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

Calcium deficiency appears to play a central role in the development of involutional osteoporosis, especially in Japan, where calcium intake has been traditionally low, never reaching the current recommended daily allowance (RDA) of 600 mg/d. Compromised 1,25(OH)2 vitamin D synthesis in the aging kidney and age-bound changes of the intestine itself lead to calcium malabsorption; in addition, decreasing dietary intake of fat-soluble vitamins and reduced solar exposure associated with inadequate physical activity may contribute to calcium deficiency in old age. High salt intake and increasing protein and phosphate intake tend to aggravate such a tendency. These factors appear to underlie, in part, the widespread use of vitamin D derivatives for the treatment of osteoporosis in Japan. In 1981, a large-scale, double-blind clinical trial established the superior effect of 1 alpha(OH) vitamin D3 in maintaining bone density over that of placebo. The effect of 0.5 micrograms/d 1,25-(OH)2D3 (calcitriol) in two divided doses compared favorably with that of 1 micrograms/d of 1 alpha(OH) vitamin D3 in a recently conducted multicenter, double-blind study on 596 patients with involutional osteoporosis. Spinal fracture rate was also reduced to one-half by administration of the vitamin D derivative for 1 year to 800 patients with osteoporosis.
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PMID:Studies of osteoporosis in Japan. 232 70

The effects of oral calcitriol (0.25 and 0.50 micrograms/d), together with calcium (1 g/d), on calcium absorption and bone resorption were measured in postmenopausal osteoporotic women with calcium malabsorption. Radiocalcium absorption was significantly improved and urinary hydroxyproline/creatinine excretion significantly reduced on both doses, but the higher dose caused an unacceptable incidence of hypercalcemia. In 49 patients treated for an average of 15 months with the lower dose, there was a nonsignificant gain in forearm bone mass of 0.4 +/- 0.3 mg/cm/mo (approximately 1/2% per annum) compared with a significant decrease in 17 untreated patients of 3.8 +/- 1.3 mg/cm/mo (approximately 5% per annum).
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PMID:Calcium and calcitriol therapy in osteoporotic postmenopausal women with impaired calcium absorption. 232 73

Severe, recalcitrant hypocalcemia and hungry bone syndrome can complicate parathyroidectomy in end-stage renal disease patients. Treatment with prolonged and massive doses of intravenous calcium, with calcitriol supplementation, is often necessary, but potentially dangerous and may prolong hospitalization. Three CAPD patients (including 1 with malabsorption) were safely treated by adding 1 to 3 ampules (10-30 mL) of 10% calcium gluconate solution to each bag of dialysate for up to 29 months. Continuous ambulatory intraperitoneal calcium (CAIC) therapy was initiated postoperatively and continued on an outpatient basis until the patients' hungry bone syndrome resolved and serum calcium normalized. Complications such as visible dialysate precipitation or an increased rate of peritonitis were not observed. Mean total calcium uptake was approximately 137 to 226 mg/exchange. We conclude that CAIC therapy is a safe, effective treatment both for CAPD patients with postparathyroidectomy hypocalcemia with hungry bone syndrome, as well as in patients with hypocalcemia secondary to malabsorption.
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PMID:Successful treatment of postparathyroidectomy hypocalcemia using continuous ambulatory intraperitoneal calcium (CAIC) therapy. 248 83

Conflicting results are reported in the literature concerning the changes in intestinal calcium absorption in rheumatoid arthritis (RA). In the present work, intestinal calcium absorption was studied in 27 postmenopausal women with RA, using whole body counting as the study method and orally administered Ca-47 as the tracer. Nobody was on corticosteroid therapy, but all received non-steroidal anti-inflammatory drugs and hydroxy chloroquine or gold compounds. The mean calcium absorption was 22.3% of the dose administered, with a standard deviation of 8.0%. The results obtained were not significantly different from those of 40 age- and sex-matched controls (mean +/- SD: 22.0% +/- 6.0%). Our findings seem to exclude the hypothesis of calcium malabsorption as one of the causes leading to osteoporosis in RA.
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PMID:Intestinal calcium absorption in rheumatoid arthritis. A study using whole body counting. 251 42

The effect of two avian reovirus isolates (2408 and 1733) on digestion and nutrient metabolism in infected chickens was assessed by an in vitro absorption assay and clinical blood chemistry analysis. Birds of various ages were inoculated orally and intratracheally with reovirus and sampled periodically for the respective assays. Transitory malabsorption was observed in the duodenum of birds infected with reovirus 2408. Conversely, increased absorption was detected in the ileum of these same birds. Clinical blood chemistry analyses of birds infected with both isolates revealed that severely affected birds had abnormally elevated plasma total protein, plasma albumin, and calcium levels. Decreases were found in percent bone ash and, due to abnormally high globulin levels, in albumin:globulin (A:G) ratios. A significant (P less than 0.05) correlation between body weights and total protein, albumin, A:G ratio, and bone ash was found in infected birds. The most pronounced metabolic and physiologic changes occurred in the severely affected birds, and, in general, pathogenicity of the isolates was reflected by the degree of metabolic change.
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PMID:In vitro and in vivo characterization of avian reoviruses. II. Clinical evaluation of chickens infected with two avian reovirus pathotypes. 254 42

