Premature Atrial Contractions on the Screening Electrocardiogram and Risk of Ischemic Stroke: The Reasons for Geographic and Racial Differences in Stroke Study.
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SUBMITTER: O'Neal WT
PROVIDER: S-EPMC5018917 | biostudies-other | 2016
REPOSITORIES: biostudies-other
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Project description:Background and purposeThe purpose of this case-cohort study was to examine urinary arsenic levels in relation to incident ischemic stroke in the United States.MethodsWe performed a case-cohort study nested within the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort. A subcohort (n=2486) of controls was randomly sampled within region-race-sex strata while all incident ischemic stroke cases from the full REGARDS cohort (n=671) were included. Baseline urinary arsenic was measured by inductively coupled plasma-mass spectrometry. Arsenic species, including urinary inorganic arsenic and its metabolites monomethylarsonic acid and dimethylarsinic acid, were measured in a random subset (n=199). Weighted Cox's proportional hazards models were used to calculate hazard ratios and 95% confidence intervals of ischemic stroke by arsenic and its species.ResultsThe average follow-up was 6.7 years. Although incident ischemic stroke showed no association with total arsenic or total inorganic arsenic, for each unit higher level of urinary monomethylarsonic acid on a log-scale, after adjustment for potential confounders, ischemic stroke risk increased ≈2-fold (hazard ratio=1.98; 95% confidence interval: 1.12-3.50). Effect modification by age, race, sex, or geographic region was not evident.ConclusionsA metabolite of arsenic was positively associated with incident ischemic stroke in this case-cohort study of the US general population, a low-to-moderate exposure area. Overall, these findings suggest a potential role for arsenic methylation in the pathogenesis of stroke, having important implications for future cerebrovascular research.
| S-EPMC5742041 | biostudies-literature
Project description:BACKGROUND:Whether smoking increases the risk of atrial fibrillation (AF) remains debatable due to inconsistent reports. METHODS:We examined the association between smoking and incident AF in 11,047 participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study, one of the largest biracial, population-based cohort studies in the USA. Baseline (2003-2007) cigarette smoking status and amount (pack-years) were self-reported. Incident AF was determined by electrocardiography and history of a prior physician diagnosis at a follow-up examination conducted after a median of 10.6 years. RESULTS:During follow-up, 954 incident AF cases were identified; 9.5% in smokers vs. 7.8% in non-smokers; p<0.001. In a model adjusted for socio-demographics, smoking (ever vs. never) was associated with a 15% increased risk of AF [OR (95%CI): 1.15(1.00, 1.31)], but this association was no longer significant after further adjustment for cardiovascular risk factors [OR (95% CI): 1.12 (0.97, 1.29)]. However, heterogeneities in the association were observed among subgroups; the association was stronger in young vs. old participants [OR (95%CI): 1.31 (1.03, 1.67) vs. 0.99 (0.83-1.18) respectively; interaction p-value=0.005] and in those with vs. without prior cardiovascular disease [OR (95%CI): 1.18 (0.90, 1.56) vs. 1.06 (0.90, 1.25) respectively; interaction p-value 0.0307]. Also, the association was significant in blacks but not in whites [OR (95%CI): 1.51 (1.12, 2.05) vs. 0.99 (0.84, 1.16), respectively], but the interaction p-value did not reach statistical significance (interaction p-value=0.65). CONCLUSIONS:The association between smoking and AF is possibly mediated by a higher prevalence of cardiovascular risk factors in smokers, but there is marked heterogeneity in the strength of this association among subgroups which may explain the conflicting results in prior studies.
