Sex differences in plasma clozapine and norclozapine concentrations in clinical practice and in relation to body mass index and plasma glucose concentrations: a retrospective survey

BACKGROUND

Clozapine is widely prescribed and, although effective, can cause weight gain and dysglycemia. The dysmetabolic effects of clozapine are thought to be more prevalent in women with this gender on average attaining 17 % higher plasma clozapine concentrations than men.

METHODS

We investigated the relationship between dose, body mass index (BMI), plasma glucose concentration, and plasma clozapine and N-desmethylclozapine (norclozapine) concentrations in 100 individuals with a severe enduring mental illness.

RESULTS

Mean (10th/90th percentile) plasma clozapine concentrations were higher for women [0.49 (0.27-0.79) mg/L] compared with men [0.44 (0.26-0.70) mg/L] (F = 2.2; p = 0.035). There was no significant gender difference in the prescribed clozapine dose. BMI was significantly higher in women [mean (95 % CI) = 34.5 (26.0-45.3)] for females compared with 32.5 (25.2-41.0) for males. Overall, BMI increased by 0.7 kg/m(2) over a mean follow-up period of 210 days. A lower proportion, 41 % of women had a fasting blood glucose ≤6.0 mmol/L (<6.0 mmol/L is defined by the International Diabetes Federation as normal glucose handling), compared with 88 % of men (χ (2) = 18.6, p < 0.0001).

CONCLUSIONS

We have shown that mean BMI and blood glucose concentrations are higher in women prescribed clozapine than in men. Women also tended to attain higher plasma clozapine concentrations than men. The higher BMI and blood glucose in women may relate to higher tissue exposure to clozapine, as a consequence of sex differences in drug metabolism.

Baseline bleeding risk and arterial access site practice in relation to procedural outcomes after percutaneous coronary intervention

BACKGROUND

Transradial access (TRA) has been associated with reduced access site-related bleeding complications and mortality after percutaneous coronary intervention (PCI). It is unclear, however, whether these observed benefits are influenced by baseline bleeding risk.

OBJECTIVES

This study investigated the relationship between baseline bleeding risk, TRA utilization, and procedure-related outcomes in patients undergoing PCI enrolled in the British Cardiovascular Intervention Society database.

METHODS

Baseline bleeding risk was calculated by using modified Mehran bleeding risk scores in 348,689 PCI procedures performed between 2006 and 2011. Four categories for bleeding risk were defined for the modified Mehran risk score (MMRS): low (<10), moderate (10 to 14), high (15 to 19), and very high (≥20). The impact of baseline bleeding risk on 30-day mortality and its relationship with access site were studied.

RESULTS

TRA was independently associated with a 35% reduction in 30-day mortality risk (odds ratio [OR]: 0.65 [95% confidence interval (CI): 0.59 to 0.72]; p < 0.0001), with the magnitude of mortality reduction related to baseline bleeding risk (MMRS <10, OR: 0.73 [95% CI: 0.62 to 0.86]; MMRS ≥20, OR: 0.53 [95% CI: 0.47 to 0.61]). In patients with an MMRS <10, TRA was used in 71,771 (43.2%) of 166,083 PCI procedures; TRA was used in 8,655 (40.1%) of 21,559 PCI procedures in patients with an MMRS ≥20, illustrating that TRA was used less in those at highest risk from bleeding complications (p < 0.0001).

CONCLUSIONS

TRA was independently associated with reduced 30-day mortality, and the magnitude of this effect was related to baseline bleeding risk; those at highest risk of bleeding complications gained the greatest benefit from adoption of TRA during PCI.

Impact of age on the prognostic value of left ventricular function in relation to procedural outcomes following percutaneous coronary intervention: insights from the British Cardiovascular Intervention Society

BACKGROUND

Around one third of patients undergoing percutaneous coronary intervention (PCI) have left ventricular (LV) dysfunction. Whilst the prevalence of LV dysfunction is known to increase with age, the prevalence of LV dysfunction in different age groups in the PCI setting is not known and the effect of age on the prognostic value of LV function in the PCI setting has not been examined.

METHODS

The relationship between LV function and 30-day mortality in patients undergoing PCI in different age groups (<60 years, 60 to <70 years, 70 to <80 years and ≥80 years) was studied in 246,840 patients in the UK between 2006 and 2011.

