Stability of E' centers induced by 4.7eV laser radiation in SiO2

The kinetics of E' centers (silicon dangling bonds) induced by 4.7eV pulsed laser irradiation in dry fused silica was investigated by in situ optical absorption spectroscopy. The stability of the defects, conditioned by reaction with mobile hydrogen of radiolytic origin, is discussed and compared to results of similar experiments performed on wet fused silica. A portion of E' and hydrogen are most likely generated by laser-induced breaking of Si-H precursors, while an additional fraction of the paramagnetic centers arise from another formation mechanism. Both typologies of E' participate to the reaction with H_2 leading to the post-irradiation decay of the defects. This annealing process is slowed down on decreasing temperature and is frozen at T=200K, consistently with the diffusion properties of H_2 in silica.Comment: 12 pages, 3 figures, in press on J. Non cryst. solids (2007

Antihypertensive Drug Class and Adherence: An Electronic Monitoring Study

Background: Medication adherence is essential to optimizing blood pressure (BP) control. Prior research has demonstrated differences in pharmacy refill patterns according to antihypertensive drug class. No prior study has assessed the association between drug class and day-to-day adherence. Methods: Between 2011 and 2014, we enrolled a convenience sample of 149 patients with persistently uncontrolled hypertension from two inner-city clinics and concurrently measured adherence of up to four antihypertensive medications using electronic pillboxes during the interval between two primary care visits. The main outcome was mean percent of days adherent to each drug. Mixed effects regression analyses were used to assess the association between drug class and adherence adjusting for age, gender, race, ethnicity, education, health insurance, coronary artery disease, heart failure, chronic kidney disease, diabetes, number of medications, days monitored, and dosing frequency. Results: The mean age was 64 years; 72% women, 75% Hispanic, 88% prescribed ≥1 BP medication. In unadjusted analyses, adherence was lower for beta-blockers (70.9%) compared to angiotensin receptor blocking agents (75.0%, P = 0.11), diuretics (75.9%, P < 0.001), calcium channel blockers (77.6%, P < 0.001) and angiotensin-converting enzyme inhibitors (78.0%, P < 0.0001). In the adjusted analysis, only dosing frequency (P = 0.0001) but not drug class (P = 0.71) was associated with medication adherence. Conclusions: Antihypertensive drug class was not associated with electronically measured adherence after accounting for dosing frequency amongst patients with uncontrolled hypertension. Low adherence to beta-blockers may have been due to the common practice of prescribing multiple daily dosing. Providers may consider using once daily formulations to optimize adherence and should assess adherence among all treated patients with uncontrolled hypertension. Key words: blood pressure drug class hypertension medication adherence

Elucidating the Association Between Depressive Symptoms, Coronary Heart Disease, and Stroke in Black and White Adults: The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

Background Depression is a relapsing and remitting disease. Prior studies on the association between depressive symptoms and incident cardiovascular disease (CVD) have been limited by single measurements, and few if any have examined both incident coronary heart disease and stroke in a large biracial national cohort. We aimed to assess whether time‐dependent depressive symptoms conferred increased risk of incident CVD. Methods and Results Between 2003 to 2007, 22 666 black and white participants (aged ≥45 years) without baseline CVD in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were recruited. Cox proportional hazards regression analyses assessed the association between up to 3 measurements of elevated depressive symptoms (4‐item Center for Epidemiologic Studies Depression Scale score ≥4) and incident coronary heart disease, stroke, and CVD death adjusting for age, sex, region, income, health insurance, education, blood pressure, cholesterol, medication, obesity, diabetes mellitus, kidney disease, C‐reactive protein, corrected QT interval, atrial fibrillation, left ventricular hypertrophy, smoking, alcohol, physical inactivity, medication adherence, and antidepressant use. The participants’ average age was 63.4 years, 58.8% were female, and 41.7% black. Time‐varying depressive symptoms were significantly associated with CVD death (adjusted hazard ratio 1.30, 95% CI 1.04–1.63), with a trend toward significance for fatal and nonfatal stroke (adjusted hazard ratio 1.26, 95% CI 0.99–1.60) but not fatal and nonfatal coronary heart disease (adjusted hazard ratio 1.11, 95% CI 0.89–1.38). Race did not moderate the association between depressive symptoms and CVD. Conclusions Proximal depressive symptoms were associated with incident fatal and nonfatal stroke and CVD death even after controlling for multiple explanatory factors, further supporting the urgent need for timely management of depressive symptoms

