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

While about 50 million Americans malabsorb lactose, the colonic metabolism of this disaccharide may prevent the symptomatic state known as lactose intolerance. Elucidation of the clinical importance of lactose malabsorption requires comparison of symptoms after ingestion of lactose with those following an identical appearing lactose-free control. This paper reviews the extensive literature concerning lactose-induced symptoms and the value of lactose digestive aids. Poorly controlled studies have suggested that a cup of milk results in appreciable symptoms in the majority of lactase-deficient subjects. In contrast, controlled trials in unselected lactose malabsorbers of subjects claiming severe lactose intolerance indicate that symptoms from a cup of milk are no greater than that with a lactose-hydrolyzed control. An increasing fraction of subjects experience symptoms as the lactose load is increased, with the majority having symptoms when the equivalent of 1 L of milk is ingested as a single dose. Further studies are required to determine the tolerance to several cups of milk taken throughout the day. Available digestive aids include pre-hydrolyzed milk and lactase preparations that can be added to milk (which is then incubated) or ingested with milk. While these products are effective in reducing symptoms, it should be emphasized that there appears to be no need for these preparations when the dosage of milk is limited to one cup per day.
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PMID:Review article: the treatment of lactose intolerance. 882 45

The relationship of lactase malabsorption to osteoporosis is unclear. We examined the relationship of self-reported lactose intolerance (LI) to bone mineral density (BMD) in perimenopausal Finnish women. A random population sample of 2025 women aged 48-59, who underwent spinal and femoral BMD measurement with dual X-ray absorptiometry in Kuopio, Finland during 1989-1991 formed the study population. Out of these women, 162 women reported LI. The mean dairy calcium intake was 558 mg/day in women with LI and 828 mg/day in other women (p < 0.0001). The mean spinal BMDs were 1.097 and 1.129 g/cm2 (-2.8%) (p = 0.016) and the mean femoral BMDs were 0.906 and 0.932 g/cm2 (-2.8%) (p = 0.012) for the LI and other women, respectively. After adjusting for weight, age, years since menopause, and the history of hormone replacement therapy, these differences changed to -2.7% (p = 0.016) for the spinal and -2.4% (p = 0.012) for the femoral BMD, respectively. Dairy calcium intake was an independent determinant of femoral BMD. The addition of calcium intake variables into the multivariate model did not affect the spinal BMD difference, but weakened the femoral BMD difference to -1.9% (p = 0.075). Our results suggest that LI slightly reduces perimenopausal BMD, possibly through reduced calcium intake.
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PMID:Does lactose intolerance predispose to low bone density? A population-based study of perimenopausal Finnish women. 902 43

The recognition of hydrogen nonexcretion in up to 20% of tested subjects and the large ethnic differences in the prevalence of lactose malabsorption make it necessary to reassess the diagnostic usefulness of the lactose tolerance test and the hydrogen breath test. Both tests were performed in 83 consecutive patients with suspected lactose malabsorption who ingested 50 g lactose. On a separate day a hydrogen breath test was performed after 25 g lactulose. The prevalence of hydrogen nonexcretion was 18%. The diagnostic usefulness of hydrogen breath test was influenced both by the individual threshold for hydrogen excretion and the amount of malabsorbed lactose. In addition to baseline values, breath samples for hydrogen measurements have to be taken at 30, 60, 90, 180, and 240 minutes after ingestion of lactose. For the lactose tolerance test only one measurement of serum glucose at 30 minutes is needed in addition to the baseline measurement. The combination of both tests excludes the influence of hydrogen nonexcretion, but even if a combined diagnostic approach utilizing the lactose hydrogen breath test and lactose tolerance test is used, 6% of patients presenting with symptoms suggestive of lactose intolerance cannot be classified.
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PMID:Assessment of the influence of hydrogen nonexcretion on the usefulness of the hydrogen breath test and lactose tolerance test. 890 Nov 27

