N-3 Fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring

OBJECTIVE

We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring.

DESIGN

Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days.

MEASUREMENTS

Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitamin A, E and C concentrations, and (iii) antioxidant enzymes activities in erythrocytes. The plasma lipid concentrations and fatty acid composition were also determined.

RESULTS

Diabetes increased plasma triglyceride and cholesterol concentrations, whereas macrosomia was associated with enhanced plasma cholesterol and triglyceride levels, which diminished by feeding n-3 PUFA diet. N-3 PUFA diet also reduced increased plasma TBARS and corrected the decreased ORAC values in diabetic rats and their macrosomic offspring. EPAX diet increased the diminished vitamin A levels in diabetic mothers and vitamin C concentrations in macrosomic pups. Also, this diet improved the decreased erythrocyte superoxide dismutase and glutathione peroxidase activities in diabetic and macrosomic animals.

CONCLUSION

Diabetes and macrosomia were associated with altered lipid metabolism, antioxidant enzyme activities and vitamin concentrations. N-3 PUFA diet improved hyperlipidemia and restored antioxidant status in diabetic dams and MAC offspring.

Antioxidant status in alcohol-related diabetes mellitus in Beninese subjects

In the present study, we investigated the antioxidant status in diabetes mellitus, related or not to alcohol consumption. A total of 38 type 1, 48 type 2 and 42 alcohol-related diabetic patients were selected. Total antioxidant status was assessed through the oxygen radical absorbance capacity of the plasma and the determination of enzymatic and non-enzymatic antioxidant molecules. Serum triglycerides, total cholesterol and HDL-cholesterol concentrations were determined and the lipid peroxydation was evaluated by measuring thiobarbituric acid reactive substances (TBARS) assay. Plasma total antioxidant capacity was more decreased in alcohol-related diabetes than that in type 1 and type 2 diabetes, regardless of the complications (retinopathy and renal failure). Plasma vitamin E concentrations were significantly decreased whereas those of vitamin C increased in all of the diabetic patients compared to the controls, irrespective to the complications. In addition, superoxide dismutase and glutathione peroxidase activities were reduced in all the patients (type 1, type 2 and alcohol-related), irrespective to the complications. Glutathione reductase activity was diminished in type 1 and alcohol-related, but not in type 2, diabetic patients. Glutathione (GSH) concentrations significantly decreased in all diabetic patients with a significant decrease in alcohol-related diabetic patients. Excessive alcohol consumption appears as an oxidative aggravating factor in diabetes mellitus. Besides, alcohol-related diabetes highly resembles to type 1 diabetes as far as the antioxidant parameters are concerned.

Kidney function and mortality among patients with left ventricular systolic dysfunction

Kidney disease has emerged as a risk factor for mortality in heart failure populations. The objective of this study was to determine the impact of different stages of kidney dysfunction (defined using the Kidney Disease Outcomes Quality Initiative [K/DOQI] classification system) and changes in kidney function on mortality in a cohort of patients with heart failure. A retrospective analysis was conducted of data from the randomized controlled trials Studies of Left Ventricular Dysfunction. A total of 6640 participants with asymptomatic and symptomatic heart failure were studied. Estimated GFR (eGFR) were calculated and then categorized according to the K/DOQI classification system into the following categories: > or =90, 60 to 89, 30 to 59, and 15 to 29 ml/min per 1.73 m2. Reduction in eGFR from baseline was calculated and subsequently categorized according to rate of decline (<5, 5 to 10, 11 to 15, and >15 ml/min per 1.73 m2 per year). Independent of baseline differences, lower levels of eGFR were associated with a higher total mortality compared with those with eGFR > or =90 ml/min (30 to 59 ml/min per 1.73 m2: hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.10 to 1.59, P = 0.004; 15 to 29 ml/min per 1.73 m2: HR 2.54, 95% CI 1.54 to 4.19, P < 0.001). eGFR deteriorated rapidly (>15 ml/min per 1.73 m2 per year) in 12% of participants. This decline was associated with a significant increase in mortality compared with slower decline (<5 ml/min per 1.73 m2 per year), despite adjustments for baseline kidney function, baseline heart failure, or change in heart failure (HR 5.63; 95% CI 4.90 to 6.46; P < 0.0001). The levels of eGFR from the K/DOQI classification system are associated with mortality in a well-characterized heart failure population. Rate of decline in kidney function is a strong predictor of increased mortality in this population, independent of worsening heart failure and baseline kidney function.