RESULTS

Prevalent LV dysfunction in patients undergoing PCI increased with age; 25,106/83,161 (30.2%: <60 years), 24,114/76,895 (31.4%: 60 to <70 years), 23,580/64,711 36.4% (70 to <80 years) and 9,851/22,073 (44.6%) in patients aged 80 or over (P < 0.0001). Poor LV function was independently associated with increased risk of 30-day mortality outcomes in all age groups (OR 5.65:95% CI 4.21-7.58, age <60 years; OR 5.07: 95% CI 3.91-6.57, age 60 to <70 years; OR 4.50: 95% CI 3.64-5.57, 70 to <80 years and OR 4.83:95% CI 3.79-6.15, age ≥80 years).

CONCLUSIONS

Our analysis suggests that worsening LV function is an important independent predictor of worse 30-day mortality outcomes across all age groups and underscores the need for a measure of LV function in all patients for accurate risk stratification prior to PCI.

Evidence that multiple defects in lipid regulation occur before hyperglycemia during the prodrome of type-2 diabetes

BACKGROUND

Blood-vessel dysfunction arises before overt hyperglycemia in type-2 diabetes (T2DM). We hypothesised that a metabolomic approach might identify metabolites/pathways perturbed in this pre-hyperglycemic phase. To test this hypothesis and for specific metabolite hypothesis generation, serum metabolic profiling was performed in young women at increased, intermediate and low risk of subsequent T2DM.

METHODS

Participants were stratified by glucose tolerance during a previous index pregnancy into three risk-groups: overt gestational diabetes (GDM; n = 18); those with glucose values in the upper quartile but below GDM levels (UQ group; n = 45); and controls (n = 43, below the median glucose values). Follow-up serum samples were collected at a mean 22 months postnatally. Samples were analysed in a random order using Ultra Performance Liquid Chromatography coupled to an electrospray hybrid LTQ-Orbitrap mass spectrometer. Statistical analysis included principal component (PCA) and multivariate methods.

FINDINGS

Significant between-group differences were observed at follow-up in waist circumference (86, 95%CI (79-91) vs 80 (76-84) cm for GDM vs controls, p<0.05), adiponectin (about 33% lower in GDM group, p = 0.004), fasting glucose, post-prandial glucose and HbA1c, but the latter 3 all remained within the 'normal' range. Substantial differences in metabolite profiles were apparent between the 2 'at-risk' groups and controls, particularly in concentrations of phospholipids (4 metabolites with p ≤ 0.01), acylcarnitines (3 with p ≤ 0.02), short- and long-chain fatty acids (3 with p<  = 0.03), and diglycerides (4 with p ≤ 0.05).

INTERPRETATION

Defects in adipocyte function from excess energy storage as relatively hypoxic visceral and hepatic fat, and impaired mitochondrial fatty acid oxidation may initiate the observed perturbations in lipid metabolism. Together with evidence from the failure of glucose-directed treatments to improve cardiovascular outcomes, these data and those of others indicate that a new, quite different definition of type-2 diabetes is required. This definition would incorporate disturbed lipid metabolism prior to hyperglycemia.

Haemostatic factors, lipoproteins and long-term mortality in a multi-ethnic population of Gujarati, African-Caribbean and European origin

OBJECTIVES

To examine the relations between haemostatic factors and lipoproteins with mortality in British Europeans, African-Caribbeans (AfC) and Gujarati Indians.

METHODS

A prospective cohort study of 331 subjects (40-79 years), followed-up over 26 years for mortality. Apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), factor VII coagulant activity (FVIIc), fibrinogen and von Willebrand Factor (vWF) were measured at baseline in 118 Europeans, 100 AfC and 113 Gujaratis. Aortic pulse wave velocity (aPWV) was measured in 174 participants.

RESULTS

147 (44.4%) subjects died during a median of 24 years follow-up with 69 cardiovascular deaths. Women at baseline had higher, and AfC males the lowest FVIIc and Apo-A1 levels. Baseline age-sex and ethnicity adjusted FVIIc levels were higher in those who died (131.0 vs. 117.4%; P = 0.048). In similarly adjusted partial correlations, Apo-A1 was inversely related to arterial stiffness (ρ = -0.23, P = 0.04). Over the 26 years follow-up, participants below the median (i.e. with lower concentration) of FVIIc, Fibrinogen, Apo-B and vWF had better survival rates than those with higher concentrations; those with higher concentrations of Apo-A1 had better survival. In Cox multivariable regression analyses including sex, ethnicity and aPWV, independently increased risk of all-cause mortality came only from SBP (per 5 mmHg); P = 0.011), age (per year); P < 0.0001 and FVIIc at 7% (per 10-unit; HR 1.07 (1.02, 1.12); P = 0.008. Separately, Apo-A1 (HR 0.12 (0.02, 0.75; P = 0.029) was independently associated with a very significant 88% reduction in all-cause mortality.

