Selenium depletion in patients with gastrointestinal diseases: are there any predictive factors?

BACKGROUND: Patients with intestinal disease are at risk of developing selenium deficiency due to impaired intestinal absorption. The aim of the present study was to evaluate selenium status and to identify predictive factors of selenium depletion in patients with gastrointestinal disease. METHODS: The concentration of selenium and the activity of glutathione peroxidase in plasma and erythrocytes were measured by fluorometry and by spectrophotometry. Eighty-six patients with Crohn's disease, 40 patients with ulcerative colitis, and 39 patients with various other gastrointestinal diseases were studied. Twenty-seven patients (16%) received home parenteral nutrition. Stool mass, faecal fat, and vitamin B12 absorption were analysed in 100 patients. RESULTS: The plasma selenium concentration was decreased in 85% of the patients receiving supplementary parenteral nutrition and in 20% of the patients receiving oral nutrition, among them in 26% of the patients with Crohn's disease. Almost all patients with ulcerative colitis had normal selenium levels. A statistically significant correlation was found between plasma selenium and vitamin B12 absorption, stool mass, faecal fat excretion, body mass index, P-albumin, P-zinc, and the length of the remaining small bowel. Stepwise regression analyses showed that the strongest predictors of selenium deficiency were stool mass, vitamin B12 absorption, and the length of the small-bowel resection. CONCLUSION: Selenium deficiency is common in patients with severe gastrointestinal disorders. The deficiency is mainly related to malabsorption, and a low selenium level was almost invariably present in patients who needed parenteral supplementation due to gut failure.

The metabolism of [75Se]selenite in patients with short bowel syndrome.

BACKGROUND: Patients on home parenteral nutrition (HPN) require significantly higher amounts of selenium compared with controls. The purpose of the present study was to investigate if selenium deficiency of patients with short bowel syndrome is caused by selenium malabsorption or by excessive intestinal or renal loss. METHODS: The metabolism of [75Se]selenite was investigated in eight selenium-depleted short bowel patients on HPN and in six control subjects. The isotope was given orally, and in a subsequent study as bolus injection or as 12-hour IV infusion. RESULTS: The fractional intestinal absorption of selenium was significantly reduced in the patients (2% to 58%, median 20%) when compared with the reference group (79% to 91%, median 82%) (p < .001). Within the group of patients we found a positive significant correlation between fractional selenium absorption and the length of the remaining small intestine (r = 0.95, p < .05). After parenteral [75Se]selenite administration, the patients showed a significantly higher fecal loss and a significantly reduced urinary excretion of 75Se when compared with the controls. Bolus injection vs 12-hour infusion of [75Se]selenite did not affect the cumulative fecal or urinary 75Se excretion in the HPN patients. CONCLUSIONS: Reduced intestinal selenium absorption is probably the most important cause of the selenium deficiency reported in patients with short bowel syndrome, but increased endogenous intestinal selenium loss and low selenium intake may also contribute. Despite the renal counterregulation, which results in a low urinary selenium excretion, HPN patients need a supply of selenium with their parenteral nutrition.

Bone loss and oral state in patients on home parenteral nutrition.

BACKGROUND: The purpose was to analyze changes in the mandible and the forearm bone mineral content and oral state in patients on home parenteral nutrition due to short bowel syndrome in relation to the bone mineral values and oral findings in a normal population. METHODS: The bone mineral content was measured by dual-photon absorptiometry and the dental and periodontal state were studied in 15 adults patients (12 women, and 3 men, aged 26 to 65 years). All patients were on free oral intake as a supplement to the parenteral nutrition. RESULTS: Forty-seven percent of the patients (2 males, 2 young and 3 elderly females) showed mandibular osteoporosis (Z-scores < -2.00), and all young females showed Z-scores < 0. Moreover, 34% of the patients showed osteoporosis in the forearm bones (Z-scores < -2.00) and also radiographic signs of osteoporotic fractures of the columna. The dental and the periodontal state in the patients did not differ clearly from that of the normal Danish population of the same age. CONCLUSIONS: Such patients seem to have a high risk of developing systemic osteoporosis, including the jaws, but apparently do not show a higher risk for deterioration of the dental or periodontal state than age-matching normals from the same population.

