In a case of bulimia, which laboratory finding is most likely to be elevated due to self-induced vomiting?

In cases of bulimia, particularly when self-induced vomiting is a frequent behavior, one common laboratory finding is an elevation in amylase levels. This occurs because amylase is an enzyme produced primarily by the salivary glands, and it becomes elevated when there is increased stimulation of these glands, which can be associated with repeated vomiting episodes. The mechanical action of vomiting and the chronic irritation of the salivary glands lead to the release of amylase into the bloodstream.

While other electrolytes like potassium, magnesium, and calcium can also be affected due to the fluid and electrolyte imbalances caused by vomiting, they typically manifest as decreased levels, particularly potassium, which is crucial for maintaining normal cellular function and can be depleted with excessive vomiting. The case of elevated amylase specifically points to the physiological response of the salivary glands to repeated purging behaviors commonly observed in bulimia.