CONCLUSIONS

Despite a relatively small sample size, long-term follow-up suggests an independent effect of the prothrombotic state (via FVIIc) and apo-A1 (a constituent of HDL) on mortality.

Arterial access site utilization in cardiogenic shock in the United Kingdom: is radial access feasible?

BACKGROUND

Cardiogenic shock (CS) remains the leading cause of mortality in patients hospitalized with acute myocardial infarction (AMI). The transradial access site (TRA) has become increasingly adopted as a default access site for percutaneous coronary intervention (PCI); however, even in experienced centers that favor the radial artery as the primary access site during PCI, patients presenting in CS are often treated via the transfemoral access site (TFA); and commentators have suggested that CS remains the final frontier that has given even experienced radial operators pause. We studied the use of TRA in patients presenting in CS in a nonselected high-risk cohort from the British Cardiovascular Intervention database over a 7-year period (2006-2012).

METHODS

Mortality (30-day) and major adverse cardiac and cerebrovascular events (a composite of in-hospital mortality, in-hospital myocardial reinfarction, target vessel revascularization, and cerebrovascular events) were studied based on TFA and TRA utilization in CS patients. The influence of access site selection was studied in 7,231 CS patients; TFA was used in 5,354 and TRA in 1,877 patients.

RESULTS

Transradial access site was independently associated with a lower 30-day mortality (hazard ratio [HR] 0.56, 95% CI 0.46-0.69, P = 0 < .001), in-hospital major adverse cardiac and cerebrovascular events (HR 0.64, 95% CI 0.53-0.76, P < .0001) and major bleeding (HR 0.37, 95% CI 0.18-0.73, P = .004).

CONCLUSIONS

Although the majority of PCI cases performed in patients with cardiogenic shock in the United Kingdom are performed through the TFA, the radial artery represents an alternative viable access site in this high-risk cohort of patients in experienced centers.

Socioeconomic deprivation independently predicts symptomatic painful diabetic neuropathy in type 1 diabetes

INTRODUCTION

Painful peripheral neuropathy in people with type 1 diabetes is a disabling and costly complication. A greater understanding of predisposing factors and prescribing may facilitate more effective resource allocation.

METHODS

The Townsend index of deprivation (numerically higher for greater disadvantage) was examined in the pseudonymised records of 1621 (684 females) individuals with type 1 diabetes and related to prevalence of drug treated severe diabetes related neuropathic pain.

RESULTS

Treatment for neuropathic pain was initiated in 280 patients, who were older at 57.1 vs 45.6 years and had greater BMI (29.8 vs 27.8kg/m(2); p<0.0001). HbA1C was similar between groups, whilst eGFR was lower in the neuropathic pain group. Amitriptyline was the most commonly prescribed agent (46.8% of total prescriptions). Duloxetine (60mg daily) was prescribed in 9.3% of cases. There were significant differences between the groups for the Townsend index, with a greater proportion (34.3% vs 21.7%) of patients with treated neuropathic pain having a score of ≥1 (X(2)=19.9, p<0.001). Multivariate logistic regression analyses indicated that each unit increment in Townsend index was associated with a 11% increased odds of requiring neuropathic pain treatment [odds ratio (95% CI) 1.11 (1.05-1.17), p<0.001]. This was independent of age: 1.04 (1.02-1.05), BMI: 1.03 (1.01-1.05), HbA1C: 1.15 (1.05-1.24), male gender: 0.74 (0.55-0.98), systolic BP and eGFR. Inclusion of depression and mixed anxiety/depressive disorder did not change the risk estimates.

CONCLUSION

Amitriptyline was the most commonly used agent for treatment of diabetes related neuropathic pain with Duloxetine much less used. A higher level of socioeconomic deprivation may predispose to severe neuropathic pain in diabetes. Differential allocation of resources may benefit this group.

Bariatric surgery and its impact on cardiovascular disease and mortality: a systematic review and meta-analysis

BACKGROUND

Bariatric surgery has been shown to improve cardiovascular risk factors but long term benefits for survival and cardiovascular events are still uncertain.

