Economic evaluation of the use of octreotide for prevention of complications following pancreatic resection

Recent studies have concluded that octreotide can prevent complications in patients undergoing pancreatic resections. Given the acquisition cost of octreotide, a cost-effectiveness analysis was performed to establish whether if the additional cost associated with its use was justified by a decrease in the consumption of other resources. To evaluate success rates and complication rates, a meta-analysis of double-blind, randomized, controlled clinical trials was conducted. The rates for pancreatic fistula and fluid collection were 10.7% (95% confidence interval [CI] 7.9 to 13.4) and 3.6% (95% CI 1.9 to 5.2) for octreotide vs. 23.4% (95% CI 19.7 to 27. 1) and 8.8% (95% CI 6.2 to 11.3) for placebo. In a second phase we evaluated the treatment cost for patients with and without complications using two different models of cost savings. In the first model the cost to treat a pancreatic fistula was calculated as the per diem rate (as determined by Statistics Canada) multiplied by the incremental length of stay associated with the complication. In the second model we used data from institutions participating in the Ontario Case Costing Project. In model 1 the estimated incremental length of hospital stay attributed to a pancreatic fistula was 7 days, based on a review of the literature, and the per diem was $552. In model 2 the average cost of care for patients with or without complication was $32,347 (n = 17; 95% CI $20,882 to $43,812) and $11, 169 (n = 18; 95% CI $7558 to $14,779), respectively. The data suggest that when compared to placebo, octreotide is a dominant treatment strategy. In model 1, in a cohort of 100 patients, octreotide saved an average of $853 per patient while allowing 16 incremental patients to avoid complications. In model 2 use of octreotide resulted in an average savings of $1642 per patient while still allowing 16 patients to avoid complications. Detailed one-way and two-way sensitivity analyses suggest that both models were robust. The use of octreotide is a cost-effective strategy in patients undergoing elective pancreatic resection. Consideration should be given to extending its use to patients who are at high risk for development of complications following pancreatic surgery and who do not have any contraindications to the use of this drug.

A pharmacoeconomic analysis of Neoral without intravenous cyclosporine in liver transplantation in Canada

Neoral, a microemulsion formulation of cyclosporin A (CsA), has improved absorption compared to Sandimmune and has allowed induction of immunosuppression in liver transplantation (LT) without the use of intravenous (i.v.) CsA. The improved bioavailability with less inter- and intra-patient dosing variability coupled with the lack of requirement for i.v. CsA may provide a mechanism for cost savings when Neoral is used for induction immunosuppression. This retrospective case-control study compares the relative costs associated with Neoral induction without i.v. CsA versus induction with i.v. CsA followed by oral CsA in adult liver transplant recipients. Twenty consecutive patients receiving Neoral 12-15 mg/kg per d were compared to a control group of 21 patients receiving i.v. CsA followed by oral CsA for induction. Both groups received the same rapidly tapered dose of methyl-prednisilone. Health care resource utilization was assigned based on days in hospital and acute rejection episodes (ARE). Hospital per diem rates at specified care levels were used to assign costs associated with hospital stay, while a previously developed case-costing model was used to assign costs to episodes of acute rejection. All patients were followed for a 3-month period post-transplant. Although there was a trend towards shorter hospital stay in the Neoral group the majority of cost savings were achieved by reducing costs associated with episodes of acute rejection. There were seven and 19 episodes of ARE in the Neoral and i.v. CsA groups respectively (p < 0.05.) A separate cost effective assessment of the effect of reducing rejection by decision tree analysis demonstrated a cost reduction of $2162 per patient. The savings achieved with Neoral proved robust on sensitivity analysis. The change of practice to an induction immunosuppression regimen of Neoral without i.v. CsA has achieved a cost savings in adult liver transplantation at our center.

Mitochondrial DNA sequence polymorphism, VO2max, and response to endurance training

Mitochondrial DNA sequence variation was determined in 46 sedentary young adult males who took part in ergocycle endurance training programs in two laboratories to assess whether mitochondrial DNA variants were associated with individual differences in maximal oxygen uptake (VO2max) and its response to training. VO2max was obtained from a progressive ergocycle test to exhaustion. White blood cell mitochondrial DNA was characterized with the restriction fragment length polymorphism (RFLP) technique using 22 restriction enzymes and human mitochondrial DNA as a probe for hybridization. Multiple mitochondrial DNA variants were detected with 15 of the enzymes. Some subjects exhibited many RFLPs, while others showed no variation. These RFLPs (morphs) were generated by base substitutions located in gene regions coding for mitochondrial proteins as well as in the noncoding regions. Carriers of three mitochondrial DNA morphs, two in the subunit 5 of the NADH dehydrogenase gene and one in the tRNA for threonine, had a VO2max (ml.kg-1.min-1) in the untrained state significantly higher than noncarriers, while carriers of one mitochondrial DNA morph in subunit 2 of NADH dehydrogenase had a lower initial VO2max. Endurance training increased VO2max by a mean of 0.5 l of O2, with individual differences ranging from gains of 0.06 to 1.03. After adjustment for training site and initial VO2max, a lower response was observed for three carriers of a variant in subunit 5 of the NADH dehydrogenase detected with HincII (mean gain of 0.28 l; P < 0.05). These results suggest that sequence variation in mitochondrial DNA may contribute to individual difference in VO2max and its response to training.

