Nutrient Transporter Expression in the Jejunum in Relation to Body Mass Index in Patients Undergoing Bariatric Surgery.

Nutrient tranters (NT) facilitate nutrient absorption and contribute to the regulation of circulating nutrients. In this cross-sectional study, we determined the associations between the level of obesity; mRNA abundance for NTs; and serum concentrations of amino acids, short-chain fatty acids, and glucose in patients with morbid obesity undergoing a Roux-en-Y gastric bypass. Proximal jejunal samples were obtained at the time of surgery from 42 patients (90% female, age = 42.6 ± 11.9 years, pre-operative body mass index (BMI) = 55.5 ± 11.3 kg/m²) undergoing a Roux-en-Y gastric bypass. RNA was extracted from the jejunal mucosa and quantitative real-time-PCR was performed for the NTs studied. BMI negatively correlated with jejunal mRNA abundance of the amino acid NTs TauT (r = -0.625, p < 0.0001), ASCT2 (r = -0.320, p = 0.039), LAT1 (r = -0.304, p = 0.05). BMI positively correlated with jejunal mRNA abundance of the lactate/short-chain fatty acid NT SMCT1 (r = 0.543, p = 0.0002). Serum concentrations of the short-chain fatty acids, butyric, valeric, and isocaproic acid correlated positively with BMI (n = 30) (r = 0.45, r = 0.44, r = 0.36, p ≤ 0.05; respectively). Lower jejunal mRNA abundance for the amino acid NTs TauT, ASCT2, and LAT1 could protect against further obesity-related elevations in circulating amino acids. The positive correlation between BMI and the jejunal mRNA abundance of the high-affinity short-chain fatty acid/monocarboxylate transporter SMCT1 is intriguing and requires further investigation.

Outcomes among elderly bariatric patients at a high-volume center.

BACKGROUND: Bariatric surgery in elderly patients remains controversial. With a growing morbidly obese elderly population, management strategies and treatment outcomes need to be evaluated. METHODS: We reviewed all bariatric cases from 2001 to 2005 at a single institution. The preoperative factors (body mass index, smoking status, co-morbid conditions, number of medications) and surgical information (operation and length of stay) were recorded. Patients >60 years old who had undergone Roux-en-Y gastric bypass (RYGB) were followed up, and their surgical outcomes were analyzed (reduction in medications, resolution of diabetes mellitus and hypertension, percentage of excess body weight loss, complications, and mortality). RESULTS: Of 1065 patients, 76 (7.1%) were aged > or =60 years. Of these 76 patients, 61 (5.7%) underwent RYGB. The other 989 patients (92.9%) were <60 years old, and 952 of these underwent RYGB. In the older group, the mean number of co-morbid conditions was 10 +/- 3.3, 70.5% had diabetes, and 83.6% had hypertension. In the younger group, the mean number of co-morbidities was 4.7 +/- 2.3. The mean number of preoperative medications was 10 +/- 4.5 in the older group compared with 6.0 +/- 4.3 in the younger group. The mean length of stay was 2.9 days in both groups. Postoperatively, medications were reduced by nearly 50% in both groups. Diabetes and hypertension resolved or improved significantly in both groups. The mean percentage of excess body weight loss was lower in the older patients (54.9% versus 60.1%; P = .09). The 90-day operative mortality rate was 1.64% in the older group versus 0.53% for the younger group (P = NS). CONCLUSION: Our data support the use of RYGB in older patients in programs prepared to comprehensively manage the medical co-morbidities. Although the percentage of excess body weight loss was less, the mortality was acceptable despite the greater number of co-morbidities. Both diabetes and hypertension were more common in this population, with trends toward better improvement after RYGB than in younger patients.