METHODS

We searched MEDLINE and EMBASE for parallel group studies that evaluated the clinical outcomes associated with bariatric surgery as compared to non-surgical treatment. Relevant studies were pooled using random effects meta-analysis for risk of myocardial infarction, stroke, cardiovascular events and mortality.

RESULTS

14 studies met the inclusion criteria, which included 29,208 patients who underwent bariatric surgery and 166,200 nonsurgical controls (mean age 48 years, 30% male, follow up period ranged from 2 years to 14.7 years). Four studies were considered at moderate-high risk of bias, whilst ten studies were at moderate or lower risk of bias. Compared to nonsurgical controls there was more than 50% reduction in mortality amongst patients who had bariatric surgery (OR 0.48 95% CI 0.35-0.64, I2=86%, 14 studies). In pooled analysis of four studies with adjusted data, bariatric surgery was associated with a significantly reduced risk of composite cardiovascular adverse events (OR 0.54 95% CI 0.41-0.70, I2=58%). Bariatric surgery was also associated with significant reduction in specific endpoints of myocardial infarction (OR 0.46 95% CI 0.30-0.69, I2=79%, 4 studies) and stroke (OR 0.49 95% CI 0.32-0.75, I2=59%, 4 studies).

CONCLUSIONS

Data from observational studies indicates that patients undergoing bariatric surgery have a reduced risk of myocardial infarction, stroke, cardiovascular events and mortality compared to non-surgical controls. Future randomized studies should investigate whether these observations are reproduced in a clinical trials setting.

Aortic pulse wave velocity improves cardiovascular event prediction: an individual participant meta-analysis of prospective observational data from 17,635 subjects

OBJECTIVES

The goal of this study was to determine whether aortic pulse wave velocity (aPWV) improves prediction of cardiovascular disease (CVD) events beyond conventional risk factors.

BACKGROUND

Several studies have shown that aPWV may be a useful risk factor for predicting CVD, but they have been underpowered to examine whether this is true for different subgroups.

METHODS

We undertook a systematic review and obtained individual participant data from 16 studies. Study-specific associations of aPWV with CVD outcomes were determined using Cox proportional hazard models and random effect models to estimate pooled effects.

RESULTS

Of 17,635 participants, a total of 1,785 (10%) had a CVD event. The pooled age- and sex-adjusted hazard ratios (HRs) per 1-SD change in loge aPWV were 1.35 (95% confidence interval [CI]: 1.22 to 1.50; p < 0.001) for coronary heart disease, 1.54 (95% CI: 1.34 to 1.78; p < 0.001) for stroke, and 1.45 (95% CI: 1.30 to 1.61; p < 0.001) for CVD. Associations stratified according to sex, diabetes, and hypertension were similar but decreased with age (1.89, 1.77, 1.36, and 1.23 for age ≤50, 51 to 60, 61 to 70, and >70 years, respectively; pinteraction <0.001). After adjusting for conventional risk factors, aPWV remained a predictor of coronary heart disease (HR: 1.23 [95% CI: 1.11 to 1.35]; p < 0.001), stroke (HR: 1.28 [95% CI: 1.16 to 1.42]; p < 0.001), and CVD events (HR: 1.30 [95% CI: 1.18 to 1.43]; p < 0.001). Reclassification indices showed that the addition of aPWV improved risk prediction (13% for 10-year CVD risk for intermediate risk) for some subgroups.

CONCLUSIONS

Consideration of aPWV improves model fit and reclassifies risk for future CVD events in models that include standard risk factors. aPWV may enable better identification of high-risk populations that might benefit from more aggressive CVD risk factor management.

Excess Cardiovascular Risk Burden in Jamaican Women Does Not Influence Predicted 10-Year CVD Risk Profiles of Jamaica Adults: An Analysis of the 2007/08 Jamaica Health and Lifestyle Survey

Background

Black Caribbean women have a higher burden of cardiovascular disease (CVD) risk factors than their male counterparts. Whether this results in a difference in incident cardiovascular events is unknown. The aim of this study was to estimate the 10 year World Health Organization/International Society for Hypertension (WHO/ISH) CVD risk score for Jamaica and explore the effect of sex as well as obesity, physical activity and socioeconomic status on these estimates.