Prognostic Value of Troponin T and I Among Asymptomatic Patients With End-Stage Renal Disease

Background— The prognostic usefulness of troponin enzymes in end-stage renal disease (ESRD) patients is controversial. To resolve this uncertainty of troponin as a prognostic tool, we conducted a systematic review to quantify the association between elevated troponin I or T and long-term total mortality among ESRD patients not suspected of having acute coronary syndrome.

Methods and Results— We conducted an unrestricted search from the MEDLINE, EMBASE, and DARE bibliographic databases to December 2004 using the terms troponin.mp. or exp troponin and exp kidney, exp renal, exp kidney disease exp renal replacement therapy . We also manually searched review articles and bibliographies to supplement the search. Studies were included if they were prospective observational studies, used cardiac-specific troponin assays, and evaluated long-term risk of death or cardiac events for asymptomatic ESRD patients. Two authors independently abstracted data on study and patient characteristics. Studies findings were stratified according to troponin T or I levels. We used a random-effects model to pool study results and tested for heterogeneity using χ 2 testing and used funnel-plot inspection to evaluate the presence of publication bias. Data from 28 studies (3931 patients) published between 1999 and December 2004 were included in this review. Patients received dialysis for a median duration of 4 years, with a mean follow-up of 23 months. From the pooled analysis, elevated troponin T (>0.1 ng/mL) was significantly associated with increased all-cause mortality (relative risk, 2.64; 95% CI, 2.17 to 3.20). Although the prognostic effect sizes were all consistent with a positive relationship between troponin T and mortality, there was significant heterogeneity in the magnitude of these effect sizes ( P =0.015). The funnel plot showed evidence of publication bias. Elevated troponin T was also strongly associated with increased cardiac death. Studies evaluating troponin I included a wide variety of assays and differing cut points, rendering synthesis of the study findings difficult.

Conclusions— Elevated troponin T (>0.1 ng/mL) identifies a subgroup of ESRD patients who have poor survival and a high risk of cardiac death despite being asymptomatic. These findings suggest that troponin T is a promising risk stratification tool and may help frame therapeutic decisions. The clinical interpretation of elevated troponin I levels, however, remain unclear, largely because of the lack of standardization of assays.

Registered indians and tobacco taxation: a culturally-appropriate strategy?

Taxation of tobacco is a widely-used strategy that prompts smoking cessation among adults and reduces cigarette consumption among continuing smokers. Registered Indian tobacco use prevalence is at least double that of the rest of Canadians and is in part due to the lower cost of tobacco products purchased on reserve by Registered Indians (RIs) as they are tax exempt. Although registered Indian communities have the ability to collect tax on tobacco products and direct the use of these revenues, this strategy is rarely utilized. Tobacco taxation could have substantial health and economic benefits to RI communities, but perhaps is not culturally-appropriate. In order to better support RI communities, governments and other organizations need to examine this policy instrument in the context of RI populations.

Effect of Aralia cachemirica Decne root extracts on blood glucose level in normal and glucose loaded rats

An aqueous and alcoholic extract of the roots of Aralia cachemirica (Araliaceae) were evaluated for hypoglycemic activity in normal fasted and glucose induced hyperglycemic rats. The aqueous and alcoholic extracts at a dose of 250 mg/kg showed statistically significant (p < 0.01) hypoglycemic activity in glucose loaded animals however no effect was observed in normal fasted rats.

