Soil organic carbon is not just for soil scientists: measurement recommendations for diverse practitioners.

Soil organic carbon (SOC) regulates terrestrial ecosystem functioning, provides diverse energy sources for soil microorganisms, governs soil structure, and regulates the availability of organically bound nutrients. Investigators in increasingly diverse disciplines recognize how quantifying SOC attributes can provide insight about ecological states and processes. Today, multiple research networks collect and provide SOC data, and robust, new technologies are available for managing, sharing, and analyzing large data sets. We advocate that the scientific community capitalize on these developments to augment SOC data sets via standardized protocols. We describe why such efforts are important and the breadth of disciplines for which it will be helpful, and outline a tiered approach for standardized sampling of SOC and ancillary variables that ranges from simple to more complex. We target scientists ranging from those with little to no background in soil science to those with more soil-related expertise, and offer examples of the ways in which the resulting data can be organized, shared, and discoverable.

Cost-effectiveness analysis of exenatide once-weekly versus dulaglutide, liraglutide, and lixisenatide for the treatment of type 2 diabetes mellitus: an analysis from the UK NHS perspective.

OBJECTIVE: To assess the cost-effectiveness of exenatide 2 mg once-weekly (EQW) compared to dulaglutide 1.5 mg QW, liraglutide 1.2 mg and 1.8 mg once-daily (QD), and lixisenatide 20 µg QD for the treatment of adult patients with type 2 diabetes mellitus (T2DM) not adequately controlled on metformin. METHODS: The Cardiff Diabetes Model was applied to evaluate cost-effectiveness, with treatment effects sourced from a network meta-analysis. Quality-adjusted life years (QALYs) were calculated with health-state utilities applied to T2DM-related complications, weight changes, hypoglycemia, and nausea. Costs (GBP £) included drug treatment, T2DM-related complications, severe hypoglycemia, nausea, and treatment discontinuation due to adverse events. A 40-year time horizon was used. RESULTS: In all base-case comparisons, EQW was associated with a QALY gain per patient; 0.046 vs dulaglutide 1.5 mg; 0.102 vs liraglutide 1.2 mg; 0.043 vs liraglutide 1.8 mg; and 0.074 vs lixisenatide 20 µg. Cost per patient was lower for EQW than for liraglutide 1.8 mg (-£2,085); therefore, EQW dominated liraglutide 1.8 mg. The cost difference per patient between EQW and dulaglutide 1.5 mg, EQW and liraglutide 1.2 mg, and EQW and lixisenatide 20 µg was £27, £103, and £738, respectively. Cost per QALY gained with EQW vs dulaglutide 1.5 mg, EQW vs liraglutide 1.2 mg, and EQW vs lixisenatide 20 µg was £596, £1,004, and £10,002, respectively. In the probabilistic sensitivity analysis, the probability that EQW is cost-effective ranged from 76-99%. CONCLUSION: Results suggest that exenatide 2 mg once-weekly is cost-effective over a lifetime horizon compared to dulaglutide 1.5 mg QW, liraglutide 1.2 mg QD, liraglutide 1.8 mg QD, and lixisenatide 20 µg QD for the treatment of T2DM in adults not adequately controlled on metformin alone.

Patient-reported outcomes among patients with type 2 diabetes mellitus treated with dapagliflozin in a triple-therapy regimen for 52 weeks.