Methods and Findings

Data from 40–74 year old participants in the 2007/08 Jamaica Health and Lifestyle Survey were used. Trained interviewers administered questionnaires and measured anthropometrics, blood pressure, fasting glucose and cholesterol. Education and occupation were used to assess socioeconomic status. The Americas B tables were used to estimate the WHO/ISH 10 year CVD risk scores for the population. Weighted prevalence estimates were calculated. Data from 1,432 (450 men, 982 women) participants were analysed, after excluding those with self-reported heart attack and stroke. The women had a higher prevalence of diabetes (19%W;12%M), hypertension (49%W;47%M), hypercholesterolemia (25%W;11%M), obesity (46%W;15%M) and physical inactivity (59%W;29%M). More men smoked (6%W;31%M). There was good agreement between the 10-year cardiovascular risk estimates whether or not cholesterol measurements were utilized for calculation (kappa –0.61). While 90% had a 10 year WHO/ISH CVD risk of less than 10%, approximately 2% of the population or 14,000 persons had a 10 year WHO/ISH CVD risk of ≥30%. As expected CVD risk increased with age but there was no sex difference in CVD risk distribution despite women having a greater risk factor burden. Women with low socioeconomic status had the most adverse CVD risk profile.

Conclusion

Despite women having a higher prevalence of CVD risk factors there was no sex difference in 10-year WHO/ISH CVD risk in Jamaican adults.

IGFBP2 is a biomarker for predicting longitudinal deterioration in renal function in type 2 diabetes

OBJECTIVE

Insulin-like growth factors are implicated in the development of diabetic nephropathy. IGF-binding protein 2 (IGFBP2) and IGF2 are expressed in the kidney, but their associations with diabetic nephropathy are unclear. We therefore tested the hypothesis that circulating levels of IGF2 and IGFBP2 predict longitudinal renal function in individuals with type 2 diabetes.

DESIGN AND METHODS

IGFBP2 and IGF2 measurements were performed in 436 individuals (263 males) with type 2 diabetes. Linear mixed-effect regression analysis was used to model the relationship between plasma IGFBP2 concentration and longitudinal changes in estimated glomerular filtration rate (eGFR) over an 8-year period. Analyses were also performed for IGF1, IGF2, IGFBP1 and IGFBP3 concentrations as predictors of longitudinal renal outcomes.

RESULTS

High IGFBP2 concentration at baseline was associated with a decreased eGFR over an 8-year period (β=-0.02, (95% confidence interval -0.03 to -0.01), P<0.001). High IGFBP1, IGFBP2 and IGFBP3 were also associated with low baseline eGFR concentration.

CONCLUSION

This study demonstrates that IGFBP2 is a predictor of longitudinal deterioration of renal function in type 2 diabetes.

Type 1 diabetes in Cheshire: cardiometabolic risk factor trends (2004-2009)

AIMS

In the context of changes in the last 10 years in treatment strategies for type 1 diabetes we evaluated longitudinal trends in cardiometabolic risk factor profiles in a population from North-West England.

METHODS

We retrospectively examined longitudinal case records for the period for 291 adult patients followed up between 2004 and 2009 (age range 16-85). Data search was performed through the EMIS® software provider using data held in primary care.

RESULTS

Longitudinal analysis of individually followed patients indicated a mean 0.4% reduction in HbA1c from 8.3% (67 mmol/mol) at baseline (p=0.002). The proportion of patients with an HbA1c ≥10% (86 mmol/mol) at baseline had a significant reduction over time from 14.0% to 9.5% (χ(2)=9.4, p=0.002). BMI remained unchanged (28.3 vs 28.4 kg/m(2)). However total cholesterol fell by 12.5% from 4.8mM to 4.2mM, (p<0.0001) with a corresponding 23% reduction in LDL-cholesterol from 3.0mm to 2.3mM (p<0.0001). There was a significant fall in diastolic BP (78-74 mmHg, p=0.0016). In a mixed longitudinal regression model, HbA1c was associated with LDL-C (β=0.28, p<0.001) and age (β=0.02, p=0.001), independent of BMI, gender and systolic BP.

DISCUSSION

In spite of intensive work to improve glycaemic control in type 1 diabetes, mean HbA1c remains above target for many people in our area, highlighting the difficulty of achieving glycaemic targets in type 1 diabetes. The significant reduction in diastolic BP, LDL and total cholesterol may have long-term benefit in cardiovascular event rate reduction.

