Preventing type 2 diabetes using combination therapy: design and methods of the CAnadian Normoglycaemia Outcomes Evaluation (CANOE) trial

Several studies have demonstrated that type 2 diabetes mellitus (DM) can be prevented/delayed in subjects with impaired glucose tolerance (IGT) by using pharmacologic agents and/or lifestyle interventions. However, a number of challenges remain, including the translation of lifestyle programmes to the general population and the need to achieve greater risk reductions by using pharmacologic approaches. IGT, like DM, is characterized by insulin resistance, beta-cell dysfunction and increased hepatic glucose production. We believe that the use of combination diabetes therapy would be a particularly effective diabetes prevention strategy. In this context, we initiated the Canadian Normoglycemia Outcomes Evaluation (CANOE) study, a moderately sized, randomized, double-blind, controlled trial. The primary objective of CANOE is to determine whether treatment with metformin plus rosiglitazone, in addition to a healthy living lifestyle programme, will prevent the development of DM. The secondary objective of CANOE is to determine whether this treatment approach will improve cardiovascular risk factors associated with IGT. A total of 200 patients will be recruited in Toronto and London, Ontario, and followed for an average of 4 years (range 3-5 years). Active treatment with metformin (500 mg) plus rosiglitazone (2 mg), administered as one capsule twice daily, will be compared to matched placebo. Subjects will be eligible for randomization if they have IGT and are between the ages of 30-75 years. The primary outcome will be the development of new-onset DM, diagnosed by either two fasting plasma glucose values of >or=7 mmol/l or one positive oral glucose tolerance test with a 2-h plasma glucose value of >11.0 mmol/l during the active drug phase of the trial. With a sample size of 100 participants per group, we will be able to detect a relative risk reduction of 45%, with a two-sided log-rank test with a significance level of 0.05 and 80% power, assuming that the median time to progression is 8 years in the control group and that participants will be recruited over 2 years and followed for an average of 4 years. In conclusion, the CANOE study will determine whether combination pharmacological therapy combined with a lifestyle intervention programme can significantly modify the development of diabetes in high-risk Canadians.

The disconnect: infertility patients' information and the role they wish to play in decision making

OBJECTIVE

To determine the preferred role in medical decision making of women undergoing fertility treatments and to establish whether their knowledge of treatments is adequate to inform their choices.

METHODS

Self-report survey of 404 women undergoing fertility treatments in 2 university hospitals and a private fertility clinic in Canada.

RESULTS

The women had been in fertility treatment for 2.3 +/- 2.6 years; 67.8% reported taking fertility drugs. Most (61.7%) women wanted to share knowledge equally with their doctors about possible fertility treatments. However, about half wanted to decide alone or mostly by themselves about the acceptability of treatment risks and benefits (56%), what treatments should be selected (49.8%), and when to conclude treatments (54.3%). In addition, 55.1% of the women did not know their personal eventual chances of pregnancy with fertility treatment or thought it was 50% or greater. Over half of the women (57.2%) who had taken fertility drugs were unaware of a possible link between fertility drugs and increased ovarian cancer risk. The majority of women (61.8%) who knew of this possible association reported that they learned about it from the print media. Women who knew of the association had a poor understanding of the strength of the evidence or the ability to detect or treat ovarian cancer successfully, and 88.3% thought they could reduce cancer risk by following their doctors' advice.

CONCLUSIONS

Despite these women's wishes to actively participate in fertility treatment decisions, they lacked the necessary information to do so meaningfully. Public health policymakers, professional and advocacy organizations, physicians, other healthcare providers, and women themselves must find ways to improve the general public's and patients' understanding about fertility treatment outcomes and risks.

