Lactase deficiency and lactose intolerance in a multiracial Asian population in Malaysia

BACKGROUND AND AIMS: There have been few reports on lactase deficiency (LD) and lactose intolerance (LI) in Malaysia, which has a peculiar mix of three distinct major Asian races—Malay, Chinese, and Indian. The aim of this study was to determine the prevalence of LD and LI in a young multiethnic Malaysian population. METHODS: Lactase activity was measured with a (13)CO(2) lactose breath test using an infrared spectrometer. Each subject took 25 g of lactose naturally enriched in (13)CO(2) together with 250 mL of water after an overnight fast. Breath samples were collected at baseline and at 15‐min intervals for 180 min. Subjects were asked to report gastrointestinal (GI) symptoms following ingestion of the lactose test meal. RESULTS: Of the 248 subjects tested, 216 (87.1%) were lactase deficient. We found no significant differences in the presentation of LD between gender and races. LD was found in 87.5% of males and 86.8% of females (P = 0.975) and in different races: Chinese (88.5%) versus Malay (83.1%) (P = 0.399), Indian (90.5%) versus Malay (P = 0.295), and Chinese versus Indian (P = 0.902). LI was diagnosed in only 49 (19.8%) subjects; 35 patients had diarrhea, while the remainder had at least two other GI symptoms after the lactose meal. CONCLUSION: The prevalence of LD was high in all three major ethnic groups—Malays, Chinese, and Indians. Ironically, the prevalence of LI was low overall.