HOMA-S is associated with greater HbA1c reduction with a GLP-1 analogue in patients with type 2 diabetes

Exenatide, a glucagon-like peptide-1 (GLP-1) analogue, is an effective glucoregulator for treating overweight individuals, not at target HbA1 c. This prospective study aimed to determine whether estimates of beta cell function (HOMA-B) and insulin sensitivity (HOMA-S) predict response to Exenatide treatment.Prospective data on 43 type 2 diabetes patients were collected for up to 2.8 years in UK primary care. HOMA-B and HOMA-S were estimated prior to initiating Exenatide, with monitoring of cardio-metabolic risk factors.Mean (SD) age and BMI pre-treatment were 54.1±10.5 years and 35.7±7.5 kg/m2 respectively. HbA1c decreased (mean reduction 0.9%, p=0.04; p for trend=0.01) in 61% of patients. In univariate analyses, HOMA-S as a measure of insulin sensitivity was inversely (β=- 0.41, p 0.009) related to change in HbA1c, with no relation for HOMA-B.In a random effects regression model that included age at baseline, weight, LDL-C, HDL-C and triglycerides, change in HbA1c (β= - 0.14, p<0.001) and HDL-C (β= - 0.52, p=0.011) were independently associated with increasing insulin sensitivity (r2=0.52). Thus patients with greater measured insulin sensitivity achieved greater reduction in HbA1c independent of the factors described above.In logistic regression those in the highest tertile of log-HOMA-S were 45% more likely to have a fall in HbA1c with an odds ratio (OR) of 0.55 (95% CI 0.47-0.66) p<0.0001 (log likelihood ratio for the model χ2=71.6, p<0.0001).Patients with greater measured insulin sensitivity achieve greater reduction in HbA1c with Exenatide. Determination of insulin sensitivity may assist in guiding outcome expectation in overweight patients treated with GLP-1 analogues.

Quantitative adjustment for macroprolactin is an integral part of laboratory assessment of hyperprolactinaemia

INTRODUCTION

Prolactin circulates predominantly as a 23-kDa monomer, and a high-molecular-weight form largely consisting of a complex of prolactin and an anti-prolactin IgG autoantibody, called macroprolactin. This cross-reacts with conventional laboratory assays for prolactin. We here describe how quantitative adjustment for this may assist patient management.In a consecutive series of 218 patients with prolactin elevated to 400 mu/L or more in men (normal range ≤ 180) (n=79, 36.2% of sample) and 1 000 mu/L or more in women (normal range ≤ 500) (n=139, 63.8%) a macroprolactin screen was performed using PEG precipitation.

RESULTS

Where present, median macroprolactin as a proportion of total prolactin was in women 13% (percentile 25-percentile 75: 7-25%) and in men 15% (7-30%).The distribution of macroprolactin as a proportion of total prolactin was markedly skewed to the left with 69.7% of women and 62.9% of men having macroprolactin proportion of 20% or less. There was no relation between %macroprolactin and total measured prolactin, age or gender.Of relevance to clinical management, in 24% of men and 20.5% of women, correction for estimated macroprolactin gave an adjusted monomeric prolactin level below the agreed threshold for further investigation, potentially avoiding unnecessarily referral.In our clinical series, quotation of an adjusted monomeric prolactin would have resulted in unnecessary further investigation being avoided in a number of cases.

DISCUSSION

Screening for macroprolactin is a key element of laboratory assessment for hyperprolactinaemia.In cases where measured total prolactin is significantly raised, quantitative reporting of estimated monomeric prolactin instead of just 'macroprolactin' positive' can avoid unnecessary investigations.

Adiponectin and lipid profiles compared with insulins in relation to early growth of British South Asian and European children: the Manchester children's growth and vascular health study

CONTEXT

Adiponectin, high-density lipoprotein cholesterol (HDL-C) and insulin concentrations may be important in the pathophysiology of cardiovascular disease.

OBJECTIVE

We tested the hypothesis that serum adiponectin rather than insulin differs from early life, between South Asians and Europeans, with a potentially key role in excess cardiovascular risk characteristic of adult South Asians.

DESIGN AND PARTICIPANTS

We conducted a longitudinal study of 215 British-born children of European (n = 138) and South Asian (n = 77) origin, from birth to 3 yr.

MAIN OUTCOME MEASURE

Serum adiponectin, insulin, proinsulin and HDL-C concentrations were assessed in relation to ethnic group and growth in anthropometric variables from 0-3 yr of age.