Patients with type 2 diabetes (T2DM) and inadequate glycaemic control on combination metformin (MET) and sulphonylurea (SU) were enrolled in a 24-week, double-blind, randomized, placebo-controlled study with a 28-week extension. The five-dimension EuroQol questionnaire (EQ-5D), SHIELD Weight Questionnaire-9 (WQ-9), Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire and the Diabetes Treatment Satisfaction Questionnaire (DTSQ) were used to evaluate health status and health-related quality of life (HRQoL) at baseline and week 52. Patients with dapagliflozin 10 mg + MET + SU (n = 108) were compared with patients treated with placebo + MET + SU (n = 108), using a repeated-measures mixed model. EQ-5D visual analogue scale scores, IWQOL-Lite and DTSQ scores improved in the dapagliflozin and placebo groups from baseline to week 52; however, there was no significant difference between groups (p > 0.20). EQ-5D index scores remained the same from baseline to week 52 for dapagliflozin and placebo (p = 0.54). A numerically greater proportion of the dapagliflozin group reported improvement in all nine SHIELD WQ-9 items compared with placebo, and the difference was statistically significant for physical health (p = 0.017). Over 52 weeks of therapy, patients maintained their health status and HRQoL when dapagliflozin was added to the treatment.

Cardiovascular event rates and healthcare resource utilisation among high-risk adults with type 2 diabetes mellitus in a large population-based study.

OBJECTIVE: This study ascertained the incidence and resource utilisation of non-fatal myocardial infarction (MI), stroke, coronary bypass surgery or angioplasty among adults with type 2 diabetes mellitus (T2DM) at high risk for cardiovascular disease (CVD) over 3 and 5 years. METHODS: Respondents from the US, population-based SHIELD study with T2DM and at cardiovascular risk were stratified into an established CVD cohort and a risk factors cohort. Proportion of respondents self-reporting a new MI, stroke or revascularisation was calculated. Multivariate discrete logistic hazards models were utilised. RESULTS: Incidence rate in the established CVD cohort (n = 1198) was 26.3% over 3 years (31.2%, 5 years) and in the risk factors cohort (n = 924) 18.8% over 3 years (26.0%, 5 years). Healthcare resource use was significantly greater among respondents who had a new CV event than among those not experiencing an event (p < 0.001). CONCLUSIONS: Individuals with T2DM at risk for CVD had a high incidence of CV events in this large US study, which represents a significant burden on the healthcare system.

Health-related quality of life (EQ-5D) among type 2 diabetes mellitus patients treated with dapagliflozin over 2 years.

AIMS: This study evaluated health status and health-related quality of life (HRQOL) among patients with type 2 diabetes mellitus (T2DM) treated with dapagliflozin, a highly selective sodium-glucose co-transporter 2 (SGLT2) inhibitor that lowers blood glucose by increasing glucose excretion, in a double-blind, randomised clinical trial. METHODS: Subjects with T2DM who had inadequate glycaemic control on metformin alone were enrolled in a 24-week, double-blind, randomised, placebo-controlled study with a 78-week extension period to evaluate the effect of dapagliflozin in combination with metformin. Subjects treated with dapagliflozin 10 mg + metformin (n = 89) were compared with subjects treated with placebo + metformin (n = 91) at baseline and at weeks 24, 50 and 102. EQ-5D change from baseline was derived from a repeated-measures mixed model, adjusting for baseline EQ-5D, treatment group, time point and use of rescue medication. RESULTS: Mean (SD) EQ-5D index was 0.85 (0.16) and 0.82 (0.15) at baseline and 0.85 (0.19) and 0.84 (0.19) at week 102 for dapagliflozin and placebo, respectively. The model indicated no change over 102 weeks in EQ-5D index scores in either treatment group. Mean (SD) EQ-5D visual analogue scale (VAS) was 72.5 (19.5) and 73.7 (15.6) at baseline and 79.8 (13.3) and 78.2 (12.1) at week 102 for dapagliflozin and placebo, respectively. The model indicated similar small improvements in EQ-5D VAS scores in both groups over 102 weeks. CONCLUSION: Patients maintained high HRQOL scores from baseline through week 102 in both treatment groups. Dapagliflozin, a novel SGLT2 inhibitor, did not adversely affect HRQOL over 2 years of treatment.

Changes in weight loss-related quality of life among type 2 diabetes mellitus patients treated with dapagliflozin.