Acceptance of voluntary HIV testing and the prevalence of HIV infection in women with cervical neoplasia in Toronto

Over a 13-month period (1998-99), 661 adult women under the age of 50 years with a diagnosis of high grade squamous intraepithelial lesions (HSIL) or invasive cervical cancer in the previous 5 years and who were unaware of their HIV status were approached to participate in this study. After pretest counseling, patients completed a short questionnaire about risk factors for HIV infection, had blood samples drawn for HIV testing,and arranged a follow-up appointment for test results and post-test counseling. The acceptance rate for HIV testing was 73% (N = 432 with HSIL and N = 51 with invasive cervical cancer). Most women reported heterosexual intercourse as their only risk factor for HIV infection, with the majority (95.1%) reporting more than one lifetime sexual partner. Women who declined participation were significantly older (P < 0.01) than participants and nonwhites were more likely to decline (P < 0.001). None of the study participants had positive HIV test results (0/483; 95% CI, 0.00-0.009). Although HIV testing was accepted by most women following pretest counseling, there were no women who tested HIV-positive who were previously unaware of their status. Consequently we do not recommend routine HIV testing in this population.

Relationship between toxicant transfer kinetic processes and fish oxygen consumption

Three organic compounds of different hydrophobicity, 1,2,4,5-tetrachlorobenzene (TeCB), 3,4,5,6-tetrachloroguaiacol (TeCG) and 4,6-dichlorobenzenediol (DBD), were chosen as the test chemicals to carry out a series of investigations to look at the relationship between toxicant transfer and fish metabolic rate. A significant correlation was found between the toxicant uptake rate constant (k(1)) and fish oxygen consumption, regardless of fish size and species. This correlation was improved when fish toxicant body load was expressed on a percent body lipid basis. Similarly, there also existed a significant relationship between the toxicant depuration rate constant (k(2)) and fish oxygen uptake for a range of chemicals with different octanol/water partition coefficients (K(ow)).

A physiological model to predict xenobiotic concentration in fish

A physiological model was developed to estimate fish body toxicant load based on information regarding the chemical exposure regime, fish body weight, lipid content and oxygen uptake. The general model was tested in which an oxygen database (OXYREF) was used to predict fish toxicant body burden. Based on the quantitative analysis, it was shown that the model was reliable and accurate in estimating fish body burden of a number of non-metabolized aquatic toxicants. This modified model possesses some functional reality which enables more realistic predictions, making it useful in the practice of aquatic environmental risk assessment.

Screening of preformed oxidised low density lipoprotein isolated by a polyanion precipitation method. Its correlation with serum triglyceride levels

For clinical and epidemiological screening a simple and sensitive methodology was developed for detection of preformed lipid peroxides (LPO) in low density lipoprotein (LDL). For this purpose, the iodometric assay of El-Saadani et al. (J Lipid Res 1989;30:627-30) was adapted to the fraction containing LDL isolated by polyanion precipitation avoiding ultracentrifugation. This fraction also includes intermediate density lipoprotein. Stratifying 53 individuals by their serum triglyceride levels (TG) the highest quartile showed a highly significant elevation of LDL-LPO compared with the lowest one (69.2 +/- 41.2 vs 22.9 +/- 10.0 nmol mg-1 LDL-apo B, P < 0.001). LDL-LPO concentration also showed a strong correlation with TG (r = 0.73, P < 0.00001) and significant inverse correlations with high density lipoprotein cholesterol (HDL-C) and HDL3-C subfraction (r = -0.37, P < 0.01 and r = -0.38, P = 0.01, respectively). The TG/HDL-C ratio, which is closely associated with insulin resistance, was strongly correlated with LDL-LPO (r = 0.83, P < 0.00001). Significant elevations of LPO were observed in phenotypic hyperlipoproteinemias (HLP) IIb and IV (P < 0.01 and P < 0.02, respectively) and when expressing LPO in mol/mol of LDL-apo B, two- and 2.5-fold higher values were found in types IIb and IV HLP, respectively, compared with normolipidemic subjects, suggesting a more oxidative environment for apo B in both phenotypes. No variations in LPO were found in type IIa HLP. This simple assay for in vivo detection of LDL-LPO, emphasises the possible atherogenic effect of TG through their oxidative capacity and suggests the integration of LPO to the cluster of associated risk factors: high TG, low HDL-C and insulin resistance.

