Increasing Children's physical Activity by Policy (CAP) in preschools within the Stockholm region: study protocol for a pragmatic cluster-randomized controlled trial.

BACKGROUND: Systematic reviews suggest that preschool environmental/organizational changes may be effective in increasing physical activity (PA) levels of preschool children, but evidence is scarce regarding feasible, effective, and equitable interventions that can be scaled up. Specifically, it is essential to understand whether introducing a multicomponent organizational change in terms of policy in the preschool context may be beneficial for children's PA levels and concomitant health outcomes. To bridge this knowledge gap, our main aim is to examine the feasibility and effectiveness of a policy package in increasing PA levels in preschool children, using a large-scale pragmatic cluster-randomized controlled trial. METHODS: This proposed study is a pragmatic cluster-randomized controlled trial with two conditions (intervention and control with a 1:1 ratio) with preschools as clusters and the unit of randomization. We aim to recruit approximately 4000 3-5-year-old children from 90 preschools and retain more than 2800 children from 85 preschools to provide adequate statistical power for the analyses. The intervention to implement is a co-created, multicomponent policy package running for 6 months in preschools randomized to intervention. Change in accelerometer measured PA levels in children between intervention and control from pre- and post-intervention will be the primary outcome of the study, while secondary outcomes include health outcomes such as musculoskeletal fitness, psychosocial functioning, and absence due to illness in children among others. Implementation will be studied carefully using both quantitative (dose, fidelity) and qualitative (interview) methodologies. The change in primary and secondary outcomes, from pre- to post-intervention, will be analyzed with linear mixed-effect models (to allow both fixed and random effects) nested on a preschool level. DISCUSSION: This is a large-scale co-creation project involving the City of Stockholm, childcare stakeholders, preschool staff, and the research group with the potential to influence more than 30,000 preschool children within the Stockholm area. The study will add reliable evidence for the implementation of PA policies at the organizational level of preschools and clarify its potential effect on objectively measured PA and health markers in children. TRIAL REGISTRATION: ClinicalTrials.gov NCT04569578 . Prospectively registered on September 20, 2020.

Association of Energy and Macronutrients Intake with S-Klotho Plasma Levels in Middle-Aged Sedentary Adults: A Cross-Sectional Study.

BACKGROUND: The ageing process can be influenced by energy intake and different macronutrients within the diet. The soluble form of the α-Klotho gene (called S-Klotho) is widely considered as a powerful anti-ageing biomarker. OBJECTIVE: To analyze the association of energy, dietary energy density and macronutrient intake with S-Klotho plasma levels in middle-aged sedentary adults. METHODS: A total of 72 (52.8% women) middle-aged sedentary adults (53.7 ± 5.2 years old) participated in the study. Energy and macronutrients intake (i.e. fat, carbohydrate and protein) were assessed using three non-consecutive 24-h recalls. S-Klotho plasma levels were measured in the Ethylenediaminetetraacetic acid (EDTA) plasma using a solid-phase sandwich enzyme-linked immunosorbent assay. RESULTS: No association was observed between energy, dietary energy density or macronutrient intake and S-Klotho plasma levels in men (all P≥ 0.1). We found an inverse association between energy, protein and carbohydrate intake with S-Klotho plasma levels in women (all P≤0.043), which disappeared after controlling for age, lean mass index and sedentary time. An inverse association was observed between dietary energy density and S-Klotho plasma levels in women after controlling for covariates (all P≤0.05). CONCLUSION: In summary, the present study showed an inverse association of dietary energy density with S-Klotho plasma levels in middle-aged women. In addition, our data suggest that the associations between energy and macronutrient intake could be highly dependent on lean mass and sedentary time.

Interprofessional simulation-based team-training and self-efficacy in emergency medicine situations.

