Measurement of waist circumference predicts coronary atherosclerosis beyond plasma adipokines

OBJECTIVE

The association of plasma adipokines beyond waist circumference (WC) with coronary artery calcification (CAC), a measure of subclinical atherosclerosis, is unknown.

DESIGN AND METHODS

Asymptomatic Caucasian individuals from two community-based cross-sectional studies (n = 1,285) were examined and multivariate analysis of traditional risk factors was performed, then WC and adipokines (adiponectin and leptin) were added. Incremental value of each was tested with likelihood ratio testing.

RESULTS

Beyond traditional risk factors, WC (Tobit regression ratio 1.69, P < 0.001) and plasma leptin (1.57, P < 0.001) but not plasma adiponectin (P = 0.75) were independently associated with CAC. In nested models, neither adiponectin (χ(2) = 0.76, P = 0.38) nor leptin (χ(2) = 1.32, P = 0.25) added value to WC beyond traditional risk factors, whereas WC added incremental value to adiponectin (χ(2) = 28.02, P < 0.0001) and leptin (χ(2) = 13.58, P = 0.0002).

CONCLUSION

In the face of important biomarkers such as plasma adiponectin and leptin, WC remained a significant predictor of CAC beyond traditional risk factors underscoring the importance of WC measurement during cardiovascular risk assessment.

Identification and analysis of the first 2009 pandemic H1N1 influenza virus from U.S. feral swine

The first case of pandemic H1N1 influenza (pH1N1) virus in feral swine in the United States was identified in Texas through the United States Department of Agriculture (USDA) Wildlife Services' surveillance program. Two samples were identified as pandemic influenza by reverse transcriptase quantitative PCR (RT-qPCR). Full-genome Sanger sequencing of all eight influenza segments was performed. In addition, Illumina deep sequencing of the original diagnostic samples and their respective virus isolation cultures were performed to assess the feasibility of using an unbiased whole-genome linear target amplification method and multiple sample sequencing in a single Illumina GAIIx lane. Identical sequences were obtained using both techniques. Phylogenetic analysis indicated that all gene segments belonged to the pH1N1 (2009) lineage. In conclusion, we have identified the first pH1N1 isolate in feral swine in the United States and have demonstrated the use of an easy unbiased linear amplification method for deep sequencing of multiple samples.

Canagliflozin improves glycaemic control over 28 days in subjects with type 2 diabetes not optimally controlled on insulin

AIM

Canagliflozin is a sodium-glucose co-transporter 2 (SGLT2) inhibitor that is being investigated for the treatment of type 2 diabetes mellitus (T2DM).

METHODS

This was a randomized, double-blind, placebo-controlled, parallel-group, 28-day study conducted at two sites, in 29 subjects with T2DM not optimally controlled on insulin and up to one oral antihyperglycaemic agent. Subjects were treated with canagliflozin 100 mg QD or 300 mg twice daily (BID) or placebo. Safety, tolerability, pharmacokinetic characteristics and pharmacodynamic effects of canagliflozin were examined. Glucose malabsorption following a 75-g oral glucose challenge was also examined.

RESULTS

Canagliflozin pharmacokinetics were dose-dependent, and the elimination half-life ranged from 12 to 15 h. After 28 days, the renal threshold for glucose excretion was reduced; urinary glucose excretion was increased; and A1C, fasting plasma glucose and body weight decreased in subjects administered canagliflozin (A1C reductions: 0.19% with placebo, 0.73% with 100 mg QD, 0.92% with 300 mg BID; body weight changes: 0.03 kg increase with placebo, 0.73 kg reduction with 100 mg QD, 1.19 kg reduction with 300 mg BID). Glucose malabsorption was not observed with canagliflozin treatment. There were no deaths, serious adverse events or severe hypoglycaemic episodes. The incidence of adverse events was similar across groups. There were no clinically meaningful changes in routine laboratory safety tests, vital signs or electrocardiograms.

CONCLUSION

In subjects receiving insulin and oral antihyperglycaemic therapy, canagliflozin was well tolerated without evidence for glucose malabsorption, had pharmacokinetic characteristics consistent with once-daily dosing, and improved glycaemic control.

