Systemic administration of local anesthetic agents to relieve neuropathic pain

BACKGROUND

Lidocaine, mexiletine, tocainide, and flecainide are local anesthetics which give an analgesic effect when administered orally or parenterally. Early reports described the use of intravenous lidocaine or procaine to relieve cancer and postoperative pain. Interest reappeared decades later when patient series and clinical trials reported that parenteral lidocaine and its oral analogs tocainide, mexiletine, and flecainide relieved neuropathic pain in some patients. With the recent publication of clinical trials with high quality standards, we have reviewed the use of systemic lidocaine and its oral analogs in neuropathic pain to update our knowledge, to measure their benefit and harm, and to better define their role in therapy.

OBJECTIVES

To evaluate pain relief and adverse effect rates between systemic local anesthetic-type drugs and other control interventions.

SEARCH METHODS

We searched MEDLINE (1966 through 15 May 2004), EMBASE (January 1980 to December 2002), Cancer Lit (through 15 December 2002), Cochrane Central Register of Controlled Trials (2nd Quarter, 2004), System for Information on Grey Literature in Europe (SIGLE), and LILACS, from January 1966 through March 2001. We also hand searched conference proceedings, textbooks, original articles and reviews.

SELECTION CRITERIA

We included trials with random allocation, that were double blinded, with a parallel or crossover design. The control intervention was a placebo or an analgesic drug for neuropathic pain from any cause.

DATA COLLECTION AND ANALYSIS

We collected efficacy and safety data from all published and unpublished trials. We calculated combined effect sizes using continuous and binary data for pain relief and adverse effects as primary and secondary outcome measurements, respectively.

MAIN RESULTS

Thirty-two controlled clinical trials met the selection criteria; two were duplicate articles. The treatment drugs were intravenous lidocaine (16 trials), mexiletine (12 trials), lidocaine plus mexiletine sequentially (one trial), and tocainide (one trial). Twenty-one trials were crossover studies, and nine were parallel. Lidocaine and mexiletine were superior to placebo [weighted mean difference (WMD) = -11; 95% CI: -15 to -7; P < 0.00001], and limited data showed no difference in efficacy (WMD = -0.6; 95% CI: -7 to 6), or adverse effects versus carbamazepine, amantadine, gabapentin or morphine. In these trials, systemic local anesthetics were safe, with no deaths or life-threatening toxicities. Sensitivity analysis identified data distribution in three trials as a probable source of heterogeneity. There was no publication bias.

AUTHORS' CONCLUSIONS

Lidocaine and oral analogs were safe drugs in controlled clinical trials for neuropathic pain, were better than placebo, and were as effective as other analgesics. Future trials should enroll specific diseases and test novel lidocaine analogs with better toxicity profiles. More emphasis is necessary on outcomes measuring patient satisfaction to assess if statistically significant pain relief is clinically meaningful.

Basic Mechanisms of Pain

It has been well established that pain reflects complex, linked neuroendocrine responses that go far beyond a sensory alarm system. Accordingly, there may be significant medical consequences of inadequate recognition or treatment of pain.

Adipocytokines as features of the metabolic syndrome determined using confirmatory factor analysis

PURPOSE

Confirmatory factor analysis (CFA) was used to test the hypothesis whether adipocytokines are associated with the risk factor cluster that characterizes the metabolic syndrome (MetS).

METHODS

Data from 134 nondiabetic subjects were analyzed using CFA. Insulin sensitivity (SI) was quantified using intravenous glucose tolerance tests, visceral fat area by computed tomography and fasting high-density lipoprotein, triglycerides, monocyte chemoattractant protein-1 (MCP-1), serum amyloid A (SAA), tumor necrosis factor (TNF)-α, adiponectin, resistin, leptin, interleukin (IL)-6, C-reactive protein (CRP), and plasminogen activator inhibitor (PAI)-1 were measured.

RESULTS

The basic model representing the MetS included six indicators comprising obesity, SI, lipids, and hypertension, and demonstrated excellent goodness of fit. Using multivariate analysis, MCP-1, SAA, and TNF-α were not independently associated with any of the MetS variables. Adiponectin, resistin, leptin, CRP, and IL-6 were associated with at least one of the risk factors, but when added to the basic model decreased all goodness-of-fit parameters. PAI-1 was associated with all cardiometabolic factors and improved goodness-of-fit compared with the basic model.

CONCLUSIONS

Addition of PAI-1 increased the CFA model goodness of fit compared with the basic model, suggesting that this protein may represent an added feature of the MetS.

β-cell loss and β-cell apoptosis in human type 2 diabetes are related to islet amyloid deposition

Amyloid deposition and reduced β-cell mass are pathological hallmarks of the pancreatic islet in type 2 diabetes; however, whether the extent of amyloid deposition is associated with decreased β-cell mass is debated. We investigated the possible relationship and, for the first time, determined whether increased islet amyloid and/or decreased β-cell area quantified on histological sections is correlated with increased β-cell apoptosis. Formalin-fixed, paraffin-embedded human pancreas sections from subjects with (n = 29) and without (n = 39) diabetes were obtained at autopsy (64 ± 2 and 70 ± 4 islets/subject, respectively). Amyloid and β cells were visualized by thioflavin S and insulin immunolabeling. Apoptotic β cells were detected by colabeling for insulin and by TUNEL. Diabetes was associated with increased amyloid deposition, decreased β-cell area, and increased β-cell apoptosis, as expected. There was a strong inverse correlation between β-cell area and amyloid deposition (r = -0.42, P < 0.001). β-Cell area was selectively reduced in individual amyloid-containing islets from diabetic subjects, compared with control subjects, but amyloid-free islets had β-cell area equivalent to islets from control subjects. Increased amyloid deposition was associated with β-cell apoptosis (r = 0.56, P < 0.01). Thus, islet amyloid is associated with decreased β-cell area and increased β-cell apoptosis, suggesting that islet amyloid deposition contributes to the decreased β-cell mass that characterizes type 2 diabetes.

Insulin resistance is the best predictor of the metabolic syndrome in subjects with a first-degree relative with type 2 diabetes

Although obesity is associated with insulin resistance and the metabolic syndrome (MetS), some obese individuals are metabolically healthy. Conversely, some lean individuals are insulin resistant (IR) and at increased cardiometabolic risk. To determine the relative importance of insulin sensitivity, BMI and waist circumference (WC) in predicting MetS, we studied these two extreme groups in a high-risk population. One thousand seven hundred and sixty six subjects with a first-degree relative with type 2 diabetes were stratified by BMI and homeostasis model assessment of insulin resistance (HOMA(IR)) into groups. IR groups had higher triglycerides, fasting glucose, and more diabetes than their BMI-group insulin sensitive (IS) counterparts. Within both IS and IR groups, obesity was associated with higher HOMA(IR) and diastolic blood pressure (BP), but no difference in other metabolic variables. MetS (Adult Treatment Panel III (ATPIII)) prevalence was higher in IR groups (P < 0.001) and more subjects met each MetS criterion (P < 0.001). Within each BMI category, HOMA(IR) independently predicted MetS (P < 0.001) whereas WC did not. Within IS and IR groups, age and WC, but not BMI, were independent determinants of MetS (P < 0.001). WC was a less meaningful predictor of MetS at higher values of HOMA(IR). HOMA(IR) was a better predictor of MetS than WC or BMI (receiver operating characteristic (ROC) area under the curve 0.76 vs. 0.65 vs. 0.59, P < 0.001). In conclusion, insulin sensitivity rather than obesity is the major predictor of MetS and is better than WC at identifying obese individuals with a healthier metabolic profile. Further, as many lean individuals with a first-degree relative with type 2 diabetes are IR and metabolically unhealthy, they may all benefit from metabolic testing.

Preeclampsia and risk of developing subsequent diabetes

OBJECTIVE

Determine whether preeclampsia is associated with developing diabetes.

METHODS

Subsequent diabetes was ascertained using ICD-9 codes, pharmacy and glucose data in a retrospective cohort study of 2,032 women with preeclampsia and 29,431 without preeclampsia.

RESULTS

During a median follow-up of 8.2 years, 342 women developed diabetes. Preeclampsia was associated with a higher risk of diabetes adjusting for age, primigravidity, and gestational diabetes (hazard ratio, HR 1.82, 95%CI 1.26, 2.62) and in women without gestational diabetes (n = 30,109; HR 1.86, 95%CI 1.22, 2.84).

CONCLUSION

Women with preeclampsia have greater risk of developing diabetes, even in the absence of gestational diabetes.

Body mass index is associated with increased creatinine clearance by a mechanism independent of body fat distribution

CONTEXT

Although obesity has been, in general, associated with glomerular hyperfiltration, visceral adiposity has been suggested to be associated with reduced glomerular filtration.

OBJECTIVE

The aim of the study was to evaluate the differential effects of obesity and body fat distribution on glomerular filtration.

DESIGN AND SETTING

We conducted a cross-sectional study of the Japanese-American community in Seattle, Washington.

PARTICIPANTS

We studied a representative sample of second-generation Japanese-American men and women with normal glucose tolerance (n = 124) and impaired glucose metabolism (impaired fasting glucose and/or impaired glucose tolerance) (n = 144) residing in King County, Washington.