Teamwork quality has been shown to influence patient safety, and simulation-based team-training (SBTT) is an effective means to increase this quality. However, long-term effects are rarely studied. This study aims to investigate the long-term effects of interprofessional SBTT in emergency medicine in terms of global confidence, self-efficacy in interprofessional communication and in emergency medicine situations. Newly graduated doctors, nurses, auxiliary nurses, and medical and nursing students participated. Four emergency medicine scenarios focused on teamwork according to the A-B-C-D-E-strategy. All participants increased their global confidence from 5.3 (CI 4.9-5.8) before to 6.8 (CI 6.4-7.2; p < .0001) after SBTT. Confidence in interprofessional communication increased from 5.3 (CI 4.9-5.8) to 7.0 (CI 6.6-7.4; p < .0001). Students had the greatest gain. The self-efficacy following the A-B-C-D-E strategy increased from 4.9 (CI 4.4-5.3) to 6.6 (CI 6.2-7.0). Again, students had the steepest increase. Newly graduated doctors achieved a superior increase in global confidence as compared to nurses and auxiliary nurses (p < .0001). Their propensity to recommend SBTT to colleagues was 9.9 (CI 9.8-10.0). The positive effects were sustained over a six-month period, indicating that interprofessional SBTT had a positive impact on competence development, and a potential to contribute to increased team quality in emergency medicine care.

Cardiovascular problems associated with IVF therapy.

We are now in the beginning of the fifth decade of in vitro fertilization (IVF) with more than ten million children born and an annual growth rate of half a million. It was recently found that there is a sevenfold increase in the incidence of pulmonary embolism (PE) during the first trimester of an IVF pregnancy as compared to spontaneous pregnancy. PE is a major cause of maternal mortality, and it is thus of outmost importance to understand the pathophysiological mechanism. The oestrogen surge during the ovarian stimulation has been hypothesized to be the initiating pathophysiological event. A support of this is a current report showing that embryo transfer performed directly after ovarian stimulation increased the risk of PE more than eightfold, whereas no such increase was noted after delayed embryo transfer. This increased risk coincides with a persisting increased oestrogen level. Further reported cardiovascular problems are arterial thromboses, pre-eclampsia and gestational hypertension. Global haemostasis tests change in the direction of increased coagulability, but mostly within normal limits. Cell-bound haemostasis and in particular platelet activation are less studied. However, a major increase in the number of microvesicles (MVs) and markers indicating platelet activation was reported during ovarian stimulation. We now need longitudinal data concerning haemostatic variables that extends into the first trimester. A major research focus should be to identify biomarkers that could be used already before instigation of IVF. Another way to avoid risk could be to delay embryo transfer by adapting a freeze-all strategy.

Fat and fat-free mass of healthy Swedish children show tracking during early life, but there are differences.

AIM: Obesity may start early in life. We investigated relationships between size and body composition variables in infancy and at 4 years of age using valid estimates of body composition. The results were compared to those obtained when body mass index (BMI) was used to estimate body fatness at 4 years. METHODS: Using air displacement plethysmography, size, fat mass and fat-free mass were studied, between 2007 and 2015, in 253 full-term healthy Swedish children at 1 week, 12 weeks and 4 years of age. RESULTS: Positive associations between variables in infancy and at 4 years were found at 1 and 12 weeks for weight, height, BMI, fat-free mass and fat-free mass index (p ≤ 0.002) and for fat mass, per cent body fat and fat mass index (p ≤ 0.04) at 12 weeks. Fat mass gained during infancy correlated positively (p ≤ 0.031) with per cent fat mass, fat mass index and BMI, all at 4 years. In girls, gains in fat-free mass during infancy correlated with BMI (p = 0.0005) at 4 years. CONCLUSION: The results provide information regarding body composition trajectories during early life and demonstrate limitations of BMI as a proxy for body fatness when relating early weight gain to variables, relevant for later obesity risk.

Physical fitness and psychological health in overweight/obese children: A cross-sectional study from the ActiveBrains project.

