Comparison of lactose intolerance in healthy Kuwaiti and Asian volunteers.

OBJECTIVE To study and compare the incidence of lactose intolerance among Kuwaiti and Asian healthy volunteers as measured by breath hydrogen level following challenge with lactose drink. SUBJECTS AND METHODS The study involved 70 Kuwaiti and 79 Asian healthy volunteers. The volunteers were physicians, medical students and other hospital workers. The study was carried out prospectively at Amiri Hospital, Kuwait. None of the volunteers was sick or had taken antibiotics or any other drug that could influence breath hydrogen level 2 weeks prior to the study. After an overnight fast 20-ml baseline samples of exhaled air were collected from each volunteer prior to oral administration of 40 g of lactose drink. Following this, the same amount of exhaled air was collected at 30-min intervals for 2 h. All samples were analyzed for hydrogen level using a Quintron microlyzer. Hydrogen level of 20 ppm more than baseline value was considered positive. RESULTS The basal breath hydrogen levels were 12.49 +/- 8.4 and 6.97 +/- 6.9 for Kuwaitis and Asians, respectively. Thirty-three (47%) of the 70 Kuwaitis and 46 (58%) of the 79 Asians were positive for the breath hydrogen test. The clinical symptoms of flatulence, abdominal pain, and diarrhea were associated with high levels of breath hydrogen. CONCLUSION The findings indicate that the Kuwaiti volunteers had higher breath hydrogen levels than Asians, but the incidence of lactose intolerance was similar in both groups.