Dissection of Systems, Cell Populations and Molecules

This paper summarizes studies on antibody formation in the bone marrow and the suppressive effects of intravenous immunization with allogeneic blood cells on T-cell function in mice. The latter studies were extended by employing the limiting dilution culture system developed in Ivan Lefkovits' laboratory and implemented in collaboration with Lucien Aarden. Thereby, the functional data were complemented with frequencies of alloantigen-activated helper (Th) and suppressor T cells after intravenous alloimmunization. These results led the Rotterdam group to studies on the prevention of rejection of the foetal 'allograft'. Th cells are central in foetal allograft rejection and pregnancy success. Characteristic for human pregnancy is the production of the glycoprotein chorionic gonadotropin (hCG) hormone. The in vivo liberated peptide fragments originating from nicking of the sequence MTRVLQGVLPALPQ in the beta-chain of hCG were considered for their immunoregulating capacity related to pregnancy success. These peptides - prepared synthetically - (MTR, MTRV, LQG, LQGV, VLPALP and others) indeed showed a remarkable spectrum of biological effects (e.g. modulation of angiogenesis, inhibition of septic shock syndrome, prevention of diabetes and reduction of ischaemia-reperfusion damage). The paper interprets and generalizes these findings and projects them into various research directions, especially towards the proteomics framework studies built up in Ivan Lefkovits' laboratory in the nineties. During the time period, when Ivan spent a mini-sabbatical in Rotterdam (months after closing down the BII) more detailed discussions were intiated. This paper is meant to keep the discussions between the involved research groups going on.

Ultrasonographic determination of amniotic fluid volume in normal pregnancy

Ultrasonographic assessment of amniotic fluid has important implications because documentation of abnormalities of amniotic fluid volume may provide valuable information to enhance fetal health assessment. But in our country no study was conducted to establish normal values of amniotic fluid volume. So, this study was designed to find out normal values of amniotic fluid volume at various stages of gestation. The study was conducted in the department of Radiology and Imaging, BIRDEM in collaboration with the department of Obstetrics and Gynaecology, BIRDEM from 1(st) July, 2001 to 30(th) June, 2002. One hundred and twenty patients of normal pregnancy between 15 to 38 weeks' gestation were scanned by ultrasonography and their amniotic fluid volume was measured. For each gestational age between 15 and 38 weeks, 5 patients were recruited, and only one examination was done per pregnancy. Currently, the three semi-quantitative methods of assessing amniotic fluid volume include the amniotic fluid index (AFI), single deepest pocket (SDP) and two diameter pocket (TDP). Amniotic fluid volume of the study population was measured by the three methods. The values were plotted against each week in tabulated form. Thus the normal range of amniotic fluid volume in three methods (AFI, SDP, TDP) across gestational age in normal pregnancies was established. The mean value of amniotic fluid volume in AFI, SDP and TDP were 13.224 cm, 4.679 cm and 19.252 cm(2) respectively. AFI and SDP showed amniotic fluid volume increased with increasing gestational age up to early third trimester, but volume decreased thereafter. The prevalence of false positive result for oligohydramnios was 0.83% for AFI, 0% for SDP and 23% for TDP. The prevalence of false positive result for hydramnios was 1.66% for AFI, 0.83% for SDP and 0% for TDP. Thus the normal values of amniotic fluid volume for each of the three ultrasonographic techniques in the perspective of our country were obtained from the study. As the study was conducted with a limited number of patients, further study may be carried out with a large number of observations to reevaluate the results of the study.

The 2005 Canadian Hypertension Education Program recommendations for the management of hypertension: part II - therapy

OBJECTIVE

To provide updated, evidence-based recommendations for the management of hypertension in adults.

OPTIONS AND OUTCOMES

For lifestyle and pharmacological interventions, evidence from randomized controlled trials and systematic reviews of trials was preferentially reviewed. While changes in cardiovascular morbidity and mortality were the primary outcomes of interest, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity/mortality data in this field, and for certain comorbid conditions, other relevant outcomes, such as development of proteinuria or worsening of kidney function, were considered.

