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Lactose intolerance in the stumptail macaque (Macaca arctoides): case report.

A female stumptail macaque had signs of intermittant diarrhea and chronic weight loss over a 2-year period during which she was fed a commercial laboratory maintenance diet. Intolerance of this individual to lactose, a ubiquitous constituent of most commercial primate diets, was diagnosed on the basis of lactose tolerance tests and favorable clinical response to dietary carbohydrate substitution with glucose. Oral administration of varying doses of glucose to this animal consistently produced elevations in plasma glucose concentrations exceeding 20 mg/dl, while orally-administered doses of lactose did not cause significant elevations in blood glucose concentrations.

Animals↗

Bone density in axial and appendicular skeleton in patients with lactose intolerance: influence of calcium intake and vitamin D status.

BACKGROUND: Lactose intolerance (LI) is a common enzymatic insufficiency, manifesting by poor tolerance of dairy products, leading to low calcium intake and poor calcium absorption from dairy products. These changes might lead to an impairment of bone metabolism [1]. OBJECTIVES: To evaluate the impact of LI on quantitative bone parameters in axial and appendicular skeletal sites. To assess the impact of calcium intake from dairy and non-dairy nutritional sources, calcium regulating hormones and bone turnover on quantitative bone parameters in LI patients. METHODS: We evaluated calcium intake and bone status in sixty-six patients with LI, 49 women and 17 men, aged 20 to 78. Bone mass was assessed at the lumbar spine (LS), total hip (TH) and femoral neck (FN) by dual-energy x-ray absorptiometry (DEXA) and at the radius, tibia, phalanx by quantitative ultrasound. Serum calcium, albumin, inorganic phosphate, calcium regulating hormones and markers of bone turnover were evaluated. RESULTS: Total daily calcium intake was below the recommended by the American Dietetic Association [2] in all study participants (mean 692 mg/day +/- 162). Elevated level of urinary deoxypyridinoline crosslinks (DPD) was observed in 63 (96%) patients and was negatively correlated with total daily calcium intake (r = -0.998, p = 0.025) and with nondairy calcium intake (r = -0.34, p = 0.015). Parathyroid hormone (PTH) level in the upper third of normal range (45-65 ng/L) was observed in 11 (17%) patients. Parathyroid hormone (PTH) was inversely correlated with total calcium intake (r = -0.4, p = 0.001), dairy calcium intake (r = -0.83, p = 0.05), non-dairy calcium intake (r = -0.29, p = 0.043), 25OHD(3) serum level (r = -0.3, p = 0.007) and positively correlated with bone turnover markers (deoxypyridinoline crosslinks [DPD], r = 0.36, p = 0.01 and bone specific alkaline phosphatase [BSAP] r = 0.36, p = 0.01). Decrease in quantitative bone parameters compared to age-matched controls was observed in the axial and in the appendicular skeleton in men and in postmenopausal women: mean z-score for LS -0.87 +/- 0.22 and -1.32 +/- 0.65, p = 0.004 and 0.015, tibia -1.15 +/- 0.53 and -0.44 +/- 0.044, p < 0.001 and 0.27, phalanx -0.98 +/- 0.22 and -0.52 +/- 0.98, p < 0.001. We observed decrease in bone mass in patients with serum PTH in the upper tertile of normal range in the FN (z-score -0.57 +/- 0.6 versus -0.03 +/- 0.9, p = 0.025), TH (-0.51 +/- 0.96 versus 0.04 +/- 0.9, p = 0.05) and radius (-1.84 +/- 0.27 versus -0.07 +/- 1.61, p = 0.025, respectively). z-scores in FN and TH positively correlated with serum 25OHD(3) level (r = 0.31, 0.29; p = 0.014, 0.019). In postmenopausal women serum 25OHD(3) level correlated also with LS z-scores (r = 0.52, p = 0.004); FN and TH z-scores negatively correlated with DPD level (r = -0.51, p = 0.02 and r = -0.55, p = 0.04). CONCLUSION: LI state may lead to increased bone turnover and decreased bone mass especially in men and postmenopausal women. Impaired vitamin D status and low calcium intake may be deleterious to bone in this condition.

Absorptiometry, Photon↗

Biogenesis of intestinal lactase-phlorizin hydrolase in adults with lactose intolerance. Evidence for reduced biosynthesis and slowed-down maturation in enterocytes.

