TORONTO — Although physicians commonly prescribe oral contraceptives for women with anorexia nervosa, new research presented at the annual meeting of the Endocrine Society suggests that the androgen levels are already low in these women and that they are further reduced by the use of oral contraceptives.
But the jury is still out on the long-term consequences for skeletal health and body composition in women with the disease, said Dr. Karen K. Miller of Massachusetts General Hospital, Boston.
Dr. Miller and her colleagues analyzed androgen levels in 217 community-dwelling women to determine the physiologic consequences of prescribing oral contraceptives to women with anorexia nervosa.
The investigation included four arms comprised of 137 women with anorexia nervosa who were not receiving oral contraceptives; 32 women with anorexia nervosa who were receiving oral contraceptives; 21 women of normal weight with hypothalamic amenorrhea; and 27 healthy eumenorrheic controls.
All of the women with anorexia nervosa met the DSM-IV criteria for anorexia nervosa, were less than 85% of ideal body weight, and had an intense fear of gaining weight or strong denial of low weight. Anorexic women not receiving oral contraceptives had been amenorrheic for at least 3 consecutive months and had not received hormonal contraceptives within the previous 3 months. Those receiving oral contraceptives had to have been receiving them for at least 3 months.
All of those with hypothalamic amenorrhea were 90%–110% of ideal body weight; had been amenorrheic for at least 3 months; had normal FSH, prolactin, testosterone, and free testosterone levels; an LH-to-FSH ratio of less than 2.5; absence of hirsutism; and no history of an eating disorder.
Healthy controls were 90%–110% of ideal body weight and eumenorrheic. Controls were excluded from the study if they had a history of amenorrhea or an eating disorder, had a history of any major medical illness, or if they had used oral contraceptives within the previous 3 months.
The mean body mass index (BMI), percent ideal body weight, percent fat, total fat mass, and fat-free mass were lower in the anorexia nervosa groups, compared with women who had hypothalamic amenorrhea and the healthy controls. Analysis of the androgen levels in the four groups showed that total testosterone levels were lower in women with anorexia nervosa than they were in healthy controls.
Levels of total testosterone were similar in anorexic women who received oral contraceptives and those who did not receive them. The total testosterone levels were normal in women with hypothalamic amenorrhea, said Dr. Miller.
The levels of free testosterone were lower in women with anorexia nervosa than they were in healthy controls, and the lowest levels occurred in women with anorexia nervosa and who were receiving oral contraceptives. The levels were normal in women with hypothalamic amenorrhea.
The investigators also found that the levels of dehydroepian- drosterone (DHEAS) were lower only in women with anorexia nervosa who were receiving oral contraceptives, compared with healthy controls. DHEAS levels were normal in women with anorexia nervosa not receiving contraceptives and in women with hypothalamic amenorrhea.
Free testosterone levels were predictive of bone mineral density and body composition in women with anorexia nervosa, hypothalamic amenorrhea, and healthy controls. DHEAS levels also predicted bone density, but were weaker predictors than free testosterone and did not predict fat-free mass, Dr. Miller said.
Intervention studies are needed to determine the relationship between androgens and bone density and body composition in women with anorexia nervosa, she added. Studies are also needed to determine whether oral contraceptive use is harmful to their skeletal health.