EVIDENCE

MEDLINE searches were conducted from November 2003 to October 2004 to update the 2004 recommendations. Reference lists were scanned, experts were contacted, and the personal files of the subgroup members and authors were used to identify additional published studies. All relevant articles were reviewed and appraised independently, using prespecified levels of evidence, by content and methodology experts. As per previous years, only studies that had been published in the peer-reviewed literature were included; evidence from abstracts, conference presentations and unpublished personal communications was not included.

RECOMMENDATIONS

Lifestyle modifications to prevent and/or treat hypertension include the following: perform 30 min to 60 min of aerobic exercise on four to seven days of the week; maintain a healthy body weight (body mass index of 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm for men and less than 88 cm for women); limit alcohol consumption to no more than 14 units per week in men or nine units per week in women; follow a reduced fat, low cholesterol diet with an adequate intake of potassium, magnesium and calcium; restrict salt intake; and consider stress management (in selected individuals). Treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and any comorbid conditions. Blood pressure should be lowered to 140/90 mmHg or less in all patients, and to 130/80 mmHg or less in those with diabetes mellitus or chronic kidney disease. Most adults with hypertension require more than one agent to achieve target blood pressures. For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic hypertension with or without systolic hypertension include beta-blockers (in those younger than 60 years), angiotensin-converting enzyme (ACE) inhibitors (except in black patients), long-acting calcium channel blockers and angiotensin receptor antagonists. Other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine calcium channel blockers and angiotensin receptor antagonists. Certain comorbid conditions provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with diabetes mellitus, ACE inhibitors or angiotensin receptor antagonists (or thiazides in patients with diabetes mellitus without albuminuria) are appropriate first-line therapies; and in patients with nondiabetic chronic kidney disease, ACE inhibitors are recommended. All hypertensive patients should have their fasting lipids screened, and those with dyslipidemia should be treated using the thresholds, targets and agents recommended by the Canadian Hypertension Education Program Working Group on the management of dyslipidemia and the prevention of cardiovascular disease. Selected patients with hypertension, but without dyslipidemia, should also receive statin therapy and/or acetylsalicylic acid therapy.

VALIDATION

All recommendations were graded according to the strength of the evidence and voted on by the 43 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.

Differences in need for antihypertensive drugs among those aware and unaware of their hypertensive status: a cross sectional survey

Background

Lack of antihypertensive use among hypertensive individuals is a major public health problem. It remains unclear as to how much of this lack of treatment is because of failure to diagnose hypertension or failure to initiate drug treatment for those with a diagnosis of hypertension. The primary aim of this study was to determine the proportion of those untreated individuals who would be recommended to start drug therapy for control of blood pressure among those aware or unaware of their diagnosis of hypertension.

Methods

The Canadian Heart Health Surveys (1986 – 1992), a national, cross-sectional descriptive survey (n = 23 129), was used to determine the proportion of individuals who were untreated, yet satisfied the 2004 Canadian hypertension guidelines for initiating drug therapy. Patients were divided into subgroups of those aware and unaware of having a diagnosis of hypertension according to self reported awareness from the survey.

Results

Of those with untreated hypertension (= 140/90 mmHg), only 37% were aware of their diagnosis. 74% of untreated individuals aware of their diagnosis of hypertension would require drug therapy, compared to 57% of those who were unaware. Of those >65 years of age, 52% of aware individuals needed drug therapy whereas only 34% of unaware elderly would need drug treatment.

Conclusion

In both unaware and aware subgroups, the majority of patients with untreated hypertension would benefit from antihypertensive drug therapy according to the 2004 Canadian Hypertension recommendations. The proportion of untreated patients that still need drug therapy was higher among those who were aware compared to those who were unaware. This finding suggests that the major gap in hypertension control may be in initiating drug therapy rather than in diagnosing hypertension. Further studies are needed to confirm these results to ultimately help strategize public health efforts in controlling hypertension.