Jejunoileal bypass (JIB) has been widely performed for treatment of excessive obesity. Formation of calcium oxalate stones is a common side effect. Since, under physiological conditions, the intestinal absorption of calcium and that of oxalate are interrelated, intestinal oxalate and calcium absorption were measured in the present study by isotope techniques in 19 JIB patients and 20 healthy controls. The JIB patients showed pronounced hyperoxaluria and markedly increased absorption of oxalate, with a urinary excretion of 14C-oxalate of 29 +/- 19% (controls 6.2 +/- 3.7%; p less than 0.001). There was a strong correlation between the intestinal absorption and urinary excretion of oxalate in the JIB patients (r = 0.72; p less than 0.001). Furthermore, their oxalate kinetics was altered, with continued urinary excretion of 14C-oxalate for up to 48 hours. The JIB patients also had reduced calcium absorption (36 +/- 9.1% vs. 47 +/- 9.0%; p less than 0.001) and patients with malabsorption of calcium and low urinary calcium had the highest intestinal absorption and urinary excretion of oxalate. It is concluded that hyperoxaluria in JIB patients is due to a significant extent to hyperabsorption of oxalate.
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PMID:Intestinal absorption of oxalate and calcium in patients with jejunoileal bypass. 259 24

Electrolytic imbalance is a frequent finding in malabsorption syndrome. Derangement of calcium metabolism present clinically in different variants is most serious. Some patients develop hypocalcemia manifesting clinically with specific myasthenia, paresthesias, convulsions, hemorrhages, etc. In other variants severe skeletal lesions are seen which may become dominating in the clinical picture though hypocalcemia was absent. Investigation of calcium metabolism, hormonal profile (parathormone, in particular) in malabsorption syndrome can prognosticate and prevent the onset of osteomalacia.
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PMID:[Osteopathy in malabsorption syndromes]. 261 13

Calcium deficiency causes osteoporosis in experimental animals because the skeleton is sacrificed for the preservation of the plasma (ionic) calcium and to meet obligatory calcium losses in the feces and urine. (Vitamin D deficiency, on the other hand, causes rickets and osteomalacia largely because of the loss of the calcemic action of vitamin D, which leads to hypocalcemia, secondary hyperparathyroidism, and hypophosphatemia.) The concept that human osteoporosis, particularly in postmenopausal women, results from negative calcium balance represents a working hypothesis that fits many, but not all of the available data. In normal women, the crucial event is a rise in obligatory urinary calcium loss, which may result from an increase in the complexed fraction of the plasma calcium, due in turn to an increase in plasma bicarbonate. Prospective trials with calcium supplements have, however, yielded conflicting results. In osteoporotic women, a further increase in urinary calcium combined with calcium malabsorption produces a further increase in bone resorption, but some impairment of bone formation due to declining androgens may constitute an additional risk factor with advancing age. The suppressibility of urinary hydroxyproline by calcium supplementation in those patients who can absorb calcium, and by calcitriol in those who cannot, supports the calcium deficiency model, but more trials are needed to establish its validity.
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PMID:The calcium deficiency model for osteoporosis. 264 3

Glucocorticoid induced osteoporosis (GC-OP) is the most important form of all secondary osteoporoses. Mainly from in vitro and animal studies a lot of information exists concerning the underlying pathogenetic mechanisms. Some findings are still controversial but it is generally accepted that the three most important mechanisms are inhibition of osteoblastic matrix formation, stimulation of osteoclastic bone resorption and deterioration of intestinal calcium resorption with consecutive mild secondary hyperparathyroidism. In the individual patients the time between the beginning of corticoid therapy and clinical manifestation of osteoporosis varies considerably. If there is really a threshold dosage of corticoids is still debated. Besides dosage and duration of steroids age, sex, other risk factors of osteoporosis and underlying disease may be important factors. In contrast to the clinical prominence of GC-OP only little experience exists in counteracting the detrimental effects of corticoids on bone tissue. For pure prevention it seems reasonable to overcome intestinal calcium malabsorption by calcium or vitamin D. Concerning treatment of manifest GC-OP we studied the effect of salmon calcitonin (sCT) in patients with chronic obstructive lung disease. 18 patients injected themselves 100 U sCT every second day subcutaneously while 18 randomized patients served as untreated controls. There was a significant pain reduction in the sCT group and after six months the mineral content of the distal radius had increased by 2.7% despite a daily mean intake of 16.2 mgs prednisone during that time. In the control group (mean daily prednisone dose 16.8 mgs) the mineral content decreased with 3.5% on the average (p less than 0.001).
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PMID:Glucocorticoid-induced osteoporosis. 266 65

The effect of a long acting somatostatin analogue SMS 201-995 on stomal effluents in patients with severe short bowel syndrome was investigated in a double blind placebo controlled balance study. Six patients, five with Crohn's disease and one with radiation enteropathy were studied. Five patients had a jejunostomy and one an ileostomy. The patients had a normal food intake, but because of severe malabsorption had received home parenteral nutrition for several years. Faecal mass was reduced (p less than 0.005) and intestinal net sodium absorption was increased (p less than 0.005) by intravenous infusion of SMS 25 micrograms/h. Net absorption of potassium, calcium, magnesium phosphate, zinc, nitrogen and fat was not influenced. Subcutaneous injections of 50 micrograms SMS every 12 hours had a similar effect on net intestinal absorption of sodium and water. Four patients continued with a five to six months open follow up study when subcutaneous SMS in the same dose was administered by the patients at home. The effect on faecal sodium loss persisted, but in one patient faecal mass gradually increased and finally exceeded pretreatment values. SMS may decrease net absorption of water and sodium following reduced secretion of digestive juices rather than by increasing absorptive capacity. SMS may be useful as an antidiarrhoeal drug in patients with high output jejuno- or ileostomies, but in patients who need permanent parenteral nutrition the effect is too small to significantly alter management.
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PMID:Effect of a long acting somatostatin analogue SMS 201-995 on jejunostomy effluents in patients with severe short bowel syndrome. 231 26


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