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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lactose loading tests and other means were used to determine the pattern of primary "adult" lactose malabsorption (LM) and milk use among 171 subjects, including 122 children and 49 adults, almost all of them Pima Indians of Arizona. LM develops at quite young ages in full-blooded Pima children: already in the 3- to 4-year age group, 40% had LM. Of 62 full-blooded Indians (greater than or equal to 4 years of age), 59 (95%) had LM. Of 41 Indians (greater than or equal to 4 years) who were of mixed Indian-northern European ancestry, however, only 25 (61%) had LM, and, among them, prevalence of LM correlated with degree of northern European admixture. Whereas only 21% of Pima lactose absorbers reported symptoms after the loading test, 72% of malabsorbers did so, with older malabsorbers more likely to experience symptoms. In their everyday lives, only 23% of malabsorbers recognized symptoms brought on by milk consumption, but the percentage of malabsorbers making such an association increased with age. Nevertheless the Pima, adults as well as children, continue to drink reasonable quantities of milk. Family pedigrees are consistent with the hypothesis that adult lactose absorption is inherited as an autosomal dominant trait. Over-all results of this study, moreover, support the geographic hypothesis advanced to explain ethnic or racial differences in prevalence of LM, rather than the induction hypothesis.
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PMID:Lactose malabsorption among the Pima indians of Arizona. 57 95

Lactose-tolerance-test (LTT), ethanol-lactose-tolerance-test (ELTT), 14CO2 breath test and 14C-glucose determination were simultaneously performed in 27 healthy subjects, 16 patients with a Billroth II gastrectomy and 6 patients with a malabsorption syndrome. Intestinal mucosal lactase was absent or significant diminished in 5 of the B II cases and in all patients with malabsorption. In the lactase deficient patients a diminished serum glucose rise after ingestion of 50 g lactose was observed in LTT as well as in ELTT. False positive results in LTT could not be prevented by performing the ELTT. Furthermore the ELTT is not suitable for ambulant investigations because of the required high ethanol load of 0.5 g/kg. Most reliable results were obtained by determination of 14C-serum-glucose after oral application of about 15 muCi of 14C lactose. In respect to lactase level neither false positive nor false negative results were observed. For clinical investigations the procedure of isolation and measurement of 14C-glucose is too laborious however. 14CO2-exhalation test cannot be recommended because of many false positive and false negative results. Moreover 14CO2-exhalation seemed to be insensible and predominant depending on factors other than lactose absorption.
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PMID:[Diagnostics of lactose-malabsorption: value of tolerance tests and 14CO2 exhalation test in patients with and without lactase deficiency (author's transl)]. 99 41

Lactose-intolerant postweaning rats were fed experimental diets including yogurt, quargs prepared from yogurt culture and buttermilk culture, and two types of whey obtained from quarg processing. After feeding each diet for a period of 7 d, absence of blood glucose elevation and occurrence of diarrhea were used as indicators of lactose malabsorption. Blood glucose assays and absence of diarrhea indicated that yogurt and quargs prepared from yogurt and buttermilk culture were well tolerated by the rats. Wheys containing the same levels of viable organisms and lactose as the quargs caused severe symptoms of diarrhea and poor lactose absorption as indicated by no changes in blood glucose levels. Plate counts and enzyme assays of gastrointestinal contents confirmed presence of viable culture organisms and beta-galactosidase activity after feeding the two types of quarg. The availability of viable organisms, the exogenous lactase activity, and especially the slow gastric emptying may all have contributed to more efficient hydrolysis and digestion of lactose from quargs and yogurt than from the wheys.
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PMID:Lactose absorption by postweaning rats from yogurt, quarg, and quarg whey. 190 66

The nutritional needs of children with human immunodeficiency virus infection are poorly understood. Twenty-eight children with vertically transmitted human immunodeficiency virus infection were evaluated for carbohydrate malabsorption using lactose hydrogen breath tests and d-xylose absorption studies. Lactose malabsorption was a common finding in human immunodeficiency virus-infected children and occurred in 8 of 20 patients who had no identifiable enteric pathogen. Lactose malabsorption occurred at an earlier age in human immunodeficiency virus-infected children than in an age-matched group of 45 symptomatic control children (P = 0.02). However, lactose malabsorption was not associated with higher rates of diarrhea or growth failure. Abnormalities in d-xylose absorption were not significantly associated with either diarrhea or growth failure. However, 39% of d-xylose studies (9 of 23) showed abnormal results and were significantly associated with enteric infections (P = 0.004). Abnormalities in small-bowel morphology were found in 4 of 9 children with growth failure, 3 of whom had an enteric infection and low d-xylose absorption. Lactose hydrogen breath testing and d-xylose testing showed carbohydrate malabsorption in 61% of children (17 of 28). This study demonstrates that human immunodeficiency virus-infected children are at risk for malabsorptive disorders, which are not always related to clinical symptoms. We speculate that human immunodeficiency virus may be directly involved in the development of lactose malabsorption. Carbohydrate malabsorption in human immunodeficiency virus-infected children may not be the only factor responsible for growth failure.
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PMID:Malnutrition and carbohydrate malabsorption in children with vertically transmitted human immunodeficiency virus 1 infection. 201 74