The effect of selenium supplementation on skeletal and cardiac muscle in selenium-depleted patients.

BACKGROUND: The purpose of the present study was to evaluate the effect of sodium selenite on skeletal and cardiac muscular function in patients with severe Se deficiency. METHODS: Skeletal and cardiac muscular function was investigated in 10 selenium depleted patients on long-term home parenteral nutrition because of short bowel syndrome. The following examinations were applied: Skeletal muscle biopsy, muscular force test (Kin-Com dynamometer test), electromyography (EMG) and radionuclide ventriculography. The patients were blindly randomized to intravenous supplementation with selenium 200 micrograms 5 to 7 times per week or placebo for 4 months. Hereafter the examinations were repeated. The patients randomized to placebo received selenium in an open study for a further 4 months and hereafter their skeletal and cardiac function was reevaluated. RESULTS: Plasma selenium increased to normal levels from median .21 mumol/l (range 0-.69) to 1.25 mumol/l (range .9-2.27) following selenium repletion. The muscle biopsies showed only minor abnormalities. The only change after selenium supplementation was a small but statistically significant increase of the mean diameter of fiber type 1. The muscle strength of the quadriceps muscle was unchanged after selenium substitution. EMG did not reveal signs of myopathy. The cardiac function was normal and remained unchanged. CONCLUSION: Despite severe selenium depletion ten patients on long term home parenteral nutrition had normal cardiac function, and no clinically significant signs of skeletal myopathy. The only change after selenium supplementation was a small but statistically significant increase of the mean diameter of muscle fiber type 1.

Selenium depletion in patients on home parenteral nutrition. The effect of selenium supplementation.

Severe selenium (Se) depletion was found in nine patients receiving long-term home parenteral nutrition because of short bowel syndrome. Plasma Se ranged from 0-0.51 (median 0.21 mumol/L), and erythrocyte Se ranged from 0.7-2.6 (median 1.8 mumol/gHgb), which was significantly lower than in the controls. Glutathione peroxidase (GSHPx) in plasma and erythrocytes was also decreased. After bolus injections with 200 micrograms Se/d in the form of sodium selenite for 4 mo, followed by 100 micrograms/d for 8 mo, plasma Se increased to values slightly but significantly higher than in the controls. Erythrocyte Se reached normal levels in most of the patients after 4 mo substitution, but it remained lower than in the controls. Following Se supplementation, plasma and erythrocyte GSHPx did not differ between patients and controls. These data suggest that all patients receiving long-term parenteral nutrition because of short bowel syndrome should receive at least 100 micrograms sodium selenite/d when given as bolus injections to avoid Se depletion.

Selenium status in patients with Crohn's disease.

Twenty-seven of 66 patients with Crohn's disease had reduced concentrations of selenium and glutathione peroxidase in plasma and erythrocytes. When the patients were subgrouped according to the length of resected small bowel, a significant reduction of selenium and glutathione peroxidase in both plasma and erythrocytes was only found in patients with a resection > 200 cm. A highly significant correlation between selenium and glutathione peroxidase was found in plasma (r = 0.81) as well as in erythrocytes (r = 0.62), but no correlation was observed in the control group. A statistically significant correlation was also found between plasma selenium and the Harvey-Bradshaw score (r = -0.44), body mass index (wt/ht2) (r = 0.47), and plasma albumin (r = 0.29). Patients with a small-bowel resection > 200 cm appear to be at risk of developing severe selenium deficiency. These patients should have their selenium status monitored and probably receive selenium supplementation.

Calcium treatment of enteric hyperoxaluria after jejunoileal bypass for morbid obesity.

The effect of oral calcium on oxalate absorption was studied in eight patients with secondary hyperoxaluria after jejunoileal bypass for morbid obesity during a standardized diet with a fixed supply of fat, calcium, and oxalate. A supplementary calcium dose of 2000 mg/day reduced renal oxalate excretion from 119 to 60 mg/24 h (median values, p < 0.01). Correspondingly, 14C-oxalate absorption decreased from 28% to 9% (p < 0.01). No statistically significant increase in urinary calcium was observed. The study shows that renal oxalate excretion in patients with enteric hyperoxaluria can be reduced by oral calcium. However, we doubt that it has any practical, clinical importance.