OBJECTIVES: To examine the associations of physical fitness (i.e. cardiorespiratory fitness, muscular strength, and speed/agility) with psychological distress and psychological well-being in overweight/obese pre-adolescent children. DESIGN: 110 overweight/obese children (10.0±1.1years old, 61 boys) from the ActiveBrains project (http://profith.ugr.es/activebrains) participated in this cross-sectional study. METHODS: Physical fitness was evaluated by the ALPHA battery test. Cardiorespiratory fitness was additionally evaluated by a maximal incremental treadmill. Stress was assessed by the Children's Daily Stress Inventory, anxiety by the State-Trait Anxiety Inventory, depression by the Children Depression Inventory, positive affect and negative affect by the Positive and Negative Affect Scale for Children, happiness by the Subjective Happiness Scale, optimism by the Life Orientation Test, and self-esteem by the Rosenberg Self-Esteem questionnaire. Linear regression adjusted for sex and peak height velocity was used to examine associations. RESULTS: Absolute upper-body muscular strength was negatively associated with stress and negative affect (ß=-0.246, p=0.047; ß=-0.329, p=0.010, respectively). Furthermore, absolute lower-body muscular strength was negatively associated with negative affect (ß=-0.301, p=0.029). Cardiorespiratory fitness, expressed by the last completed lap, and relative upper-body muscular strength were positively associated with optimism (ß=0.220, p=0.042; ß=0.240, p=0.017, respectively). Finally, absolute upper-body muscular strength was positively associated with self-esteem (ß=0.362, p=0.003) independently of sex and weight status (p for interactions >0.3), and absolute lower-body muscular strength was also positively associated with self-esteem (ß=0.352, p=0.008). CONCLUSIONS: Muscular strength was associated with psychological distress (i.e. stress and negative affect) and psychological well-being (i.e. optimism and self-esteem) as well as cardiorespiratory fitness was associated with optimism. Therefore, increased levels of physical fitness, specifically muscular strength, could have significant benefits for overweight/obese children psychological health.

Correlates of ideal cardiovascular health in European adolescents: The HELENA study.

BACKGROUND AND AIMS: The ideal cardiovascular health (iCVH) construct consists of 4 health behaviors (smoking status, body mass index, physical activity and diet) and 3 health factors (total cholesterol, blood pressure and fasting glucose). A greater number of iCVH components in adolescence are related to better cardiovascular health, but little is known about the correlates of iCVH in adolescents. Thus, the aim of the study was to examine correlates of iCVH in European adolescents. METHODS AND RESULTS: The study comprised 637 European adolescents with complete iCVH data. Participants were part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional, multicenter study conducted in 9 different European countries. Correlates investigated were sex and age, family affluence scale, maternal education, geographic location, sleep time, television viewing, duration of pregnancy, birth weight and breastfeeding. Younger adolescents, those whose mothers had medium/high education or those who watched television less than 2 h per day had a greater number of iCVH components compared to those who were older, had a mother with low education or watched television 2 h or more daily (P ≤ 0.01). CONCLUSION: Since in our study older adolescents had worse iCVH than younger adolescents, early promotion of cardiovascular health may be important. Future studies may also investigate the usefulness of limiting television viewing to promote iCVH. Finally, since adolescents of mothers with low education had poorer iCVH, it may be of special interest to tailor public health promotion to adolescents from families with low socioeconomic status.

Longitudinal assessment of body composition in healthy Swedish children from 1 week until 4 years of age.

BACKGROUND/OBJECTIVES: Knowledge of longitudinal body composition development is required to identify the mechanisms behind childhood overweight and obesity and to prevent these conditions. However, accurate data on this development in early childhood are lacking. Our aim was to describe the longitudinal body composition development in healthy young Swedish children. SUBJECTS/METHODS: Body size and composition were assessed in 26 children using air-displacement plethysmography (1 and 12 weeks and 4.4 years of age) and isotope dilution (1.5 and 3 years of age) and compared with available reference data. RESULTS: Body fat (%) for boys (n=16) was 12.8±3.9 (1 week), 25.6±4.8 (12 weeks), 28.2±3.8 (1.5 years), 27.3±5.1 (3 years) and 26.1±3.5 (4.4 years). For girls (n=10) these values were 15.3±2.9, 25.7±3.9, 27.9±3.3, 26.3±7.2 and 26.0±5.3, respectively. These values were above the Fomon reference values at 1.5 years of age and later and higher than the Butte reference (P<0.05) for boys at 1.5 years of age. At all ages the coefficients of variation were higher for body fat (%) (12-30%) than for BMI (4-11%). CONCLUSIONS: At 4 years of age our children had more body fat than indicated by reference data. This high level may have already been established at 1.5 years of age but our small sample and the lack of appropriate reference data limit the possibility of drawing firm conclusions. Our results demonstrate the limitations of BMI when investigating overweight and obesity in early life and highlight the need for appropriate reference body composition data in infants and young children.European Journal of Clinical Nutrition advance online publication, 23 August 2017; doi:10.1038/ejcn.2017.125.

