the blood is high," Gaida said.
The researchers theorise that cholesterol deposits lead to inflammation of the tendons, and that this leads to structural changes, which make the area vulnerable to injury and pain, he said.
In the studies they analysed, people with less healthy blood cholesterol levels were more likely in general to have tendon problems, and to have worse pain associated with arm and shoulder musculoskeletal injuries.
But the findings can't prove that high cholesterol causes tendon issues. In fact, tendon injury can limit physical activity, which may affect cholesterol, so the relationship could also go in the opposite direction, the authors note in the British Journal of Sports Medicine.
"The pain is likely due to the accumulation of cholesterol, though the accumulation of cholesterol may very well have a genetic component," said Louis J. Soslowsky, founding director of the Penn Center for Musculoskeletal Disorders at the University of Pennsylvania, who was not part of the new review.
Obesity can exacerbate both high cholesterol and tendon pain, Soslowsky said.
"The association between cholesterol and tendinopathy needs further investigation, including whether lowering lipids through lifestyle changes, such as diet and physical activity patterns, could help treat tendon pain," Gaida said.
"However, the more important benefit of identifying a link between cholesterol and tendinopathy is the potential for early detection of high cholesterol, and management of cardiovascular disease risk, in those presenting with tendon pain," he said.
"There is some data that shows statins increase tendon and/or muscle pain so while lowering cholesterol is likely to aid in preventing tendon injury and/or improving tendon healing, its role on pain is not as clear," Soslowsky said.
Doctors should consider screening people with tendon pain for high cholesterol, and people who increase their physical activity after finding out they have high cholesterol should do so gradually so that their tendons have time to adapt, Gaida said.