Effects of laparoscopic Roux-en-Y gastric bypass on glucose-6 phosphate dehydrogenase activity in obese type 2 diabetics.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting enzyme of the pentose phosphate pathway that provides the majority of NADPH required for lipid biosynthesis. G6PD overexpression has been implicated in insulin resistance, hyperlipidemia, and increased oxidative stress in animals. This study examines G6PD expression in obese diabetic and nondiabetic subjects pre- and post-laparoscopic Roux-en-Y gastric bypass (LRYGB). METHODS: Patients undergoing LRYGB were recruited for the IRB-approved study and placed in either the diabetic (n = 11) or nondiabetic group (n = 16) (diabetic, HbA1c > 6.5%; nondiabetic, HbA1c < 6.0%). Blood samples were collected at baseline and throughout the first 3 postoperative months. Liver, adipose, and omental samples were taken during surgery. Results are expressed as mean ± SEM and were compared statistically using the Mann-Whitney test. RESULTS: The two groups were not significantly different at baseline except for fasting glucose and HbA1c. G6PD activity (nm/min/mg protein) was significantly higher in red blood cells (RBCs) (3.12 ± 1.39 vs. 0.67 ± 0.14) and liver (17.23 ± 2.40 vs. 9.74 ± 2.18) in diabetics compared to nondiabetics. There was good correlation between increased liver G6PD activity and the severity of diabetes as measured by HbA1c (r (2) = 0.525) and fasting glucose (r (2) = 0.542). No significant difference was found in the adipose or omental G6PD expression. Both groups experienced a significant increase in G6PD blood activity shortly following surgery (1 week) followed by a reduction 3 months after surgery. CONCLUSION: These results are the first ever seen in human subjects and demonstrate increased G6PD activity in diabetics compared to nondiabetics. These results suggest a correlation between G6PD activity and the severity of type 2 diabetes. The early increases in G6PD activity after LRYGB were unexpected and longer follow-up is needed to determine the effects of LRYGB on G6PD activity.

The effect of Roux-en-Y gastric bypass on prescription drug costs.

BACKGROUND: This study examines the effect of weight loss following laparoscopic Roux-en-Y gastric bypass (RYGBP) for morbid obesity on prescription drug costs in patients over the age of 54. METHODS: 78 patients aged 55 to 75 who met the inclusion criteria were identified in a database of 1,060 morbidly obese patients undergoing LRYGBP between March 2001 and March 2003. All prescription drugs and dosages were recorded preoperatively and postoperatively at 6 months, 1 year, and yearly thereafter. Drug history was obtained from the patient and verified by records from referring physicians' offices. The cost of a 30-day supply of each drug was obtained from 3 retail sources and averaged. RESULTS: The average pre-LRYGBP cost of prescription drugs was $368.65 per month per patient. The average annualized cost at 6 months after LRYGBP was $119.10 per month (down 68%), at 1 year $118.67 (down 68%) and at 2 years $104.68 per month (down 72%). CONCLUSIONS: Weight loss resulting from LRYGBP significantly reduces obesity-related morbidities, resulting in a substantial reduction in medication needs in patients over the age of 54. The projected cost savings realized in the 78 patients in this study amounts to approximately $240,566.04 annually.