The association of sleep with metabolic pathways and metabolites: evidence from the Dietary Approaches to Stop Hypertension (DASH)-sodium feeding study.

INTRODUCTION: Sleep is increasingly being viewed as an issue of public health concern, yet few epidemiologic studies have explored associations between sleep habits and metabolomic profile. OBJECTIVES: To assess the association between sleep and blood metabolites. METHODS: We examined the association between sleep and 891 fasting plasma metabolites in a subgroup of 106 participants from the Dietary Approaches to Stop Hypertension (DASH)-Sodium feeding trial (1997-1999). We produced two sleep variables to analyze, sleep midpoint (median time between bedtime and waketime) and sleep duration, as well as bedtime and wake time. Metabolites were measured using liquid and gas chromatography, coupled with mass spectrometry. We assessed associations between sleep variables and log transformed metabolites using linear mixed-effects models. We combined the resulting p-values using Fisher's method to calculate associations between sleep and 38 metabolic pathways. RESULTS: Sixteen pathways were associated (p < 0.05) with midpoint. Only the γ-glutamyl amino acid metabolism pathway reached Bonferroni-corrected threshold (0.0013). Eighty-three metabolites were associated with midpoint (FDR < 0.20). Similar associations were found for wake time. Neither bed time nor duration were strongly associated. The top metabolites (pathways given in brackets) associated with sleep were erythrulose (advanced glycation end-product) (positive association) and several γ-glutamyl pathway metabolites, including CMPF (fatty acid, dicarboxylate), isovalerate (valine, leucine and isoleucine and fatty acid metabolism) and HWESASXX (polypeptide) (inverse association). CONCLUSION: Within our study, several metabolites that have previously been linked to inflammation and oxidative stress (processes involved in diseases such as cardiovascular disease and cancer) were found to be associated with sleep.

EMS medical direction and prehospital practices for acute cardiovascular events.

OBJECTIVE: The purpose of this analysis was to determine whether there is an association between type of emergency medical services (EMS) medical direction and local EMS agency practices and characteristics specifically related to emergency response for acute cardiovascular events. METHODS: We surveyed 1,292 EMS agencies in nine states. For each cardiovascular prehospital procedure or practice, we compared the proportion of agencies that employed paid (full- or part-time) medical directors with the proportion of agencies that employed volunteer medical directors. We also compared the proportion of EMS agencies who reported direct interaction between emergency medical technicians (EMTs) and their medical director within the previous four weeks with the proportion of agencies who reported no direct interaction. Chi-square tests were used to assess statistical differences in proportion of agencies with a specific procedure by medical director employment status and medical director interaction. We repeated these comparisons using t-tests to evaluate mean differences in call volume. RESULTS: The EMS agencies with prehospital cardiovascular response policies were more likely to report employment of a paid medical director and less likely to report employment of a volunteer medical director. Similarly, agencies with prehospital cardiovascular response practices were more likely to report recent medical director interaction and less likely to report absence of recent medical director interaction. Mean call volumes for chest pain, cardiac arrest, and stroke were higher among agencies having paid medical directors (compared with agencies having volunteer medical directors) and agencies having recent medical director interaction (compared with agencies not having recent medical director interaction). CONCLUSIONS: Our study demonstrated that EMS agencies with a paid medical director and agencies with medical director interaction with EMTs in the previous four weeks were more likely to have prehospital cardiovascular procedures in place. Given the strong relationship that both employment status and direct interaction have with the presence of these practices, agencies with limited resources to provide a paid medical director or a medical director that can be actively involved with EMTs should be supported through partnerships and other interventions to ensure that they receive the necessary levels of medical director oversight.

Factors associated with emergency medical services scope of practice for acute cardiovascular events.

OBJECTIVES: To examine prehospital emergency medical services (EMS) scope of practice for acute cardiovascular events and characteristics that may affect scope of practice; and to describe variations in EMS scope of practice for these events and the characteristics associated with that variability. METHODS: In 2008, we conducted a telephone survey of 1,939 eligible EMS providers in nine states to measure EMS agency characteristics, medical director involvement, and 18 interventions authorized for prehospital care of acute cardiovascular events by three levels of emergency medical technician (EMT) personnel. RESULTS: A total of 1,292 providers responded to the survey, for a response rate of 67%. EMS scope of practice interventions varied by EMT personnel level, with the proportion of authorized interventions increasing as expected from EMT-Basic to EMT-Paramedic. Seven of eight statistically significant associations indicated that EMS agencies in urban settings were less likely to authorize interventions (odds ratios <0.7) for any level of EMS personnel. Based on the subset of six statistically significant associations, fire department-based EMS agencies were two to three times more likely to authorize interventions for EMT-Intermediate personnel. Volunteer EMS agencies were more than twice as likely as nonvolunteer agencies to authorize interventions for EMT-Basic and EMT-Intermediate personnel but were less likely to authorize any one of the 11 interventions for EMT-Paramedics. Greater medical director involvement was associated with greater likelihood of authorization of seven of the 18 interventions for EMT-Basic and EMT-Paramedic personnel but had no association with EMT-Intermediate personnel. CONCLUSIONS: We noted statistically significant variations in scope of practice by rural vs. urban setting, medical director involvement, and type of EMS service (fire department-based/non-fire department-based; volunteer/paid). These variations highlight local differences in the composition and capacity of EMS providers and offer important information for the transition towards the implementation of a national scope of practice model.

An emergency medical services toolkit for improving systems of care for stroke in North Carolina.

The Centers for Disease Control and Prevention is partnering with the National Association of Chronic Disease Directors and the North Carolina Office of EMS to design, develop, and implement an emergency medical services (EMS) performance improvement toolkit to evaluate opportunities to improve the emergency identification and treatment of acute stroke. The EMS Acute Stroke Care Toolkit is being developed, tested, and implemented in all 100 counties in the state by the EMS Performance Improvement Center, the agency that provides technical assistance for EMS in North Carolina. The toolkit helps each EMS system in defining, measuring, and analyzing their system of care and promotes collaboration through public education, regional stroke planning with hospitals, EMS service configuration, EMS staffing patterns, EMS education, and timely care delivery. We outline the issues surrounding acute stroke care, the role of emergency medical systems in stroke care, and the components of the EMS Acute Stroke Care Toolkit designed to improve EMS systems and outcomes for stroke patients.