Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Osteoporosis and magnesium (Mg) deficiency often occur in malabsorption syndromes such as gluten-sensitive enteropathy (GSE). Mg deficiency is known to impair parathyroid hormone (PTH) secretion and action in humans and will result in osteopenia and increased skeletal fragility in animal models. We hypothesize that Mg depletion may contribute to the osteoporosis associated with malabsorption. It was our objective to determine Mg status and bone mass in GSE patients who were clinically asymptomatic and on a stable gluten-free diet, as well as their response to Mg therapy. Twenty-three patients with biopsy-proven GSE on a gluten-free diet were assessed for Mg deficiency by determination of the serum Mg, red blood cell (RBC) and lymphocyte free Mg2+, and total lymphocyte Mg. Fourteen subjects completed a 3-month treatment period in which they were given 504-576 mg MgCl2 or Mg lactate daily. Serum PTH, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and osteocalcin were measured at baseline and monthly thereafter. Eight patients who had documented Mg depletion (RBC Mg2+ < 150 microM) underwent bone density measurements of the lumbar spine and proximal femur, and 5 of these patients were followed for 2 years on Mg therapy. The mean serum Mg, calcium, phosphorus and alkaline phosphatase concentrations were in the normal range. Most serum calcium values fell below mean normal and the baseline serum PTH was high normal or slightly elevated in 7 of the 14 subjects who completed the 3-month treatment period. No correlation with the serum calcium was noted, however. Mean serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and osteocalcin concentrations were also normal. Despite only 1 patient having hypomagnesemia, the RBC Mg2+ (153 +/- 6.2 microM; mean +/- SEM) and lymphocyte Mg2+ (182 +/- 5.5 microM) were significantly lower than normal (202 +/- 6.0 microM, p < 0.001, and 198 +/- 6.8 microM, p < 0.05, respectively). Bone densitometry revealed that 4 of 8 patients had osteoporosis of the lumbar spine and 5 of 8 had osteoporosis of the proximal femur (T-scores < or = -2.5). Mg therapy resulted in a significant rise in the mean serum PTH concentration from 44.6 +/- 3.6 pg/ml to 55.9 +/- 5.6 pg/ml (p < 0.05). In the 5 patients given Mg supplements for 2 years, a significant increased in bone mineral density was observed in the femoral neck and total proximal femur. This increase in bone mineral density correlated positively with a rise in RBC Mg2+. This study demonstrates that GSE patients have reduction in intracellular free Mg2+, despite being clinically asymptomatic on a gluten-free diet. Bone mass also appears to be reduced. Mg therapy resulted in a rise in PTH, suggesting that the intracellular Mg deficit was impairing PTH secretion in these patients. The increase in bone density in response to Mg therapy suggests that Mg depletion may be one factor contributing to osteoporosis in GSE.
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PMID:Magnesium deficiency: possible role in osteoporosis associated with gluten-sensitive enteropathy. 911 91

The search for diets to improve the nutritive utilization of protein and magnesium in malabsorption syndrome led us to study goat milk, because of its particular nutritional characteristics, and to compare it with cow milk, which is most commonly consumed. We studied the nutritive utilization of protein and magnesium in transected rats (control) and in rats with resection of 50% of the distal small intestine. The diets used were the standard diet recommended by the American Institute of Nutrition and diets based on lyophilized goat or cow milk. The consumption of goat milk produces better protein efficiency ratio and food conversion efficiency values, particularly in rats with intestinal resection, together with a higher nutritive utilization of protein. Magnesium apparent digestibility coefficient is not modified by intestinal resection in rats fed with goat milk-based diet, on the contrary to the standard and cow milk diets. Magnesium apparent digestibility coefficient is greater for the goat milk group, which is reflected in the greater quantity of this mineral stored in bone. These results demonstrate the beneficial effect of goat milk on the nutritive utilization of protein and on magnesium bioavailability, especially in animals with resection of the distal small intestine.
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PMID:Study of nutritive utilization of protein and magnesium in rats with resection of the distal small intestine. Beneficial effect of goat milk. 1450 32

Cardiovascular (CV) complications, associated with space flight (SF), are caused by microgravity, hypokinesia and radiation, particularly beyond earth orbit, with all three conducive to oxidative stress. Except for emergencies, pharmaceuticals appear to be contraindicated, because of unpredictable side effects from malabsorption (M) and potential hepatic and renal impairment. Magnesium (Mg) depletion and elevations of cytokines (interleukin 6) occur during SF, conducive to self-sustaining vascular inflammation mechanisms. There are potential endothelial injuries (EI) and reduced Cyclic GMP (a second messenger of nitric oxide: NO) and elevated urinary excretion of C-peptide (insulin resistance: IR). Recent findings that show reductions in vascular endothelial growth factor (VEGF) suggest that this may result from SF-related thrombocytopenia since platelets (P) are the major source of VEGF, and that NO might play a role. Both VEGF and Mg are vital for angiogenesis, endothelial function and reendothelialization. Insulin is necessary for VEGF expression. To prevent SF-related CV complications in the presence of IR and M and with the potential for renal insufficiency, closely monitored subcutaneous (SC) Mg should be provided. The dosage can be monitored by sublingual intracellular Mg assays. Needed is development of a SC Mg reservoir device, which can be replenished before extra-vehicular activities (EVA) and which must be reliable despite vigorous movements during EVA, that can last up to 8 hours. This could also be protective against decompression sickness and EVA-related 100% oxygen requirements before and during this activity, both of which predispost to EI.
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PMID:The case for a subcutaneous magnesium product and delivery device for space missions. 1546 57


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