Metabolic responses to exercise. Effects of endurance training and implications for diabetes

In this study, some important metabolic responses to exercise will be discussed, and aspects of particular interest for patients with diabetes mellitus will be emphasized. Alterations in the metabolic responses to exercise induced by physical endurance training and consequences of training for metabolism of plasma lipids and lipoproteins will be discussed. Glucoregulation during exercise is not perfect in normal subjects and is less so in patients with diabetes mellitus. For instance, during intense exercise, large increases in the plasma glucose concentration occur and a state of insulin resistance exists for a few hours after intense exercise. Even so, increased sensitivity to insulin is found the day after intense exercise and also shortly after more moderate intensity exercise, both in healthy subjects and in patients with diabetes mellitus. Increased sensitivity to insulin is also found after endurance training, whereas insulin sensitivity is decreased after inactivity. Exercise training increases the ability of muscle to take up and oxidize free fatty acids during exercise and also increases the activity of the enzyme lipoprotein lipase in muscle. The activity of lipoprotein lipase in muscle correlates with muscle insulin sensitivity. This might explain why insulin resistance is often associated with hypercholesterolemia, hypertriglyceridemia, and low high-density lipoprotein cholesterol.

Mitochondrial DNA sequence polymorphism, VO2max, and response to endurance training

Mitochondrial DNA sequence variation was determined in 46 sedentary young adult males who took part in ergocycle endurance training programs in two laboratories to assess whether mitochondrial DNA variants were associated with individual differences in maximal oxygen uptake (VO2max) and its response to training. VO2max was obtained from a progressive ergocycle test to exhaustion. White blood cell mitochondrial DNA was characterized with the restriction fragment length polymorphism (RFLP) technique using 22 restriction enzymes and human mitochondrial DNA as a probe for hybridization. Multiple mitochondrial DNA variants were detected with 15 of the enzymes. Some subjects exhibited many RFLPs, while others showed no variation. These RFLPs (morphs) were generated by base substitutions located in gene regions coding for mitochondrial proteins as well as in the noncoding regions. Carriers of three mitochondrial DNA morphs, two in the subunit 5 of the NADH dehydrogenase gene and one in the tRNA for threonine, had a VO2max (ml.kg-1.min-1) in the untrained state significantly higher than noncarriers, while carriers of one mitochondrial DNA morph in subunit 2 of NADH dehydrogenase had a lower initial VO2max. Endurance training increased VO2max by a mean of 0.51 of O2, with individual differences ranging from gains of 0.06 to 1.03. After adjustment for training site and initial VO2max, a lower response was observed for three carriers of a variant in subunit 5 of the NADH dehydrogenase detected with HincII (mean gain of 0.28 I; P less than 0.05). These results suggest that sequence variation in mitochondrial DNA may contribute to individual difference in VO2max and its response to training.

NcoI RFLP in human brain creatine kinase gene (CKBB)

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Mitochondrial DNA polymorphism detected with the restriction enzymes BstNI and BclI in a French Canadian population

The enzymes BstNI and BclI were used to detect various human mitochondrial DNA RFLPs in a sample of 104 unrelated French Canadians. These sequence variations were found in total white blood cell DNA probed with whole human mitochondrial DNA. With BstNI, 6 mitochondrial DNA restriction patterns (morphs) were identified. BstNI morphs 2-6 each differ from morph 1 by one single distinct restriction site gain or loss on the mitochondrial DNA molecule. Although BstNI morph 1 was found in most of the subjects (80%), each other morph was observed at a frequency of at least 3%. With the enzyme BclI, 4 different morphs were detected. Morphs 2-4 also result from different single restriction site alteration as compared with BclI morph 1. The morph 1 was clearly the most frequent (95%) while morphs 3 and 4 were present in only 1% of the subjects. These data indicate that the enzyme BstNI and, to a much lesser extent, the enzyme BclI detect mitochondrial DNA polymorphism in Caucasians. They are therefore of interest for population genetics studies.

Transient increase in basal insulin levels in severely diabetic rats submitted to physical training

Physical training improves glucose homeostasis in rats with experimental diabetes mellitus. The present study has been designed to ascertain if this beneficial effect is maintained or lost after a few days of inactivity. Male Wistar rats were injected with streptozotocin (STZ, 50 mg/kg) and those presenting one week later a blood glucose value between 250 and 400 mg/dl were retained in the protocol and randomly assigned to a sedentary (n = 18) or trained group (n = 23). An I.V. glucose tolerance test (0.5 g/kg) was performed in previously cannulated rats 64 h (trained rats; n = 15) or 12 days (detrained rats, n = 8) after the last bout of exercise. In comparison with results obtained in their sedentary counterparts (419 +/- 15 mg/dl), basal glucose levels were significantly lower in trained (362 +/- 20; p less than 0.05), but not in detrained rats (429 +/- 15; NS). Similar differences in plasma glucose levels were observed after glucose loading, even though the glucose disappearance rate constant was not significantly improved by training. Furthermore, basal insulin levels were significantly higher (p less than 0.01) in trained than in sedentary rats (20 +/- 3 vs 12 +/- 2 microU/ml) but such a difference had disappeared in detrained rats (9 +/- 2 microU/ml). These results indicate that the training-induced improvement in glucose homeostasis of diabetic rats is a transient phenomenon which is associated with an increase in circulating insulin levels. This suggests that the beneficial effect of training is not due solely to enhanced insulin sensitivity.