Oral copper absorption in men with morbid obesity

Copper deficiency has been reported in patients with severe obesity, both before and after bariatric surgery, the latter at increased rates. However, little is known about the absorption of copper. Because of differences in copper dynamics between men and women in the limited available data, we evaluated copper absorption in men who were candidates for bariatric surgery. All patients gave informed consent, approved by the University of Pennsylvania Institutional Review Board, to participate in a pharmacokinetics study. After a 12-h fast, body composition was measured using air displacement plethysmography and a single oral dose of 4mg copper gluconate was given followed by serial measures of serum copper over 10h. Meals and snacks very low in copper were provided. The seven participants had age 52±8years, BMI 44.87±9.01kg/m² and fat free mass 77.92±14.45kg. Baseline serum copper was 36.1±19.5μg/dL and ceruloplasmin was 50.86±4.58mg/dL. Peak copper absorption occurred within 1-2h. The AUC for six subjects was 254.6±151.3μg/100mLh. The estimated volume of distribution (1.98±0.36L) was ∼25mL/kg fat free mass. In these severely obese men, copper absorption occurred early in spite of their normal copper status, suggesting no impairment of absorption due to obesity. Further studies of copper absorption after the significant weight loss and possible malabsorption derived from bariatric surgery are needed.