Antihypertensive medications and diastolic dysfunction progression in an African American population

Although different classes and combinations of antihypertensive agents have demonstrated effectiveness in management of hypertension, the choice of drugs in African American patients is often different. To purpose of this study is to determine whether there is an association between class of antihypertensive medication and diastolic dysfunction progression in an African American population. Methods: A retrospective cohort study of African American patients with echocardiograms demonstrating diastolic dysfunction from an echocardiogram database for an academic medical centre. The main outcome measures were change in diastolic function grade as a function of time and associated risk factors. Twelve risk factors evaluated were considered in the analysis: age, body mass index (BMI), Diabetes Mellitus, tobacco use, use of Beta Blockers, Angiotensin Converting Enzymes (ACE) inhibitors, Angiotensin Receptor Blockers, Calcium Channel Blockers, diuretics, left ventricular hypertrophy, and left atrial size. Results: During the 6-year retrospective cohort study period, there were 96 patients in the database with 2 or more echocardiograms demonstrating diastolic dysfunction; representing 302 echocardiograms. The mean time between echocardiograms was 2.6 years. The mean age was 64.2 (±10.1) with 78 % female and a mean BMI 31.2 (±7.4). The majority of subjects had Grade I diastolic dysfunction at the initial examination (N = 87 (90.6%)). Approximately 22.9% (n = 22) of the study cohort demonstrated diastolic dysfunction progression. In univariate risk factor analysis, age was the only risk factor associated with progression, as younger patients were more likely to progress (p < 0.05). In multivariate analysis use of calcium channel blockers was protective against diastolic dysfunction progression (p < 0.05), with CCB users having an odds ratio of 0.28 (0.09, 0.90) relative to non-users. Conclusions: Our study showed use of Calcium channel blockers to have a protective effect against progression of diastolic dysfunction in this African American cohort. Identifying factors that can mediate disease progression is particularly important for hypertensive African Americans, who have significantly higher rates of developing disease complications such as diastolic heart failure

Urban native vegetation remnants support more diverse native bee communities than residential gardens in Australia's southwest biodiversity hotspot

Native bees are declining in many regions, often associated with loss of natural habitat. Urbanisation replaces natural vegetation with a highly-modified landscape, where residential gardens are a major component of urban greenspace. While many cities retain native vegetation remnants within the urban matrix, these are often small, isolated and degraded. However, there is little empirical evidence on the capacity of residential gardens to provide equivalent or beneficial habitat for native bees, and which local and landscape factors influence bee assemblages. We surveyed bee assemblages in the southwest Australian biodiversity hotspot at seven residential gardens and seven bushland remnants over two years. We recorded 153 species/morphospecies of native bees. Native bees were more abundant in bushland remnants than residential gardens. Abundance of the introduced honeybee Apis mellifera was generally high, and did not differ between habitats. Bushland remnants hosted more species, and rare and unique species, than did residential gardens. Native bee body-size and nesting guilds varied in their response to habitat type. Native bee abundance and richness increased with abundance of native plant species, but decreased with total flower species richness. Native bee species richness was negatively impacted by urbanisation (built space and isolation from bushland reserves). There were no significant relationships between honeybee abundance and local and landscape factors. Our study demonstrates that while residential gardens can host native bees, urban bushland remnants harbour a more comprehensive suite of species and are key for the conservation of native bee populations