Young adults who are overweight
or obese may be particularly likely to need a hip
replacement later in life, a large study suggests.
Using national data on 1.2 million adults,
researchers in Norway found that those who were
overweight or obese were at greater risk of eventually
needing a total hip replacement due to severe arthritis.
Men and women who were heavy before the age of 25
were especially at risk.
The findings underscore the importance of heading
off excessive weight gain in childhood and adolescence,
conclude the researchers, led by Dr. Gunnar Flugsrud
of Ulleval University Hospital in Oslo. Their report
is published in the journal Arthritis & Rheumatism.
The researchers based their findings on data from
two Norwegian national registries. One included
weight and height information on 1.2 million adults
who were screened for tuberculosis between 1963
and 1975. That information was matched with data
from a registry of total hip replacements performed
between 1987 and 2003.
In general, the researchers found, the risk of
hip replacement rose along with body mass index
(BMI), a measure of weight in relation to height.
People who were overweight or obese based on BMI
were two to three times more likely than normal-weight
adults to need a hip replacement.
But this was particularly true of those who were
overweight as young adults. Women who were obese
before age 25, for example, were nearly three times
more likely than their thin peers to eventually
need a hip replacement.
The effect of BMI was less pronounced, however,
among women whose weight was measured when they
were in their 50s or 60s. The researchers found
a similar pattern among men.
"Being overweight when young had a higher impact
than being overweight when older," Flugsrud and
colleagues write.
The researchers looked only at hip replacements
performed due to osteoarthritis, a gradual breakdown
of the cartilage cushioning the joints. It's possible,
write Flugsrud's team, that the hip-joint cartilage
is more vulnerable to damage earlier in life.
"Our findings highlight the desirability of prevention
and early treatment of obesity," the researchers
conclude.
It remains unknown, they add, whether weight loss
decreases the risk of developing hip arthritis.
SOURCE: Arthritis & Rheumatism, March 2006.