Enzymatic activity, biosynthesis, and maturation of lactasephlorizin hydrolase (LPH) were investigated in adult volunteers with suspected lactose intolerance. Mean LPH activity in jejunal biopsy homogenates of these individuals was 31% compared to LPH-persistent individuals, and was accompanied by a reduced level of LPH-protein. Mean sucrase activity in individuals with low LPH was increased to 162% and was accompanied by an increase in sucrase-isomaltase (SI)-protein. Biosynthesis of LPH, SI, and aminopeptidase N (APN) was studied in organ culture of small intestinal biopsy specimens. In individuals with LPH restriction, the rate of synthesis of LPH was drastically decreased, reaching just 6% of the LPH-persistent group after 20 h of culture, while the rate of synthesis of SI appeared to be increased. In addition, maturation of pro-LPH to mature LPH occurred at a slower rate in LPH-restricted tissue. Immunoelectron microscopy revealed an accumulation of immunoreactive LPH in the Golgi region of enterocytes from LPH-restricted individuals and reduced labeling of microvillus membranes. Therefore, lactose intolerance in adults is mainly due to a decreased biosynthesis of LPH, either at the transcriptional or translational level. In addition, intracellular transport and maturation is retarded in some of the LPH-restricted individuals, and this leads to an accumulation of newly synthesized LPH in the Golgi and a failure of LPH to reach the microvillus membrane.

Adult↗

[Lactose intolerance in the differential diagnosis of abdominal pain in children].

In the period from 1990 to 1992 542 children aged 0-15 years were examined by the breath hydrogen test for abdominal pain and chronic nutritional disorder. The results of lactose tests were pathological in 107 children with abdominal pain and 95 with chronic nutritional disorder. The authors followed 107 children with abdominal pain and directed their attention to its relationship to lactose intolerance. It was confirmed to be the only cause of abdominal pain in twenty-six children (24.3%). In spite of the well known pathogenetic mechanism of lactose intolerance leading to abdominal pain and metheorism and loose stools, an atypical clinical course was observed in these patients. There were no complaints associated with the intake of milk in history, the abdominal pain being the leading symptom in all patients but four who had loose stools. There was an improvement of clinical symptoms after the low-lactose diet.

Abdominal Pain↗

Lactose intolerance in infants.

Cathy Taylor describes the pathophysiology and aetiology of lactose intolerance and how to diagnose and treat it. Management of the infant by the primary health care team is discussed, with emphasis on advice and nutritional support that can be recommended to parents.

Breast Feeding↗

Intestinal-transit and lactose intolerance in chronic alcoholics.

Intestinal transit time of lactulose and malabsorption of lactose were measured by hydrogen excretion in breath following ingestion of 20 g lactulose or 25 g lactose. Patients were 20 recently drinking, adequately nourished, chronic, male alcoholics. Many (65%) complained of diarrhea while drinking actively. Small bowel transit was significantly shorter in alcoholics with diarrhea (62 +/- 8.6 min) than in normal controls (93 +/- 10.4 min, p less than 0.05). It increased significantly after 8-10 days abstinence, to a value of 101.5 +/- 11 min, not significantly different from normal controls. Following lactulose 75% of alcoholics developed diarrhea after 1-2 days compared with only 15% after 8-10 days of abstinence; 40% had diarrhea after lactose in the initial study, whereas no subjects had diarrhea from the same dose after a period of sobriety. These data suggest that drinking alcoholics have an increased sensitivity to osmotic loads, which is associated with diarrhea, shortened transit time, and lactose intolerance. Abnormalities disappeared 8-10 days following cessation of drinking and normal diet.

Adult↗

The relationship between lactose tolerance test results and symptoms of lactose intolerance.

OBJECTIVE: A standard for the assessment of lactose malabsorption does not exist. As measured by lactose tolerance tests, insufficient increase in blood glucose or increased breath hydrogen (H2) excretion after lactose ingestion is regarded as pathological. In this study, we have tried to elucidate the relationship between lactose tolerance test results and symptoms after a lactose challenge. This relationship might be an indicator for the validity of the test. METHODS: In a prospective study, 309 consecutive patients with suspected lactose malabsorption underwent a lactose tolerance test. After consumption of 50 g of lactose, blood glucose and breath H2 concentrations were measured. During the test (240 min), the severity of bloating, flatulence, abdominal distention, and diarrhea were semiquantitatively scored as 0, 1, or 2. The individual sum of these four scores was calculated and denoted as the total symptom score (TSS). All subjects were classified according to their TSS to compare symptoms with peak breath-H2 concentration and change in blood glucose concentration, respectively. RESULTS: The glucose and breath H2 response were pathological in 51.1 and 39.5% of cases, respectively. A stepwise increase in TSS of 1 point was associated with a significant increase (p < 0.05) in mean peak H2 concentration. However, a significantly lower glucose increment compared with patients with a TSS of 0 was found only in patients with a TSS of 2 or 4. The mean symptom score differed significantly between the positive and negative breath tests (p < 0.001), but did not differ between the positive and negative glucose response results. CONCLUSIONS: This study shows that GI symptoms after a lactose challenge are strongly associated with the amount of H2 excretion. The relationship between the increase in glucose concentration and symptoms after a lactose load is less evident. Thus, the H2 breath test seems to be superior to the measurement of blood glucose increment as a diagnostic tool in lactose malabsorption, although the true predictive value of this test only can be determined after a period of dietary treatment.