Individuals with sufficient intestinal lactase hydrolyze ingested lactose to galactose and glucose and these monosaccharides are absorbed. Lactose is not digested completely when intestinal lactase activity is low and the disaccharide is malabsorbed. Breath hydrogen excretion after lactose ingestion is used commonly to diagnose lactose malabsorption. However, no direct tests are currently used to assess lactose absorption. We tested a new method of assessing lactose absorption in 26 healthy individuals. Each subject ingested 50 g of lactose. Participants were evaluated for lactose malabsorption using a standard 3-h breath hydrogen test. In addition, the urinary excretions of galactose, lactose, and creatinine were quantitated for 3-5 h after lactose ingestion. On the basis of breath hydrogen analysis after lactose ingestion, 12 individuals were lactose malabsorbers (defined as a rise in the breath hydrogen concentration of greater than 20 parts per million above the baseline value). The 14 subjects who did not malabsorb lactose by breath hydrogen testing (defined as a rise in the breath hydrogen concentration of less than or equal to 20 parts per million above the baseline value), had significantly more galactose in their urine 1, 2, and 3 h after lactose ingestion than lactose malabsorbers. The ratio of excreted lactose to excreted galactose was significantly decreased in lactose absorbers compared with lactose malabsorbers (p less than 0.001). Determination of the ratio of urinary galactose to urinary creatinine separated lactose absorbers from lactose malabsorbers completely (p less than 0.001). We conclude from this study that the determination of urinary galactose, urinary lactose/galactose ratio, and urinary galactose/creatinine ratio may be used to assess lactose digestion and absorption in healthy adults.
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PMID:Assessment of lactose absorption by measurement of urinary galactose. 277 42

Lactose tolerance tests were performed in 33 women with osteoporosis and 33 control women matched for age. A questionnaire was used to elicit any history of milk intolerance and the subjects' daily intake of calcium derived from milk and dairy products. Eleven patients and four controls gave a history of milk intolerance (p less than 0.01); 13 patients had lactose malabsorption compared with four controls (p less than 0.01). The daily intake of calcium derived from milk was significantly lower in patients (125 (SEM 20) mg v 252 (43) mg; p less than 0.05). Curves of blood glucose concentrations during the lactose tolerance test in subjects with lactose malabsorption were significantly flatter in patients than controls (p less than 0.05). The fasting blood glucose concentration was higher (5.44 (0.17) mmol/l (98 (3) mg/100 ml) in the patients than the controls (4.88 (0.11) mmol/l (88 (2) mg/100 ml); p less than 0.05), although body weight was significantly lower (61.6 (2.2) kg v 66.3 (1.6) kg; p less than 0.05). Absorption of lactose is significantly impaired in women with "idiopathic" osteoporosis; this combined with low consumption of milk and a subclinical disorder of glucose metabolism may be a major factor in the development of idiopathic osteoporosis in women.
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PMID:Lactose absorption, milk consumption, and fasting blood glucose concentrations in women with idiopathic osteoporosis. 308 Jan 15

Women with symptoms indicative of irritable bowel syndrome who had not consulted a physician were compared with female patients at a gastroenterology clinic to investigate whether self-selection for treatment accounts for psychologic abnormalities in clinic patients' with irritable bowel syndrome. Two sets of diagnostic criteria were compared: restrictive criteria based on the work of Manning and conventional criteria (abdominal pain plus altered bowel habits). Lactose malabsorbers were included as a control group because they have medically explained bowel symptoms similar to those that define irritable bowel syndrome. Thus they control for the causative effects of chronic bowel symptoms on psychologic distress. Women who met restrictive criteria for irritable bowel syndrome but had not consulted a physician had no more symptoms of psychologic distress on the Hopkins Symptom Checklist than asymptomatic controls. However, medical clinic patients with both irritable bowel syndrome and lactose malabsorption had significantly more psychologic symptoms than asymptomatic controls or nonconsulters with the same diagnoses. Individuals who met only the conventional criteria for irritable bowel syndrome reported more psychologic distress than controls, whether or not they consulted a physician. These results suggest that (a) symptoms of psychologic distress are unrelated to irritable bowel syndrome but influence which patients consult a doctor and (b) conventional diagnostic criteria identify more psychologically distressed individuals than do restrictive criteria.
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PMID:Symptoms of psychologic distress associated with irritable bowel syndrome. Comparison of community and medical clinic samples. 339 18

