Anorexia nervosa may stunt the growth and impact the future height of teenage girls, according to data from 255 adolescents.
Illness and malnutrition during critical child and adolescent growth periods may limit adult height, but the effect of anorexia nervosa (AN) on growth impairment and adult height has not been well studied, wrote Dalit Modan-Moses, MD, of Chaim Sheba Medical Center, Tel Aviv, and colleagues.
Individuals with AN lose an unhealthy amount of weight on purpose through dieting, sometimes along with excessive exercise, binge eating, and/or purging, and because the condition occurs mainly in adolescents, the subsequent malnutrition may impact growth and adult height, they said.
In a study published in the Journal of Clinical Endocrinology & Metabolism, the researchers reviewed data from 255 adolescent girls who were hospitalized for AN at an average age of 15 years. They measured the girls’ height at the time of hospital admission, discharge, and at adulthood. The participants were followed in an outpatient clinic after hospital discharge with biweekly visits for the first 2 months, monthly visits for the next 4 months, and every 3 months until they reached 18 years of age. The average body mass index of the patients at the time of admission was 16 kg/m2 and the average duration of illness was 2 years. Of the 225 patients, 174 had a diagnosis of restrictive type anorexia nervosa and 81 had binge-purge type.
The midparental target height was based on an average of the parents’ heights and subtracting 6.5 cm. The main outcome of adult height was significantly shorter than expected (P = .006) based on midparental target height. Although the patients’ heights increased significantly during hospitalization, from 158 cm to 159 cm (P < .001), “the change in height-SDS [standard deviation scores] was not significant and height-SDS at discharge remained significantly lower compared to the expected in a normal population,” the researchers noted.
Although premorbid height SDS in the study population were similar to normal adolescents, the height-SDS measurements at hospital admission, discharge, and adulthood were significantly lower than expected (–0.36, –0.34, and –0.29, respectively).
Independent predictors of height improvement from hospital admission to adulthood were patient age and bone age at the time of hospital admission, linear growth during hospitalization, and change in luteinizing hormone (LH) during hospitalization, based on a stepwise forward linear regression analysis.
The findings were limited by several factors including the inpatient study population, which may limit the generalizability to patients with less severe illness, as well as incomplete data on LH levels, which were undetectable in 19% of the patients, the researchers noted. However, the study is among the largest to describe growth in female AN patients and included data on linear growth and LH not described in other studies, they said.
“Our study is unique in presenting complete growth data (premorbid, admission, discharge, AH) as well as target height, laboratory results and bone age data in a large cohort of adolescent females with AN,” they wrote.
The findings not only support the need for early intervention in patients with AN and the need for long-term weight gain to achieve catch-up growth, but also may apply to management of malnutrition in adolescents with chronic diseases such as cystic fibrosis and inflammatory bowel disease, they concluded.