Accumulation of non-traditional risk factors for coronary heart disease is associated with incident coronary heart disease hospitalization and death

Assessing multiple traditional risk factors improves prediction for late-life diseases, including coronary heart disease (CHD). It appears that non-traditional risk factors can also predict risk. The objective was to investigate contributions of non-traditional risk factors to coronary heart disease risk using a deficit accumulation approach.Community-dwelling adults with no known history of CHD (n = 2195, mean age 46.9±18.7 years, 51.8% women) participated in the 1995 Nova Scotia Health Survey. Three risk factor indices were constructed to quantify the proportion of deficits present in individuals: 1) a 17-item Non-Traditional Risk Factor Index (e.g. sinusitis, arthritis); 2) a 9-item Traditional Risk Factor Index (e.g. hypertension, diabetes); and 3) a frailty index (25 items combined from the other two index measures). Ten-year risks of CHD events (defined as CHD-related hospitalization and CHD-related mortality) were evaluated.The Non-Traditional Risk Factor Index, made up of health deficits unrelated to CHD, was independently associated with incident CHD events over 10 years after controlling for age, sex, and the Traditional Risk Factor Index [adjusted {adj.} Hazard Ratio {HR} = 1.31; Confidence Interval {CI} 1.14-1.51]. When all health deficits, both those related and unrelated to CHD, were included in a frailty index the corresponding adjusted hazard ratio was 1.61; CI 1.40-1.85.Both traditional and non-traditional risk factor indices are independently associated with incident CHD events. CHD risk assessment may benefit from consideration of general health information as well as from traditional risk factors.Lindsay M. K. Wallace, Olga Theou, Susan A. Kirkland, Michael R. H. Rockwood, Karina W. Davidson, Daichi Shimbo, Kenneth Rockwoo

Association Between High Perceived Stress Over Time and Incident Hypertension in Black Adults: Findings From the Jackson Heart Study.

Background Chronic psychological stress has been associated with hypertension, but few studies have examined this relationship in blacks. We examined the association between perceived stress levels assessed annually for up to 13 years and incident hypertension in the Jackson Heart Study, a community-based cohort of blacks. Methods and Results Analyses included 1829 participants without hypertension at baseline (Exam 1, 2000-2004). Incident hypertension was defined as blood pressure≥140/90 mm Hg or antihypertensive medication use at Exam 2 (2005-2008) or Exam 3 (2009-2012). Each follow-up interval at risk of hypertension was categorized as low, moderate, or high perceived stress based on the number of annual assessments between exams in which participants reported "a lot" or "extreme" stress over the previous year (low, 0 high stress ratings; moderate, 1 high stress rating; high, ≥2 high stress ratings). During follow-up (median, 7.0 years), hypertension incidence was 48.5%. Hypertension developed in 30.6% of intervals with low perceived stress, 34.6% of intervals with moderate perceived stress, and 38.2% of intervals with high perceived stress. Age-, sex-, and time-adjusted risk ratios (95% CI) associated with moderate and high perceived stress versus low perceived stress were 1.19 (1.04-1.37) and 1.37 (1.20-1.57), respectively (P trend&lt;0.001). The association was present after adjustment for demographic, clinical, and behavioral factors and baseline stress (P trend=0.001). Conclusions In a community-based cohort of blacks, higher perceived stress over time was associated with an increased risk of developing hypertension. Evaluating stress levels over time and intervening when high perceived stress is persistent may reduce hypertension risk

Projected impact of polypill use among US adults: Medication use, cardiovascular risk reduction, and side effects

Background Polypills, which include multiple medications for reducing cardiovascular disease (CVD) risk in a single pill, have been proposed for population-wide use. The number of US adults eligible for polypills and potential benefits are unknown. Methods The National Health and Nutrition Examination Survey 2003-2004 and 2007-2008 were analyzed to estimate treatment rates for medications proposed for inclusion in polypills (aspirin, statin, an angiotensin-converting enzyme [ACE] inhibitor, and a thiazide-type diuretic for those without and a β-blocker for those with a history of myocardial infarction) among US adults. The number of coronary heart disease (CHD) and stroke events potentially prevented through polypill use was projected by published meta-analyses and 3 large population-based cohort studies. Two polypill eligibility criteria were analyzed: (1) US adults ≥55 years and (2) US adults with a history of CVD. Results There are 67.6 million US adults ≥55 years and 15.4 million US adults with a history of CVD and, thus, eligible for polypills using the 2 outlined criteria. In 2007 to 2008, 37.3% of US adults ≥55 years and 57.0% of those with a history of CVD were taking statins. Use of other polypill medications was also low. Polypill use by US adults aged ≥55 years is projected to potentially prevent 3.2 million CHD events and 1.7 million strokes over 10 years. Among those with a history of CVD, the potential to prevent of 0.9 million CHD events and 0.5 million strokes is projected. Conclusions Polypills have the potential to lower CVD incidence substantially among US adults