An evaluation of the effects of exogenous ethephon, an ethylene releasing compound, on photosynthesis of mustard (Brassica juncea) cultivars that differ in photosynthetic capacity

BACKGROUND

The stimulatory effect of CO2 on ethylene evolution in plants is known, but the extent to which ethylene controls photosynthesis is not clear. Studies on the effects of ethylene on CO2 metabolism have shown conflicting results. Increase or inhibition of photosynthesis by ethylene has been reported. To understand the physiological processes responsible for ethylene-mediated changes in photosynthesis, stomatal and mesophyll effects on photosynthesis and ethylene biosynthesis in response to ethephon treatment in mustard (Brassica juncea) cultivars differing in photosynthetic capacity were studied.

RESULTS

The effects of ethephon on photosynthetic rate (PN), stomatal conductance (gS), carbonic anhydrase (CA) activity, 1-aminocyclopropane carboxylic acid synthase (ACS) activity and ethylene evolution were similar in both the cultivars. Increasing ethephon concentration up to 1.5 mM increased PN, gS and CA maximally, whereas 3.0 mM ethephon proved inhibitory. ACS activity and ethylene evolution increased with increasing concentrations of ethephon. The corresponding changes in gs and CA activity suggest that the changes in photosynthesis in response to ethephon were triggered by altered stomatal and mesophyll processes. Stomatal conductance changed in parallel with changes in mesophyll photosynthetic properties. In both the cultivars ACS activity and ethylene increased up to 3.0 mM ethephon, but 1.5 mM ethephon caused maximum effects on photosynthetic parameters.

CONCLUSION

These results suggest that ethephon affects foliar gas exchange responses. The changes in photosynthesis in response to ethephon were due to stomatal and mesophyll effects. The changes in gS were a response maintaining stable intercellular CO2 concentration (Ci) under the given treatment in both the cultivars. Also, the high photosynthetic capacity cultivar, Varuna responded less to ethephon than the low photosynthetic capacity cultivar, RH30. The photosynthetic capacity of RH30 increased with the increase in ethylene evolution due to 1.5 mM ethephon application.

Impaired oxidant/antioxidant status and LDL-fatty acid composition are associated with increased susceptibility to peroxidation of LDL in diabetic patients

This study was carried out to determine the relationships between oxidant/antioxidant status, in vitro LDL oxidizability and LDL-fatty acid composition in diabetes mellitus. Plasma total antioxidant capacity (oxygen radical absorbance capacity, ORAC) and LDL-cholesteryl ester fatty acids were investigated in type 1 and type 2 diabetic subjects with and without complications. The degree of LDL oxidation was determined by the measurement of hydroperoxide levels before and after in vitro peroxidative stress with CuSO4. ORAC values were decreased in diabetic subjects who showed high basal hydroperoxide levels. Oxidizability of LDL in these subjects was higher than in control subjects and it was unrelated to LDL-fatty acid composition. However, in type 2 diabetic subjects with complications, alterations in LDL-fatty acid composition were associated with their enhanced oxidative susceptibility. LDL-fatty acid alterations might be an additional factor that influences LDL oxidizability especially in type 2 diabetes. In conclusion, diabetes mellitus is associated with enhanced oxidative stress and defective antioxidant/oxidant balance regardless the type of diabetes and presence of complications.

Development of a perioperative medicine research agenda: a cross sectional survey

BACKGROUND

Post-operative complications are a significant source of morbidity and mortality for patients undergoing surgery. However, there is little research in the emerging field of perioperative medicine beyond cardiac risk stratification. We sought to determine the research priorities for perioperative medicine using a cross sectional survey of Canadian and American general internists.

METHODS

Surveys were electronically sent to 312 general internists from the Canadian Society of Internal Medicine and 130 internists from the perioperative medicine research interest group within the US based Society of General Internal Medicine. The questionnaire contained thirty research questions and respondents were asked to rate the priority of these questions for future study.

RESULTS

The research topics with the highest ratings included: the need for tight control of diabetes mellitus postoperatively and the value of starting aspirin on patients at increased risk for postoperative cardiac events. Research questions evaluating the efficacy and safety of perioperative interventions had higher ratings than questions relating to the prediction of postoperative risk. Questions relating to the yield of preoperative diagnostic tests had the lowest ratings (p < 0.001 for differences across these categories).