MAIN OUTCOME MEASURES

Glomerular filtration rate was estimated by 24-h urinary creatinine clearance, body size by body mass index (BMI), and intra-abdominal fat (IAF), sc fat (SCF), and lean thigh areas by CT scan.

RESULTS

Creatinine clearance was positively correlated with BMI (r = 0.429; P < 0.001), fasting glucose (r = 0.198; P = 0.001), and insulin levels (r = 0.125; P = 0.042), as well as IAF (r = 0.239; P < 0.001), SCF (r = 0.281; P < 0.001), and lean thigh (r = 0.353; P < 0.001) areas. The association between creatinine clearance and BMI remained significant after adjustments for IAF, SCF areas, and fasting insulin levels (r = 0.337; P < 0.001); whereas IAF and SCF areas were not independently associated with creatinine clearance after adjusting for BMI. Creatinine clearance increased with increasing BMI after adjusting for fasting insulin, fasting glucose, IAF and SCF areas in subjects with normal glucose tolerance (r = 0.432; P < 0.001) and impaired glucose metabolism (r = 0.471; P < 0.001).

CONCLUSIONS

BMI rather than body fat distribution is an independent determinant of creatinine clearance in nondiabetic subjects. Lean body mass, rather than adiposity, may explain this association.

Maternal Hemodynamic Changes Associated with Furosemide Treatment

OBJECTIVE

To assess the pharmacodynamic effects of furosemide in pregnancy.

METHODS

Twenty-one pregnant women who received furosemide 20 mg daily had cardiac output (CO), stroke volume (SV), and total peripheral resistance (TPR) measured by Doppler technique before and after treatment.

RESULTS

Furosemide was initiated at 22.4 +/- 6.0 weeks gestation. CO and SV decreased (mean +/- SD: 1.2 +/- 0.2 L/min and 17+/-3 mL, respectively), whereas TPR increased (101+/-26 dyne.sec.cm(-5); p < 0.001 for all) after 2.9+/-1.4 weeks. Hemodynamics did not approach the expected mean for pregnancy.

CONCLUSIONS

While furosemide improved the hyperdynamic circulation in pregnancy, it did not lower blood pressure or cause clinically significant vasoconstriction.

Are we optimizing gestational diabetes treatment with glyburide? The pharmacologic basis for better clinical practice

Glyburide's pharmacokinetics (PK) and pharmacodynamics have not been studied in women with gestational diabetes mellitus (GDM). The objective of this study was to assess steady-state PK of glyburide, as well as insulin sensitivity, beta-cell responsivity, and overall disposition indices after a mixed-meal tolerance test (MMTT) in women with GDM (n = 40), nonpregnant women with type 2 diabetes mellitus (T2DM) (n = 26), and healthy pregnant women (n = 40, MMTT only). At equivalent doses, glyburide plasma concentrations were approximately 50% lower in pregnant women than in nonpregnant subjects. The average umbilical cord/maternal plasma glyburide concentration ratio at the time of delivery was 0.7 +/- 0.4. Insulin sensitivity was approximately fivefold lower in women with GDM as compared with healthy pregnant women. Despite comparable beta-cell responsivity indices, the average beta-cell function corrected for insulin resistance was more than 3.5-fold lower in women with glyburide-treated GDM than in healthy pregnant women. Women with GDM in whom glyburide treatment has failed may benefit from alternative medication or dosage escalation; however, fetal safety should be kept in mind.

Oral disposition index predicts the development of future diabetes above and beyond fasting and 2-h glucose levels

OBJECTIVE

We sought to determine whether an oral disposition index (DI(O)) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DI(O) by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and beta-cell function.

RESEARCH DESIGN AND METHODS

A total of 613 Japanese-American subjects (322 men and 291 women) underwent a 75-g oral glucose tolerance test (OGTT) at baseline, 5 years, and 10 years. Insulin sensitivity was estimated as 1/fasting insulin or homeostasis model assessment of insulin sensitivity (HOMA-S). Insulin response was estimated as the change in insulin divided by change in glucose from 0 to 30 min (DeltaI(0-30)/DeltaG(0-30)).

RESULTS

DeltaI(0-30)/DeltaG(0-30) demonstrated a curvilinear relationship with 1/fasting insulin and HOMA-S with a left and downward shift as glucose tolerance deteriorated. The confidence limits for the slope of the log(e)-transformed estimates included -1 for DeltaI(0-30)/DeltaG(0-30) versus 1/fasting insulin for all glucose tolerance groups, consistent with a hyperbolic relationship. When HOMA-S was used as the insulin sensitivity measure, the confidence limits for the slope included -1 only for subjects with normal glucose tolerance (NGT) or impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) but not diabetes. On the basis of this hyperbolic relationship, the product of DeltaI(0-30)/DeltaG(0-30) and 1/fasting insulin was calculated (DI(O)) and decreased from NGT to IFG/IGT to diabetes (P < 0.001). Among nondiabetic subjects at baseline, baseline DI(O) predicted cumulative diabetes at 10 years (P < 0.001) independent of age, sex, BMI, family history of diabetes, and baseline fasting and 2-h glucose concentrations.

CONCLUSIONS

The DI(O) provides a measure of beta-cell function adjusted for insulin sensitivity and is predictive of development of diabetes over 10 years.

Clonidine pharmacokinetics in pregnancy

The objective of this study was to determine the pharmacokinetic parameters of clonidine during pregnancy compared with previously published data in nonpregnant subjects. Serial blood and urine samples were collected in 17 women during mid to late pregnancy over one steady-state dosing interval to determine clonidine noncompartmental pharmacokinetic parameters (n = 17) and creatinine clearance. In six of these pregnant subjects, maternal and umbilical cord (venous and arterial) plasma samples were collected at the time of delivery for measurement of clonidine concentrations. Clonidine apparent oral clearance was found to be 440 +/- 168 ml/min during pregnancy compared with 245 +/- 72 ml/min as previously reported in nonpregnant subjects (p < 0.0001) (Cunningham et al., 1994). There was a strong correlation (r = 0.82, p < 0.001) between clonidine renal clearance, adjusted for variation in glomerular filtration rate, and urine pH. Umbilical cord to maternal plasma clonidine concentration ratios were 1.0 +/- 0.1 (arterial) and 1.0 +/- 0.1 (venous). In conclusion, clonidine is cleared more rapidly in pregnant women than in nonpregnant subjects. At the time of delivery, the fetus is exposed to similar plasma clonidine concentrations as the mother.

An examination of beta-cell function measures and their potential use for estimating beta-cell mass

A characteristic and dominant feature of type 2 diabetes is a reduction in beta-cell function that is associated with a decrease in beta-cell volume. A decline in the first-phase insulin response following intravenous glucose administration can be demonstrated as the fasting glucose concentration increases. This response is completely absent before the glucose threshold that defines diabetes has been reached and at a time when beta-cells are clearly still present, implying that a functional beta-cell lesion has to exist independent of beta-cell loss. Surgical or chemical reductions of up to 65% of beta-cell volume demonstrate that functional adaptation of the normal beta-cell prevents a rise in fasting glucose or reduction in first-phase insulin response. However, the ability of glucose to potentiate the beta-cell's response to non-glucose secretagogues is reduced and is more closely associated with the reduction in beta-cell volume. The future, in terms of prevention and treatment of type 2 diabetes, lies in the ability to prevent and revert both beta-cell loss and dysfunction. However, until beta-cell volume can be quantified reliably and non-invasively, we will need to rely on the ability of glucose to potentiate insulin release as the best surrogate estimate of the number of beta-cells.

Modestly elevated glucose levels during pregnancy are associated with a higher risk of future diabetes among women without gestational diabetes mellitus

OBJECTIVE

To determine whether 1-h oral glucose challenge test (OGCT) or 3-h oral glucose tolerance test (OGTT) results below gestational diabetes mellitus (GDM) criteria are associated with developing diabetes.

RESEARCH DESIGN AND METHODS

A retrospective cohort study was performed among women without GDM who had a pregnancy OGCT (n = 24,780) or OGTT (n = 6,222). Subsequent diabetes was ascertained by ICD-9 codes or pharmacy or laboratory data over a median follow-up of 8.8 years.

RESULTS

Diabetes risk increased across OGCT quartiles: adjusted hazard ratio (HR) 1.67 (95% CI 1.07-2.61) for 5.4-6.2 mmol/l, 2.13 (1.39-3.25) for 6.3-7.3 mmol/l, and 3.60 (2.41-5.39) for >or=7.4 mmol/l compared with <or=5.3 mmol/l. Women with one abnormal OGTT result had a higher risk compared with those with normal values (HR 2.08 [95% CI 1.35-3.20]).

CONCLUSIONS

Women with modestly elevated glucose levels below the threshold for GDM had a higher risk for diabetes.

Mu-opioid antagonists for opioid-induced bowel dysfunction

BACKGROUND

Opioid-induced bowel dysfunction (OBD) is characterized by constipation, incomplete evacuation, bloating, and increased gastric reflux. OBD occurs both acutely and chronically, in multiple disease states, resulting in increased morbidity and reduced quality of life.

OBJECTIVES

To compare the efficacy and safety of traditional and peripherally active opioid antagonists versus conventional interventions for OBD.

SEARCH STRATEGY

We searched MEDLINE, the Cochrane Central Register of Controlled Trials and EMBASE in January 2007. Additional reports were identified from the reference lists of retrieved papers.