AIMS: This study evaluated change in health-related quality of life (HRQOL) associated with ongoing weight change among patients with type 2 diabetes mellitus (T2DM) treated with dapagliflozin, a highly selective sodium-glucose cotransporter 2 (SGLT2) inhibitor that lowers blood glucose by increasing urinary glucose excretion and is associated with body weight reductions. METHODS: Patients with T2DM who had inadequate glycaemic control on metformin (MET) alone were enrolled in a 24-week, double-blind, randomized, placebo-controlled study with a 78-week extension to evaluate the effect of dapagliflozin + MET on body weight. Patients also completed the Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes Weight Questionnaire-9 (SHIELD-WQ-9), a weight change-related HRQOL survey. Difference in proportions of patients treated with dapagliflozin 10 mg + MET (n = 89) or placebo + MET (n = 91) who reported improvement in HRQOL was analysed with Fisher's exact test. RESULTS: Dapagliflozin patients had significantly greater weight loss than placebo patients over 102 weeks (p < 0.05). This corresponded to a numerically greater proportion of dapagliflozin-treated patients reporting ongoing weight loss and associated improvements in most HRQOL domains at three different evaluation points (weeks 24, 50 and 102) than placebo-treated patients. In a post-hoc analysis among patients who reported ongoing weight loss regardless of treatment arm, a significantly greater proportion of patients reporting weight loss versus weight gain reported improvements in physical health, self-esteem and overall HRQOL at weeks 24, 50 and 102. CONCLUSIONS: Dapagliflozin-induced weight loss was associated with improvement in overall HRQOL. Overall, ongoing weight loss was associated with improvements in several HRQOL domains compared with weight gain.

Health-related quality of life association with weight change in type 2 diabetes mellitus: perception vs. reality.

AIMS: This study compared health-related quality of life (HRQOL) in adults with type 2 diabetes mellitus (T2DM) who reported their perception of weight change vs. actual weight change. METHODS: Respondents to the US Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) 2008 survey were asked if they had lost, maintained or gained weight compared with 1 year earlier (perception). Respondents also provided their actual weight and completed the SHIELD WQ-9 questionnaire to report how weight change affected 9 aspects of daily life. Perceived weight loss or gain was compared with measured weight change reported (2007 weight - 2008 weight) in those with T2DM. RESULTS: In respondents reporting weight loss (n = 762), 75.4% lost weight and 15.9% gained weight. For respondents reporting weight gain (n = 392), 70.2% gained weight and 19.6% lost weight. HRQOL did not differ between those who reported weight loss and actually lost weight vs. those who reported weight loss and actually gained weight (p > 0.05), except for self-esteem (p = 0.004). HRQOL was similar for those who reported weight gain and actually gained weight vs. those who reported weight gain, but actually lost weight (p > 0.20). Respondents who had perceived weight loss had significantly better HRQOL than those who perceived that they had gained weight. CONCLUSIONS: Perception of weight loss/gain may be as powerful as actual weight loss/gain in impacting HRQOL among adults with T2DM. Interventions that help individuals lose weight or perceive weight loss in addition to lowering glucose will assist in improving HRQOL.

Rate and risk predictors for development of self-reported type-2 diabetes mellitus over a 5-year period: the SHIELD study.

AIMS: This investigation determined the proportion of adults newly diagnosed as having type-2 diabetes mellitus (T2DM), and ascertained risk predictors for development of self-reported T2DM. METHODS: The US Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) survey was a 5-year longitudinal study of adults with and without diabetes mellitus. Adults completed a baseline health questionnaire in 2004 and ≥1 annual follow-up survey through 2009. Respondents with no self-reported diagnosis of diabetes at baseline were followed to measure rate of and assess risk factors for development of T2DM over 5 years. RESULTS: Among 8582 respondents without diabetes at baseline, 622 (7.2%) reported a diagnosis of T2DM over the subsequent 5 years. Increasing age, family history of T2DM, body mass index ≥30 kg/m(2), abdominal obesity, excessive thirst, asthma, gestational diabetes and 'high blood sugar without diabetes' significantly increased the risk of developing T2DM (p < 0.05 for each). Good to excellent health status and self-reported circulatory problems decreased the risk (p < 0.05 for each). CONCLUSIONS: Among this representative US adult population, the rate of developing T2DM was 7.2% over 5 years. Predictors of T2DM diagnosis identified in this analysis were readily obtainable via self-report.