The feasibility of assessing women's perceptions of the risks and benefits of fertility drug therapy in relation to ovarian cancer risk

OBJECTIVE

To determine the feasibility of asking women undergoing fertility treatment the maximum increased risk of ovarian cancer they would be willing to tolerate in order to take ovulation-induction drugs.

DESIGN

A prospective pilot study of women attending fertility clinics over a 2-month period.

SETTING

Two tertiary care fertility clinics in Toronto.

PATIENT(S)

Sixty-one English-speaking women were approached and 85% (n = 52) were enrolled.

INTERVENTION(S)

A self-administered questionnaire with fertility-specific questions. Thirty-eight women also were asked to complete standardized scales of anxiety and optimism.

MAIN OUTCOME MEASURE(S)

Women's report of the maximum level of lifetime risk of ovarian cancer they were willing to tolerate in order to undergo fertility treatment.

RESULT(S)

Seventy-nine percent were willing to accept an increased risk of ovarian cancer. Only 24% understood that treatment for ovarian cancer usually was not curative.

CONCLUSION(S)

A majority of patients were willing to tolerate a modest increase in their lifetime risk of ovarian cancer because of fertility treatment, most basing their estimate of acceptable risk on limited awareness of the issue.

Human Mn-superoxide dismutase in pulmonary epithelial cells of transgenic mice confers protection from oxygen injury

To test directly whether mitochondrial Mn-superoxide dismutase (Mn-SOD) protects the lung epithelium from oxygen-induced injury, transgenic mice were produced in which the expression of human Mn-SOD mRNA was directly by transcriptional elements from the human pulmonary surfactant protein C gene. Human Mn-SOD mRNA was expressed in a lung-specific manner, and increased Mn-SOD protein was detected within mitochondria of alveolar Type II and nonciliated bronchiolar cells of the distal respiratory epithelium of the transgenic mice. The activity of Mn-SOD, but not catalase, CuZn-SOD, or glutathione peroxidase, was increased in lungs of transgenic mice. Transgenic mice were highly protected from lung injury during exposure to 95% oxygen, surviving significantly longer than nontransgenic littermates. Pulmonary pathology demonstrated decreased hemorrhage, hyaline membrane formation, and alveolar and interstitial edema in transgenic animals. The finding that increased Mn-SOD in distal respiratory epithelial cells confers protection from oxygen injury provides a basis for novel therapies to protect lung from injury during oxygen therapy of acute and chronic lung diseases.

Significant increase of high-density lipoprotein2-cholesterol under prolonged simvastatin treatment

In a contribution to a prolonged multicenter study 15 patients with primary hypercholesterolemia were treated with simvastatin, a competitive inhibitor of HMG-CoA reductase. The first part of the study was done in a double-blind fashion comparing the effect of this new drug with that of gemfibrozil during 12 weeks, and after this period on open-label treatment was started with the administration to all the patients of simvastatin in doses ranging from 2.5 to 40 mg q.p.m. Persistent and significant reductions (P less than 0.001) were achieved for total serum cholesterol (TC), LDL-cholesterol (LDL-C), apo B and triglycerides: by 38, 49, 44 and 33%, respectively, after 40 weeks of the open-label extension. From week 12, LDL-C levels were maintained at a cut point less than or equal to 140 mg/dl in every patient throughout the study. At week 40, cholesterol values of HDL subfractions showed a significant increase in HDL2-C (28%, P less than 0.01) and a concomitant reduction in HDL3-C (12%, P less than 0.01) in spite of a nonsignificant elevation of total HDL-C (by 6%). The HDL2-C/HDL3-C ratio rose by 47% (P less than 0.001) and the TC/HDL-C ratio was significantly reduced by 43%: from 6.1 +/- 1.2 to 3.5 +/- 0.7 (mean +/- SD, P less than 0.001). No adverse effects were detected. Our results suggest a conversion of HDL3 into HDL2, which could imply a beneficial effect of simvastatin upon the so-called reverse cholesterol transport, in addition to the striking reduction in atherogenic lipoproteins.

