Dietary nitrate does not modify blood pressure and cardiac output at rest and during exercise in older adults: a randomised cross-over study

Dietary nitrate (NO₃^-) supplementation has been associated with improved vascular and metabolic health. We conducted a double-blind, cross-over, placebo-controlled RCT to investigate the effects of 7-d consumption of beetroot juice compared with placebo on (1) blood pressure (BP) measured in resting conditions and during exercise, (2) cardiac and peripheral vascular function and (3) biomarkers of inflammation, oxidative stress and endothelial integrity. Twenty non-smoking healthy participants aged 60–75 years and BMI 20.0–29.9 kg/m² were recruited. Measurement was conducted before and after each 7-d intervention period. Consumption of NO₃^- had no effect on resting systolic and diastolic BP. NO₃^- consumption did not improve indexes of central and peripheral cardiac function responses during cardiopulmonary exercise testing. Dietary NO₃^- supplementation did not modify biomarkers of inflammation, oxidative stress and endothelial integrity. This study does not support the short-term benefits of dietary NO₃^- supplementation on physiological and biochemical markers of vascular health in older healthy adults.

Reasons for participation and non-participation in a randomized controlled trial: postal questionnaire surveys of women eligible for TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears)

Background Better understanding of motivators for, and barriers to, participation in randomized controlled trials (RCTs) in different study populations and settings has the potential to improve participation of historically under-represented groups (eg, women) in future trials.

Purpose To investigate reasons why women agreed, or declined, to participate in a RCT.

Methods In two postal questionnaire-based studies, we investigated women's reasons for participation or non-participation in TOMBOLA, a RCT comparing management policies for low-grade cervical abnormalities. Four-hundred and ninety-two TOMBOLA participants (response rate 56%) completed questionnaires on reasons for participation. One-hundred and thiry-seven women (38%) who declined TOMBOLA participation completed questionnaires on reasons for this.

Results Eighty percent of women reported that one of their reasons for attending their TOMBOLA recruitment appointment was worries about their smear result. Ninety-four percent participated in the RCT because it was a worthwhile contribution to the cervical screening programme and other women; for 70% this was the most important reason. These proportions did not vary by socio-demographic factors. Thirty-two percent thought participation would result in better care. The most common reason for non-participation was preference for follow-up from the woman's GP. Logistical issues (eg, inconvenient appointments, travel time, arranging time off work or child-care) were commonly cited. Fourteen percent were too frightened to participate; this was unrelated to the grade of the recruitment smear. Limitations Response rates were not high, but there was little evidence of response bias. Structured questionnaires were used.

Conclusions Future research should address how best to deliver information to ensure different social groups appreciate potential benefits of RCT participation and provide reassurance regarding fears about participation. Simple strategies (eg, appealing to the altruism of potential participants or offering flexible recruitment clinic locations and times) might enhance RCT recruitment rates. This in turn would ensure best use of research resources thus bringing the greatest benefits to participants and the population.

Effect of community-based newborn care on cause-specific neonatal mortality in Sylhet district, Bangladesh: findings of a cluster-randomized controlled trial

OBJECTIVES

Community-based maternal and newborn intervention packages have been shown to reduce neonatal mortality in resource-constrained settings. This analysis uses data from a large community-based cluster-randomized trial to assess the impact of a community-based package on cause-specific neonatal mortality and draws programmatic and policy implications. In addition, the study shows that cause-specific mortality estimates vary substantially based on the hierarchy used in assigning cause of death, which also has important implications for program planning. Therefore, understanding the methods of assigning causes of deaths is important, as is the development of new methodologies that account for multiple causes of death. The objective of this study was to estimate the effect of two service delivery strategies (home care and community care) for a community-based package of maternal and neonatal health interventions on cause-specific neonatal mortality rates in a rural district of Bangladesh.

STUDY DESIGN

Within the general community of the Sylhet district in rural northeast Bangladesh. Pregnancy histories were collected from a sample of women in the study area during the year preceding the study (2002) and from all women who reported a pregnancy outcome during the intervention in years 2004 to 2005. All families that reported a neonatal death during these time periods were asked to complete a verbal autopsy interview. Expert algorithms with two different hierarchies were used to assign causes of neonatal death, varying in placement of the preterm/low birth weight category within the hierarchy (either third or last). The main outcome measure was cause-specific neonatal mortality.

RESULT

Deaths because of serious infections in the home-care arm declined from 13.6 deaths per 1000 live births during the baseline period to 7.2 during the intervention period according to the first hierarchy (preterm placed third) and from 23.6 to 10.6 according to the second hierarchy (preterm placed last).

CONCLUSION

This study confirms the high burden of neonatal deaths because of infection in low resource rural settings like Bangladesh, where most births occur at home in the absence of skilled birth attendance and care seeking for newborn illnesses is low. The study demonstrates that a package of community-based neonatal health interventions, focusing primarily on infection prevention and management, can substantially reduce infection-related neonatal mortality.