CONCLUSION

The results of this survey suggest that practicing general internists believe that interventions studies are a priority within perioperative medicine. These findings should help prioritize research in this emerging field.

Smoking-attributable mortality among British Columbia's first nations populations

OBJECTIVES

First Nations (FN) people have high smoking rates and there is a need to examine their mortality related to smoking.

METHODS

Smoking-attributable fractions and smoking-attributable mortality (SAM) rates were calculated for the FN and British Columbia (BC) populations during 1997 and 2001.

RESULTS

Among FN adults, total age- and gender-adjusted SAM rates were 39.9 and 28.6 per 10,000 during 1997 and 2001, with potentially 19.0% and 17.3% of all deaths being preventable if smoking were eliminated. Among the BC adult population, total SAM age- and gender-adjusted rates were 27.8 and 25.3 per 10,000 during 1997 and 2001, and up to 21.8% and 20.8% of deaths were potentially preventable if smoking were eliminated. Among FN infants, SAM crude rates were 6.8 and 3.6 per 10,000 during 1997 and 2001, with 8.0% and 8.3% of infant deaths being potentially preventable if smoking were eliminated. Infant SAM crude rates among the general population were 1.4 per and 1.0 per 10,000 during 1997 and 2001 and 2.8% and 2.3% of deaths were potentially preventable if smoking were eliminated.

CONCLUSIONS

Total adult age- and gender-adjusted SAM rates for both populations were substantive. Additional interventions that prevent and reduce tobacco use by FN people are indicated, particularly given their high rates of smoking. The high total SAM rates for FN infants also suggest the need for interventions.

Further delineation of Hennekam syndrome

We report four children from four inbred Arab families with varying manifestations of Hennekam syndrome and additional features that have not been previously reported. These include abnormalities of the middle ear, anomalous pulmonary venous drainage, interrupted inferior vena cava, polysplenia, crossed renal ectopia, median position of the liver and multiple cavernous haemangiomas. In addition, in one case lymphoedema was absent and oedema due to hypoproteinaemia appeared at 6 years of age. Since anomalies of the veins and the consequent developmental abnormalities of the lymphatics might lead to alterations in the fluid balance of the embryo, we hypothesize that altered fluid dynamics due to defective vascular and lymphatic development might disrupt critical events in craniofacial morphogenesis resulting in Hennekam syndrome.

Diuretic and nephroprotective effect of Jawarish Zarooni Sada--a polyherbal unani formulation

A number of drugs, both single and compound preparations are used widely in Tibb-e-Unani (Unani medicine) in the management of renal diseases. But such drugs mostly, have not been investigated for their described effects. Jawarish Zarooni Sada (JZS) is one such polyherbal preparation containing 15 ingredients, mainly described to be diuretic and nephroprotective. Therefore, in the present study ethanol and water extracts of JZS (300 mg each) were investigated for diuretic activity by measuring the total urine output over a period of 6h. Sodium and potassium level in urine sample was also estimated. Nephroprotective activity of JZS against gentamicin-induced nephrotoxicity was investigated by administering JZS along with high dose of gentamicin (40 mg/kg) and elevation of serum urea and serum creatinine was taken as the index of nephrotoxicity. JZS showed significant diuretic and nephroprotective effect.

Kinetic spectrophotometric method for the determination of silymarin in pharmaceutical formulations using potassium permanganate as oxidant

A new simple and sensitive kinetic spectrophotometric method for the determination of silymarin in pure form and in pharmaceutical formulations is described. The method is based on the oxidation of the drug with potassium permanganate at pH 7.0 +/- 0.2. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 530 nm. The calibration graph is linear in the range of 18-50 microg x m(-1). The method has been successfully applied to the determination of silymarin in pharmaceutical formulations. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

Thiazide diuretics in the management of hypertension

Hypertension is highly prevalent in Canada, affecting more than 20% of all adults. Thiazide diuretics have been shown in numerous studies to be effective agents for controlling blood pressure and reducing cardiovascular disease and death in hypertensive patients. Thiazide diuretics are recommended as initial first line therapy for uncomplicated hypertension in the 2003 Canadian Hypertension recommendations. However, these agents are underutilized and in Canada, the proportion of persons with hypertension treated with diuretics is declining. To improve understanding of thiazide diuretic use, this document outlines the clinical pharmacology of thiazide diuretics, evidence for effectiveness in treating hypertension, as well as the side effects and controversies surrounding their use.