The response of contractile and non-contractile vacuoles of Paramecium calkinsi to widely varying salinities

Paramecium calkinsi from tidal marshes survive a wide salinity range. Fluid output of contractile vacuoles of these cells decreased as salinity of the medium to which they were acclimated increased, and both pulse rate and vacuole volume were used to regulate output. When cells were first exposed to more dilute medium, contractile vacuoles greatly increased volume so that fluid output increased even though pulse rate decreased. In cells shifted to a more concentrated medium, contractile vacuole output decreased by decreasing pulse rate. The contractile vacuole is surrounded by a set of collecting structures which change form as the salinity changes. Distensible ampullae are found in media of low salinity and collecting canals are found in media of high salinity. When cells are shifted from high salinity to low, the number of ampullae increases and the number of canals decreases. When cells are shifted from low salinity to high, the number of ampullae decreases and the number of canals decreases. Other non-contracting vacuoles also appear in response to a hypoosmotic shock. These include vacuoles within the cell as well as "blisters" on the surface. The number and frequency of blisters increases with the size of the hypoosmotic shock. They detach from cells without resulting in any visible loss of cytoplasm. Non-contractile vacuoles may play a role in sequestering and removing excess water that the contractile vacuoles cannot handle.

Treatment of acute myocardial infarction with subcutaneous heparin at low doses

Heparin has been used intensively in the treatment of acute myocardial infarction and preinfarction angina (PA) at full doses as a single drug by us. However, heparin may be used at smaller doses for similar purposes. These doses are not exactly anticoagulant, even though they reduce blood hypercoagulability, and act mainly in an antithrombotic capacity. We studied 529 patients with acute myocardial infarction, of whom 262 were treated with subcutaneous heparin at low doses (5000 IU every 12 h) and 267 received conventional therapy without antithrombotic drugs. Heparin used was Heparina (Abbott) and Liquemine (Roche), in vials with the equivalence 1 cm3 = 50 mg = 5000 IU. Blood rheologic factors (thromboelastography, platelet adhesiveness, total blood viscosity, and number of platelets) were determined in all patients, those treated with heparin at low doses and also the control group, before and after the 30-day treatment period. Diagnosis was based on clinical symptoms, laboratory studies, and electrocardiogram examination. In both the 262 patients treated with heparin at low doses and in the control group of 267 patients, baseline values of rheological factors were high. After 30 days (i.e., after study completion) these high values which are statistically significant compared with normal values, with p less than 0.0001 for both groups, remained constant in the control group who did not receive heparin. On the contrary, in the group treated with heparin at low doses, all these factors changed. Heparin provides protection against thrombosis by increasing the negative charge of the vessel wall and by other reactions at the endothelial surface. Heparin requires a plasmatic component called antithrombine III.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of bezafibrate on low levels of high density lipoprotein cholesterol in normolipidemia. Study in coronary patients and their first degree relatives

A pharmacological study was carried out in a group of 20 subjects composed of 13 coronary patients and 7 normal close relatives (first degree) who were considered at a high risk for coronary heart disease (CHD) because of their low levels of high density lipoprotein cholesterol (HDLch) (mean +/- SD: 34.1 +/- 5.2 mg/dl) and their high total cholesterol/HDLch (Tch/HDLch) ratio (mean +/- SD:6.7 +/- 1.1), despite their normal serum lipid values. With the purpose of normalizing these parameters they were submitted to a 4-month treatment with bezafibrate, a hypolipidemic agent which has a known effect in increasing HDLch and in decreasing the Tch/HDLch ratio. At the end of the study total serum cholesterol and triglycerides decreased significantly by 10 and 30%, respectively (p less than 0.01). HDL increased in its cholesterol content by 33% reaching a value of 45.4 +/- 9.8 mg/dl (mean +/- SD, p less than 0.01) as well as in its apolipoprotein A1 (Apo A1) content (13%, p less than 0.02). HDL2 subfraction also rose in cholesterol and in Apo A1: by 90 and 38%, respectively (p less than 0.01). HDL3 subfraction rised only its cholesterol content by 24% (p less than 0.01). Tch/HDLch ratio was significantly reduced (p less than 0.01) to a value of 4.6 +/- 0.9 (mean +/- SD). Total serum Apo B diminished by 14% (p less than 0.01). No adverse effects were observed during the follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Pilot study of the effect of raubasine on platelet biological activity

