Phenylthiocarbamide taste sensitivity in chronic peptic ulcer.

Ability to taste phenylthiocarbamide is genetically determined and has been investigated as a possible genetic marker for disease. This study examined phenylthiocarbamide taste sensitivity in gastric and duodenal ulcer disease. The study sample included 164 patients with gastric ulcer, 134 with duodenal ulcer, and 299 community controls. Eight concentrations of phenylthiocarbamide in distilled water were obtained by binary serial dilution. The lowest concentration distinguished by taste from distilled water defined taste threshold. Bimodality of threshold distributions distinguished nontasters from tasters. Comparisons of patients with controls gave odds ratios of nontaste in gastric ulcer and duodenal ulcer of, respectively, 0.7 (P greater than 0.1) and 1.3 (P greater than 0.03). The power of detecting at least a twofold difference between patients and controls in the odds of nontaste was 80%. Nontaste was more common in duodenal than in gastric ulcer patients (odds ratio = 2.0, P = 0.02). Taste sensitivity was unassociated with other genetic factors related to ulcer--ABO blood group, secretor status, and serum pepsinogen 1 level. The difference between gastric and duodenal ulcer patients in the ability to taste phenylthiocarbamide may be genetic; however, this study's inability, despite substantial power, to detect at least a twofold difference between patients and controls suggests that if phenylthiocarbamide taste sensitivity is a genetic factor in peptic ulcer, the relationship is weak.