The relationship between primary lactase deficiency, the amount of lactose in the diet, and symptoms of intolerance continues to be debated. Primary adult lactase deficiency is common with a worldwide occurrence of near 70%. Lactase-deficient individuals malabsorb lactose but may or may not show intolerance symptoms. The development of symptoms appears to depend on the dose of lactose ingested, whether it is accompanied by a meal or other food, rate of gastric emptying, and small intestine transit time. Lactose loads of 15 g or greater produce symptoms in the majority of lactase-deficient persons. However, when lactose loads of up to 12 g are fed, symptoms can be minimal or absent. Tolerance to yogurt, acidophilus milk, and other microbe-containing dairy foods has been suggested and is thought to be due to either a low lactose content or in vivo autodigestion by microbial beta-galactosidase. Up to 20 g of lactose in yogurt is tolerated well by lactase-deficient persons. Associated with the consumption of yogurt is a three- to fourfold reduction in lactose malabsorption as compared with similar lactose consumption in milk. Improved lactose digestion appears due to autodigestion by microbial beta-galactosidase. This enzyme may be released from yogurt culture by gastric or bile acid digestion. Feeding yogurt that was pasteurized following fermentation, with only trace amounts of microbial beta-galactosidase activity, results in a threefold increase in lactose malabsorption as compared with feeding yogurt with a viable culture. However, pasteurized yogurt also is tolerated well by lactase-deficient persons, suggesting that tolerance of up to 20 g of lactose in yogurt may be independent of lactose malabsorption. The enhanced lactose absorption and tolerance observed with yogurt feeding are not apparent when unfermented acidophilus milk or cultured milk are fed.
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PMID:Milk intolerance and microbe-containing dairy foods. 355 56

A study of regional differences in prevalence of primary adult lactose malabsorption in Italy was conducted on 205 subjects. Their origin was determined by their grandparents' birthplace, 89 from northern, 65 from central, and 51 from southern areas of Italy. Lactose malabsorption was diagnosed with standard oral lactose tolerance test and blood glucose determinations. Lactose malabsorbers showed symptoms more frequently than absorbers after the test load of lactose (p less than 0.01) they also reported milk intolerance more frequently (p less than 0.01). Prevalence of lactose malabsorption is significantly lower in the central sample (19%) than in the northern (52%) and southern (41%) samples (p less than 0.01). This finding contrasts with the hypothesis of a continuous increase in frequency of lactose malabsorption from northern to southern Europe and is probably due to the complex genetic history of the Italian population.
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PMID:Primary adult lactose malabsorption in Italy: regional differences in prevalence and relationship to lactose intolerance and milk consumption. 356 3

Protein, fat and carbohydrate absorption in preterm infants fed on human milk or formulae are reviewed. Even in the most premature infants absorption of protein is satisfactory. Nitrogen net absorption is about 85-90% of intake and results slightly lower with human milk than with formulae. The lower apparent digestibility of human milk is probably due to the poorly degraded IgA immunoglobulins and the rapid transit time. Lactose is well tolerated by the preterm infants despite the low lactase activity at birth. Glucose polymers, which have a low osmotic activity and are suitable for increasing carbohydrate intake of formulae, are well absorbed probably for the activity of salivary amylase and brush border glucoamylase, which have been shown to be well developed at birth. Premature infants absorb fat poorly. This malabsorption that increases with the lowering of gestational age is due to low pancreatic lipase activity and to low intraluminal concentration of bile salts. Due to its bile stimulated lipase activity, non-heat-treated human milk used at least in part is an effective method to improve fat absorption in preterm infants. Faecal energy determined using a calorimetric bomb appears to be a simple and an accurate method to predict faecal fat and avoiding expensive and cumbersome analysis.
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PMID:[Absorption of proteins, carbohydrates and fats in the preterm neonate]. 357 19


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