Howard, Barbara V.

Background The association of social isolation or lack of social network ties in older adults is unknown. This knowledge gap is important since the risk of heart failure (HF) and social isolation increase with age. The study examines whether social isolation is associated with incident HF in older women, and examines depressive symptoms as a potential mediator and age and race and ethnicity as effect modifiers. Methods and Results This study included 44 174 postmenopausal women of diverse race and ethnicity from the WHI (Women's Health Initiative) study who underwent annual assessment for HF adjudication from baseline enrollment (1993–1998) through 2018. We conducted a mediation analysis to examine depressive symptoms as a potential mediator and further examined effect modification by age and race and ethnicity. Incident HF requiring hospitalization was the main outcome. Social isolation was a composite variable based on marital/partner status, religious ties, and community ties. Depressive symptoms were assessed using CES‐D (Center for Epidemiology Studies‐Depression). Over a median follow‐up of 15.0 years, we analyzed data from 36 457 women, and 2364 (6.5%) incident HF cases occurred; 2510 (6.9%) participants were socially isolated. In multivariable analyses adjusted for sociodemographic, behavioral, clinical, and general health/functioning; socially isolated women had a higher risk of incident HF than nonisolated women (HR, 1.23; 95% CI, 1.08–1.41). Adding depressive symptoms in the model did not change this association (HR, 1.22; 95% CI, 1.07–1.40). Neither race and ethnicity nor age moderated the association between social isolation and incident HF. Conclusions Socially isolated older women are at increased risk for developing HF, independent of traditional HF risk factors. Registration URL: http://www.clinicaltrials.gov ; Unique identifier: NCT00000611.

AbstractIntroductionData on cigarette smoking prevalence among Alaska Native and American Indian (ANAI) people are limited to cross-sectional studies or specific subpopulations. Using data from the Alaska Education and Research toward Health (EARTH) Study 10-year follow-up, this study assessed patterns of smoking from baseline and factors associated with current use.Aims and MethodsEARTH Study urban south central ANAI participants (N = 376; 73% women) provided questionnaire data on smoking at baseline and 10-year follow-up. Multivariable-adjusted logistic regression assessed whether gender, cultural factors (Tribal identity, language spoken in the home), depressive symptoms (PHQ-9), baseline smoking status, and baseline cigarettes per day (CPD) were associated with current smoking at follow-up.ResultsCurrent smoking was 27% and 23% at baseline and follow-up, respectively. Of baseline smokers, 60% reported smoking at follow-up (77% men, 52% women). From multivariable-adjusted analyses, the odds of current smoking at follow-up were lower among women than men, those who never or formerly smoked versus currently smoked at baseline, and smoking <10 CPD compared with ≥10 CPD at baseline. PHQ-9 score or cultural variables were not associated with smoking at follow-up. Smoking fewer baseline CPD was associated with former smoking status (ie, quitting) at follow-up among women, but not men.ConclusionsOur project is among the first to longitudinally explore smoking within an ANAI cohort. While we observed persistent smoking during a 10-year period, there were important differences by gender and CPD in quitting. These differences may be important to enhance the reach and efficacy of cessation interventions for ANAI people.ImplicationsThis study contributes novel longitudinal information on cigarette smoking prevalence during a 10-year period among Alaska Native and American Indian (ANAI) people. Prior data on smoking prevalence among ANAI people are limited to cross-sectional studies or specific subpopulations. Our project is among the first to longitudinally explore smoking prevalence within an ANAI cohort. We observed persistent smoking during a 10-year period. The study also contributes information on differences by gender and cigarettes smoked per day in quitting. These findings have implications for enhancing the reach and efficacy of cessation interventions for ANAI people.