| S-EPMC5735021 | biostudies-literature
Project description:The standard for stroke risk stratification is the Framingham Stroke Risk Function (FSRF), an equation requiring an examination for blood pressure assessment, venipuncture for glucose assessment, and ECG to determine atrial fibrillation and heart disease. We assess a self-reported stroke risk function (SRSRF) to stratify stroke risk in comparison to the FSRF.Participants from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke) were evaluated at baseline and followed for incident stroke. The FSRF was calculated using directly assessed stroke risk factors. The SRSRF was calculated from 13 self-reported questions to exclude those with prevalent stroke and assess stroke risk. Proportional hazards analysis was used to assess incident stroke risk using the FSRF and SRSRF.Over an average 8.2-year follow-up, 939 of 23?983 participants had a stroke. The FSRF and SRSRF produced highly correlated risk scores (rSpearman=0.852; 95% confidence interval, 0.849-0.856); however, the SRSRF had higher discrimination of stroke risk than the FSRF (cSRSRF=0.7266; 95% confidence interval, 0.7076-0.7457; cFSRF=0.7075; 95% confidence interval, 0.6877-0.7273; P=0.0038). The 10-year stroke risk in the highest decile of predicted risk was 11.1% for the FSRF and 13.4% for the SRSRF.A simple self-reported questionnaire can be used to identify those at high risk for stroke better than the gold standard FSRF. This instrument can be used clinically to easily identify individuals at high risk for stroke and also scientifically to identify a subpopulation enriched for stroke risk.
| S-EPMC5493147 | biostudies-literature
Project description:Insulin resistance is associated with increased stroke risk, but the effect has not been adequately examined separately in white and black populations.The association of baseline insulin resistance with risk of cerebral infarction (CI) and intracerebral hemorrhage (ICH) was assessed in 12 366 white and 6782 black participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort, recruited between 2003 and 2007 and followed for an average of 5.7 years. Insulin resistance was measured with the homeostasis model assessment-insulin resistance.There were 364 incident CI and 41 incident ICH events. The risk for CI increased with the log of insulin resistance in whites (hazards ratio [HR]ln(IR)=1.17; 95% confidence interval [CI], 1.00-1.38) but was largely attenuated by adjustment for stroke risk factors (HRln(IR)=1.05; 95% CI, 0.88-1.26). There was no association in blacks (HRln(IR)=1.01; 95% CI, 0.81-1.25). After adjustment for demographic factors and risk factors, there was a significant difference by race in the association of insulin resistance with risk of ICH (P=0.07), with a decrease in the risk of ICH in whites (HRln(IR)=0.61; 95% CI, 0.35-1.04) but a nonsignificant increase in blacks (HRln(IR)=1.20; 95% CI, 0.60-2.39).These data support the growing evidence that insulin resistance may play a more important role in stroke risk among white than black individuals and suggest a potentially discordant relationship of insulin resistance on CI and ICH among whites.
| S-EPMC4430474 | biostudies-literature
Project description:BackgroundCirculatory and vascular changes across consecutive pregnancies may increase the risk of later-life cerebrovascular health outcomes.MethodsThe association between parity and incident stroke was assessed among 7674 white and 6280 black women, aged 45 years and older, and enrolled in the REasons for Geographic and Racial Differences in Stroke Study from 2003 to 2007. Parity was assessed at baseline, and incident stroke was ascertained from physician-adjudicated medical records through September 2014. Cox proportional hazards models were used to estimate hazard ratios (HR) for the association between parity and stroke, adjusting for baseline measures.ResultsAt baseline, 12.7% of white women and 16.2% of black women reported 1 live birth, while 8.2% and 19.0%, respectively, reported 5 or more live births. Mean follow-up time was 7.5 years (standard deviation = 2.8); there were 447 incident strokes. A significant interaction between race and parity was detected (P = .05). Among white women, those with 5 or more live births had a higher stroke risk than those with 1 live birth (HR = 1.57; 95% confidence interval [CI] .93-2.65). However, the association was eliminated after adjustment for baseline characteristics (HR = 1.00, 95% CI .59-1.71). For black women, those with 5 or more live births had the highest stroke risk compared with those with 1 live birth (HR = 1.91, 95% CI 1.25-2.93), but the association was attenuated and no longer statistically significant after adjustment for confounders (HR = 1.40, 95% CI .89-2.18).ConclusionsIn adjusted models, no statistically significantassociations were observed between parity and stroke risk in a diverse cohort of U.S. women. Further studies are needed to elucidate the role of lifestyle and psychosocial factors in the race-specific associations that were observed.