Adult↗

Lactose intolerance associated with cataracts.

A 50-day-old boy with severe lactose intolerance is described. In addition to vomiting, failure to thrive, dehydration, metabolic acidosis and amino aciduria, bilateral cataracts were also found. At three months of age, a computerized axial tomography scan and an electroencephalogram were abnormal, and myoclonic spasms began at the age of seven months.

Cataract↗

Clinical picture of hypolactasia and lactose intolerance.

Selective adult-type hypolactasia, the main cause of primary malabsorption of lactose, shows considerable variation in terms of its symptoms, which mainly depend on the amount of milk consumption. The article discusses congenital lactase deficiency and familial lactose intolerance. Links between hypolactasia and non-specific abdominal complaints, coronary heart disease and cataract are presented. The decrease in lactase activity in the brush border of jejunal mucosa, associated with diseases of the mucosa or any other condition which damages the enterocytes, is discussed as a cause of secondary hypolactasia. It is shown that adult-type primary hypolactasia and selective lactose malabsorption represent a major problem in the everyday work of general practitioners, particularly in populations where hypolactasia is common. Therefore, the examination and treatment of non-selected patients with vague abdominal complaints is important in primary health care. As the need for calcium in humans is largely met by the intake of milk, the consumption of milk has to be in amounts that are tolerable for the individual.

Abdominal Pain↗

The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance.

1) Most humans, like other mammals, gradually lose the intestinal enzyme lactase after infancy and with it the ability to digest lactose, the principle sugar in milk. At some point in prehistory, a genetic mutation occurred and lactase activity persisted in a majority of the adult population of Northern and Central Europe. 2) Persistence of intestinal lactase, the uncommon trait worldwide, is inherited as a highly penetrant autosomal-dominant characteristic. Both types of progeny are almost equally common when one parent is a lactose maldigester and the other a lactose digester. 3) The incidence of lactose maldigestion is usually determined in adults by the administration in the fasting state of a 50-g dose of lactose in water, the equivalent of that in 1 L of milk. Measurement is made of either the subsequent rise in blood glucose or the appearance of additional hydrogen in the breath. It is also sometimes identified by measuring lactase activity directly in a biopsy sample from the jejunum. For children the test dose is reduced according to weight. Depending on the severity of the lactase deficiency and other factors, the test dose may result in abdominal distention, pain, and diarrhea. 4) The frequency of lactose maldigestion varies widely among populations but is high in nearly all but those of European origin. In North American adults lactose maldigestion is found in approximately 79% of Native Americans, 75% of blacks, 51% of Hispanics, and 21% of Caucasians. In Africa, Asia, and Latin America prevalence rates range from 15-100% depending on the population studied. 5) Whenever the lactose ingested exceeds the capacity of the intestinal lactase to split it into the simple sugars glucose and galactose, which are absorbed directly, it passes undigested to the large intestine. There it is fermented by the colonic flora, with short-chain fatty acids and hydrogen gas as major products. The gas produced can cause abdominal distention and pain and diarrhea may also result from the fermentation products. 6) Among individuals with incomplete lactose digestion, there is considerable variation in awareness of lactose intolerance and in the quantity of lactose that can be ingested without symptoms. A positive standard lactose test is not a reliable predictor of the ability of an individual to consume moderate amounts of milk and milk products without symptoms. In usual situations the quantity of lactose ingested at any one time is much less than in the lactose-tolerance test.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Abdominal pain associated with lactose ingestion in children with lactose intolerance.