SELECTION CRITERIA

Studies were included if they were randomized controlled trials that investigated the efficacy of mu-opioid antagonists for OBD.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent review authors and included demographic variables, diagnoses, interventions, efficacy, and adverse events.

MAIN RESULTS

Twenty-three studies met inclusion criteria and provided data on 2871 opioid antagonist-treated patients. The opioid antagonists investigated were alvimopan (nine studies), methylnaltrexone (six), naloxone (seven), and nalbuphine (one). Meta-analysis demonstrated that methylnaltrexone and alvimopan were better than placebo in reversing opioid-induced increased gastrointestinal transit time and constipation, and that alvimopan appears to be safe and efficacious in treating postoperative ileus. The incidence of adverse events with opioid antagonists was similar to placebo and generally reported as mild-to-moderate.

AUTHORS' CONCLUSIONS

Insufficient evidence exists for the safety or efficacy of naloxone or nalbuphine in the treatment of OBD. Long-term efficacy and safety of any of the opioid antagonists is unknown, as is the incidence or nature of rare adverse events. Alvimopan and methylnaltrexone both show promise in treating OBD, but further data will be required to fully assess their place in therapy.

Reduced adipogenic gene expression in thigh adipose tissue precedes human immunodeficiency virus-associated lipoatrophy

CONTEXT

The expression of adipogenic genes in sc adipose tissue has been reported to be lower among patients with HIV-associated lipoatrophy than HIV-uninfected controls. It is unclear whether this is a result or cause of lipoatrophy.

OBJECTIVE

The objective of the study was to investigate the temporal relationships among changes in adipogenic gene expression in sc adipose tissue and changes in body fat distribution and metabolic complications in HIV-infected subjects on antiretroviral therapy.

DESIGN

This was a prospective longitudinal study.

SETTING

The study was conducted at HIV clinics in Seattle, Washington.

PARTICIPANTS

The study population included 31 HIV-infected and 12 control subjects.

INTERVENTIONS

Subjects were followed up for 12 months after they initiated or modified their existing antiretroviral regimen.

MAIN OUTCOME MEASURES

Changes in body composition, plasma lipids, insulin sensitivity, and gene expression in sc abdominal and thigh adipose tissue.

RESULTS

Subjects who developed lipoatrophy (n=10) had elevated fasting triglycerides [3.16 (sd 2.79) mmol/liter] and reduced insulin sensitivity as measured by frequently sampled iv glucose tolerance test [1.89 (sd 1.27)x10(-4) min(-1)/microU.ml] after 12 months, whereas those without lipoatrophy (n=21) did not show any metabolic complications [triglycerides 1.32 (sd 0.58) mmol/liter, P=0.01 vs. lipoatrophy; insulin sensitivity 3.52 (sd 1.91)x10(-4) min(-1)/microU.ml, P=0.01 vs. lipoatrophy]. In subjects developing lipoatrophy, the expression of genes involved in adipocyte differentiation, lipid uptake, and local cortisol production in thigh adipose tissue was significantly reduced already at the 2-month visit, several months before any loss of extremity fat mass was evident.

CONCLUSIONS

In HIV-infected subjects, lipoatrophy is associated with elevated fasting triglycerides and insulin resistance and might be caused by a direct or indirect effect of antiretroviral drugs on sc adipocyte differentiation.

Within-subject variability of measures of beta cell function derived from a 2 h OGTT: implications for research studies

AIMS/HYPOTHESIS

Knowledge of the within-subject variability of a parameter is required to properly design and calculate sample sizes for longitudinal studies. We sought to determine the day-to-day variability of measures of beta cell function derived from an OGTT.

METHODS

Thirty-seven adults (13 with normal glucose tolerance, ten with impaired glucose tolerance, 14 with type 2 diabetes) underwent a standard 2 h 75 g OGTT on two separate days (median time between tests, 7 days; range, 5-14). From these data, the reproducibility of several indices of beta cell function were determined: insulinogenic index (DeltaI(0-30)/DeltaG(0-30)), early C-peptide response (DeltaCP(0-30)/DeltaG(0-30)), incremental AUC insulin to glucose response (incAUC(ins)/incAUC(glu)), integrated insulin secretion response from 0 to 120 min (IS/Glu(0-120)) and indices of beta cell function derived from a mathematical model.

RESULTS

Within-subject variability for DeltaI(0-30)/DeltaG(0-30) (CV 57.1%) was higher than DeltaCP(0-30)/DeltaG(0-30) (CV 34.7%). Measures integrated over the full 120 min of the OGTT, incAUC(ins)/incAUC(glu) (CV 24.9%) and IS/Glu(0-120) (CV 17.4%), demonstrated less variability. The mathematical model-derived measures of beta cell glucose sensitivity (CV 20.3%) and potentiation (CV 33.0%) showed moderate variability. The impact of the different measures' variability on sample size (30% change from baseline) is demonstrated by calculated sample sizes of 89 for DeltaI(0-30)/DeltaG(0-30), 37 for DeltaCP(0-30)/DeltaG(0-30), 21 for incAUC(ins)/incAUC(glu) and 11 for IS/Glu(0-120).

CONCLUSIONS/INTERPRETATION

Some OGTT-derived indices of beta cell function, in particular the insulinogenic index, demonstrate high within-subject variability. Integrated measures that utilise multiple time points and measures that use C-peptide show less variability and may lead to a reduced sample size requirement.

Relationship of liver enzymes to insulin sensitivity and intra-abdominal fat

OBJECTIVE

The purpose of this study was to determine the relationship between plasma liver enzyme concentrations, insulin sensitivity, and intra-abdominal fat (IAF) distribution.

RESEARCH DESIGN AND METHODS

Plasma gamma-glutamyl transferase (GGT), aspartate transaminase (AST), alanine transaminase (ALT) levels, insulin sensitivity (insulin sensitivity index [S(I)]), IAF area, and subcutaneous fat (SCF) area were measured in 177 nondiabetic subjects (75 men and 102 women, aged 31-75 years) with no history of liver disease. On the basis of BMI (< or > or = 27.5 kg/m2) and S(I) (< or > or = 7.0 x 10(-5) min/pmol) subjects were divided into lean insulin sensitive (LIS, n = 53), lean insulin resistant (LIR, n = 60), and obese insulin resistant (OIR, n = 56) groups.

RESULTS

Levels of all three liver enzymes were higher in men than in women (P < 0.0001 for each). In men, GGT levels were higher in insulin-resistant than in insulin-sensitive subjects (P < 0.01). In women, GGT levels were higher in the OIR than in the LIS group (P < 0.01) but no different in the LIR group. There was no difference in ALT and AST levels among the LIS, LIR, and OIR groups. GGT was associated with S(I) (r = -0.26, P < 0.0001), IAF area (r = 0.22, P < 0.01), waist-to-hip ratio (WHR) (r = 0.25, P = 0.001), BMI (r = 0.17, P < 0.05), and SCF area (r = 0.16, P < 0.05) after adjustments for age and sex. In men, only S(I) (r = -0.29, P < 0.05) remained independently correlated with GGT in multiple regression analysis. In women, IAF area (r = 0.29, P < 0.01) and WHR (r = 0.29, P < 0.01) were independently associated with GGT, but S(I) was not.

CONCLUSIONS

In nondiabetic men GGT but not AST or ALT levels, are inversely related to insulin sensitivity independent of IAF area. However in women, GGT is related to measures of central body fat rather than to insulin sensitivity.

Intra-abdominal fat accumulation predicts the development of the metabolic syndrome in non-diabetic Japanese-Americans

AIMS/HYPOTHESIS

Intra-abdominal fat (IAF) is an important risk factor for CHD and type 2 diabetes, and in cross-sectional studies is associated with the metabolic syndrome (MetS). Our aim was to determine whether IAF accumulation predicts the future development of MetS in non-diabetic Japanese-Americans.

SUBJECTS AND METHODS

We conducted a prospective study of 457 Japanese-American men and women (mean+/-SD: age 51.5 +/- 12.0 years, BMI 23.9 +/- 3.1 kg/m(2)) without diabetes or MetS at baseline. Of these, 408 completed a 5-year follow-up and 366 completed a 10-year follow-up. BMI, waist circumference, IAF and subcutaneous fat (SCF) areas by computed tomography, blood pressure, fasting plasma glucose, insulin, triacylglycerol and HDL-cholesterol were measured at baseline and at 5- and 10-year follow-up. MetS was defined using National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

Incidence of MetS was 15.3% at 5 years and 17.8% at 10 years. A change of 1 SD in IAF area was associated with a 2.1-fold increase in the odds of MetS at 10 years (odds ratio = 2.08, 95% CI 1.41-3.07) after adjusting for age, sex, baseline IAF and the presence of each individual MetS criteria at baseline. This association was independent of changes in fasting insulin and SCF areas.

CONCLUSIONS/INTERPRETATION

We conclude that IAF accumulation over time independently predicts the development of MetS and thus may play an important role in the development of MetS in Japanese-Americans.

Progressive loss of beta-cell function leads to worsening glucose tolerance in first-degree relatives of subjects with type 2 diabetes

OBJECTIVE

The relative roles of insulin resistance and beta-cell dysfunction in the pathogenesis of impaired glucose tolerance (IGT) and type 2 diabetes are debated. First-degree relatives of individuals with type 2 diabetes are at increased risk of developing hyperglycemia.

