IGF-1 and Bone Loss in Women With Anorexia Nervosa

Not Applicable

Completed

Brief Summary: Anorexia nervosa is an eating disorder that can cause thinning of the bones (a decrease in bone density). A significant decrease in bone density is called osteopenia or osteoporosis. Sometimes the loss of bone density can be severe enough to cause breaks and fractures of the bones. It is not known what causes the bones to thin in anorexia nervosa. Women who have this condition often have thin or weak bones that are more likely to break. They also have very low levels of a chemical called IGF-1 in their body. This chemical is very important for increasing bone growth in puberty and for maintaining healthy adult bones. The investigators would like to find out if giving rhIGF-1 followed by risedronate or risedronate alone can lead to an increase in bone formation, bone density, and bone strength in women with anorexia nervosa.

Recruitment & Eligibility

Inclusion Criteria

Age 18-45 years
AN defined by DSM-IV diagnostic criteria, including weight less than 85% of ideal body weight (restricting or binge/purge type, BMI 15-17.5) OR meet criteria for sub-threshold AN, i.e., all DSM-IV criteria except that patients can have a BMI of <18.5 kg/m2 with or without amenorrhea
Oral contraceptive use prior to enrollment
BMD T score < -1.0
Normal FSH and TSH or free T4
Normal serum 25-OH vitamin D (>20 ng/mL) and calcium levels
Ongoing care from a primary care provider
Agree to use barrier contraception

Exclusion Criteria

Any subject with contraindications to risedronate
Any subject with binge-purge subtype of anorexia nervosa who vomits regularly as their form of purging (vs. those who use laxatives or diuretics) and who have significant periodontal disease, tooth erosion or an invasive dental or periodontal procedure within the previous three months.
Any disease known to affect bone, including untreated thyroid dysfunction, Cushing's or renal failure
Any medication known to affect bone metabolism within 3 months of the study, excluding oral contraceptives. Bisphosphonates must have been discontinued for at least one year before participation
Serum potassium <3.0 meq/L
Serum ALT >3 times upper limit of normal
eGFR of less than 30 ml/min
Pregnant and/or breastfeeding
Diabetes mellitus
Active substance abuse, including alcohol
History of malignancy
Atraumatic fracture within the prior year

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Placebo for 12 months
rhIGF-1 followed by Risedronate	rhIGF-1	Sequential therapy with rhIGF-1 (started at a dose of 30 mcg/kg subcutaneous BID and titrated) for 6 months followed by 6 months of risedronate 35mg PO once weekly
Risedronate	Risedronate	Risedronate 35mg PO once weekly for 12 months
rhIGF-1 followed by Risedronate	Risedronate	Sequential therapy with rhIGF-1 (started at a dose of 30 mcg/kg subcutaneous BID and titrated) for 6 months followed by 6 months of risedronate 35mg PO once weekly