RESULTS

Serum adiponectin was lower in South Asian children, despite their smaller size, notable at age 3-6 months (9.5 vs. 11.8 mg/liter; P = 0.04), with no ethnic differences in serum lipids or insulin or proinsulin. In mixed-effects longitudinal models for HDL-C, determinants were adiponectin (P = 0.034), age (P < 0.001), and body mass index (P < 0.001) but not ethnicity. None of these or growth variables affected either insulin or proinsulin. In a fully adjusted mixed-effects longitudinal model including age, sex, insulin, and proinsulin, the independent determinants of serum adiponectin were height [21.3 (95% confidence interval = 31.7-10.8 cm lower, for every 1 mmol/liter increase in adiponectin, P < 0.001], HDL-C [2.8 (1.3-4.2) mmol/liter higher, P < 0.0001], body mass index (lower, P = 0.03), and South Asian ethnicity (lower, P = 0.01).

CONCLUSIONS

These British South Asian-origin infants have lower serum adiponectin but no differences in HDL-C or insulin molecules. In South Asians, factors affecting adiponectin metabolism in early life, rather than insulin resistance, likely determine later excess cardiovascular risk.

Total cardiovascular risk approach to improve efficiency of cardiovascular prevention in resource constrain settings

OBJECTIVES

To determine the population distribution of cardiovascular risk in eight low- and middle-income countries and compare the cost of drug treatment based on cardiovascular risk (cardiovascular risk thresholds ≥ 30%/≥ 40%) with single risk factor cutoff levels.

STUDY DESIGN AND SETTING

Using World Health Organization (WHO) and the International Society of Hypertension risk prediction charts, cardiovascular risk was categorized in a cross-sectional study of 8,625 randomly selected people aged 40-80 years (mean age, 54.6 years) from defined geographic regions of Nigeria, Iran, China, Pakistan, Georgia, Nepal, Cuba, and Sri Lanka. Cost estimates for drug therapy were calculated for three countries.

RESULTS

A large fraction (90.0-98.9%) of the study population has a 10-year cardiovascular risk <20%. Only 0.2-4.8% are in the high-risk categories (≥ 30%). Adopting a total risk approach and WHO guidelines recommendations would restrict unnecessary drug treatment and reduce the drug costs significantly.

CONCLUSION

Adopting a total cardiovascular risk approach instead of a single risk factor approach reduces health care expenditure by reducing drug costs. Therefore, limited resources can be more efficiently used to target high-risk people who will benefit the most. This strategy needs to be complemented with population-wide measures to shift the cardiovascular risk distribution of the whole population.

Chirped-pulse amplification with narrowband pulses

We demonstrate a compact hyperdispersion stretcher and compressor pair that permit chirped-pulse amplification in Nd:YAG. We generate 750 mJ, 0.2 nm FWHM, 10 Hz pulses recompressed to an 8 ps near-transform-limited duration. The dispersion-matched pulse compressor and stretcher impart a chirp of 7300 ps/nm, in a 3 m x 1 m footprint.

Isotope-specific detection of low-density materials with laser-based monoenergetic gamma-rays

What we believe to be the first demonstration of isotope-specific detection of a low-Z and low density object shielded by a high-Z and high-density material using monoenergetic gamma rays is reported. The isotope-specific detection of LiH shielded by Pb and Al is accomplished using the nuclear resonance fluorescence line of L7i at 478 keV. Resonant photons are produced via laser-based Compton scattering. The detection techniques are general, and the confidence level obtained is shown to be superior to that yielded by conventional x-ray and gamma-ray techniques in these situations.