RESEARCH DESIGN AND METHODS

We evaluated the evolution of insulin sensitivity, beta-cell function, glucose effectiveness, and glucose tolerance over 7 years in 33 nondiabetic, first-degree relatives of type 2 diabetic individuals using frequently sampled tolbutamide-modified intravenous and oral glucose tolerance tests.

RESULTS

Subjects gained weight, and their waist circumference increased (P < 0.05). Insulin sensitivity, the acute insulin response to glucose, and glucose effectiveness did not change significantly. However, when we accounted for the modulating effect of insulin sensitivity on insulin release, beta-cell function determined as the disposition index decreased by 22% (P < 0.05). This decrease was associated with declines in intravenous and oral glucose tolerance (P < 0.05 and P < 0.001, respectively). Of the subjects with normal glucose tolerance at the first assessment, we compared those who progressed to IGT with those who did not. The disposition index was 50% lower in the progressors than in the nonprogressors at follow-up (P < 0.05).

CONCLUSIONS

The decline in glucose tolerance over time in first-degree relatives of type 2 diabetic individuals is strongly related to the loss of beta-cell function. Thus, early interventions to slow the decline in beta-cell function should be considered in high-risk individuals.

Amoxicillin pharmacokinetics in pregnant women: modeling and simulations of dosage strategies

Amoxicillin is recommended for anthrax prevention in pregnancy. The objective of this study was to evaluate the pharmacokinetics of amoxicillin during pregnancy and postpartum (PP). Sixteen women received amoxicillin during gestation (18-22 weeks (T2) and 30-34 weeks (T3)) as well as 3 months postpartum (PP) to evaluate single-dose pharmacokinetics. Amoxicillin compartmental pharmacokinetic parameters were used to simulate amoxicillin concentration-time profiles following different dosage strategies. Amoxicillin CL(renal) (T2: 24.8+/-6.7 l/h, P<0.001; T3: 24.0+/-3.9 l/h, P<0.001; and PP: 15.3+/-2.6 l/h) and renal CL(secretion) (T2: 280+/-105 ml/min, P<0.002; T3: 259+/-54 ml/min, P<0.001; and PP: 167+/-47 ml/min) were higher during pregnancy than postpartum. Simulations suggest that amoxicillin concentrations adequate to prevent anthrax may be difficult to achieve during pregnancy and postpartum. Increases in amoxicillin CL(renal) and renal CL(secretion) reflect increases in filtration and secretory transport or diminished reabsorption in the kidneys. Amoxicillin may not be an appropriate antibiotic for post-anthrax exposure prophylaxis.

Plasma pancreatic polypeptide levels are associated with differences in body fat distribution in human subjects

AIMS/HYPOTHESIS

Pancreatic polypeptide (PP) is produced by the F-cells of the pancreas, and its plasma concentration has been used as a marker of parasympathetic activity. Recent work in rodents suggests that there is both sympathetic and parasympathetic innervation of white adipose tissue and that parasympathetic activity is anabolic resulting in lipid accumulation. We have examined whether in humans increased PP levels are associated with increased intra-abdominal fat (IAF), and thereby insulin resistance.

MATERIALS AND METHODS

We measured PP levels in 177 non-diabetic subjects (75 male/102 female; age 32-75 years) 3 min after an i.v. glucose bolus during a frequently sampled intravenous glucose tolerance test. IAF and s.c. fat (SCF) areas were measured by CT scan. The insulin sensitivity index (S (I)) was quantified using Bergman's minimal model.

RESULTS

PP levels were higher in men than in women (96.2 +/- 72.2 vs 76.1 +/- 55.0 pg/ml, mean +/- SD, p = 0.037), as was IAF area (124.7 +/- 67.4 vs 83.0 +/- 57.7 cm(2), p < 0.001). While PP levels were significantly associated with IAF (r = 0.16, p = 0.031), WHR (r = 0.30, p < 0.001) and age (r = 0.37, p < 0.01), they were not associated with SCF (r = 0.02, p = 0.829). The association between PP and IAF was not independent of age and/or sex. S(I) was negatively associated with PP levels (r = -0.17, p = 0.026) and IAF area (r = -0.65, p < 0.001). The association between S(I) and PP disappeared after adjusting for IAF area, indicating that S(I) was not a major determinant of PP levels.

CONCLUSIONS/INTERPRETATION

In humans, age and sex may modulate the association between plasma PP level and IAF area, suggesting that they may be determinants of parasympathetic activity and thus IAF accumulation.

Dysregulation of the hypothalamic-pituitary-adrenal axis in postpartum depression

Postpartum depression (PPD) affects at least 10% to 15% of postpartum women, including more than 600,000 American mothers in 2003 alone. Dramatic changes in the hypothalamic-pituitary-adrenal (HPA) system in the transition from pregnancy to postpartum coupled with research on the psychobiology of depression provided the foundation for this study. The purpose of this study was to compare the reactivity and regulation of the HPA axis components, adrenocorticotropic hormone (ACTH) and cortisol, in depressed and nondepressed postpartum women. A comparative, longitudinal study design was used with 22 normal, healthy, nondepressed pregnant women. Physiologic and postpartum depression data were collected at 6 and 12 weeks postpartum at a university clinical research center. Maximal treadmill exercise stimulated plasma ACTH and serum cortisol levels which were measured before, during, and after 20 min of exercise. Postpartum depression was measured with the Postpartum Depression Screening Scale. Lag within-subject ACTH levels predicting cortisol regression slopes were significantly different between the depressed and nondepressed groups at both 6 and 12 weeks. The depressed group showed no relationship between their ACTH and cortisol levels, with higher ACTH and lower cortisol levels when compared with the nondepressed group. The expected regulated relationship with cortisol levels rising in response to rising ACTH levels was found in the non-depressed group. These findings indicate that the HPA axis was dysregulated in the depressed group, but regulated in the nondepressed group at 6 and 12 weeks postpartum. This pattern of higher ACTH levels to stimulate less cortisol is similar to patterns found in women with early life stresses.

Patient controlled opioid analgesia versus conventional opioid analgesia for postoperative pain

BACKGROUND

Patients may control postoperative pain by self-administration of intravenous opioids using devices designed for this purpose (patient controlled analgesia or PCA). A 1992 meta-analysis by Ballantyne found a strong patient preference for PCA over conventional analgesia but disclosed no differences in analgesic consumption or length of postoperative hospital stay. Although Ballantyne's meta-analysis found that PCA did have a small but statistically significant benefit upon pain intensity, Walder's review in 2001 did not find a significant differences in pain intensity and pain relief between PCA and conventionally treated groups.

OBJECTIVES

To evaluate the efficacy of PCA versus conventional analgesia (such as a nurse administering an analgesic upon a patient's request) for postoperative pain control.

SEARCH STRATEGY

Randomized controlled trials (RCTs) were identified from the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2004, Issue 3), MEDLINE (1966 to 2004), and EMBASE (1994 to 2004). Additional reports were identified from the reference lists of retrieved papers.

SELECTION CRITERIA

RCTs of PCA versus conventional analgesia that employed pain intensity as a primary or secondary outcome were selected. These trials included RCTs that compared PCA without a continuous background infusion versus conventional parenteral analgesic regimens. Studies that explicitly stated they involved patients with chronic pain were excluded.

DATA COLLECTION AND ANALYSIS

Trials were scored using the Oxford Quality Scale. Meta-analyses were performed of outcomes that included analgesic efficacy assessed by a Visual Analog Scale (VAS), analgesic consumption, patient satisfaction, length of stay and adverse effects. A sufficient number of the retrieved trials reported these parameters to permit meta-analyses.

MAIN RESULTS

Fifty-five studies with 2023 patients receiving PCA and 1838 patients assigned to a control group met inclusion criteria. PCA provided better pain control and greater patient satisfaction than conventional parenteral 'as-needed' analgesia. Patients using PCA consumed higher amounts of opioids than the controls and had a higher incidence of pruritus (itching) but had a similar incidence of other adverse effects. There was no difference in the length of hospital stay.

AUTHORS' CONCLUSIONS

This review provides evidence that PCA is an efficacious alternative to conventional systemic analgesia for postoperative pain control.

Gestational diabetes mellitus increases the risk of cardiovascular disease in women with a family history of type 2 diabetes

OBJECTIVE

We sought to determine whether a history of gestational diabetes mellitus (GDM) further increases the risk of cardiovascular disease (CVD) in parous women with first-degree relatives with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Women with (n = 332) and without (n = 663) a history of GDM were compared regarding 1) the revised National Cholesterol Education Program Adult Treatment Panel III metabolic syndrome criteria, 2) the prevalence of type 2 diabetes, and 3) self-reported CVD.

