New Insights on the Risk for Cardiovascular Disease in African Americans: The Role of Added Sugars

African Americans are at increased risk for cardiovascular and metabolic diseases, including obesity, high BP, diabetes, CKD, myocardial infarction, and stroke. Here we summarize the current risks and provide an overview of the underlying risk factors that may account for these associations. By reviewing the relationship between cardiovascular and renal diseases and the African-American population during the early 20th century, the historic and recent associations of African heritage with cardiovascular disease, and modern population genetics, it is possible to assemble strong hypotheses for the primary underlying mechanisms driving the increased frequency of disease in African Americans. Our studies suggest that underlying genetic mechanisms may be responsible for the increased frequency of high BP and kidney disease in African Americans, with particular emphasis on the role of APOL1 polymorphisms in causing kidney disease. In contrast, the Western diet, particularly the relatively high intake of fructose-containing sugars and sweetened beverages, appears to be the dominant force driving the increased risk of diabetes, obesity, and downstream complications. Given that intake of added sugars is a remediable risk factor, we recommend clinical trials to examine the reduction of sweetened beverages as a primary means for reducing cardiovascular risk in African Americans.     

Long-term perspective on wildfires in the western USA

Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in the American West and compare this record to independent fire-history data from historical records and fire scars. There has been a slight decline in burning over the past 3,000 y, with the lowest levels attained during the 20th century and during the Little Ice Age (LIA, ca. 1400–1700 CE [Common Era]). Prominent peaks in forest fires occurred during the Medieval Climate Anomaly (ca. 950–1250 CE) and during the 1800s. Analysis of climate reconstructions beginning from 500 CE and population data show that temperature and drought predict changes in biomass burning up to the late 1800s CE. Since the late 1800s , human activities and the ecological effects of recent high fire activity caused a large, abrupt decline in burning similar to the LIA fire decline. Consequently, there is now a forest “fire deficit” in the western United States attributable to the combined effects of human activities, ecological, and climate changes. Large fires in the late 20th and 21st century fires have begun to address the fire deficit, but it is continuing to grow.Forest fires in the western United States have been increasing in size (1) and possibly severity (2) for several decades. The increase in fire has prompted multiple investigations into both the causes (3, 4) and consequences of this shift for communities, ecosystems, and climate (5). Climate changes and human activities have both contributed to the observed changes in fire, but understanding the nature and magnitude of these impacts has been challenging first because there is substantial ecological heterogeneity and variability in terms of vegetation, soils, hydrology, topography, and other factors that affect fire regimes across the western United States, and second because most fire-history data come from recent decades and centuries when climate and human activities have both undergone rapid and unique transformations. As a result, studies tend to focus either on local ecological and anthropogenic factors that drive fire at fine scales (6, 7), or on climatic influences at broad scales (3, 4). Furthermore, the limited temporal scope of many fire-history studies does not provide adequate context for examining the joint impacts of climate and human activities on broad-scale, long-term fire regime changes. In addition, projections of future climate change and its ecosystem impacts place the expected changes well outside the range of variations in the past few centuries. Thus, coupling multi-decadal-to millennial-scale data on fire, climate changes, and human activities can reveal linkages among these components that are often missed in studies restricted to finer scales or fewer factors.Here we use sedimentary charcoal accumulation rates to construct variations in levels of burning for the past 3,000 y in the western United States (i.e., the West) and compare this record to independent fire-history data from historical records and fire scars. The long charcoal records enable identification of baseline shifts in fire regimes that cannot be detected with shorter records and allow us to view the nature and extent of human impacts on fire in a long-term context; this approach helps to distill the dominant patterns in fire activity across the West, but it does not reveal the important differences in fire controls and effects among vegetation types, ecoregions, or elevation gradients that exist at finer spatial scales (e.g., ref. 8).Our focus here is specifically on multi-decadal-to-centennial-scale variations in fire over the past few millennia and on the West as a whole. Climatic variations on this time scale are characterized by extended periods of persistent anomalies, such as the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) (9, 10), which feature broad-scale (i.e., across the whole of the western United States) anomalies of both surface climates and atmospheric circulation (10). We use temperature (10), drought (9), and population (11) data to compare with the fire-history reconstructions. We also construct a simple statistical model for predicting biomass burning from the temperature and drought data. Our analysis builds on the rich historical narratives of fire in the western United States (12) as well as on many more detailed but shorter broad-scale studies (4, 13, 14). The results illustrate the importance of climate in explaining the variations in fire over time, and show the development of a 20th century “fire deficit” related to the combined effects of fire exclusion, land-use change, and ongoing climate change.     

Low rate of active treatment of patients with hilar cholangiocarcinoma

Introduction

The results of surgical resection and palliative chemotherapy use in hilar cholangiocarcinoma (HC) have been well publicised but the proportion of patients able to undergo these treatments and the comparative outcomes in a population of patients with HC are less well known.

Methods

Patients with HC were identified by review of all patients undergoing percutaneous cholangiography over a nine-year period (2002–2010) in a tertiary facility. The treatment undertaken and outcomes were recorded.

Results

Overall, 68 patients were identified (37 female) with a median age of 70 years. Forty-five (66%) were treated solely by insertion of a metal stent (median survival 4.73 months) and nine (13%) also received palliative chemotherapy (median survival 13.7 months). Persisting jaundice after stent insertion was noted in 18 of 35 patients (51%) tested within one month of death. Fourteen patients (21%) underwent surgical resection (median survival 20.2 months).

Conclusions

Patients undergoing surgical resection had significantly longer survival than those receiving only a palliative stent but not compared with those also receiving palliative chemotherapy, with short-term follow-up. Only a third of patients, however, receive active treatment (surgery or chemotherapy) and improvements in long-term biliary palliation are needed.