Long-Term Iron and Vitamin B12 Deficiency Are Present after Bariatric Surgery, Despite the Widespread Use of Supplements.

There are few long-term nutritional studies in subjects undergoing bariatric surgery that have assessed weight regain and nutritional deficiencies. In this study, we report data 8 years after surgery on weight loss, use of dietary supplements and deficit of micronutrients in a cohort of patients from five centres in central and northern Italy. The study group consisted of 52 subjects (age: 38.1 ± 10.6 y, 42 females): 16 patients had Roux-en-Y gastric bypass (RYGB), 25 patients had sleeve gastrectomy (SG) and 11 subjects had adjustable gastric banding (AGB). All three bariatric procedures led to sustained weight loss: the average percentage excess weight loss, defined as weight loss divided by excess weight based on ideal body weight, was 60.6% ± 32.3. Despite good adherence to prescribed supplements, 80.7% of subjects (72.7%, AGB; 76.7%, SG; 93.8 %, RYGB) reported at least one nutritional deficiency: iron (F 64.3% vs. M 30%), vitamin B12 (F 16.6% vs. M 10%), calcium (F 33.3% vs. M 0%) and vitamin D (F 38.1% vs. M 60%). Long-term nutritional deficiencies were greater than the general population among men for iron and among women for vitamin B12.

Endothelial dysfunction and increased oxidative stress in mitochondrial diseases.

MDs (mitochondrial diseases) are a clinically heterogeneous group of disorders characterized by impairment of the respiratory chain function with altered oxidative phosphorylation. We tested the hypothesis that the function of vascular endothelium is affected by increased oxidative stress in MDs. A total of 12 patients with MDs and pair-matched controls were studied. Endothelial function was assessed by measuring FMD (flow-mediated vasodilation) of brachial and common femoral arteries. The test was repeated after vitamin C (500 mg, twice a day) and E (400 mg, once a day) supplementation for 30 days and 90 days after vitamin withdrawal. FMD was reduced in patients compared with controls [AUC/τ (time-averaged area under the curve) for the brachial artery, 1.05±0.24 compared with 4.19±0.59% respectively, P<0.001; AUC/τ for the femoral artery, 0.98±0.19 compared with 2.36±0.29% respectively, P=0.001; values are means±S.E.M.] and correlated (brachial artery) with plasma lactate (r=-0.63, P<0.01). Urinary 8-iso-PGF2α (8-iso-prostaglandin F2α) was higher in patients than controls (505.6±85.9 compared with 302.5±38.7 pg/mg of creatinine; P<0.05) and correlated with plasma lactate (r=0.70, P<0.05). Immunohistochemical analysis showed 8-iso-PGF2α staining in MD-affected striated muscle cells and in blood vessels in muscle biopsies of patients. Antioxidant vitamins transiently restored FMD in patients [ΔAUC/τ (change in AUC/τ) for the brachial artery, +1.38±0.49%, P<0.05; ΔAUC/τ for the femoral artery, +0.98±0.24%, P<0.01] but had no effect on FMD in controls (brachial artery, -1.3±0.63%; and common femoral artery, -0.58±0.30%), thus abolishing the differences between patients and controls. The results of the present study indicate that oxidative stress is increased and is, at least partly, responsible for endothelial dysfunction in MDs.