Prevalence and predictors of severe autonomic failure in patients with insulin-dependent type 2 diabetes mellitus and coronary artery disease: pilot study.

BACKGROUND: Presence of severe autonomic failure (SAF), defined as coincidence of abnormal heart rate turbulence and abnormal deceleration capacity, identifies a group of patients with very poor prognosis among post-infarction patients with diabetes mellitus. However, factors contributing to development of SAF are entirely unknown. Here, we aimed to identify clinical, biochemical, and hemodynamic factors predicting SAF in a consecutive cohort of diabetic patients with coronary artery disease (CAD). METHODS: Between January 2010 and July 2011, we prospectively enrolled 97 patients with insulin-dependent type 2 diabetes mellitus and stable CAD in sinus rhythm. Heart rate turbulence (as marker of autonomic reflex activity) and deceleration capacity (as marker of autonomic tonic activity) were calculated from 24-hour Holter recordings. Uni- and multivariable logistic regression analysis included duration of diabetes mellitus, diabetic neuropathy, retinopathy, nephropathy, level of HbA(1c), left ventricular ejection fraction (LVEF), brain natriuretic peptide, presence of multivessel disease, and history of myocardial infarction. RESULTS: Ten (10.3%) of the 97 patients exhibited signs of SAF. Patients with SAF were characterized by longer duration of diabetes (25 years vs 15 years), higher prevalence of diabetic neuropathy (70% vs. 36%), retinopathy (80% vs 45%) and nephropathy (90% vs 55%), significantly higher levels of HbA(1c) (9.0% vs 7.4%; P = .002) and a lower LVEF (30% vs.55%; P = .001). On multivariable analysis, LVEF ≤ 35% and HbA(1c) >8% were the only factors which were independently associated with SAF (odds ratios of 23.1 [95% CI, 1.8-287.0]; P = .015 and 6.6 [1.1-40.1]; P = .043). DISCUSSION: In patients with insulin-dependent type 2 diabetes mellitus and CAD, presence of SAF correlates with both glycemic control and diabetic complications. Impaired LVEF and increased level of HbA(1c) were independently associated with SAF.

Identification and quantification of 1-hydroxybutene-2-yl mercapturic acid in human urine by UPLC- HILIC-MS/MS as a novel biomarker for 1,3-butadiene exposure.

1,3-Butadiene (BD) is a Class 1 carcinogen present at workplaces, in polluted air, in automobile exhaust, and in tobacco smoke. 2-Hydroxybutene-1-yl mercapturic acid (2-MHBMA) is a urinary metabolite often measured as a biomarker for exposure to BD. Here, we show for the first time that an additional MHBMA isomer is present at significant amounts in human urine, 1-hydroxybutene-2-yl mercapturic acid (1-MHBMA). For its quantification, a highly sensitive UPLC-HILIC-MS/MS method was developed and validated. Analyzing urinary samples of 183 volunteers, we demonstrate that 1-MHBMA is a novel and potentially more reliable biomarker for BD exposure than the commonly analyzed 2-MHBMA.

A simple and robust UPLC-SRM/MS method to quantify urinary eicosanoids.

Eicosanoids are key mediators and regulators of inflammation and oxidative stress often used as biomarkers for diseases and pathological conditions such as cardiovascular and pulmonary diseases and cancer. Analytically, comprehensive and robust quantification of different eicosanoid species in a multi-method approach is problematic because most of these compounds are relatively unstable and may differ in their chemical properties. Here we describe a novel ultra-performance liquid chromatography-selected reaction monitoring mass spectroscopy (UPLC-SRM/MS) method for simultaneous quantification of key urinary eicosanoids, including the prostaglandins (PG) tetranor PGE-M, 8-iso-, and 2,3-dinor-8-iso-PGF(2α); the thromboxanes (TXs) 11-dehydro- and 2,3-dinor-TXB2; leukotriene E4; and 12-hydroxyeicosatetraenoic acid. In contrast to previous methods, which used time-consuming and complex solid phase extraction, we prepared samples with a simple liquid/liquid extraction procedure. Because collision-induced dissociation produced characteristic product ions for all analytes, no derivatization step for SRM/MS analysis was necessary. Analytes were separated with a short UPLC reversed-phase column (1.7 µm particles), allowing shorter run times than conventional HPLC columns. The method was validated and applied to human urine samples showing excellent precision, accuracy, detection limits, and robustness. In summary, the developed method allows robust and sensitive profiling of urinary eicosanoid species, making it a useful and valuable tool for biomarker profiling in clinical/toxicological studies.

A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the determination of phenolic polycyclic aromatic hydrocarbons (OH-PAH) in urine of non-smokers and smokers.

Polycyclic aromatic hydrocarbons (PAH) are products of the incomplete combustion of organic materials and, therefore, occur ubiquitously in the environment and also in tobacco smoke. Since some PAH have been classified as carcinogens, it is important to have access to suitable analytical methods for biomarkers of exposure to this class of compounds. Past experience has shown that measuring a profile of PAH metabolites is more informative than metabolites of a single PAH. Assessment of environmental and smoking-related exposure levels requires analytical methods with high sensitivity and specificity. In addition, these methods should be fast enough to allow high throughput. With these pre-conditions in mind, we developed and validated a high-performance liquid chromatographic method with tandem mass spectrometric detection (LC-MS/MS) for the determination of phenolic metabolites of naphthalene, fluorene, phenanthrene and pyrene in urine of smokers and non-smokers. Sample work-up comprised enzymatic hydrolysis of urinary conjugates and solid-phase extraction on C18 cartridges. The method showed good specificity, sensitivity, and accuracy for the intended purpose and was also sufficiently rapid with a sample throughput of about 350 per week. Application to urine samples of 100 smokers and 50 non-smokers showed significant differences between both groups for all measured PAH metabolites, and strong correlations with markers of daily smoke exposure in smoker urine. Urinary levels were in good agreement with previously reported data using different methodologies. In conclusion, the developed LC-MS/MS method is suitable for the quantification of phenolic PAH metabolites of naphthalene, fluorene, phenanthrene, and pyrene in smoker and non-smoker urine.

Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption.

Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile.

Enrichment and properties of urinary pre-S-phenylmercapturic acid (pre-SPMA).

In benzene metabolism, pre-S-phenylmercapturic acid (pre-SPMA) is the precursor to S-phenylmercapturic acid (SPMA). Urinary pre-SPMA/SPMA ratios are variable. For the determination of urinary SPMA as a biomarker of exposure to benzene it is essential to completely convert pre-SPMA to SPMA. We developed a procedure for the enrichment and determination of urinary pre-SPMA by LC-MS/MS which allowed us to trace the conversion of pre-SPMA to SPMA. Complete conversion was found upon treatment of urine with HCl (37%) at pH 1.1. Previously reported treatment of urine with concentrated H(2)SO(4) was found to yield SPMA levels higher than after HCl treatment. The origin of that extra SPMA amount is unknown. In conclusion, our findings suggest that pre-treatment of urine with HCl to adjust the pH to 0.5-1 is essential for complete conversion of pre-SPMA to SPMA and should be applied prior to analysis of SPMA in urine.