Fluoride exposure and bone status in patients with chronic intestinal failure who are receiving home parenteral...

Metabolic bone disease is frequent in chronic intestinal failure. Because fluoride has a major effect on bones, the status of both fluoride and bone was studied in long-term home parenteral nutrition (HPN) patients.

We studied 31 adults aged (x +/- SD) 56.3 +/- 15.1 y, mainly patients with short-bowel syndrome, who had been receiving HPN for >1 y. Bone mineral density (BMD) was measured by absorptiometry, and serum fluoride was measured by using a fluoride-sensitive electrode. All patients ate and drank ad libitum. HPN (3.4 +/- 1.2 times/wk) complemented oral nutrition. Potential explicative factors were estimated by using a linear regression model (mixed-effects model).

Of 120 fluoride dosages (2-6/patient), 102 were above the upper normal limit (1.58 micromol/L) at the laboratory. Mean (+/- SD) daily fluoride supply was 8.03 +/- 7.71 mg (US adequate intake: 3.1 mg/d for women and 3.8 for men; tolerable upper normal limit: 10 mg/d); intravenous fluoride varied from 0.06 to 1.45 mg, and oral fluoride varied from 0.09 to 27.8 mg. Serum fluoride concentrations were correlated with creatinine clearance and fluoride supply. BMD was significantly lower in the femoral neck than in the spinal area. After adjustment for sex and the duration of HPN, only the effect of serum fluoride on spinal BMD was significant. Two patients had symptoms of fluorosis, eg, calcaneum fissures, interosseous calcifications, or femoral neck osteoporosis.

In chronic intestinal failure, high intakes of fluoride are frequent because of the beverages ingested to compensate for stool losses. Hyperfluoremia has an effect on bone metabolism and may increase skeletal fragility. The consumption of fluoride-rich beverages for extended periods is therefore not advisable.