BackgroundGuidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease.Methods and ResultsTwo researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment–insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged <50 years, men, and people with type 2 diabetes, hypertension, dyslipidemia, or metabolic syndrome appeared to benefit more.ConclusionsThis meta-analysis showed that exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions.

Background Heart Failure (HF) is an important and growing public health problem in women. Risk factors for incident hospitalized HF with preserved (HFpEF) compared to reduced ejection fraction (HFrEF) in women, and differences by race/ethnicity, are not well characterized. Methods and Results We prospectively evaluated the risk factors for incident hospitalized HFpEF and HFrEF in a multi-racial cohort of 42,170 post-menopausal women followed for a mean of 13.2 years. Cox regression models with time dependent covariate adjustment were used to define risk factors for HFpEF and HFrEF. Differences by race/ethnicity regarding incidence rates, baseline risk factors and their population attributable risk percentage (PAR%) were analyzed. Risk factors for both HFpEF and HFrEF were as follows: older age, Caucasian race, diabetes, cigarette smoking, and hypertension. Obesity, history of coronary heart disease (other than myocardial infarction (MI)), anemia, atrial fibrillation and more than one co-morbidity, were associated with HFpEF but not HFrEF. History of MI was associated with HFrEF but not HFpEF. Obesity was found to be a more potent risk factor for African American women compared with Caucasian women for HFpEF (p for interaction= 0.007). For HFpEF, the PAR% was greatest for hypertension (40.9%) followed by obesity (25.8%), with the highest PAR% found in African Americans for these risk factors. Conclusions In this multi-racial cohort of postmenopausal women, obesity stands out as a significant risk factor for HFpEF, with the strongest association in African American women. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000611.

Poor housing conditions have been linked with worse health outcomes and infectious disease spread. Since the relationship of poor housing conditions with incidence and mortality of COVID-19 is unknown, we investigated the association between poor housing condition and COVID-19 incidence and mortality in US counties. MethodsWe conducted cross-sectional analysis of county-level data from the US Centers for Disease Control, US Census Bureau and John Hopkins Coronavirus Resource Center for 3135 US counties. The exposure of interest was percentage of households with poor housing conditions (one or greater of: overcrowding, high housing cost, incomplete kitchen facilities, or incomplete plumbing facilities). Outcomes were incidence rate ratios (IRR) and mortality rate ratios (MRR) of COVID-19 across US counties through 4/21/2020. Multilevel generalized linear modeling (with total population of each county as a denominator) was utilized to estimate relative risk of incidence and mortality related to poor housing conditions with adjustment for population density and county characteristics including demographics, income, education, prevalence of medical comorbidities, access to healthcare insurance and emergency rooms, and state-level COVID-19 test density. We report incidence rate ratios (IRRs) and mortality ratios (MRRs) for a 5% increase in prevalence in households with poor housing conditions. ResultsAcross 3135 US counties, the mean percentage of households with poor housing conditions was 14.2% (range 2.7% to 60.2%). On April 21 st , the mean (SD) number of cases and deaths of COVID-19 were 255.68 (2877.03) cases and 13.90 (272.22) deaths per county, respectively. In the adjusted models standardized by county population, with each 5% increase in percent households with poor housing conditions, there was a 50% higher risk of

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IMPORTANCEHemoglobin A 1c (HbA 1c ) reflects past glucose concentrations, but this relationship may differ between those with sickle cell trait (SCT) and those without it.OBJECTIVE To evaluate the association between SCT and HbA 1c for given levels of fasting or 2-hour glucose levels among African Americans. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study using data collected from 7938 participants in 2 community-based cohorts, the Coronary Artery Risk Development in Young Adults (CARDIA) study and the Jackson Heart Study (JHS).From the CARDIA study, 2637 patients contributed a maximum of 2 visits (2005)(2006)(2007)(2008)(2009)(2010)(2011); from the JHS, 5301 participants contributed a maximum of 3 visits (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013). All visits were scheduled at approximately 5-year intervals. Participants without SCT data, those without any concurrent HbA 1c and glucose measurements, and those with hemoglobin variants HbSS, HbCC, or HbAC were excluded. Analysis of the primary outcome was conducted using generalized estimating equations (GEE) to examine the association of SCT with HbA 1c levels, controlling for fasting or 2-hour glucose measures.EXPOSURES Presence of SCT. MAIN OUTCOMES AND MEASURESHemoglobin A 1c stratified by the presence or absence of SCT was the primary outcome measure. RESULTSThe analytic sample included 4620 participants (mean age, 52.3 [SD, 11.8] years; 2835 women [61.3%]; 367 [7.9%] with SCT) with 9062 concurrent measures of fasting glucose and HbA 1c levels. In unadjusted GEE analyses, for a given fasting glucose, HbA 1c values were statistically significantly lower in those with (5.72%) vs those without (6.01%) SCT (mean HbA 1c difference, −0.29%; 95% CI, −0.35% to −0.23%). Findings were similar in models adjusted for key risk factors and in analyses using 2001 concurrent measures of 2-hour glucose and HbA 1c concentration for those with SCT (mean, 5.35%) vs those without SCT (mean, 5.65%) for a mean HbA 1c difference of −0.30% (95% CI, −0.39% to −0.21%). The HbA 1c difference by SCT was greater at higher fasting (P = .02 for interaction) and 2-hour (P = .03) glucose concentrations. The prevalence of prediabetes and diabetes was statistically significantly lower among participants with SCT when defined using HbA 1c values (29.2% vs 48.6% for prediabetes and 3.8% vs 7.3% for diabetes in 572 observations from participants with SCT and 6877 observations from participants without SCT; P<.001 for both comparisons).CONCLUSIONS AND RELEVANCE Among African Americans from 2 large, well-established cohorts, participants with SCT had lower levels of HbA 1c at any given concentration of fasting or 2-hour glucose compared with participants without SCT. These findings suggest that HbA 1c may systematically underestimate past glycemia in black patients with SCT and may require further evaluation.

Activation of the renin-angiotensin-aldosterone system may play a significant role in the development of insulin resistance and diabetes in African Americans.

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