The prevalence of lactase deficiency and lactose intolerance in Chinese children of different ages

To determine lactose metabolism and lactase activity in Chinese children of different ages, prevalence of lactase deficiency (LD), and lactose intolerance (LI) Methods All 1168 healthy subjects between 3 and 13 years were recruited from schools in four large cities in China They were screened by a 25?g lactose tolerance test Some subjects were challenged with 50?g milk powder on different days Both indicators, the expiratory H 2 concentration and intolerance symptoms, were analyzed Results LD occurred in 38 5% of children in the 3-5 year age group, and 87% of the 7-8 year and 11-13 year old groups The age of occurrence for LD may be at 7-8 years among Chinese children The prevalence of LI among Chinese children was 12 2% at age 3-5 years, 33 1% at age 7-8 years, and 30 5% at age 11-13 years, respectively Conclusion The results demonstrate that LD is very common in Chinese children from these four cities LD and LI have a dose dependent response: lactose absorption and symptoms are based on lactase activity The relationship between breast feeding history (or the history of cow milk intake) and lactase activity among Chinese children has not been established

Patients with functional bowel disorder have disaccharidase deficiency:A single-center study from Russia

BACKGROUND Functional bowel disorder(FBD)may be caused by a decrease in disaccharidase activity.Thus,the timely diagnosis of disaccharidase deficiency could lead to a better prognosis in patients with this condition.AIM To determine the potential value of intestinal disaccharidases glucoamylase,maltase,sucrase,and lactase in understanding the etiology and pathogenesis of FBD.METHODS A total of 82 FBD patients were examined.According to the Rome IV criteria(2016),23 patients had diarrhea-predominant irritable bowel syndrome(IBS),33 had functional diarrhea,10 had constipation-predominant IBS,4 had functional constipation,and 12 had mixed IBS.The Dahlqvist method was used to measure disaccharidase activity in the brush-border membrane of mature enterocytes of the small intestine,in duodenal biopsies obtained during esophagogastroduodenoscopy.RESULTS Lactase deficiency was detected in 86.5%of patients,maltase deficiency in 48.7%,sucrase deficiency in 50%,and glucoamylase deficiency in 84.1%.The activities of all enzymes were reduced in 31.7%of patients,and carbohydrase deficiency was detected in 63.5%of patients.The low activity of enzymes involved in membrane digestion in the small intestine was found in 95.2%of patients.CONCLUSION In 78 of the 82 patients with FBD,gastrointestinal symptoms were associated with disaccharidase deficiency.

Hydrogen breath test for the diagnosis of lactose intolerance,is the routine sugar load the best one?

AIM: To evaluate the prevalence of lactose intolerance (LI) following a load of 12.5 g in patients diagnosed as high-grade malabsorbers using the hydrogen breath test (HBT)-25.METHODS: Ninety patients showing high-grade malabsorption at HBT-25 were submitted to a second HBT with a lactose load of 12.5 g.Peak hydrogen production,area under the curve of hydrogen excretion and occurrence of symptoms were recorded.RESULTS: Only 16 patients (17.77%) with positive HBT-25 proved positive at HBT-12.5.Hydrogen production was lower as compared to HBT-25 (peak value 21.55 parts per million (ppm) ± 29.54 SD vs 99.43 ppm ± 40.01 SD; P < 0.001).Symptoms were present in only 13 patients.The absence of symptoms during the high-dose test has a high negative predictive value (0.84) for a negative low-dose test.The presence of symptoms during the first test was not useful for predicting a positive low-dose test (positive predictive value 0.06-0.31).CONCLUSION: Most patients with a positive HBT-25 normally absorb a lower dose of lactose and a strict lactose restriction on the basis of a "standard" HBT is,in most instances,unnecessary.Thus,the 25 g lactose tolerance test should probably be substituted by the 12.5 g test in the diagnosis of LI,and in providing dietary guidelines to patients with suspected lactose malabsorption/intolerance.