Hyperamylasemia and its relationship to binge-purge episodes: development of a clinically relevant laboratory test.

Hyperamylasemia and parotid hypertrophy are conditions found in bulimic patients. The authors studied serum amylase levels in 56 underweight anorectics, 24 weight-recovered anorectics, 23 normal-weight bulimics, and 31 volunteer women. Normal-weight bulimic patients had significantly higher admission serum amylase values (mean +/- SE = 73.4 +/- 8.0 IU/L) than controls (40.8 +/- 2.4 IU/L). Additionally, the serum amylase test distinguished between restrictor anorectics (N = 31, 44.7 +/- 4.7 IU/L) and bulimic anorectics (N = 25, 68.8 +/- 8.6 IU/L, p less than .05) with a high degree of specificity and a fair degree of sensitivity. A subsample (N = 7) of bulimics showed twofold to fourfold increases in serum amylase values after a controlled period of binge eating and vomiting, whereas normal volunteers showed no change in serum amylase values (p less than .001) after ingesting a large meal. Serum amylase values declined significantly within 6 to 15 days of admission. However, after passes off the unit, serum amylase values returned to admission values, presumably as a result of binge-vomit episodes. The authors observe that modest increases of serum amylase values appear to be a consequence of binge-vomit behavior and suggest that serial serum amylase determination may be useful in monitoring the degree of patient abstinence in therapeutic programs.