RESULTS

Women with prior GDM were younger (48.6 +/- 0.7 vs. 52.4 +/- 0.6 years [means +/- SE];P < 0.001) and less likely to be postmenopausal (48.3 vs. 57.9%; P < 0.005). Although both groups were obese (BMI 34.4 +/- 1.2 vs. 33.7 +/- 0.6 kg/m(2)), women with prior GDM were more likely to have metabolic syndrome (86.6 vs. 73.5%; P < 0.001) and type 2 diabetes (93.4 vs. 63.3%; P < 0.001). Moreover, they had a higher prevalence of CVD (15.5 vs. 12.4%; adjusted odds ratio 1.85 [95% CI 1.21-2.82];P = 0.005) that occurred at a younger age (45.5 +/- 2.2 vs. 52.5 +/- 1.9 years;P = 0.02) and was independent of metabolic syndrome (1.74 [1.10-2.76]; P = 0.02) and type 2 diabetes (1.56 [1.002-2.43];P < 0.05).

CONCLUSIONS

Among women with a family history of type 2 diabetes, those with prior GDM were even more likely to not only have CVD risk factors, including metabolic syndrome and type 2 diabetes, but also to have experienced CVD events, which occurred at a younger age. Thus, women with both a family history of type 2 diabetes and personal history of GDM may be especially suitable for early interventions aimed at preventing or reducing their risk of CVD and diabetes.

Opioids for neuropathic pain

BACKGROUND

The use of opioids for neuropathic pain remains controversial. Studies have been small, have yielded equivocal results, and have not established the long-term risk-benefit ratio of this treatment.

OBJECTIVES

To assess the efficacy and safety of opioid agonists for the treatment of neuropathic pain.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (2nd Quarter 2005), MEDLINE (1966 to June 2005), and EMBASE (1980 to 2005 Week 27) for articles in any language, and reference lists of reviews and retrieved articles.

SELECTION CRITERIA

Trials were included in which opioid agonists were given to treat central or peripheral neuropathic pain of any etiology, pain was assessed using validated instruments, and adverse events were reported. Studies in which drugs other than opioid agonists were combined with opioids or opioids were administered epidurally or intrathecally were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent investigators and included demographic variables, diagnoses, interventions, efficacy, and adverse effects.

MAIN RESULTS

Twenty-three trials met the inclusion criteria and were classified as short-term (less than 24 hours; n = 14) or intermediate-term (median = 28 days; range = eight to 70 days; n = 9). The short-term trials had contradictory results. In contrast all nine intermediate-term trials demonstrated opioid efficacy for spontaneous neuropathic pain. Meta-analysis of seven intermediate-term studies showed mean post-treatment visual analog scale scores of pain intensity after opioids to be 13 points lower on a scale from zero to 100 than after placebo (95% confidence interval -16 to -9; P < 0.00001). The most common adverse events were nausea (33% opioid versus 9% control: number needed to treat to harm (NNH) 4.2) and constipation (33% opioid versus 10% control: NNH 4.2), followed by drowsiness (29% opioid versus 12% control: NNH 6.2), dizziness (21% opioid versus 6% control: NNH 7.1), and vomiting (15% opioid versus 3% control: NNH 8.3). Where reported, 23 (11%) of 212 participants withdrew because of adverse events during opioid therapy versus nine (4%) of 202 receiving placebo.

AUTHORS' CONCLUSIONS

Short-term studies provide only equivocal evidence regarding the efficacy of opioids in reducing the intensity of neuropathic pain, whereas intermediate-term studies demonstrate significant efficacy of opioids over placebo, which is likely to be clinically important. Reported adverse events of opioids are common but not life threatening. Further randomized controlled trials are needed to establish long-term efficacy, safety (including addiction potential), and effects on quality of life.

Diabetic nephropathy in pregnancy: suboptimal hypertensive control associated with preterm delivery

BACKGROUND

Nephropathy complicates 5% to 10% of pregnancies in women with diabetes and is associated with adverse outcomes. Given the importance of blood pressure (BP) control in reducing cardiovascular and renal complications outside of pregnancy, we hypothesized that poorly controlled hypertension in early pregnancy among women with diabetic nephropathy would be associated with adverse outcomes.

METHODS

To examine the impact of hypertensive control in early pregnancy on perinatal outcomes, we performed a retrospective cohort study of pregnancies complicated by diabetic nephropathy with "Above Target" mean arterial pressure (> or = 100 mm Hg; N = 21) and "Below Target" mean arterial pressure (< 100 mm Hg; N = 22), which approximates the American Diabetes Association and the Seventh Report of the Joint National Committee recommended target of 130/80 mm Hg, measured at < 20 weeks' gestation.

RESULTS

There were no differences in maternal age (mean +/- SEM: 27.2 +/- 1.2 v 29.5 +/- 1.0 years), duration of diabetes (median, range: 17.5, 13 to 24 v 16, 1 to 25 years), or glucose control (glycosylated hemoglobin [HbA1c] 8.0% +/- 0.3% v 8.1% +/- 0.4%) between the Above and Below Target groups. The Above Target group had more proteinuria (4.69 +/- 1.08 v 1.65 +/- 0.43 g/24 h; P = .007) and higher serum creatinine levels (1.23 +/- 0.17 v 0.85 +/- 0.06 mg/dL; P = .02). The Above Target group was more likely to deliver at < 32 weeks' gestation (38.1% v 4.6%; P = .007). The increased risk of preterm delivery remained significant after adjusting for duration of diabetes and glucose control.

CONCLUSIONS

Suboptimal control of hypertension in early pregnancy in women with diabetic nephropathy is associated with a significant risk of preterm delivery. Improved preconceptional control of hypertension may reduce adverse perinatal outcomes in women with diabetic nephropathy.

Music for pain relief

BACKGROUND

The efficacy of music for the treatment of pain has not been established.

OBJECTIVES

To evaluate the effect of music on acute, chronic or cancer pain intensity, pain relief, and analgesic requirements.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, PsycINFO, LILACS and the references in retrieved manuscripts. There was no language restriction.

SELECTION CRITERIA

We included randomized controlled trials that evaluated the effect of music on any type of pain in children or adults. We excluded trials that reported results of concurrent non-pharmacological therapies.

DATA COLLECTION AND ANALYSIS

Data was extracted by two independent review authors. We calculated the mean difference in pain intensity levels, percentage of patients with at least 50% pain relief, and opioid requirements. We converted opioid consumption to morphine equivalents. To explore heterogeneity, studies that evaluated adults, children, acute, chronic, malignant, labor, procedural, or experimental pain were evaluated separately, as well as those studies in which patients chose the type of music.

MAIN RESULTS

Fifty-one studies involving 1867 subjects exposed to music and 1796 controls met inclusion criteria. In the 31 studies evaluating mean pain intensity there was a considerable variation in the effect of music, indicating statistical heterogeneity ( I(2) = 85.3%). After grouping the studies according to the pain model, this heterogeneity remained, with the exception of the studies that evaluated acute postoperative pain. In this last group, patients exposed to music had pain intensity that was 0.5 units lower on a zero to ten scale than unexposed subjects (95% CI: -0.9 to -0.2). Studies that permitted patients to select the music did not reveal a benefit from music; the decline in pain intensity was 0.2 units, 95% CI (-0.7 to 0.2). Four studies reported the proportion of subjects with at least 50% pain relief; subjects exposed to music had a 70% higher likelihood of having pain relief than unexposed subjects (95% CI: 1.21 to 2.37). NNT = 5 (95% CI: 4 to 13). Three studies evaluated opioid requirements two hours after surgery: subjects exposed to music required 1.0 mg (18.4%) less morphine (95% CI: -2.0 to -0.2) than unexposed subjects. Five studies assessed requirements 24 hours after surgery: the music group required 5.7 mg (15.4%) less morphine than the unexposed group (95% CI: -8.8 to -2.6). Five studies evaluated requirements during painful procedures: the difference in requirements showed a trend towards favoring the music group (-0.7 mg, 95% CI: -1.8 to 0.4).

AUTHORS' CONCLUSIONS

Listening to music reduces pain intensity levels and opioid requirements, but the magnitude of these benefits is small and, therefore, its clinical importance unclear.

Impact of differences in fasting glucose and glucose tolerance on the hyperbolic relationship between insulin sensitivity and insulin responses

OBJECTIVE

To determine whether the hyperbolic relationship between insulin sensitivity and the acute insulin response to glucose (AIRg) exists in subjects with impaired fasting glucose (IFG) or decreased glucose tolerance.

RESEARCH DESIGN AND METHODS

We studied 219 healthy subjects (88 male and 131 female subjects, aged 26-75 years) with fasting plasma glucose (FPG) <6.11 mmol/l. Subjects underwent an intravenous glucose tolerance test to determine the insulin sensitivity index (Si), AIRg, and the glucose disappearance constant (Kg), the latter a measure of intravenous glucose tolerance.

RESULTS

Si and AIRg were inversely related for the entire cohort, and this relationship was not significantly different from hyperbolic. The inverse relationship between Si and AIRg was not significantly different when compared between groups based on fasting glucose (normal fasting glucose [NFG], FPG <5.56 mmol/l vs. IFG, FPG 5.56-6.11 mmol/l) or by the Kg quartile. However, the curve relating Si and AIRg was left shifted in the IFG compared with NFG group (P < 0.001) and was progressively more left shifted with decreasing Kg (P < 0.001), consistent with decreasing beta-cell function. These changes were not observed for the curves relating Si and fasting insulin, suggesting that in the fasting state beta-cell function is maintained even in patients with mild IFG. Finally, the disposition index (DI) (Si x AIRg) was calculated as a measure of beta-cell function. The DI progressively decreased with increasing FPG, even in the group of subjects classified as NFG.

