Salivary enzyme activity in anorexic persons—a controlled clinical trial

Abstract

Objectives: Patients with anorexia nervosa are at high risk for general and oral diseases. However, not all anorexic patients suffer from them, irrespective of the severity of their eating disorder. It is often speculated that differences in the saliva are important; however, little is known about salivary parameters in anorexic patients. The aim of the clinical trial was to evaluate stimulated and resting salivary flow rate and the activity of the following enzymes in both types of saliva: amylase, aspartate amino transferase (AST), alanine amino transferase (ALT), collagenase, lysozyme, peroxidase, serine and acidic proteases, and trypsin in persons with anorexia nervosa (AN) and to compare them with those of healthy controls.

Materials and methods: Sixty-six subjects participated (28 patients with anorexia nervosa, 38 matched healthy controls).

Results: Regarding flow rate, stimulated and unstimulated levels were significantly lower in the AN group than in the controls. Activities of collagenase and AST in stimulated saliva were significantly higher in anorexic participants. In the AN group, changes due to salivary stimulation were found for the activity of acidic proteases, AST, and lysozyme.

Conclusion: Reduced salivary flow might be one indicator of anorexia. Despite starvation and anorexia development, salivary key enzymes show physiological activity. This indicates a partial adaptation of the organism to severe condition during malnutrition.

Clinical relevance: Further research is needed into possible role of reduced collagenase and transaminase activities in maintaining protection against external noxae and bacteria which might have impact on general oral health among patients with anorexia nervosa.

Keywords: Amylase; Anorexia nervosa; Eating disorders; Enzymes; Lysozyme; Peroxidase; Protease; Saliva.