Impact of A1C Screening Criterion on the Diagnosis of Pre-Diabetes Among U.S. Adults

OBJECTIVE New clinical practice recommendations include A1C as an alternative to fasting glucose as a diagnostic test for identifying pre-diabetes. The impact of these new recommendations on the diagnosis of pre-diabetes is unknown. RESEARCH DESIGN AND METHODS Data from the National Health and Nutrition Examination Survey 1999–2006 (n = 7,029) were analyzed to determine the percentage and number of U.S. adults without diabetes classified as having pre-diabetes by the elevated A1C (5.7–6.4%) and by the impaired fasting glucose (IFG) (fasting glucose 100–125 mg/dl) criterion separately. Test characteristics (sensitivity, specificity, and positive and negative predictive values) using IFG as the reference standard were calculated. RESULTS The prevalence of pre-diabetes among U.S. adults was 12.6% by the A1C criterion and 28.2% by the fasting glucose criterion. Only 7.7% of U.S. adults, reflecting 61 and 27% of those with pre-diabetes by A1C and fasting glucose, respectively, had pre-diabetes according to both definitions. A1C used alone would reclassify 37.6 million Americans with IFG to not having pre-diabetes and 8.9 million without IFG to having pre-diabetes (46.5 million reclassified). Using IFG as the reference standard, pre-diabetes by the A1C criterion has 27% sensitivity, 93% specificity, 61% positive predictive value, and 77% negative predictive value. CONCLUSIONS Using A1C as the pre-diabetes criterion would reclassify the pre-diabetes diagnosis of nearly 50 million Americans. It is imperative that clinicians and health systems understand the differences and similarities in using A1C or IFG in diagnosis of pre-diabetes

Generalizability of SPRINT Results to the U.S. Adult Population

Background In SPRINT (Systolic Blood Pressure Intervention Trial), a systolic blood pressure (SBP) goal of <120 mm Hg resulted in lower cardiovascular disease (CVD) risk compared with an SBP goal of <140 mm Hg. Objectives The purpose of this study was to estimate the prevalence, number, and characteristics of U.S. adults meeting SPRINT eligibility criteria and determine the broader population to whom SPRINT could be generalized. Methods We conducted a cross-sectional, population-based study using data from the National Health and Nutrition Examination Survey, 2007 to 2012. The SPRINT inclusion criteria were age ≥50 years, SBP 130 to 180 mm Hg depending on the number of antihypertensive medication classes being taken, and high CVD risk (history of coronary heart disease, estimated glomerular filtration rate of 20 to 59 ml/min/1.73 m2, 10-year CVD risk ≥15%, or age ≥75 years). Exclusion criteria were diabetes, history of stroke, >1 g in 24 h of proteinuria daily, heart failure, estimated glomerular filtration rate <20 ml/min/1.73 m2, or receiving dialysis. Treated hypertension was defined by self-reported use of medication to lower blood pressure with ≥1 class of antihypertensive medication identified through a pill bottle review. Results Overall, 7.6% (95% confidence interval [CI]: 7.0% to 8.3%) or 16.8 million (95% CI: 15.7 to 17.8 million) U.S. adults, and 16.7% (95% CI: 15.2% to 18.3%) or 8.2 million (95% CI: 7.6 to 8.8 million) adults with treated hypertension met the SPRINT eligibility criteria. Among both the overall U.S. population and adults with treated hypertension, the percentage meeting SPRINT eligibility criteria increased with older age, was higher among males than females, and was higher among non-Hispanic whites compared with non-Hispanic blacks or Hispanics. Of U.S. adults eligible for SPRINT, 51.0% (95% CI: 47.8% to 54.1%) or 8.6 million (95% CI: 8.0 to 9.1 million) were not treated for hypertension. Conclusions A substantial percentage of U.S. adults meet the eligibility criteria for SPRINT