The ability of inflammatory bowel disease (IBD) patients to tolerate dairy products and the guidance they receive from physicians and nutritionists on this subject are important considerations in the management of their IBD. Although most affected persons are able to consume a glass of milk daily without discomfort, additional consideration must be given to specific factors that can be relevant to certain individuals. The declaration by patients that they are "dairy sensitive" may be related to lactose intolerance or malabsorption, the long-chain triacylglycerol content of milk, allergy to milk proteins, as well as psychologic factors and the misconception that dairy products can be detrimental to their health. The prevalence of lactose malabsorption is significantly greater in patients with Crohn disease involving the small bowel than it is in patients with Crohn disease involving the colon or ulcerative colitis. In the latter colonic conditions the prevalence of lactose malabsorption is mainly determined by ethnic risk, which is based on genetic factors. In addition, lactose malabsorption in Crohn disease of the small bowel may be determined by factors other than lactase enzyme activity, such as bacterial overgrowth and/or small bowel transit time. Physicians differ widely in the advice they give their patients: some dogmatically advise avoidance of dairy products when the diagnosis is made whereas others discount the possible role of dairy in the management of IBD. IBD patients avoid dairy products more than they would need to based on the prevalence of lactose malabsorption and/or milk intolerance, probably partly because of incorrect patient perceptions and arbitrary advice from physicians and authors of popular diet books. Adequate scientific and clinical information is now available to permit recommendations about the intake of dairy products for each IBD patient.
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PMID:Dairy sensitivity, lactose malabsorption, and elimination diets in inflammatory bowel disease. 902 46

Forty HIV-infected adult patients at different disease stages and 44 healthy volunteers were evaluated for lactose malabsorption using the hydrogen breath test after 20 g lactose ingestion. All subjects were previously tested for breath hydrogen (H2) excretion after 12 g lactulose ingestion. The presence of intestinal superinfections, gastrointestinal symptoms and the intensity of clinical intolerance after lactose load were accurately searched in each patient. The cumulative H2 excretion after lactulose did not significantly differ between the different groups studied. The prevalence of lactose malabsorption turned out to be significantly higher (P < 0.001) in HIV-infected patients (70%) than in controls (34%). Moreover, in patients in more advanced disease stages the degree of lactose malabsorption was significantly greater than in patients at earlier disease stages, who did not differ from healthy volunteers. Furthermore the degree of lactose intolerance was significantly greater (P < 0.001) in symptomatic patients than in those without intestinal symptoms and in healthy volunteers, while no significant difference was observed between these latter groups. The results here demonstrate the negative impact of HIV infection on lactose absorptive capacity in adult patients, particularly marked in more advanced stages of the disease, suggesting that, in addition to the presence of the virus alone, other factors may contribute to determine the enterokinetic alterations responsible for lactase deficiency.
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PMID:The impact of HIV infection on lactose absorptive capacity. 927 21

Lactose intolerance is widespread, with adult-type hypolactasia being the predominant cause of lactose malabsorption. Daily ingestion of less than 240 mL of milk is well tolerated by most lactose-intolerant adults. Some persons with normal lactase activity may become symptomatic on consumption of products containing lactose. Lactose maldigestion may coexist in adults with irritable bowel syndrome and in children with recurrent abdominal pain. Management consists primarily of dietary changes. People who avoid dairy products should receive calcium supplementation and should be advised to read ingredient labels carefully. Several lactase replacement products are available, but their efficacy varies.
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PMID:When to suspect lactose intolerance. Symptomatic, ethnic, and laboratory clues. 974 7

Frequent complications of Crohn's disease include disorders of bone mineralization. They are due to a reduced dietary calcium supply in patients with lactose intolerance and a certain degree of malabsorption of calcium as well as vitamin D. The position is made worse by corticoids used in treatment of the basic disease, because they interfere not only with vitamin D conversion into its active (and much more effective) metabolites but also with osteoid formation In the early diagnosis of demineralization a densitometer can be used; markers of bone metabolism are used so far less frequently. As to treatment either blockers of enhanced bone resorption can be used (Ca, vitamin D, bisphosphonates and thyrocalcitonin) or substances stimulating new formation of bone (F, growth factors, in postmenopausal women hormonal substitution treatment) or a combination of preparations from both groups can be used. An irreplaceable part is played also by exercise, depending, of course, on the patient's general condition.
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PMID:[Disorders of bone mineralization and their treatment in Crohn's disease]. 982 96