The causal relationship between lactose ingestion and gastrointestinal symptoms is questionable. The aim of this study was to assess symptoms associated with milk ingestion in children with lactose maldigestion. Thirty children (11 males) age 3 to 17 years with lactose maldigestion were studied. In a double-blind, crossover design, subjects ingested 240 mL daily of either lactose-hydrolyzed or lactose-containing milk for 14 days. Diaries were kept daily that recorded diet, medication use, and symptoms. There was a significant increase in abdominal pain experienced by study participants during the lactose ingestion period when compared to the lactose-free period. We conclude that ingestion of 12 g of lactose daily is associated with increased abdominal pain in susceptible children with lactose maldigestion. A trial of dietary lactose restriction may be beneficial in reducing abdominal pain in children with lactose maldigestion.

Abdominal Pain↗

Comparative uptake of calcium from milk and a calcium-rich mineral water in lactose intolerant adults: implications for treatment of osteoporosis.

Despite the links between low calcium (Ca) intake and age-related bone loss, hypertension, and colon cancer, the majority of Western populations have average daily Ca intakes substantially below recommended daily allowances. Although dietary products are widely known as a rich and valuable source of Ca in the diet, consumption of diary products is low and has been decreasing because of perceptions of excess calories and fat in the diet, as well as taste aversions. During the last decade, a marked increase in the consumption of bottled waters has occurred. Since some of these waters are characterized by high concentrations of Ca, we have studied Ca bioavailability from a Ca-rich water, using 15 lactose intolerant male individuals as subjects, and compared such bioavailability to that from milk. We report herein that the bioavailability of Ca from the water was generally as good as or better than that from milk, a food product well known for its very high Ca bioavailability. Indeed, in eight of 15 subjects, there was a higher level of Ca absorption from mineral water than from milk; bioavailability was equal in five of 15 subjects; in contrast, in two of 15 subjects, the bioavailability of Ca absorption from milk was greater than that from the mineral water. The potential implications of this observation for the prevention and management of age-related bone loss are important for preventive medicine and indicate a new, important source of dietary Ca for lactose intolerant individuals.

Adult↗

[Lactose intolerance. Its definition, its prevalence in Mexico, and its implications in milk consumption].

In this document we describe some aspects of lactose and milk intolerance, discuss the results of studies carried out previously in Mexico, and report an investigation whose objective was to quantify the impact of lactose intolerance on the habitual consumption of milk in an open population. The prevalence of lactose intolerance and its effect on the consumption of milk was studied in three regions of Mexico. The design of the study was prospective, randomized, double-blind and crossover. The presence of milk intolerance was investigated in 960 subjects with ages between 6 months and 99 years who, as a function of age, received 240 or 360 mL of intact milk and the same amount of hydrolyzed milk. We quantified the consumption of milk and the presence of symptoms after ingesting the tested milk. Seven percent manifested symptoms with the intact milk but only 2% with the hydrolyzed milk (p < 0.001). The presence of symptoms in the intolerant subjects was significantly associated with a lower consumption of milk in comparison with the tolerant individuals (p < 0.001). On the other hand, the consumption of milk appeared to be only marginally associated with the intolerance and its symptoms. We conclude that lactose intolerance does not appear to be a major factor in determining milk consumption in Mexican healthy populations.

Adolescent↗

[Use of a fermented powdered milk in malnourished or lactose intolerant children].

Lactase deficient subjects, who form the bulk of the world population, absorb yogurt lactose because the bacteria used for fermentation produce beta-galactosidase. From a milk fermented by these bacteria and dried by a temperature-controlled process a power could be obtained which possess residual lactase activity but, unlike yogurt, does not need storage at low temperature. The lactose of this fermented powdered milk is perfectly absorbed, as proved by hydrogen respiratory tests performed in 35 lactose intolerant African subjects living in isolated villages. In 25 malnourished children under 3 years of age, this milk allowed renutrition without inducing diarrhoea--a result which could not have been obtained with ordinary milk in two-thirds of the cases. This type of food is potentially valuable to feed the large population of the third world.

Adolescent↗

Lactose intolerance in Iran.

One hundred five Iranian subjects, ranging in age from 4 months to 25 years, were tested for lactose absorption and tolerance. After ingesting a lactose dose, on the basis of low blood glucose response, 68% of the subjects were malabsorbers. Prevalence of lactose malabsorption increased with age, i.e., 31% of the children less than 3 years of age malabsorbed lactose, whereas 86% of adults did so. Clinical manifestations of lactose intolerance were shown by 39% of all subjects; of those who were lactose malabsorbers, only 57% manifested clinical symptoms. Among the lactose malabsorbers, the lowest prevalence of clinical symptoms occurred among the children less than 3 years of age and the highest in adults.

Adolescent↗