Which laboratory abnormality is most likely found in a patient with severe anorexia nervosa?

In patients with severe anorexia nervosa, the body undergoes significant metabolic and physiological changes due to extreme malnutrition and weight loss. One of the notable laboratory findings is an increase in total cholesterol levels. This phenomenon can be attributed to the body's response to starvation.

When the body is deprived of nutrients, it begins to mobilize fat stores, leading to alterations in lipid metabolism. As a result, the liver may produce more cholesterol in an attempt to provide the body with energy and essential metabolites. Elevated total cholesterol is often seen in patients with anorexia nervosa, particularly when they are in a state of malnutrition, even though one might expect that with weight loss and reduced dietary intake, cholesterol levels would fall. The body’s homeostatic mechanisms react to the lack of intake by altering cholesterol production, thus leading to this laboratory abnormality.

In contrast, other choices like increased creatinine may suggest kidney impairment or dehydration, which are not as directly associated with the physiological changes from anorexia nervosa. Increased follicle-stimulating hormone often occurs due to disruptions in the hypothalamic-pituitary-gonadal axis, indicating altered reproductive hormone levels, but is not as definitive as increased total cholesterol. An increased glomerular filtration rate