Underutilisation of cardiovascular medications among at-risk individuals.

AIMS: Guidelines recommend antihypertensive, lipid-lowering and/or antiplatelet therapy for prevention of cardiovascular disease (CVD). This study examined the utilisation of cardiovascular therapies among individuals at CVD risk to assess adherence to guidelines. METHODS: Respondents to the SHIELD study were classified based on National Cholesterol Education Program Adult Treatment Panel III risk categories. High coronary heart disease (CHD) risk (n = 7510) was defined as self-reported diagnosis of heart disease/heart attack, narrow or blocked arteries, stroke or diabetes; moderate risk (n = 4823) included respondents with > or = 2 risk factors (i.e., men > 45 years, women > 55 years, hypertension, low high-density lipoprotein cholesterol, smoking and family history of CHD); and low risk (n = 5307) was 0-1 risk factor. Respondents reporting a myocardial infarction, stroke or revascularisation at baseline (prior CVD event) (n = 3777), those reporting a new CVD event during 2 years of follow up (n = 953), and those with type 2 diabetes mellitus (n = 3937) were evaluated. The proportion of respondents reporting treatment with lipid-lowering, antiplatelet or antihypertensive agents was calculated. RESULTS: Utilisation of lipid-lowering therapy was low (< or = 25%) in each group. Prescription antithrombotic therapy was minimal among respondents with prior CVD events, but 47% received antihypertensive medication. No use before or after a new CVD event was reported by 36% of respondents for lipid-lowering, 32% for antithrombotic and > 50% for antihypertensive medications. CONCLUSIONS: More than 50% of at-risk respondents and > 33% of respondents with new CVD events were not taking CVD therapy as recommended by guidelines.

Self-reported diagnosis of heart disease: results from the SHIELD study.

OBJECTIVE: This study evaluated the self-reported method of diagnosis of heart disease (HD) to elucidate whether diagnosis is occurring at early, presymptomatic stages as recommended by the prevention guidelines. METHODS: Respondents to the 2006 survey in the US population-based Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) reported whether a physician told them that they had HD, including heart attack, angina, heart failure, angioplasty or heart bypass surgery. Self-report of age at diagnosis, specialty of physician who made the diagnosis and whether the diagnosis was made after having symptoms, during routine screening or while being treated for another health problem were assessed. Year of diagnosis was categorised into 3-year intervals from 1985 to 2006. Individuals with HD diagnosis with and without type 2 diabetes mellitus (T2DM) were compared using chi-square tests. RESULTS: Of 1573 respondents reporting a diagnosis of HD, > 87% were white, > 49% were men and 38% had T2DM. Approximately 19% of respondents reported that their HD diagnosis was made during routine screening. A significantly greater percentage of HD respondents with T2DM reported the diagnosis being made based on symptoms (54%) and while being treated for another health problem (22%) compared with respondents without diabetes (48% symptoms and 15% other health problem, p > 0.05). HD was diagnosed primarily by cardiologists (> 60%) and family doctors (> 25%). CONCLUSION: There remains a missed opportunity to diagnose HD at earlier stages through routine screening or during treatment of other health conditions such as diabetes, as many individuals were not diagnosed until they were symptomatic.

Self-reported prevalence and awareness of metabolic syndrome: findings from SHIELD.