| S-EPMC5362279 | biostudies-literature
Project description:Stroke is a major public health concern worldwide given the associated morbidity and mortality. Smoking is a risk factor for stroke, but the relationship between secondhand smoke (SHS) exposure and stroke has been inconsistent to date. The aim of the current study was to examine the association of SHS exposure and risk of stroke and its subtypes (ischemic and hemorrhagic stroke) among nonsmokers.Demographic and clinical characteristics were compared by SHS exposure status for African American and white nonsmokers aged ?45 years in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study in 2014. Hazard ratios (HRs) and corresponding 95% CIs were calculated by Cox proportional hazards models to assess the relationship between SHS exposure and stroke risk.Of the 21,743 participants (38% African American, 45% male), SHS exposure in the past year was reported by 23%. Compared with those without SHS exposure, exposed participants were more likely to be female, white, younger, and reside with a smoker (all p<0.001). A total of 428 incident strokes were observed from April 2003 to March 2012 during a mean follow-up of 5.6 years. The risk of overall stroke was increased 30% among those with SHS exposure after adjustment for other stroke risk factors (95% CI=2%, 67%). This relationship appeared to be driven by ischemic strokes.SHS exposure is independently associated with an increased risk of stroke. Future studies are needed to confirm these findings and examine the role of long-term effects of SHS exposure on stroke outcomes.
| S-EPMC4656115 | biostudies-literature
Project description:BACKGROUND AND PURPOSE:Galectin-3 is a biomarker of atherosclerotic and cardiovascular disease, and may be a useful marker for ischaemic stroke risk. METHODS:The Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort enrolled and examined 30 239 US participants between 2003 and 2007 (41% black, 59% white and 55% in the southeastern stroke belt). Baseline galectin-3 was measured in 526 subjects with incident ischaemic stroke over 5.4 years and in a cohort random sample (CRS) of 947 participants. Cox proportional hazards models were used to calculate hazard ratios (HRs) of ischaemic stroke by quartiles of galectin-3. RESULTS:In the CRS, galectin-3 was significantly higher with older age, black race, female sex, body mass index, hypertension, diabetes mellitus and kidney disease, and also in those who developed incident stroke. Participants with galectin-3 levels in the fourth versus first quartile had a 2.3-fold increased stroke risk [95% confidence interval (CI) 1.6, 3.4] in an unadjusted model. An interaction with age was found (P = 0.06), and therefore age-stratified analyses were performed. Amongst those younger than age 64, baseline galectin-3 in the second-fourth quartiles was associated with increased stroke risk (HR 3.0, 95% CI 1.6, 5.5) compared to the first quartile in an age-, race- and sex-adjusted model. The HR was 2.0 (95% CI 1.0, 4.0) with multivariable adjustment. There was no association amongst older participants. CONCLUSIONS:Galectin-3 was associated with incident ischaemic stroke in younger but not older individuals. Confirmation of this finding, and elucidation of its implications for stroke pathophysiology and prevention, is needed.
| S-EPMC7008611 | biostudies-literature
Project description:ABO blood type is an inherited trait associated with coagulation factor levels and vascular outcomes.To assess the association of blood type with stroke and whether blood type contributes to racial disparities in stroke in the United States.The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study recruited 30 239 participants between 2003 and 2007. Using a case-cohort design, blood type was genotyped in 646 participants with stroke and a 1104-participant cohort random sample. Cox models that adjusted for Framingham stroke risk factors were used to assess the association of blood type with stroke.During 5.8 years of follow-up, blood types A or B vs. type O were not associated with stroke. Blood type AB vs. O was associated with an increased risk of stroke (adjusted hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.01-3.30). The association of blood type AB vs. O was greater in those without diabetes (adjusted HR 3.33, 95% CI 1.61-6.88) than those with diabetes (adjusted HR 0.49, 95% CI 0.17-1.44) (P interaction = 0.02). Factor VIII levels accounted for 60% (95% CI 11%-98%) of the association of AB blood type and stroke risk.Blood type AB is associated with an increased risk of stroke that is not attenuated by conventional stroke risk factors, and factor VIII levels were associated with 60% of the association. While blood type AB is rare in the US population, it is a significant stroke risk factor and may play an important role in stroke risk in these individuals.
