Malnutrition and hemodynamic status in adolescents hospitalized for anorexia nervosa.

OBJECTIVE: To determine the effects of malnutrition on hemodynamic status of adolescents hospitalized for anorexia nervosa. DESIGN: Longitudinal observational study. SETTING: Tertiary care pediatric hospital. Patients Thirty-eight adolescents with anorexia nervosa, aged 13 to 21 years, with a mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 15.9 (1.8). Intervention Subjects received standard care, including bed rest and graded nutritional therapy. A subsample of subjects (n=19) returned 11 to 57 weeks following hospitalization for a second cardiac evaluation. MAIN OUTCOME MEASURES: Results from a 15-lead electrocardiogram, echocardiogram, treadmill stress test, and spinal bone mineral density measurement. RESULTS: On admission, 26 subjects (68%) had sinus bradycardia. Bradycardia was less common in participants with a longer duration of illness (P=.04). Left ventricle mass was lower than predicted for age (Z score<-1.0) in 11 subjects (31%). Exercise tolerance was normal by all measures. Both heart rate and QT interval were predictors of spinal bone mineral density. In those who returned for follow-up, absolute measures of left ventricle mass did not change (P=.27). However, the corresponding Z scores declined over time (mean [SD] change, -0.9 [1.3]; P=.02). CONCLUSIONS: In acutely malnourished adolescents with anorexia nervosa, few truly pathologic cardiac findings were identified. Sinus bradycardia was observed in most cases. Mild reductions in left ventricle mass and left ventricle function were seen both at baseline and at follow-up, suggesting early sparing of cardiac muscle in the face of moderate malnutrition as well as a relative delay of cardiac muscle restoration. The association of hemodynamic status with altered spinal bone mineral density emphasizes the range of systems affected by malnutrition in anorexia nervosa.

The effect of bed rest on bone turnover in young women hospitalized for anorexia nervosa: a pilot study.

CONTEXT: Malnourished adolescents with anorexia nervosa (AN) requiring medical hospitalization are at high risk for skeletal insults. Even short-term bed rest may further disrupt normal patterns of bone turnover. OBJECTIVE: The objective of the study was to determine the effect of relative immobilization on bone turnover in adolescents hospitalized for AN. DESIGN: This was a short-term observational study. SETTING: The study was conducted at a tertiary care pediatric hospital. STUDY PARTICIPANTS: Twenty-eight adolescents with AN, aged 13-21 yr with a mean body mass index of 15.9 +/- 1.8 kg/m(2), were enrolled prospectively on admission. INTERVENTION: As per standard care, all subjects were placed on bed rest and graded nutritional therapy. MAIN OUTCOME MEASURE: Markers of bone formation (bone specific alkaline phosphatase), turnover (osteocalcin), and bone resorption (urinary N-telopeptides NTx) were measured. RESULTS: During the 5 d of hospitalization, serum osteocalcin increased by 0.24 +/- 0.1 ng/ml . d (P = 0.02). Urine N-telopeptides reached a nadir on d 3, declining -6.9 +/- 2.8 nm bone collagen equivalent per millimole creatinine (P = 0.01) but returned to baseline by d 5 (P > 0.05). Bone-specific alkaline phosphatase exhibited a decline that was strongly age dependent, being highly significant for younger subjects only [age 14 yr: -0.42 +/- 0.11 (P = 0.0002); age 18 yr: -0.03 +/- 0.08 (P = 0.68)]. Age had no effect on other outcome measures. CONCLUSION: Limitation of physical activity during hospitalization for patients with AN is associated with suppressed bone formation and resorption and an imbalance of bone turnover. Future interventional studies involving mechanical stimulation and/or weight-bearing activity are needed to determine whether medical protocols prescribing strict bed rest are appropriate.