PURPOSE: This study assessed awareness of metabolic syndrome and evaluated health knowledge, attitudes and behaviours of respondents at risk. METHODS: Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD), a longitudinal US population-based survey initiated in 2004, included respondents, > or = 18 years of age, reporting a diagnosis of metabolic syndrome. Prevalence of metabolic syndrome was compared in SHIELD and National Health and Nutrition Examination Survey (NHANES) 1999-2002 survey. The proportion of SHIELD respondents who had heard of and/or understood metabolic syndrome was estimated. Respondents at high risk for metabolic syndrome were stratified into attitude-behaviour categories of 'Already Doing It', 'I Know I Should' and 'Don't Bother Me' and differences in attitudes and behaviours were evaluated with chi-square tests. RESULTS: Prevalence of reported metabolic syndrome was 0.6% in SHIELD screening questionnaire respondents (n = 211,097) vs. 25.9% in NHANES (n = 10,780). Less than 15% of SHIELD baseline questionnaire respondents (n = 22,001) had heard of or understood metabolic syndrome. Attitudes toward health status were more favourable in the 'Doing' group (27% reported fair/poor health) compared with those in the 'Should' (38%) and 'Don't' (54%) groups (p < 0.0001). The 'Don't' group was most likely to prefer medications to lifestyle change (13% vs. 2-4%) compared with 'Should' and 'Doing' groups (p < 0.0001). More 'Doing' respondents (79%) than 'Should' (59%) and 'Don't' (48%) respondents reported exercising regularly (p < 0.0001). CONCLUSIONS: The lack of knowledge about metabolic syndrome reported in SHIELD indicates limited penetration of this concept into public awareness. With behaviour categories, respondents who report healthy attitudes are more likely to embrace lifestyle changes, while respondents who do not care may be more difficult to treat.

Quality of life and depression of people living with type 2 diabetes mellitus and those at low and high risk for type 2 diabetes: findings from the Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD).

OBJECTIVES: This study compared health-related quality of life (HRQoL) and depression among individuals with type 2 diabetes mellitus (T2D) and those at low or high risk for T2D. METHODS: Respondents in a population-based US 2004 survey reported whether they had T2D (n = 3530) or risk factors for T2D [abdominal obesity, body mass index (BMI) >/= 28 kg/m(2), dyslipidaemia, hypertension and history of cardiovascular disease]. Respondents without T2D were stratified into low risk (0-2 risk factors, n = 5335) and high risk (3-5 risk factors, n = 5051). SF-12 version 2 (SF-12) and Patient Health Questionnaire (PHQ)-9 were used to measure HRQoL and depression. Mean scores were compared across the three groups using analysis of variance. Linear regression identified factors associated with SF-12 Physical and Mental Component Summary scores (PCS and MCS), adjusting for age, gender, race, income, geographic region, household size, BMI and group. RESULTS: Respondents were mostly women (60%) with mean age of 54 years. Mean PCS scores for T2D and high risk (39.5 and 41.7, respectively) were significantly lower than for low risk (50.6, p < 0.001). After adjustment, high-risk and T2D groups were associated with lower PCS and MCS scores compared with low risk group (p < 0.05). Mean PHQ-9 scores and per cent with moderate-to-severe depression were significantly higher for T2D and high risk than for low risk (p < 0.01). CONCLUSIONS: Health-related quality of life and depression scores in T2D were similar to those at high risk, and indicated significant decrements in physical health and greater depression compared with low-risk respondents.

Health-related behaviours of people with diabetes and those with cardiometabolic risk factors: results from SHIELD.