CONCLUSIONS

The inverse relationship between insulin sensitivity and AIRg is consistent with a hyperbola not only in subjects with normal glucose tolerance but also with mild IFG or decreased Kg. Based on a hyperbolic relationship, a decrease in beta-cell function can be detected as FPG increases, even in patients who are normal glucose tolerant.

Resistin is not associated with insulin sensitivity or the metabolic syndrome in humans

AIMS/HYPOTHESIS

The aim of this study was to further elucidate the relationship between resistin and insulin sensitivity, body fat distribution and the metabolic syndrome in humans.

METHODS

We measured plasma resistin levels in 177 non-diabetic subjects (75 male, 102 female; age 32-75 years). BMI, waist circumference, blood pressure, lipids, glucose, plasminogen-activator inhibitor 1 (PAI-1), adiponectin and leptin levels were also measured. The insulin sensitivity index (S(I)) was quantified using Bergman's minimal model. Intra-abdominal fat (IAF) and subcutaneous fat (SQF) areas were quantified by CT scan. Presence of metabolic syndrome criteria was determined using the National Cholesterol Education Program Adult Treatment Panel III guidelines.

RESULTS

When subjects were divided into categories based on BMI (< or > or =27.5 kg/m(2)) and S(I) (< or > or = 7 x 10(-5) min(-1) [pmol/l](-1)), resistin levels did not differ between the lean, insulin-sensitive (n=53, 5.36+/-0.3 ng/ml), lean, insulin-resistant (n=67, 5.70+/-0.4 ng/ml) and obese, insulin-resistant groups (n=48, 5.94+/-0.4 ng/ml; ANOVA p=0.65). Resistin correlated with age (r=-0.22, p<0.01), BMI (r=0.16, p=0.03) and SQF (r=0.19, p=0.01) but not with S(I) (p=0.31) or IAF (p=0.52). Resistin did not correlate with the number of metabolic syndrome criteria or any of the individual metabolic syndrome criteria. In contrast, adiponectin, PAI-1 and leptin each correlated with IAF, SQF and S(I). Additionally, the number of metabolic syndrome criteria correlated with adiponectin (r=-0.32, p<0.001), leptin (r=0.31, p<0.001) and PAI-1 (r=0.26, p=0.001).

CONCLUSIONS/INTERPRETATION

In contrast to other adipokines, resistin is only weakly associated with body fat and is unlikely to be a major mediator of insulin resistance or the metabolic syndrome in humans.

Local anesthetic sympathetic blockade for complex regional pain syndrome

BACKGROUND

Local anesthetic blockade of the sympathetic chain is widely used to treat reflex sympathetic dystrophy (RSD) and causalgia. These two pain syndromes are now conceptualized as variants of a single entity: complex regional pain syndrome (CRPS). A recent meta-analysis of the topic has been published. However, this study only evaluated studies in English language and therefore it could have overlooked some randomized controlled trials.

OBJECTIVES

This systematic review had three objectives: to determine the likelihood of pain alleviation after sympathetic blockade with local anesthetics in the patient with CRPS; to assess how long any benefit persists; and to evaluate the incidence of adverse effects of the procedure.

SEARCH STRATEGY

We searched the Cochrane Pain, Palliative and Supportive Care Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS, and conference abstracts of the World Congresses of the International Association for the Study of Pain. Bibliographies from retrieved articles were also searched for additional studies.

SELECTION CRITERIA

We considered for inclusion randomized controlled trials that evaluated the effect of sympathetic blockade with local anesthetics in children or in adult patients to treat RSD, causalgia, or CRPS.

DATA COLLECTION AND ANALYSIS

The outcomes of interest were the number of patients who obtained at least 50% of pain relief shortly after sympathetic blockade (30 minutes to 2 hours) and 48 hours or later. We also assessed the presence of adverse effects in each treatment arm. A random effects model was used to combine the studies.

MAIN RESULTS

Two small randomized double blind cross over studies that evaluated 23 subjects were found. The combined effect of the two trials produced a relative risk (RR) to achieve at least 50% of pain relief 30 minutes to 2 hours after the sympathetic blockade of 1.17 (95% CI 0.80-1.72). It was not possible to determine the effect of sympathetic blockade on long-term pain relief because the authors of the two studies evaluated different outcomes.

AUTHORS' CONCLUSIONS

This systematic review revealed the scarcity of published evidence to support the use of local anesthetic sympathetic blockade as the 'gold standard' treatment for CRPS. The two randomized studies that met inclusion criteria had very small sample sizes, therefore, no conclusion concerning the effectiveness of this procedure could be drawn. There is a need to conduct randomized controlled trials to address the value of sympathetic blockade with local anesthetic for the treatment of CRPS.

Genetic background determines the extent of islet amyloid formation in human islet amyloid polypeptide transgenic mice

Genetic background is important in determining susceptibility to metabolic abnormalities such as insulin resistance and beta-cell dysfunction. Islet amyloid is associated with reduced beta-cell mass and function and develops in the majority of our C57BL/6J x DBA/2J (F(1)) male human islet amyloid polypeptide (hIAPP) transgenic mice after 1 yr of increased fat feeding. To determine the relative contribution of each parental strain, C57BL/6J (BL6) and DBA/2J (DBA2), to islet amyloid formation, we studied male hIAPP mice on each background strain (BL6, n = 13; and DBA2 n = 11) and C57BL/6J x DBA/2J F(1) mice (n = 17) on a 9% (wt/wt) fat diet for 1 yr. At the end of 12 mo, islet amyloid deposition was quantified from thioflavin S-stained pancreas sections. The majority of mice in all groups developed islet amyloid (BL6: 91%, F(1): 76%, DBA2: 100%). However, the prevalence (%amyloid-positive islets; BL6: 14 +/- 3%, F(1): 44 +/- 8%, DBA2: 49 +/- 9%, P < 0.05) and severity (%islet area occupied by amyloid; BL6: 0.03 +/- 0.01%, F(1): 9.2 +/- 2.9%, DBA2: 5.7 +/- 2.3%, p < or = 0.01) were significantly lower in BL6 than F(1) and DBA2 mice. Increased islet amyloid severity was negatively correlated with insulin-positive area per islet, in F(1) (r(2) = 0.75, P < 0.001) and DBA2 (r(2) = 0.87, P < 0.001) mice but not BL6 mice (r(2) = 0.07). In summary, the extent of islet amyloid formation in hIAPP transgenic mice is determined by background strain, with mice expressing DBA/2J genes (F(1) and DBA2 mice) being more susceptible to amyloid deposition that replaces beta-cell mass. These findings underscore the importance of genetic and environmental factors in studying metabolic disease.

A sister's risk: family history as a predictor of preeclampsia

OBJECTIVE

The purpose of this study was to determine if women with preeclampsia are more likely to have a sister who also had preeclampsia.

STUDY DESIGN

This was a population-based case-control study using data from Washington (WA) state birth certificates linked to hospital discharge records. Cases were women with gestational hypertension (n = 1611) or preeclampsia (n = 1071); controls (n = 8041) had normotensive pregnancies. All women delivered their first child between 1987 to 2002 and had a sister with a previous delivery in WA.

RESULTS

Women with preeclampsia were 2.3 times (95%CI 1.8-2.9) more likely to have a sister who had preeclampsia; those with gestational hypertension were 1.6 times (95%CI 1.3-2.0) more likely to have a sister with gestational hypertension. Similar results were obtained following stratification by age, race, smoking status, or body mass index.

CONCLUSION

The greater likelihood of preeclampsia among sisters of women with a previous preeclamptic pregnancy is consistent with a pathophysiologic role for genetic and/or behavioral factors that cluster in families.

Dietary-fat-induced obesity in mice results in beta cell hyperplasia but not increased insulin release: evidence for specificity of impaired beta cell adaptation

AIMS/HYPOTHESIS

Increased dietary fat intake is associated with obesity and insulin resistance, but studies have shown that the subsequent increase in insulin release is not appropriate for this obesity-induced insulin resistance. We therefore sought to determine whether the impaired beta cell adaptation is due to inadequate expansion of the beta cell population or to a lack of an adaptive increase in insulin release.

METHODS

Male mice were fed diets containing increasing amounts of fat (15, 30 or 45% of energy intake) for 1 year, after which islet morphology and secretory function were assessed.

RESULTS

Increased dietary fat intake was associated with a progressive increase in body weight (p<0.001). Fractional beta cell area (total beta cell area/section area) was increased with increasing dietary fat (1.36+/-0.39, 2.46+/-0.40 and 4.93+/-1.05%, p<0.001), due to beta cell hyperplasia, and was positively and highly correlated with body weight (r2=0.68, p<0.005). In contrast, insulin release following i.p. glucose did not increase with increasing dietary fat (118+/-32, 108+/-47 and 488+/-200 pmol/l per mmol/l, p=0.07) and did not correlate with body weight (r2=0.11). When this response was examined relative to fractional beta cell area (insulin release/fractional beta cell area), it did not increase but rather tended to decrease with increasing dietary fat (157+/-55, 43+/-13 and 97+/-53 [pmol/l per mmol/l]/%, p=0.06) and did not correlate with body weight (r2=0.02).

