Girls with anorexia nervosa suffer from weakening bones over time
Bone size and density are smaller in children and adolescents with anorexia nervosa (AN) and further drop slightly over time, a recent study has shown.
Researchers retrospectively analysed bone and body composition parameters in 111 young girls (mean age 15.4 years) with AN, with a mean duration of illness of 1.7 years. At baseline, none of the participants reported a history of osteoporosis or nonvertebral fractures.
In the AN patients, the mean total body (TB) and lumbar spine (LS) bone areas (BAs) were 1,835 cm2 and 36.4 cm2, respectively. TB percent predicted BA (ppBA) for age was low in AN patients compared to healthy controls, while no such difference was observed for LS ppBA for age.
Of the 111 participants, 28 percent (n=31) had underwent a follow-up dual-energy X-ray absorptiometry scan after a mean of 1.8 years. At follow-up, mean height significantly increased from 158.7 to 161.1 cm (p<0.001), as did mean weight (41.6 to 45.1 kg; p=0.002) and body mass index (16.5 to 17.6 kg/m2; p=0.014).
Notably, mean BA also showed significant increases from baseline both for the TB (1,799.8 to 1,914.5 cm2; p<0.001) and LS (36.4 to 37.9 cm2; p=0.001) sites.
However, TB bone mineral content (BMC) for height remained stagnant (53.0 to 49.8; p=0.242). Moreover, there were significant drops in bone mineral apparent density over time (–1.0 to –1.2 standard deviation scores; p=0.023) and TB percent predicted BMC for BA (97.2 percent to 95.2 percent; p=0.027).