Evaluation of the wrist-worn ActiGraph wGT3x-BT for estimating activity energy expenditure in preschool children.

BACKGROUND/OBJECTIVES: Easy-to-use and accurate methods to assess free-living activity energy expenditure (AEE) in preschool children are required. The aims of this study in healthy preschool children were to (a) evaluate the ability of the wrist-worn ActiGraph wGT3x-BT to predict free-living AEE and (b) assess wear compliance using a 7-day, 24-h protocol. SUBJECTS/METHODS: Participants were 40 Swedish children (5.5±0.2 years) in the Mobile-based intervention intended to stop obesity in preschoolers (MINISTOP) obesity prevention trial. Total energy expenditure (TEE) was assessed using the doubly labeled water method during 14 days. AEE was calculated as (TEEx0.9) minus predicted basal metabolic rate. The ActiGraph accelerometer was worn on the wrist for 7 days and outputs used were mean of the daily and awake filtered vector magnitude (mean VM total and mean VM waking). RESULTS: The ActiGraph was worn for 7 (n=34, 85%), 6 (n=4, 10%), 5 (n=1, 2.5%) and 4 (n=1, 2.5%) days (a valid day was ⩾600 awake minutes). Alone, mean VM total and mean VM waking were able to explain 14% (P=0.009) and 24% (P=0.001) of the variation in AEE, respectively. By incorporating fat and fat-free mass in the models 58% (mean VM total) and 62% (mean VM waking) in the variation of AEE was explained (P<0.001). CONCLUSIONS: The wrist-worn ActiGraph wGT3x-BT in combination with body composition variables explained up to the 62% of the variation in AEE. Given the high wear compliance, the wrist-worn ActiGraph has the potential to provide useful information in studies where physical activity in preschool children is measured.

Parental body mass index and its association with body composition, physical fitness and lifestyle factors in their 4-year-old children: results from the MINISTOP trial.

BACKGROUND/OBJECTIVES: To examine the association between parental body mass index (BMI) and their offspring's body composition, physical fitness and lifestyle factors (that is, sedentary time, physical activity and diet). SUBJECTS/METHODS: A total of 307 preschoolers (4.5±0.1 years) and their parents (fathers: 38.1±5.1 years and mothers: 35.6±4.2 years) participated in this study. Parental BMI was calculated using self-reported weight and height. Preschoolers body composition was assessed using: BMI, fat mass percentage, fat mass index, fat-free mass index (measured via air-displacement plethysmography) and waist circumference. Physical fitness was assessed by the PREFIT fitness battery. Lifestyle factors were assessed using the ActiGraph wGT3x-BT (sedentary time and physical activity), and the mobile-phone based tool for energy balance in children (diet). RESULTS: Parental BMI were positively associated with their offspring's BMI (paternal BMI: standardised beta, ß=0.233, P<0.001; maternal BMI: ß=0.186, P=0.001), fat mass index (paternal BMI: ß=0.130, P=0.026; maternal BMI: ß=0.163, P=0.005), fat-free mass index (paternal BMI: ß=0.214, P<0.001; maternal BMI: ß=0.119, P=0.036) and waist circumference (paternal BMI: ß=0.178, P=0.001; maternal BMI: ß=0.179, P=0.001). A negative association was found between maternal BMI and their offspring's standing long jump test (ß=-0.132, P=0.022). Paternal BMI was associated with their offspring's sedentary time (ß=0.100, P=0.026), whereas parental BMI was not associated with neither physical activity nor diet (all P⩾0.104). CONCLUSIONS: Parental BMI was positively associated with their offspring's BMI, fat as well as fat-free mass index and waist circumference. Moreover, a higher paternal and maternal BMI were related to higher levels of sedentary time and a lower performance in the standing long jump test of their offspring, respectively.