OBJECTIVES: The study assessed knowledge, attitudes and behaviours towards health, diabetes, diet and exercise among respondents with type 2 diabetes mellitus and those with cardiometabolic risk factors. METHODS: Respondents in the SHIELD study reported their health conditions, exercise, diet and weight loss. Three groups were assessed: (i) type 2 diabetes, (ii) high risk (HR) defined as 3-5 of the following factors: abdominal obesity, BMI > or = 28 kg/m(2), reported diagnosis of dyslipidaemia, hypertension, coronary heart disease or stroke and (iii) low risk (LR) defined as < or = 2 factors. Comparisons across groups were made using analysis of variance. RESULTS: More type 2 diabetes and HR respondents (> 46%) received recommendations to change their lifestyle habits (increase exercise and change eating habits), compared with < 29% of LR respondents, p < 0.0001. Less than 25% of respondents agreed that type 2 diabetes is not as serious as type 1 diabetes and > 85% agreed that obesity can aggravate or contribute to onset of chronic conditions. Mean number of healthcare visits was highest in type 2 diabetes (11.0) than HR (9.4) and LR (6.1) groups, p < 0.05. Type 2 diabetes and HR respondents were least likely to report exercising regularly (26%), compared with LR (37%), p < 0.05. More type 2 diabetes (70%) and HR (72%) respondents reported trying to lose weight vs. LR respondents (55%), p < 0.05. CONCLUSIONS: Type 2 diabetes and HR respondents reported attitudes and knowledge conducive to good health, but the majority of respondents did not translate these positive traits into healthy behaviour with respect to diet, exercise and weight loss.

The relationship of body mass index to diabetes mellitus, hypertension and dyslipidaemia: comparison of data from two national surveys.

The objectives of this study were to explore the relation between body mass index (BMI) and prevalence of diabetes mellitus, hypertension and dyslipidaemia; examine BMI distributions among patients with these conditions; and compare results from two national surveys. The Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) 2004 screening questionnaire (mailed survey) and the National Health and Nutrition Examination Surveys (NHANES) 1999-2002 (interview, clinical and laboratory data) were conducted in nationally representative samples>or=18 years old. Responses were received from 127,420 of 200,000 households (64%, representing 211,097 adults) for SHIELD, and 4257 participants for NHANES. Prevalence of diabetes mellitus, hypertension and dyslipidaemia was estimated within BMI categories, as was distribution of BMI levels among individuals with these diseases. Mean BMI was 27.8 kg/m2 for SHIELD and 27.9 kg/m2 for NHANES. Increased BMI was associated with increased prevalence of diabetes mellitus, hypertension and dyslipidaemia in both studies (p<0.001). For each condition, approximately [corrected] 75% or more [corrected] of patients had BMI>or=25 kg/m2. Estimated prevalence of diabetes mellitus and hypertension was similar in both studies, while dyslipidaemia was substantially higher in NHANES than SHIELD. In both studies, prevalence of diabetes mellitus, hypertension and dyslipidaemia occurred across all ranges of BMI, but increased with higher BMI. However, not all overweight or obese patients had these metabolic diseases and not all with these conditions were overweight or obese. Except for dyslipidaemia prevalence, SHIELD was comparable with NHANES. Consumer panel surveys may be an alternative method to collect data on the relationship of BMI and metabolic diseases.

A comparison of intravenous nicardipine and sodium nitroprusside in the immediate treatment of severe hypertension.

The primary objective of this study was to compare the antihypertensive efficacy and safety of intravenously administered nicardipine with that of intravenous nitroprusside (SNP) in patients with severe hypertension. The study was conducted in 121 patients with severe hypertension (diastolic blood pressure [BP] > 120 mm Hg, or systolic BP > 200 mm Hg). Patients were randomized to receive intravenous nicardipine or SNP. Drugs were administered according to a predetermined dosing schedule for a 10 to 12 h period. Sixty-one patients were randomized to intravenous nicardipine and 60 to SNP. Pretreatment BP values for the nicardipine and SNP groups were 217/128 mm Hg and 219/128 mm Hg, respectively. Therapeutic response (diastolic BP < 100 mm Hg, or a decrease of > 15 mm Hg; systolic BP < 180 mm Hg, or a decrease of > 20 mm Hg) was achieved in 98% (60/61) of patients treated with nicardipine and 93% (56/60) of patients treated with SNP. The mean decreases in systolic and diastolic BP were 61 mm Hg and 40 mm Hg after 4 h of nicardipine, and 59 mm Hg and 38 mm Hg after 4 h of SNP. The mean increases in heart rate also were similar in both groups (nicardipine, 12 beats/min; SNP 10 beats/min). The mean numbers of dose adjustments per hour required to maintain the BP reductions were lower (P < .01) in the nicardipine-treated patients (0.5 +/- 0.1 times per hour) than in the SNP-treated patients (1.5 +/- 0.2 times per hour).(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics, pharmacodynamics, and minimum effective clinical dose of intravenous nicardipine.