Diagnosis of invasive fungal infections in hematology and oncology--guidelines from the Infectious Diseases Working Party in Haematology and Oncology of the German Society for Haematology and Oncology (AGIHO)

Invasive fungal infections (IFIs) are a primary cause of morbidity and mortality in patients with hematological malignancies. Establishing a definite diagnosis of IFI in immunocompromised patients is particularly challenging and time consuming, but delayed initiation of antifungal treatment increases mortality. The limited overall outcome has led to the strategy of initiating either 'empirical' or 'preemptive' antifungal therapy before the final diagnosis. However, diagnostic procedures have been vastly improved in recent years. Particularly noteworthy is the introduction of newer imaging techniques and non-culture methods, including antigen-based assays, metabolite detection and molecular detection of fungal DNA from body fluid samples. Though varying widely in cancer patients, the risk of IFI is highest in those with allogeneic stem cell transplantation and those with acute leukemia. The AGIHO presents recommendations for the diagnosis of IFIs with risk-adapted screening concepts for febrile episodes in patients with haemato-oncological disorders.

Fibroblast growth factor 23 and risks of mortality and end-stage renal disease in patients with chronic kidney disease

CONTEXT

A high level of the phosphate-regulating hormone fibroblast growth factor 23 (FGF-23) is associated with mortality in patients with end-stage renal disease, but little is known about its relationship with adverse outcomes in the much larger population of patients with earlier stages of chronic kidney disease.

OBJECTIVE

To evaluate FGF-23 as a risk factor for adverse outcomes in patients with chronic kidney disease.

DESIGN, SETTING, AND PARTICIPANTS

A prospective study of 3879 participants with chronic kidney disease stages 2 through 4 who enrolled in the Chronic Renal Insufficiency Cohort between June 2003 and September 2008.

MAIN OUTCOME MEASURES

All-cause mortality and end-stage renal disease.

RESULTS

At study enrollment, the mean (SD) estimated glomerular filtration rate (GFR) was 42.8 (13.5) mL/min/1.73 m(2), and the median FGF-23 level was 145.5 RU/mL (interquartile range [IQR], 96-239 reference unit [RU]/mL). During a median follow-up of 3.5 years (IQR, 2.5-4.4 years), 266 participants died (20.3/1000 person-years) and 410 reached end-stage renal disease (33.0/1000 person-years). In adjusted analyses, higher levels of FGF-23 were independently associated with a greater risk of death (hazard ratio [HR], per SD of natural log-transformed FGF-23, 1.5; 95% confidence interval [CI], 1.3-1.7). Mortality risk increased by quartile of FGF-23: the HR was 1.3 (95% CI, 0.8-2.2) for the second quartile, 2.0 (95% CI, 1.2-3.3) for the third quartile, and 3.0 (95% CI, 1.8-5.1) for the fourth quartile. Elevated fibroblast growth factor 23 was independently associated with significantly higher risk of end-stage renal disease among participants with an estimated GFR between 30 and 44 mL/min/1.73 m(2) (HR, 1.3 per SD of FGF-23 natural log-transformed FGF-23; 95% CI, 1.04-1.6) and 45 mL/min/1.73 m(2) or higher (HR, 1.7; 95% CI, 1.1-2.4), but not less than 30 mL/min/1.73 m(2).

CONCLUSION

Elevated FGF-23 is an independent risk factor for end-stage renal disease in patients with relatively preserved kidney function and for mortality across the spectrum of chronic kidney disease.

The use of well controls: an unhealthy practice in psychiatric research

BACKGROUND

Studies comparing cases with controls to uncover the causes of psychiatric disorders are common in biological research. The validity of these studies depends upon adherence to the methodological principles underlying the case-control design. However, these principles are often violated. One common practice that violates these principles is the use of well controls. In this paper we describe the bias that it can cause and discuss why the use of well controls leads to invalidity in case-control studies.

METHOD

Using hypothetical numerical examples we illustrate the consequences of using well controls.

RESULTS

The results illustrate that the use of well controls can cause substantial bias. In no instance does the use of well controls improve validity.

CONCLUSIONS

We conclude that the use of well controls is an unhealthy practice in psychiatric research.

Guideline on safer conception in fertile HIV-infected individuals and couples

Ninety years ago the isolation of insulin transformed the lives of people with type 1 diabetes. Now, models based on empirical data estimate that a 25-year-old person with HIV, when appropriately treated with antiretroviral therapy, can expect to enjoy a median survival of 35 years, remarkably similar to that for someone of the same age with type 1 diabetes. It is high time we normalised the lives of people living positively with HIV. This includes the basic human right to conceive and raise children. HIV-positive individuals may be in serodiscordant relationships or in seroconcordant relationships. As health care providers, it is our responsibility to ensure we understand the opportunities and risks of natural conception in these scenarios, so that we can help our patients to make informed decisions about their own lives. Most of all, it is our duty to make family planning in the setting of positive prevention as safe as we can. This includes informed decisions on contraception, adoption, fostering, conception and prevention of mother-to-child transmission. Some months ago a dedicated group of individuals, invited and sponsored by the Southern African HIV Clinicians Society, came together in Cape Town to devise guidance in this area, recognising that there are ideal strategies that may be outside the realm of the resource constraints of the public sector or health programmes in southern Africa. This guideline therefore attempts to provide a range of strategies for various resource settings. It is up to us, the providers, to familiarise ourselves with the merits/benefits and risks of each, and to then engage patients in meaningful discussions. All the above, however, is based on the premise and prerequisite that the subject of family planning is actively raised and frequently discussed in our patient encounters.Please find a link to the update of this guideline: http://sajhivmed.org.za/index.php/hivmed/article/view/399