Medical students' opportunities to participate and learn from activities at an internal medicine ward: an ethnographic study.

OBJECTIVES: To optimise medical students' early clerkship is a complex task since it is conducted in a context primarily organised to take care of patients. Previous studies have explored medical students' perceptions of facilitation and hindrance of learning. However, the opportunities for medical student to learn within the culture of acute medicine care have not been fully investigated. This study aimed to explore how medical students approach, interact and socialise in an acute internal medicine ward context, and how spaces for learning are created and used in such a culture. DESIGN AND SETTING: Ethnographic observations were performed of medical students' interactions and learning during early clerkship at an acute internal medicine care ward. Field notes were taken, transcribed and analysed qualitatively. Data analysis was guided by Wenger's theory of communities of practice. PARTICIPANTS: 21 medical students and 30 supervisors participated. RESULTS: Two themes were identified: Nervousness and curiosity-students acted nervously and stressed, especially when they could not answer questions. Over time curiosity could evolve. Unexplored opportunities to support students in developing competence to judge and approach more complex patient-related problems were identified. Invited and involved-students were exposed to a huge variation of opportunities to learn, and to interact and to be involved. Short placements seemed to disrupt the learning process. If and how students became involved also depended on supervisors' activities and students' initiatives. CONCLUSIONS: This study shed light on how an acute internal medicine ward culture can facilitate medical students' possibilities to participate and learn. Medical students' learning situations were characterised by questions and answers rather than challenging dialogues related to the complexity of presented patient cases. Further, students experienced continuous transfers between learning situations where the potential to be involved differed in a wide variety of ways.

Development and validation of an instrument to assess patients' appraisal, emotions and action tendencies preceding care-seeking in acute myocardial infarction: The PA-AMI questionnaire.

BACKGROUND: Reducing patient delay for patients afflicted by an acute myocardial infarction is a task of great complexity, which might be alleviated if more factors that influence this delay could be identified. Although a number of self-reported instruments associated with patient delay exist, none of these taps the content of the appraisal process related to patients' subjective emotions. AIM: The aim of this study was to develop and validate a questionnaire aimed at assessing patients' appraisal, emotions and action tendencies when afflicted by an acute myocardial infarction. METHODS: An item pool was generated based on themes conceptualized in a recent qualitative study of acute myocardial infarction patients' thoughts, feelings and actions preceding the decision to seek medical care. The 'Think-Aloud Protocol' and test-retest analysis at item level were performed. The modified item pool was administered to 96 patients when treated for acute myocardial infarction. Explorative factor analysis and principal component analysis with the non-linear iterative partial least squares algorithm were performed to examine the underlying factor structure of the items. RESULTS: The findings indicated three core dimensions corresponding to three subscales, namely, 'symptom appraisal'; 'perceived inability to act'; 'autonomy preservation'. The results demonstrated acceptable measures of reliability and validity Conclusions: The PA-AMI questionnaire demonstrated satisfactory psychometric properties. Assessment of the included core dimensions may contribute to greater understanding of the appraisal processes for patients afflicted by an acute myocardial infarction.

Physical activity intensity, sedentary behavior, body composition and physical fitness in 4-year-old children: results from the ministop trial.

BACKGROUND: Existing knowledge on associations of physical activity (PA) and sedentary behavior (SB) with body composition and physical fitness in preschoolers is limited. OBJECTIVE: To examine associations of PA and SB with body composition and physical fitness in healthy Swedish 4-year-old children. METHODS: We utilized baseline data collected in 2014 for the population-based MINISTOP trial (n=307). Light-intensity PA (LPA), moderate-intensity PA (MPA), vigorous-intensity PA (VPA), moderate-to-vigorous PA (MVPA) and SB were measured using accelerometry (ActiGraph-wGT3x-BT). Body composition was measured using air-displacement plethysmography, and physical fitness (that is, cardiorespiratory fitness, lower and upper body muscular strength and motor fitness) was measured using the PREFIT fitness test battery. Multiple linear regression models adjusted for relevant confounders, and in addition, isotemporal substitution models were applied. RESULTS: Greater MVPA was associated with lower fat mass percent (%FM, P=0.015), and greater VPA and MVPA were associated with higher fat-free mass index (FFMI, P=0.002 and P=0.011). In addition, greater VPA and MVPA were associated with higher scores for all physical fitness tests (P=0.042 to P<0.001). The results for MVPA were primarily due to VPA. SB was associated with weaker handgrip strength (P=0.031) when PA was not adjusted, but after adjusting also for VPA, the significant association disappeared (P=0.25). Substituting 5 min per day of SB, LPA or MPA with 5 min per day of VPA was associated with higher FFMI and better scores for cardiorespiratory fitness and motor fitness. Correspondingly, substituting 5 min per day of VPA with SB or LPA was associated with weaker performance for lower muscular strength. CONCLUSIONS: Time spent on VPA was associated with higher FFMI and better physical fitness. The results suggest that promoting VPA may be important to improve childhood body composition and physical fitness already at an early age.