Plasma Fatty Acid Composition as a Predictor of Arterial Stiffness and Mortality

Aortic stiffness predicts cardiovascular mortality and may be influenced by dietary fat composition. The hypothesis that plasma fat composition influences arterial stiffness and subsequent mortality was tested here in a prospective study. A total of 174 randomly sampled nondiabetic participants aged 45 to 74 years were recruited from local populations, stratified by ethnicity and gender, and followed up for mortality. Aortic pulse wave velocity (PWV), blood pressure, and fatty acid composition of plasma lipids were measured at baseline. PWV was associated with increased cardiovascular mortality and inversely related to the proportions of docosahexaenoic (ρ=−0.22; P =0.02) and arachidonic acids (ρ=−0.25; P <0.001) in plasma lipids. Principal component analyses identified a cluster characterized by higher proportions of palmitate, palmitoleic and oleic acid and lower proportions of linoleic, dihomo-γ linolenic, and arachidonic acids. This cluster was positively associated with PWV, central adiposity, smoking, and increased mortality (hazard ratio: 1.13; 95% CI: 1.01 to 1.27). A second cluster, with higher proportions of arachidonic, eicosapentaenoic, and docosahexaenoic and lower proportions of oleic, palmitic, and linoleic acid levels, was associated with lower PWV and systolic blood pressure but also decreased risk of mortality (hazard ratio: 0.57; 95% CI: 0.39 to 0.82), independent of PWV and blood pressure. These data suggest that plasma fatty acid profiles characterized by a higher proportion of long-chain polyunsaturated fatty acids are associated with decreased cardiovascular mortality, independent of the impact of aortic PWV. The results are consistent with an effect of dietary sources of n-3 long-chain polyunsaturates influencing arterial stiffness and mortality.

OZSPEC-2: an improved broadband high-resolution elliptical crystal x-ray spectrometer for high-energy density physics experiments (invited)

A novel time, space, and energy-resolved x-ray spectrometer has been developed which produces, in a single snapshot, a broadband and relatively calibrated spectrum of the x-ray emission from a high-energy density laboratory plasma. The opacity zipper spectrometer (OZSPEC-1) records a nearly continuous spectrum for x-ray energies from 240 to 5800 eV in a single shot. The second-generation OZSPEC-2, detailed in this work, records fully continuous spectra on a single shot from any two of these three bands: 270-650, 660-1580, and 1960-4720 eV. These instruments thus record thermal and line radiation from a wide range of plasmas. These instruments' single-shot bandwidth is unmatched in a time-gated spectrometer; conversely, other broadband instruments are either time-integrated (using crystals or gratings), lack spectral resolution (diode arrays), or cover a lower energy band (gratings). The OZSPECs are based on the zipper detector, a large-format (100x35 mm) gated microchannel plate detector, with spectra dispersed along the 100 mm dimension. OZSPEC-1 and -2 both use elliptically bent crystals of OHM, RAP, and/or PET. Individual spectra are gated in 100 ps. OZSPEC-2 provides one-dimensional spatial imaging with 30-50 microm resolution over a 1500 microm field of view at the source. The elliptical crystal design yields broad spectral coverage with resolution E/DeltaE>500, strong rejection of hard x-ray backgrounds, and negligible source broadening for extended sources. Near-term applications include plasma opacity measurements, detailed spectra of inertial fusion Hohlraums, and laboratory astrophysics experiments.

Migration is associated with lower total, but not free testosterone levels in South Asian men

OBJECTIVE

Serum testosterone measurement is an integral part of the endocrine assessment of men. Little is known about its variation in relation to migration. We examined within a South Asian group the effect of migration to the UK on androgen levels.

DESIGN

Circulating testosterone and SHBG concentrations were measured in 97 Gujarati men resident in India and in 79 men from the same villages of origin living in Birmingham, UK. Free testosterone was calculated by Vermeulen's method. Insulin sensitivity (HOMA-S) was determined from paired fasting plasma intact insulin and glucose values.

RESULTS

Circulating testosterone was significantly lower in UK Gujarati men (17.2 nmol/l [15.7-18.7]) vs. Indian Gujarati men (21.7 [20.0-23.5]) (P = 0.0002) (age-adjusted median [95% CI]). There was no difference by migration status in circulating free testosterone. Sex hormone binding globulin (SHBG) levels were lower in UK migrants (16.8 nmol/l [15.5-18.1]) than in nonmigrants (21.9 nmol/l [20.5-23.3]) (P < 0.0001). Testosterone level correlated positively with insulin sensitivity (HOMA-S) (rho 0.16, P = 0.04). In multivariate analysis, total testosterone was independently and positively associated with logSHBG (normalized beta (beta) = 0.29, P = 0.002) and independently and negatively with waist circumference (beta = -0.19, P = 0.04), in a model also including height, age, migration status, leptin and fasting insulin.

CONCLUSION

Lower circulating testosterone in UK Gujarati men and its association with markers of insulin sensitivity suggest a profound influence of body composition change with migration on testosterone levels. The lower SHBG in this group restores parity in free testosterone. Account should be taken of SHBG in interpreting testosterone levels in men, as well as in women.