Photon lifetime in a cavity containing a slow-light medium

We investigate experimentally the lifetime of the photons in a cavity containing a medium exhibiting strong positive dispersion. This intracavity positive dispersion is provided by a metastable helium gas at room temperature in the electromagnetically induced transparency regime, in which light propagates at a group velocity of the order of 10⁴ m·s⁻¹. The results definitely prove that the lifetime of the cavity photons is governed by the group velocity of light in the cavity and not its phase velocity.

Targeting dietary fat or glycemic load in the treatment of obesity and type 2 diabetes: a randomized controlled trial

AIMS

To compare the effects of lifestyle modification programs that prescribe low-glycemic load (GL) vs. low-fat diets in a randomized trial.

METHODS

Seventy-nine obese adults with type 2 diabetes received low-fat or low-GL dietary instruction, delivered in 40-week lifestyle modification programs with identical goals for calorie intake and physical activity. Changes in weight, HbA(1c), and other metabolic parameters were compared at weeks 20 and 40.

RESULTS

Weight loss did not differ between groups at week 20 (low-fat: -5.7±3.7%; low-GL: -6.7±4.4%, p=.26) or week 40 (low-fat: -4.5±7.5%; low-GL: -6.4±8.2%, p=.28). Adjusting for changes in antidiabetic medications, subjects on the low-GL diet had larger reductions in HbA(1c) than those on the low-fat diet at week 20 (low-fat: -0.3±0.6%; low-GL: -0.7±0.6%, p=.01), and week 40 (low-fat: -0.1±1.2%; low-GL: -0.8±1.3%; p=.01). Groups did not differ significantly on any other metabolic outcomes (p≥.06).

CONCLUSIONS

Results suggest that targeting GL, rather than dietary fat, in a low-calorie diet can significantly enhance the effect of weight loss on HbA(1c) in patients with type 2 diabetes.

Clair C, Schwartz S, Iqbal N, Braunstein S, Schutta M, Rader DJ, Reilly MP. Usefulness of insulin resistance estimation and the metabolic syndrome in predicting coronary atherosclerosis in type 2 diabetes mellitus

Metabolic syndrome (MS) definitions predict cardiovascular events beyond traditional risk factors in patients with type 2 diabetes mellitus (DM) as well as subjects without DM. It has been shown that apolipoprotein B (apoB) and non-high-density lipoprotein cholesterol are associated with coronary artery calcification in DM. However, the relative value of MS, apoB lipoproteins, and estimates of insulin resistance is unknown in predicting atherosclerosis in DM. Cross-sectional analyses of white subjects in 2 community-based studies were performed (n = 611 patients with DM, n = 803 subjects without DM) using multivariate analysis of traditional risk factors and then adding MS, apoB, and homeostasis model assessment of insulin resistance (HOMA-IR). Incremental value was tested using likelihood ratio testing. Beyond traditional risk, HOMA-IR (tobit regression ratio 1.86, p = 0.002), apoB (tobit regression ratio 1.55, p = 0.001), and MS (tobit regression ratio 2.37, p = 0.007) were independently associated with coronary artery calcification in DM. In nested models, HOMA-IR added value to apoB (tobit regression ratio 1.72, p = 0.008), MS (tobit regression ratio 1.72, p = 0.011), and apoB and MS (tobit regression ratio 1.64, p = 0.021). ApoB showed a similar pattern when added to HOMA-IR (tobit regression ratio 1.51, p = 0.004), MS (tobit regression ratio 1.46, p = 0.005), and HOMA-IR and MS (tobit regression ratio 1.48, p = 0.006). MS added to apoB (tobit regression ratio 1.99, p = 0.032) but not HOMA-IR (tobit regression ratio 1.54, p = 0.221) or apoB and HOMA-IR (tobit regression ratio 1.32, p = 0.434). In conclusion, insulin resistance estimates add value to MS and apoB in predicting coronary artery calcification scores in DM and warrant further evaluation in clinic for identification of patients with DM at higher risk for atherosclerotic cardiovascular disease.