The 2004 Canadian recommendations for the management of hypertension: Part II--Therapy

OBJECTIVE

To provide updated, evidence-based recommendations for the management of hypertension in adults.

OPTIONS AND OUTCOMES

For patients who require pharmacological therapy for hypertension, a number of antihypertensive agents may be used. Randomized trials evaluating first-line therapy with diuretics, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers (CCBs), alpha-blockers, centrally acting agents or angiotensin receptor antagonists were reviewed. Also, randomized trials evaluating other agents, such as statins or acetylsalicylic acid, in patients with hypertension were reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. In addition, other relevant outcomes such as development of end-stage renal disease or changes in blood pressure were examined where appropriate.

EVIDENCE

MEDLINE searches were conducted from November 2001 to October 2003 to update the 2001 Recommendations for the management of hypertension. Reference lists were scanned, experts were contacted, and the personal files of the subgroup members and authors were used to identify additional published studies. All relevant articles were reviewed and appraised independently, using prespecified levels of evidence by content and methodology experts.

RECOMMENDATIONS

This document contains detailed recommendations and supporting evidence on treatment thresholds, target blood pressures and choice of agents for hypertensive patients with or without comorbidities. Lifestyle modifications are a key component of any antiatherosclerotic management strategy and detailed recommendations are contained in a separate document. Key recommendations for pharmacotherapy include the following: treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and comorbidities, with particular attention to systolic blood pressure; blood pressure should be lowered to 140/90 mmHg or less in all patients, and 130/80 mmHg or less in those with diabetes mellitus or renal disease (125/75 mmHg or less in those with nondiabetic renal disease and more than 1 g of proteinuria per day); most adults with hypertension require more than one agent to achieve target blood pressures; for adults without compelling indications for other agents, initial therapy should include thiazide diuretics; other agents appropriate for first-line therapy for diastolic hypertension with or without systolic hypertension include beta-blockers (in those younger than 60 years), ACE inhibitors (in non-Blacks), long-acting dihydropyridine CCBs or angiotensin receptor antagonists; other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine CCBs or angiotensin receptor antagonists; certain comorbidities provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with diabetes mellitus, ACE inhibitors or angiotensin receptor antagonists (or thiazides in patients with diabetes mellitus without albuminuria) are appropriate first-line therapies; and in patients with mild to moderate nondiabetic renal disease, ACE inhibitors are recommended; all hypertensive patients should have their fasting lipids screened and those with dyslipidemia should be treated using the thresholds, targets and agents as per the Recommendations for the management of dyslipidemia and the prevention of cardiovascular disease; and selected patients with hypertension should also receive statin and/or acetylsalicylic acid therapy.

VALIDATION

All recommendations were graded according to the strength of the evidence and voted on by the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. Individuals with irreconcilable competing interests (declared by all members, compiled and circulated before the meeting) relative to any specific recommendation were excluded from voting on that recommendation. Only recommendations achieving at least 70% consensus are reported here. These guidelines will continue to be updated annually.

An unusual cause of vesical stone: a migrant intrauterine device

Intrauterine contraceptives devices have been in use for many years. Although perforation of the uterus by an intrauterine device is not uncommon, intravesical migration with secondary stone formation is a rare complication. We report on a 32-year-old woman in whom an intrauterine contraceptive device (Copper T) migrated from her uterus into the bladder. She had lower urinary tract symptoms for nearly 2 years but sought no treatment. The onset of hematuria and fear of cancer prompted her to seek treatment. On investigation, a vesical stone was discovered that had formed on a copper T contraceptive device. It was removed via suprapubic cystostomy. In any woman in whom an intrauterine device is fitted and who presents with lower urinary tract symptoms, the possibility of intravesical migration of the device should be included in the differential diagnosis.