CONCLUSIONS/INTERPRETATION

Long-term fat feeding is associated with an increase in the beta cell population but an inadequate functional adaptation. Thus, a functional rather than a morphological abnormality appears to underlie dietary-fat-induced beta cell dysfunction.

Long-term treatment with rosiglitazone and metformin reduces the extent of, but does not prevent, islet amyloid deposition in mice expressing the gene for human islet amyloid polypeptide

Islet amyloid deposition in type 2 diabetes is associated with reduced beta-cell mass. Therefore, interventions aimed at reducing islet amyloid formation may help preserve beta-cell mass in type 2 diabetes. Rosiglitazone and metformin act by different mechanisms to improve insulin sensitivity and thereby reduce beta-cell secretory demand, resulting in decreased release of insulin and islet amyloid polypeptide (IAPP), the unique constituent of islet amyloid deposits. We hypothesized that this reduced beta-cell secretory demand would lead to reduced islet amyloid formation. Human IAPP (hIAPP) transgenic mice, a model of islet amyloid, were treated for 12 months with rosiglitazone (1.5 mg.kg(-1).day(-1), n = 19), metformin (1 g.kg(-1).day(-1), n = 18), or control (n = 17). At the end of the study, islet amyloid prevalence (percent islets containing amyloid) and severity (percent islet area occupied by amyloid), islet mass, beta-cell mass, and insulin release were determined. Islet amyloid prevalence (44 +/- 8, 13 +/- 4, and 11 +/- 3% for control, metformin-, and rosiglitazone-treated mice, respectively) and severity (9.2 +/- 3.0, 0.22 +/- 0.11, and 0.10 +/- 0.05% for control, metformin-, and rosiglitazone-treated mice, respectively) were markedly reduced with both rosiglitazone (P < 0.001 for both measures) and metformin treatment (P < 0.001 for both measures). Both treatments were associated with reduced insulin release assessed as the acute insulin response to intravenous glucose (2,189 +/- 857, 621 +/- 256, and 14 +/- 158 pmol/l for control, metformin-, and rosiglitazone-treated mice, respectively; P < 0.05 for metformin vs. control and P < 0.005 for rosiglitazone vs. control), consistent with reduced secretory demand. Similarly, islet mass (33.4 +/- 7.0, 16.6 +/- 3.6, and 12.2 +/- 2.1 mg for control, metformin-, and rosiglitazone-treated mice, respectively) was not different with metformin treatment (P = 0.06 vs. control) but was significantly lower with rosiglitazone treatment (P < 0.05 vs. control). When the decreased islet mass was accounted for, the islet amyloid-related decrease in beta-cell mass (percent beta-cell mass/islet mass) was ameliorated in both rosiglitazone- and metformin-treated animals (57.9 +/- 3.1, 64.7 +/- 1.4, and 66.1 +/- 1.6% for control, metformin-, and rosiglitazone-treated mice, respectively; P < 0.05 for metformin or rosiglitazone vs. control). In summary, rosiglitazone and metformin protect beta-cells from the deleterious effects of islet amyloid, and this effect may contribute to the ability of these treatments to alleviate the progressive loss of beta-cell mass and function in type 2 diabetes.

Second-trimester biparietal diameter/nasal bone length ratio is an independent predictor of trisomy 21

OBJECTIVE

The purpose of this study was to evaluate the association between the second-trimester fetal biparietal diameter/nasal bone length (BPD/NBL) ratio and trisomy 21.

METHODS

Thirty-one cases of trisomy 21 for which complete ultrasound images included the nasal bone were identified from the University of Washington prenatal diagnosis database and matched to 136 euploid fetuses based on maternal age, indication for referral, and gestational age.

RESULTS

The mean NBL was shorter (mean +/- SD, 2.3+/-1.7 mm versus 3.9+/-1.2 mm; P<.001) and the BPD/NBL ratio was greater (17.7 [range, 6.2-114] versus 11.7 [range, 5.8-80]; P<.001) in the fetuses with trisomy 21. The risk of trisomy 21 increased 2.4-fold (95% confidence interval [CI], 1.7-3.4) with every 1-mm decrease in NBL and increased 1.08-fold (95% CI, 1.03-1.12) with each unit increase in the BPD/NBL ratio (P<.001). A multiple logistic regression model was constructed and included the BPD/NBL ratio, maternal indications (age>or=35 years, positive serum screening results, or both, yielding a risk of <1 per 270 for trisomy 21), and sonographic markers as covariates. The BPD/NBL ratio was found to be an independent predictor of trisomy 21 (odds ratio, 1.08; 95% CI, 1.03-1.11). An analysis of receiver operating characteristic curves revealed an improvement after the BPD/NBL ratio was added to a model containing the current second-trimester screening based on maternal age, serum screening, and sonographic markers (receiver operating characteristic curve area, mean +/-SE, 0.89+/-0.03 for the model with the BPD/NBL ratio versus 0.76+/- 0.06 without the BPD/NBL ratio; P=.009).

CONCLUSIONS

The second-trimester BPD/NBL ratio was a significant and independent predictor of trisomy 21. An assessment of the BPD/NBL ratio may improve the diagnosis of trisomy 21 when used with current prenatal screening practices.

Pharmacokinetics and pharmacodynamics of atenolol during pregnancy and postpartum

Preexisting hypertension complicates 5% of all pregnancies. The objective of this study was to evaluate steady-state atenolol pharmacokinetics and pharmacodynamics (n = 17) during the second trimester (2nd T), third trimester (3rd T), and 3 months postpartum. Pregnancy as compared to 3 months postpartum (nonpregnant control) resulted in significant (P < .05) changes, including the following: 42% (2nd T) and 50% (3rd T) increase in creatinine clearance, 38% (2nd T) and 36% (3rd T) increase in atenolol renal clearance, 12% (2nd T) and 11% (3rd T) decrease in atenolol half-life, 20% (2nd T) and 28% (3rd T) increase in cardiac output, 15% (2nd T) and 23% (3rd T) increase in resting heart rate, and 22% (2nd T) and 21% (3rd T) decrease in total peripheral resistance in subjects on steady-state oral atenolol for treatment of hypertension in pregnancy. In conclusion, the renal clearance of atenolol along with creatinine clearance is increased during pregnancy. However, this does not translate into an increase in apparent oral clearance of atenolol, possibly related to the high variability in bioavailability. Atenolol administration did not appear to change the pattern of the increase in cardiac output and the decrease in total peripheral resistance, which normally occurs during pregnancy.

A reduced-fat diet and aerobic exercise in Japanese Americans with impaired glucose tolerance decreases intra-abdominal fat and improves insulin sensitivity but not beta-cell function

Lifestyle modification reduces the risk of developing type 2 diabetes and may have its effect through improving insulin sensitivity, beta-cell function, or both. To determine whether diet and exercise improve insulin sensitivity and/or beta-cell function and to evaluate these effects over time, we quantified insulin sensitivity and the acute insulin response to glucose (AIRg) in 62 Japanese Americans (age 56.5 +/- 1.3 years; mean +/- SE) with impaired glucose tolerance (IGT) who were randomized to the American Heart Association (AHA) Step 2 diet plus endurance exercise (n = 30) versus the AHA Step 1 diet plus stretching (n = 32) for 24 months. beta-Cell function (disposition index [DI]) was calculated as S(i) x AIRg, where S(i) is the insulin sensitivity index. The incremental area under the curve for glucose (incAUCg) was calculated from a 75-g oral glucose tolerance test. Intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas were measured by computed tomography. At 24 months, the Step 2/endurance group had lower weight (63.1 +/- 2.4 vs. 71.3 +/- 2.9 kg; P = 0.004) and IAF (75.0 +/- 7.9 vs. 112.7 +/- 10.4 cm(2); P = 0.03) and SCF (196.5 +/- 18.0 vs. 227.7 +/- 19.9 cm(2); P < 0.001) areas, greater S(i) (4.7 +/- 0.5 vs. 3.3 +/- 0.3 x 10(-5) min . pmol(-1) . l(-1); P = 0.01), and a trend toward lower AIRg (294.9 +/- 50.0 vs. 305.4 +/- 30.0 pmol/l; P = 0.06) and incAUCg (8,217.3 +/- 350.7 vs. 8,902.0 +/- 367.2 mg . dl(-1) . 2 h(-1); P = 0.08) compared with the Step 1/stretching group after adjusting for baseline values. There was no difference in the DI (P = 0.7) between the groups. S(i) was associated with changes in weight (r = -0.426, P = 0.001) and IAF (r = -0.395, P = 0.003) and SCF (r = -0.341, P = 0.01) areas. Thus, the lifestyle modifications decreased weight and central adiposity and improved insulin sensitivity in Japanese Americans with IGT. However, such changes did not improve beta-cell function, suggesting that this degree of lifestyle modifications may be limited in preventing type 2 diabetes over the long term.

NSAIDS or paracetamol, alone or combined with opioids, for cancer pain

BACKGROUND

NSAIDs are widely applied to treat cancer pain and are frequently combined with opioids in combination preparations for this purpose. However, it is unclear which agent is most clinically efficacious for relieving cancer-related pain, or even what may be the additional benefit of combining an NSAID with an opioid in this setting.

