Severe chronic illnesses, often accompanied by malnutrition, may lead to slowed growth in childhood and delayed adolescence. Regardless of the cause, weight loss to less than 80% to 85% of ideal body weight often results in hypothalamic GnRH deficiency. If adequate body weight and nutrition are maintained in chronic illnesses such as Crohn disease or chronic pulmonary or renal disease, sufficient gonadotropin secretion usually is present to initiate and maintain pubertal development.
Anorexia Nervosa and Bulimia Significant weight loss and psychological dysfunction occur simultaneously with anorexia nervosa (60,61). Although many anorectic girls experience amenorrhea after pubertal development begins, if the disorder begins sufficiently early,
Figure 29.13 B: A 16-year-old girl (frontal view) with primary amenorrhea who progressed in puberty until about 12 years of age. Breast budding occurred at about 10 years of age. The patient’s short stature is obvious. She proved to have hypopituitarism. Classic radiographic findings established the diagnosis of Langerhans cell–type histiocytosis (Hand-Sch¨ uller-Christian disease). C: Side view of girl shown in Figure 29.13B.
pubertal development may be delayed or interrupted (Fig. 29.14). The following constellation of associated findings confirms anorexia nervosa in most individuals: 1.
Relentless pursuit of thinness 2.
Amenorrhea, sometimes preceding the weight loss 3.
4.
5.
Distorted and bizarre attitude toward eating, food, or weight 6.
Because normal body weight is commonly maintained in bulimia, it is unusual for bulimic patients to experience either delayed development or amenorrhea. Girls with anorexia nervosa may have, in addition to hypogonadotropic hypogonadism, partial diabetes insipidus, abnormal temperature regulation, hypotension, chemical hypothyroidism with low serum triiodothyronine (T3) and high reverse T3 levels, and elevated circulating cortisol levels in the absence of evidence of hypercortisolism (62). Other common features include hypokalemia, anemia, hypoalbuminemia, high β-carotene levels, and high cholesterol levels. All features of anorexia nervosa are reversible with weight gain, except for amenorrhea (which persists in 30% to 47%) and osteopenia (i.e., it now seems that any bone lost cannot be fully recovered). Management of patients with anorexia nervosa is notoriously difficult. A team approach involving the primary clinician, psychiatrist, and nutritionist is most effective. In fact, anorexia nervosa has the highest mortality of any psychiatric disorder. Deaths are often sudden and unexpected. Cause of death (often unknown) can include hypoglycemia and electrolyte imbalance.
Figure 29.14 A: A 20-year-old college woman with anorexia nervosa. B: A 16-year-old student with anorexia nervosa. In both cases, as is true of most such patients, pubertal development had been completed and menses initiated before anorexia led to marked weight loss.
Fear of obesity, a syndrome of self-induced malnutrition common among teenage gymnasts and ballet dancers, may slow growth and delay pubertal development (63). These children voluntarily reduce their caloric intake as much as 40%, leading to nutritional growth retardation. An additive role for endurance training in the delayed development is possible, but the mechanisms are unclear at this point. These conditions are essentially severe forms of hypothalamic amenorrhea. Inevitably delayed puberty will occur unless adequate caloric intake is provided.