Antioxidant status and levels of different vitamins determined by high performance liquid chromatography in diabetic subjects with multiple complications

Plasma vitamin A, C and E levels and erythrocyte antioxidant enzyme activities were investigated in type I and type II diabetic subjects with and without complications, i.e., hypertension, coronary artery disease and renal failure. Reverse phase HPLC was used to quantify vitamin A and E levels. We observed that the vitamin C levels were not significantly different between control and diabetic subjects. However, vitamin A and E levels were significantly lower in type I and type II diabetic subjects compared to controls. Superoxide dismutase (SOD) activity was significantly lower in type II, but not in type I, diabetic patients compared to controls. Interestingly, glutathione reductase and peroxidase activities were diminished in type I, but not in type II, diabetic subjects as compared to controls. Catalase activity was lower in both types of diabetic patients in comparison with their respective controls. Altogether these results suggest that diabetes mellitus may be associated with altered antioxidant status regardless to various complications.

Accuracy of the preoperative assessment in predicting pulmonary risk after nonthoracic surgery

We examined the accuracy of preoperative assessment in predicting postoperative pulmonary risk in a prospective cohort of 272 consecutive patients referred for evaluation before nonthoracic surgery. Outcomes were assessed by an independent investigator who was blinded to the preoperative data. There were 22 (8%) postoperative pulmonary complications. Statistically significant predictors of pulmonary complications (all p < or = 0.005) were as follows: hypercapnea of 45 mm Hg or more (odds ratio, 61.0), a FVC of less than 1.5 L/minute (odds ratio, 11.1), a maximal laryngeal height of 4 cm or less (odds ratio, 6.9), a forced expiratory time of 9 seconds or more (odds ratio, 5.7), smoking of 40 pack-years or more (odds ratio, 5.7), and a body mass index of 30 or more (odds ratio, 4.1). Multiple regression analyses revealed three preoperative clinical factors that are independently associated with pulmonary complications: an age of 65 years or more (odds ratio, 1.8; p = 0.02), smoking of 40 pack-years or more (odds ratio, 1.9; p = 0.02), and maximum laryngeal height of 4 cm or less (odds ratio, 2.0; p = 0.007). Thus, preoperative factors can identify those patients referred to pulmonologists or internists who are at increased risk for pulmonary complications after nonthoracic surgery.

Assessment and reporting of perioperative cardiac risk by Canadian general internists: art or science?

OBJECTIVE

Physicians may use several validated risk indices to estimate perioperative cardiac risk, but there is little evidence for interventions to reduce this risk. We were interested in evaluating how general internists assess, define, communicate, and attempt to modify perioperative cardiac risk.

DESIGN

Cross-sectional survey of all 312 general internists in the Canadian Society of Internal Medicine with Canadian mailing addresses; 117 (38%) responded.

RESULTS

Respondents' mean age was 46 years, 79% were male, and on average they did 17 preoperative consults per month. Of the 104 respondents who routinely performed preoperative assessments, 96% (100/104) informed patients of their perioperative cardiac risk, but 77% did so only subjectively (i.e., stating risk as low, moderate, or high). Respondents provided 8, 27, and 12 different definitions for low, moderate, and high risk, respectively, with marked variability in the range of definitions they provided: from <1% to < 20% for "low risk," from 1% to 2% to 20% to 50% for "moderate risk," and from >2% to >50% for "high risk." The 67% of respondents who reported using a perioperative cardiac risk index used a variety of indices and exhibited just as much variability in their risk estimates and definitions as those who didn't use risk indices. While virtually all advised perioperative beta blockade in patients with known coronary artery disease, they varied substantially in the recommended agent or dose; further, these internists were evenly split on whether antiplatelet agents should be held or continued perioperatively.

CONCLUSIONS

These physicians differed widely in their assessment of perioperative cardiac risk and their definitions of low, moderate, or high risk. This raises concerns about whether patients (and surgeons) are provided with adequate information to make fully informed decisions about the potential risks of elective surgical operations.