The importance of body weight history in the occurrence and recovery of osteoporosis in patients with anorexia nervosa: evaluation by dual X-ray absorptiometry and bone metabolic markers

Abstract

In order to investigate the risk factors, pathogenesis and natural course of the osteoporosis frequently seen in anorexia nervosa, we measured the bone mineral density (BMD) of the lumbar spine using dual X-ray absorptiometry in 51 Japanese female patients with anorexia nervosa, and followed the change in BMD of 29 patients for 11 to 46 months. We also evaluated the serum osteocalcin and the urinary CrossLaps, degradation products of collagen I, in 103 samples obtained from 51 patients. There was a significant correlation between the spinal BMD and the duration of emaciation below a body mass index (BMI) of 15 kg/m 2 (r ¼ ¹0.652, P < 0.0001) and 16 kg/m 2 (r ¼ ¹0.647, P < 0.0001). The increase in BMD per year in the 29 patients significantly correlated with the BMI at the time of entry of each follow-up period (r ¼ 0.712, P < 0.0001). The critical BMI for a positive increase in BMD was 16.4 Ϯ 0.3 kg/m 2 (mean Ϯ S.E.M.). The serum osteocalcin declined, while the urinary CrossLaps increased in proportion to a decrease in BMI. Both markers were normalized in patients whose BMI was between 16.4 and 18.5 kg/m 2 . The ratio of urinary CrossLaps to serum osteocalcin correlated with BMI (r ¼ ¹0.664, P < 0.0001).We conclude that the body weight history is the most important predictor of the presence of osteoporosis as well as of recovery. The BMD of patients does not increase to the normal range even several years after the recovery from this disorder, and they remain a high-risk group for osteoporosis in the future.

Body mass index and disease duration are predictors of disturbed bone turnover in anorexia nervosa. A case–control study

“…The present study has demonstrated an approximately fourfold higher CTx/osteocalcin ratio in AN patients compared to healthy age-matched controls, indicating a marked uncoupling of bone formation and resorption processes (Hotta et al, 1998). BMI was a strong predictor of the aforementioned alterations in bone turnover.…”

“…The ratio of serum CTx/osteocalcin was used as index of the balance of bone remodeling (Hotta et al, 1998).…”

The effects of bone therapy on tibial bone loss in young women with anorexia nervosa

“…A study of 12 AN patients found that despite weight gain, the patients failed to increase lumbar and neck BMD (Kooh & Noriega, 1996). Thus, weight gain was found to improve bone turnover in AN patients, but did not improve BMD (Caillot-Augusseau et al, 2000;Hotta, Shibasaki, Sato, & Demura, 1998). Therefore, we concluded that the medications employed in our study might improve BMD in AN.…”

The Relationship between Serum Levels of Estradiol and Osteoprotegerin in Patients with Anorexia Nervosa

“…These results suggest that serum OPG levels may be increased by a compensatory mechanism for malnutrition and estrogen deficiency which induces an increase in bone resorption. FIFTY percent of new AN outpatients show a decrease in lumbar bone mineral density (BMD) [1][2][3][4][5][6]. We have previously reported that the mechanism of osteoporosis in AN patients is both decreased bone formation and increased bone resorption due to decreased serum levels of insulin like growth factor-I (IGF-I) and estradiol (E2) [4,5].…”

“…FIFTY percent of new AN outpatients show a decrease in lumbar bone mineral density (BMD) [1][2][3][4][5][6]. We have previously reported that the mechanism of osteoporosis in AN patients is both decreased bone formation and increased bone resorption due to decreased serum levels of insulin like growth factor-I (IGF-I) and estradiol (E2) [4,5]. Receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) have been identified as important regulators of bone turnover [7][8][9].…”