A pilot study was carried out to determine the action of raubasine (ajmalicine) an alkaloid derived from Rauwolfia serpentina, on platelet biological function in 14 patients selected because they were at risk due to complications of atherosclerosis. The determinations of platelet aggregation were done ex vivo and the following substances were used as inducing agents: adenosine diphosphate (2.5 and 5.0 X 10(-6) mol/l), collagen (0.05 mg/ml), and epinephrine (adrenaline) (1.68 X 10(-4) mol/l). 12 out of the 14 patients treated showed a reduction in platelet aggregation in at least 2 of the 3 test curves. This reduction was statistically significant for collagen (p less than 0.02) and epinephrine (p less than 0.01). A statistically significant (p less than 0.05) prolongation of the latency period of aggregation produced by collagen was found in 12 out of 14 patients and a prolongation of recalcification time produced by the reduction in platelet factor 3 was found in 9 out of 14 patients. In addition to the fact that the effect of a reduction in platelet aggregation was more evident in the second wave, these results suggest that raubasine has an inhibitory action on the release reaction of the platelets. The results obtained merit further study to confirm this property of the drug.

Elevation of high density lipoprotein cholesterol (cHDL) and reduction of the total cholesterol/cHDL index in the treatment of hyperlipoproteinaemias IIb and IV with bezafibrate

A study was carried out in 21 patients with Type IIb or Type IV hyperlipoproteinaemia to evaluate the effect of treatment with 600 mg bezafibrate per day over a period of 3 months. The results of the lipid parameters studied showed that there were significant reductions after 1 and 3-months' treatment, respectively, of 19% and 16% total cholesterol, 55% and 57% triglycerides, 19% and 15% calculated cLDL, and 55% and 58% calculated cVLDL. Over the same times, there was a significant increase in cHDL of 35% and 41%, respectively. The cT/cHDL index decreased significantly from a mean basal value of 7.81 +/- 1.44 to 4.76 +/- 0.96 after 1 month and to 4.75 +/- 0.90 after 3 months, corresponding to a 39% reduction in both instances. This index was reduced to 5.0 or less in 76% of the patients. At the end of the trial there was normalization of hyperlipoproteinaemia in 17 (81%) of the 21 patients. Tolerance of bezafibrate was satisfactory. Only 2 patients suffered mild abdominal pain, which disappeared within a few days. One patient presented slight, transitory neutropenia at the end of the 3 months of treatment.

Diazoxide for the acute control of severe hypertension complicating pregnancy: a pilot study

Four patients with hypertensive disorders of pregnancy were treated with intravenous diazoxide. In 2 patients there was profound maternal hypotension. Late deceleration of the fetal heart rate occurred in 3 patients following diazoxide administration. Possible implications of this study are discussed.

Oropharyngeal excretion of Epstein-Barr virus by patients with lymphoproliferative disorders and by recipients of renal homografts

In an attempt to associate oropharyngeal excretion of Epstein-Barr (EB) virus with lymphoproliferative disorders other than infectious mononucleosis, we tested throat gargles collected from adult subjects for the EB virus. Nine (16%) of 55 healthy persons were positive. High EB virus-excretion rates were found among patients with active acute lymphocytic leukemia (6/6, 100%), among renal homograft recipients during the third to 12th month after transplantation (26/30, 87%), and among critically ill patients with leukemia-lymphoma (14/19, 74%). Moderately high excretion rates were found among patients with myeloma (7/16, 44%), patients with poorly differentiated lymphocytic lymphoma (5/11, 44%), critically ill patients with solid cancers (15/37, 41%), and patients with chronic myelogenous leukemia (8/21, 38%). Our data suggested that the higher than normal excretion rate is realted to the basic disease process and to the general health status but not to the duration of cancer chemotherapy.