Nicardipine hydrochloride was administered intravenously to two groups of hypertensive patients: one group of 37 patients with mild to moderate hypertension and one group of 20 patients with severe hypertension. In the first group, doses of 0.5, 1, 2, and 4 mg/hr, as well as placebo, were infused for 48 hours in a double-blind fashion. Blood pressure and heart rate were monitored for this period and for the 24 hours after the infusion was discontinued. Significant decrements in blood pressure were noted with all doses; 4 mg/hr produced lowering that was greater than all other doses; 1 and 2 mg/hr produced lowering that was greater than 0.5 mg/hr but that were not different from each other. Excellent correlation of blood pressure reduction and plasma level was observed and linear kinetics existed. In the severe hypertensive patients, 1, 2, 4, 5, and 8 mg/hr were infused to established minimal and ineffective doses. One milligram per hour was an ineffective dose; 4, 5, and 8 mg/hr all produced significant reductions over the course of the study that were undistinguishable from each other. Two milligrams per hour produced modest reductions in blood pressure. Blood pressure reduction also correlated with plasma levels in the severe hypertensive group.

Effect of intracoronary nicardipine on methylergonovine-induced coronary artery spasm in patients with variant angina.

In a double-blind, randomized placebo controlled study, the effect of intracoronary (IC) nicardipine (0.4 mg) on methylergonovine (0.4 mg) induced coronary artery spasm was assessed in 16 patients with a history of variant angina. Reversal of the methylergonovine-induced coronary artery spasm was observed in 100% of patients treated with IC nicardipine and 25% of patients treated with placebo (p less than 0.01). There were no significant differences between the nicardipine and placebo treatment groups with respect to heart rate, blood pressure, proportion of patients experiencing chest pain or ST segment changes. These findings demonstrate that IC nicardipine is safe and could be effective in the reversal of coronary artery spasm in patients with variant angina.

Differential regulation of regional vascular resistance by the rostral and caudal ventrolateral medulla in the rat.

Regional vascular resistance changes were determined following chemical excitation and inhibition of the rostral vasopressor (RVLM) and caudal vasodepressor (CVLM) areas in the ventrolateral medulla. Mesenteric, renal and hindquarter vascular resistances were assessed in paralyzed and artificially ventilated urethane-anesthetized rats instrumented with pulsed-Doppler flow probes. Microinjection of the excitatory amino acid L-glutamate in the RVLM elicited a significant dose-related transient increase in blood pressure, heart rate and resistance of mesenteric, renal and hindquarter vascular beds. A similar dose-related hemodynamic profile was obtained following microinjection of muscimol, a GABAmimetic, in the CVLM. In contrast, significant dose-related decrease in blood pressure, heart rate and resistance in mesenteric and hindquarter vascular beds was observed following glutamate-induced excitation of the CVLM and muscimol-induced inhibition of the RVLM. Changes in renal vascular resistance were inconsistent in this second hemodynamic profile. Intravenous administration of the alpha 1 adrenergic antagonist, prazosin, abolished all of the hemodynamic effects elicited by excitation of the RVLM except the tachycardia. Intravenous atropine methylnitrate blocked the bradycardia associated with excitation of the CVLM but did not alter the vascular resistance changes. These results indicate that the changes in heart rate did not contribute significantly to the resistance profiles described. The changes in vascular resistance elicited by excitation and inhibition of the RVLM were correlated with increase and decrease in the greater splanchnic nerve activity, respectively. In conclusion, neuron pools in the RVLM and CVLM exert differential effects upon resistance in different vascular beds via changes in sympathetic outflow.(ABSTRACT TRUNCATED AT 250 WORDS)