OBJECTIVES

To assess the effects of NSAIDs, alone or combined with opioids, for the treatment of cancer pain.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Issue 2, 2002), MEDLINE (January 1966 to March 2003), EMBASE (January 1980 to December 2001), LILACS (January 1984 to December 2001) and reference list of articles.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials that compared NSAID versus placebo; NSAID versus NSAID; NSAID versus NSAID plus opioid; opioid versus opioid plus NSAID; or NSAID versus opioid.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse event information was collected from trials. Where there was disagreement between reviewers, the opinion of an additional reviewer was sought to resolve the issue.

MAIN RESULTS

Forty-two trials involving 3084 patients were included. Clinical heterogeneity of study methods and outcomes precluded meta-analyses and only supported a qualitative systematic review. Seven of eight papers that compared NSAID with placebo demonstrated superior efficacy of NSAID with no difference in side effects. Thirteen papers compared one NSAID with another; four reported increased efficacy of one NSAID over another. Four different studies found that one NSAID had fewer side effects than one or more others. Twenty-three studies compared NSAIDs and opioids in combination or alone with NSAID/opioid combinations. Thirteen out of 14 studies found no difference, or low clinical difference, when combining an NSAID plus an opioid versus either drug alone. Comparisons between various NSAID/opioid combinations were inconclusive. Nine studies assessed the association between dose and efficacy and safety. Four papers demonstrated increased efficacy with increased dose, but no dose-dependent increase in side effects within the dose ranges studied. Study duration ranged from single dose studies performed over six hours to crossover studies lasting six weeks; however the majority of studies were of less than seven days duration.

AUTHORS' CONCLUSIONS

Based upon limited data, NSAIDs appear to be more effective than placebo for cancer pain; clear evidence to support superior safety or efficacy of one NSAID over another is lacking; and trials of combinations of an NSAID with an opioid have disclosed either no difference (4 out of 14 papers), a statistically insignificant trend towards superiority (1 out of 14 papers), or at most a slight but statistically significant advantage (9 out of 14 papers), compared with either single entity. The short duration of studies undermines generalization of their findings on efficacy and safety of NSAIDs for cancer pain.

The effect of common clinical contaminants on amniotic fluid fluorescence polarization results

OBJECTIVE

To determine the effect of blood, meconium, and vaginal secretions on amniotic fluid (AF) fluorescence polarization results.

METHODS

Amniotic fluid was collected by transabdominal amniocentesis from women at 20-41 weeks of gestation and contaminated with blood, meconium, and vaginal secretions to concentrations of 0.5, 1, 2, 5, and 10%. An additional 20% concentration was performed with meconium and vaginal secretions. Fluorescence polarization was determined by a TDx Analyzer with the NBD-PC fluorescent probe. Results were compared for each contaminant by concentration level using repeated-measures analysis of variance.

RESULTS

Forty-eight samples from women at a mean gestational age of 35 weeks (range 20-41.5 weeks) were evaluated. Before contamination, 16 (33%) samples had fluorescence polarization values greater than 290 mPol (immature), 10 (21%) were 260- 289 mPol (transitional), and 22 (46%) were less than 260 mPol (mature). Contamination with blood significantly altered fluorescence polarization values in AF samples with baseline values in the immature and mature categories such that values trended toward the transitional range. Contamination of baseline immature samples with vaginal secretions at 20% contamination level resulted in more mature fluorescence polarization values. Contamination with meconium more than 2% in the baseline immature category or more than 20% in the baseline transitional category also resulted in significantly more mature fluorescence polarization values.

CONCLUSION

Amniotic fluid contamination with blood can result in more transitional range fluorescence polarization values, whereas contamination with meconium and vaginal secretions can result in more mature fluorescence polarization values.

Impact of intra-abdominal fat and age on insulin sensitivity and beta-cell function

The prevalence of glucose intolerance and type 2 diabetes increases with age. To determine whether the hyperbolic relationship between insulin sensitivity and the insulin response is affected by age and whether the decline in beta-cell function with age is related to increases in intra-abdominal fat or age per se, we studied 220 healthy subjects with fasting glucose <6.1 mmol/l (89 men and 131 women, aged 26-75 years, BMI 18.7-40.4 kg/m(2)). The insulin sensitivity index (S(i)) and the acute insulin response to glucose (AIRg) were determined, and from these beta-cell function was estimated as the disposition index (S(i) x AIRg). Intra-abdominal fat and subcutaneous fat areas were quantified by computed tomography. S(i) (5.40 +/- 0.5 vs. 7.86 +/- 0.7 x10(-5) min(-1)/[pmol/l]), P < 0.01) was decreased and intra-abdominal fat (117 +/- 10 vs. 81 +/- 9 cm(2), P < 0.05) was increased in the oldest (age 60-75 years) versus the youngest (age 26-44 years) quartile. The hyperbolic relationship between S(i) and AIRg was present independent of age; thus, beta-cell function measured as the disposition index (1,412 +/- 120 vs. 2,125 +/- 150 x10(-5) min(-1), P < 0.01) was lower in the oldest versus the youngest quartile. In multiple regression, intra-abdominal fat (r = -0.470, P < 0.001) but not age was associated with S(i), but both intra-abdominal fat (r = -0.198, P = 0.003) and age (r = -0.131, P = 0.05) were correlated with the disposition index. These data suggest that although intra-abdominal fat is a strong determinant of insulin sensitivity and beta-cell function, age has an independent effect on beta-cell function that may contribute to the increased prevalence of type 2 diabetes in older populations.

Intra-abdominal fat is a major determinant of the National Cholesterol Education Program Adult Treatment Panel III criteria for the metabolic syndrome

The underlying pathophysiology of the metabolic syndrome is the subject of debate, with both insulin resistance and obesity considered as important factors. We evaluated the differential effects of insulin resistance and central body fat distribution in determining the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. In addition, we determined which NCEP criteria were associated with insulin resistance and central adiposity. The subjects, 218 healthy men (n = 89) and women (n = 129) with a broad range of age (26-75 years) and BMI (18.4-46.8 kg/m2), underwent quantification of the insulin sensitivity index (Si) and intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas. The metabolic syndrome was present in 34 (15.6%) of subjects who had a lower Si [median: 3.13 vs. 6.09 x 10(-5) min(-1)/(pmol/l)] and higher IAF (166.3 vs. 79.1 cm2) and SCF (285.1 vs. 179.8 cm2) areas compared with subjects without the syndrome (P < 0.001). Multivariate models including Si, IAF, and SCF demonstrated that each parameter was associated with the syndrome. However, IAF was independently associated with all five of the metabolic syndrome criteria. In multivariable models containing the criteria as covariates, waist circumference and triglyceride levels were independently associated with Si and IAF and SCF areas (P < 0.001). Although insulin resistance and central body fat are both associated with the metabolic syndrome, IAF is independently associated with all of the criteria, suggesting that it may have a pathophysiological role. Of the NCEP criteria, waist circumference and triglycerides may best identify insulin resistance and visceral adiposity in individuals with a fasting plasma glucose <6.4 mmol/l.

Diet-induced weight loss is associated with an improvement in beta-cell function in older men

Although weight loss in older subjects has been shown to improve insulin sensitivity, it is unclear what effect this lifestyle intervention has on beta-cell function. To determine whether diet-induced weight loss can improve beta-cell function in older subjects, we studied 19 healthy male subjects (age, 65.4 +/- 0.9 yr; body mass index, 30.9 +/- 0.6 kg/m2; mean +/- SEM) before and after a 3-month 1200-kcal/d diet. The insulin sensitivity index (SI) was quantified using Bergman's minimal model. The acute insulin response to glucose (AIRg) and the maximal glucose-potentiated insulin response (AIRmax) were determined and then adjusted for SI (SI x AIRg and SI x AIRmax), thus providing measures of beta-cell function. Subjects demonstrated significant weight loss (95.6 +/- 2.4 to 86.1 +/- 2.5 kg; P < 0.001). Both fasting plasma glucose [97.3 +/- 1.6 to 95.1 +/- 1.3 mg/dl (5.4 +/- 0.09 to 5.3 +/- 0.07 mM); P = 0.05] and insulin [18.5 +/- 1.3 to 12.2 +/- 1.0 microU/ml (110.9 +/- 7.7 to 73.5 +/- 5.9 pM); P < 0.001] levels decreased. With weight loss, SI increased [1.59 +/- 0.24 to 2.49 +/- 0.32 x 10(-4) min(-1)/(microU/ml) (2.65 +/- 0.4 to 4.15 +/- 0.5 x 10(-5) min(-1)/pM); P < 0.001], whereas both AIRg [63.4 +/- 13.4 to 51.0 +/- 10.7 microU/ml (380 +/- 80 to 306 +/- 64 pM); P < 0.05] and AIRmax [314 +/- 31.4 to 259.9 +/- 33.4 microU/ml (1886 +/- 188 to 1560 +/- 200 pM); P < 0.05] decreased. Overall beta-cell function improved (SI x AIRg, 9.63 +/- 2.28 to 12.78 +/- 2.58 x 10(-3) min(-1), P < 0.05; and SI x AIRmax, 51.01 +/- 9.2 to 72.69 +/- 13.4 x 10(-3) min(-1), P < 0.05). Thus, the weight loss-associated improvements in both insulin sensitivity and beta-cell function may explain the beneficial effects of a lifestyle intervention on delaying the development of diabetes in older subjects.