| S-EPMC4913462 | biostudies-literature
Project description:Study objectivesTo examine the cross-sectional association between obstructive sleep apnea (OSA) risk and atrial fibrillation (AF) in the REasons for Geographic And Racial Differences in Stroke (REGARDS), a cohort of black and white adults.MethodsUsing REGARDS data from subjects recruited between 2003-2007, we assessed 20,351 participants for OSA status. High OSA risk was determined if the participant met at least two criteria from the Berlin Sleep Questionnaire (persistent snoring, frequent sleepiness, high blood pressure, or obesity). AF was defined as a self-reported history of a previous physician diagnosis or presence of AF on electrocardiogram. Logistic regression was used to determine odds ratio and 95% confidence interval for the association between OSA status and AF with subgroup analysis to examine effect modification by age, race, sex, and geographical region.ResultsThe prevalence of AF was 7% (n = 1,079/14,992) and 9% (n = 482/5,359) in participants at low and high risk of OSA, respectively (P < .0001). Persons at high risk of OSA had greater prevalence of diabetes and stroke history, and were more likely to be obese and taking sleep medications. In a multivariable analysis adjusted for demographics, cardiovascular risk factors, and potential confounders, high risk for OSA was associated with an increased odds of AF compared to low risk for OSA (odds ratio = 1.27, 95% confidence interval = 1.13, 1.44). This association differed significantly only by race (P for interaction = .0003). For blacks, there was a significant 58% increase in odds of AF in participants at high risk versus low risk of OSA, compared to a nonsignificant 12% increase in odds in whites. We were limited by self-reported variables, inability to adjust for obesity, and the cross-sectional nature of our study.ConclusionsHigh risk of OSA is associated with prevalent AF among blacks but not whites.CommentaryA commentary on this article appears in this issue on page 1459.
| S-EPMC6134254 | biostudies-literature
Project description:The American Heart Association developed Life's Simple 7 (LS7) as a metric defining cardiovascular health. We investigated the association between LS7 and incident stroke in black and white Americans.The Reasons for Geographic And Racial Differences in Stroke (REGARDS) is a national population-based cohort of 30 239 blacks and whites, aged ?45 years, sampled from the US population from 2003 to 2007. Data were collected by telephone, self-administered questionnaires, and an in-home examination. Incident strokes were identified through biannual participant contact followed by adjudication of medical records. Levels of the LS7 components (blood pressure, cholesterol, glucose, body mass index, smoking, physical activity, and diet) were each coded as poor (0 point), intermediate (1 point), or ideal (2 points) health. An overall LS7 score was categorized as inadequate (0-4), average (5-9), or optimum (10-14) cardiovascular health.Among 22 914 subjects with LS7 data and no previous cardiovascular disease, there were 432 incident strokes over 4.9 years of follow-up. After adjusting for demographics, socioeconomic status, and region of residence, each better health category of the LS7 score was associated with a 25% lower risk of stroke (hazard ratios, 0.75; 95% confidence interval, 0.63-0.90). The association was similar for blacks and whites (interaction P value=0.55). A 1-point higher LS7 score was associated with an 8% lower risk of stroke (hazard ratios, 0.92; 95% confidence interval, 0.88-0.95).In both blacks and whites, better cardiovascular health, on the basis of the LS7 score, is associated with lower risk of stroke, and a small difference in scores was an important stroke determinant.
| S-EPMC3816734 | biostudies-literature