Plasma zinc and copper in obesity and after intestinal bypass.

Plasma concentrations of zinc and copper were measured in 15 obese patients before intestinal bypass surgery, in 27 patients after intestinal bypass surgery, and in 52 lean control subjects. Preoperatively, the obese patients had zinc concentrations that were significantly lower than in the lean control subjects (76 +/- 3 versus 89 +/- 2 microgram/dl) (+/- SEM) and copper levels that were significantly higher (147 +/- 10 versus 119 +/- 3 microgram/dl). After intestinal bypass, plasma zinc and copper concentrations were significantly lower (zinc, 62 +/- 2 microgram/dl; copper, 90 +/- 5 microgram/dl; P less than 0.001) than in prebypass patients. One patient developed leukopenia associated with a plasma copper concentration of 36 microgram/dl. Leukocyte count and plasma copper level rose with oral copper sulfate replacement therapy. Intestinal bypass surgery may produce clinically significant decreases in plasma concentrations of zinc and copper. Careful observation and replacement therapy are indicated in all patients who develop deficiences after intestinal bypass surgery.