Background: Heart failure (HF), a leading cause of morbidity and mortality in women, continues to disproportionately affect African-American (AA) women compared to women of other races/ethnicities. In a large cohort of post-menopausal women, we investigated if AA women progress through HF stages and coronary heart disease (CHD) death more rapidly than Caucasian (Cau) or Hispanic/Latina (HL) women. Methods: We assessed the American College of Cardiology/American Heart Association (ACC/AHA) HF stage A upon enrollment into the Women’s Health Initiative (1993-1998) and the progression from Stage A to Stage C, Stage C to CHD death, up to the last date of follow-up (2010). Cox proportional hazard regressions models were used to assess disease progression risk. We adjusted for age, baseline comorbidities, duration of comorbidities, interval development of myocardial infarction, ejection fraction at HF diagnosis, socioeconomic factors, and sex specific variables. Results: At baseline, AA women were younger and had a higher percentage of Stage A HF (76%) than Cau (54%) and HL (55%) women. Overall, AA and HL women had significantly lower risk of progressing from Stage A to Stage C compared to Cau women [AA vs. Cau adjusted Hazard Ratio (HR) 0.77 (95% Confidence Interval (CI) 0.64 -0.93) p = 0.0055; HL vs. Cau HR 0.54 (95% CI 0.40 -0.71) p < 0.0001]. After stratifying by age groups(<65, 65-69, >70 years), AA women had a similar risk of progression from stage A to C compared to Cau women. When compared to Cau women, AA had an insignificant increased risk of progressing from Stage C to CHD death [adjusted HR 1.29 (95% CI 0.72 -2.32) p = 0.3883)]. Conclusions: Cau women were at higher risk for HF progression from Stage A to Stage C compared to HL women, but at similar risk as AA women. AA women had an insignificant but increased risk of progression from Stage C to CHD death compared to Cau women.

Background and Purpose— American Indians have high rates of stroke. Improved risk stratification could enhance prevention, but the ability of biochemical and echocardiographic markers of preclinical disease to improve stroke prediction is not well-defined. Methods— We evaluated such markers as predictors of ischemic stroke in a community-based cohort of American Indians without prevalent cardiovascular or renal disease. Laboratory markers included C-reactive protein, fibrinogen, urine albumin-to-creatinine ratio, and glycohemoglobin (HbA1c), whereas echocardiographic parameters comprised left atrial diameter, left ventricular mass, mitral annular calcification, and the ratio of early to late mitral diastolic velocities. Predictive performance was judged by indices of discrimination, reclassification, and calibration. Results— After adjustment for standard risk factors, only HbA1c, albuminuria, and left atrial diameter were significantly associated with first ischemic stroke. Addition of HbA1c, although not urine albumin-to-creatinine ratio, to a basic clinical model significantly improved the C-statistic (0.714 versus 0.695; P =0.044), whereas left atrial diameter modestly enhanced integrated discrimination improvement (0.90%; P =0.004), but not the C-statistic (0.701; P =0.528). When combined with HbA1c, left atrial diameter further increased integrated discrimination improvement (1.81%; P <0.001) but not the C-statistic (0.716). No marker achieved significant net reclassification improvement. Conclusions— In this cohort at high cardiometabolic risk, HbA1c emerged as the foremost predictor of ischemic stroke when added to traditional risk factors, affording substantially improved discrimination, with a more modest contribution for left atrial diameter. These findings bolster the role of HbA1c in cardiovascular risk assessment among persons with glycometabolic disorders and provide impetus for further study of the incremental value of echocardiography in high-risk populations.

Background— There are few published data on the incidence of fatal and nonfatal stroke in American Indians. The aims of this observational study were to determine the incidence of stroke and to elucidate stroke risk factors among American Indians. Methods and Results— This report is based on 4549 participants aged 45 to 74 years at enrollment in the Strong Heart Study, the largest longitudinal, population-based study of cardiovascular disease and its risk factors in a diverse group of American Indians. At baseline examination in 1989 to 1992, 42 participants (age- and sex-adjusted prevalence proportion 1132/100 000, adjusted to the age and sex distribution of the US adult population in 1990) had prevalent stroke. Through December 2004, 306 (6.8%) of 4507 participants without prior stroke suffered a first stroke at a mean age of 66.5 years. The age- and sex-adjusted incidence was 679/100 000 person-years. Nonhemorrhagic cerebral infarction occurred in 86% of participants with incident strokes; 14% had hemorrhagic stroke. The overall age-adjusted 30-day case-fatality rate from first stroke was 18%, with a 1-year case-fatality rate of 32%. Age, diastolic blood pressure, fasting glucose, hemoglobin A 1c, smoking, albuminuria, hypertension, prehypertension, and diabetes mellitus were risk factors for incident stroke. Conclusions— Compared with US white and black populations, American Indians have a higher incidence of stroke. The case-fatality rate for first stroke is also higher in American Indians than in the US white or black population in the same age range. Our findings suggest that blood pressure and glucose control and smoking avoidance may be important avenues for stroke prevention in this population.