Lactose malabsorption is characterized by a deficiency of mucosal lactase. As a consequence, lactose reaches the colon where it is broken down by bacteria to short-chain fatty acids, CO2, and H2. Bloating, cramps, osmotic diarrhea, and other symptoms of irritable bowel syndrome are the consequence and can be seen in about 50% of lactose malabsorbers. Having made the observation that females with lactose malabsorption not only showed signs of irritable bowel syndrome but also signs of premenstrual syndrome and mental depression, it was of interest to establish whether a statistical correlation existed between lactose malabsorption and mental depression. Thirty female volunteers were analyzed by measuring breath H2 concentrations after an oral dose of 50 g lactose and were classified as normals or lactose malabsorbers according to their breath H2 concentrations. All patients filled out a Beck's depression inventory questionnaire. Of the 30 female volunteers, six were lactose intolerant (20%) and 24 were normal lactose absorbers (80%). Subjects with lactose malabsorption showed a significantly higher score in the Beck's depression inventory than normal lactose absorbers did. The data thus suggest that lactose malabsorption may play a role in the development of mental depression. In lactose malabsorption high intestinal lactose concentrations may interfere with L-tryptophan metabolism and 5-hydroxytryptamine (serotonin) availability. Lactose malabsorption should be considered in patients with signs of mental depression.
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PMID:Lactose malabsorption is associated with early signs of mental depression in females: a preliminary report. 982 44

Lactose malabsorption and lactase deficiency are chronic organic pathologic conditions characterized by abdominal pain and distention, flatulence, and the passage of loose, watery stools. Though malabsorption of the sugar lactose is determinable by breath hydrogen test or jejunal biopsy, intolerance can only be confirmed by challenge with lactose-containing food, the response to which may not be immediate. The difficulty of making a positive diagnosis of these conditions has led to a proportion of lactose-intolerant patients being misdiagnosed with irritable bowel syndrome (IBS), which has a remarkably similar symptom complex and for which there is no current pathophysiologic marker. The incidence of the two disorders is approximately equal, but the actual proportion of patients with IBS incorrectly diagnosed in this way varies as a function of the methodology used. Once correct diagnosis is established, introduction of a lactose-free dietary regime relieves symptoms in most patients. Symptom similarity and the resultant incorrect diagnosis of IBS may explain the refractory nature of some patients labeled as IBS who remain largely unaware of the relationship between food intake and symptoms.
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PMID:Lactose intolerance: problems in diagnosis and treatment. 1019 5

Recent findings revealed that intragastric infusions of galactose conditioned a flavor avoidance in adult rats. To determine whether the galactose-conditioned avoidance was due to the infusion procedure, we investigated the flavor conditioning effect of orally consumed galactose. Food-restricted rats drank a flavored galactose solution, a flavored fructose solution and a flavored saccharin solution in separate one-bottle training sessions; grape, cherry and orange flavors were used. Because fructose is sweeter than galactose, saccharin was added to the galactose solution to increase its palatability. Pre- and posttraining preferences for the galactose and fructose solutions were evaluated in two-bottle choice tests. Also, preferences for the sugar-paired flavors were evaluated in two-bottle tests with the flavors presented in saccharin. In Experiment 1, rats were trained with flavored 80 g/L fructose, 80 g/L galactose + 2 g/L saccharin, and 2 g/L saccharin solutions (20 mL/d). Their preference for the flavored galactose solution changed (P < 0.01) from 76% (pretraining) to 19% (posttraining). The rats also avoided (P < 0.05) the flavor paired with the galactose solution in choice tests with the fructose-paired flavor and the saccharin-paired flavor. Similar pre- to posttraining preference reversals were obtained in Experiments 2 and 3, which used 20 g/L galactose and fructose solutions, and 20 g/L galactose and fructose solutions mixed with 20 g/L glucose, respectively. These findings, together with the intragastric infusion data, demonstrate that galactose has aversive postingestive consequences in adult rats even at low concentrations (20 g/L). Unlike lactose intolerance, which is due to intestinal malabsorption, this galactose-induced flavor avoidance is presumably due to the slow and incomplete postabsorptive metabolism of galactose.
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PMID:Galactose consumption induces conditioned flavor avoidance in rats. 1046 Feb 13


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