Community of practice and student interaction at an acute medical ward: An ethnographic study.

BACKGROUND: A deeper understanding is needed of the acute medical care setting as a learning environment for students. AIM: To explore workplace culture of an acute medical ward and students' interactions within this community. METHOD: An ethnographic design was applied. Medical and nurse students' interactions were observed and informal questioning performed. Field notes were transcribed and analysed qualitatively, inspired by Wengers' "Community of practice" theory. RESULTS: We identified four characteristics that regulated how students adapt and interact in the community of practice. Complex and stressful situations were stabilized by routines and carriers of culture. Variable composition and roles of community members were a part of the daily routine but did not seam obvious to students. Transitions through community boundaries were confusing especially for new students. Levels of importance and priority: Hierarchies and orders of priority were present as regulators of roles, routines and interactions, and of how staff approach different patient groups. CONCLUSION: The culture shaped a pattern for, and created prerequisites that challenged students' adaptation and created a space for learning. Students' task on arrival was to enter the semipermeable membrane of the community of practice and to understand and adapt to its culture, and try to become accepted.

Gestational weight gain according to Institute of Medicine recommendations in relation to infant size and body composition.

BACKGROUND: Intrauterine life may be a critical period for programming childhood obesity; however, there is insufficient knowledge concerning how gestational weight gain (GWG) affects infant fat mass (FM) and fat-free mass (FFM). OBJECTIVES: The aim of this study was to investigate relationships between GWG according to Institute of Medicine (IOM) recommendations and infant size, FM and FFM. We also investigated if the associations were different for normal-weight and overweight/obese women. METHODS: This study included 312 healthy Swedish mother-infant pairs. Infant body composition at 1 week of age was assessed using air-displacement plethysmography. Maternal GWG was defined as below, within or above the 2009 IOM recommendations. Multiple regression analyses were used. RESULTS: Compared with women whose weight gain was within IOM recommendations, women with weight gain below the recommendations had infants that were shorter (-0.7 cm, P = 0.008) when adjusting for confounders. Normal-weight women exceeding IOM recommendations had infants with higher FM (+58 g, P = 0.008) compared with normal-weight women who gained within the recommendations. No corresponding association was observed for overweight/obese women. CONCLUSIONS: Inadequate GWG was associated with shorter infants, while excessive GWG was associated with greater infant FM for women who were of normal weight before pregnancy.

Variation in the fat mass and obesity-related (FTO) genotype is not associated with body fatness in infants, but possibly with their length.

BACKGROUND: Data relating variation at the fat mass and obesity-related (FTO) locus (rs9939609) to fat mass in infancy are inconclusive. OBJECTIVE: To study relationships between FTO genotype and infant size (at 1 and 12 weeks and at 1 year of age) and body composition (at 1 and 12 weeks). METHODS: Body composition was assessed using air displacement plethysmography in 207 infants. FTO was genotyped using the TaqMan assay. RESULTS: The number of risk alleles was related to length at 1 and 12 weeks (P = 0.007-0.033) but not to fat mass. The relationship to length was stronger in boys than in girls. CONCLUSIONS: Our results suggest that the FTO genotype is not related during infancy to fat mass but is related to length in boys but not in girls.

Short- and long-term decrease of blood pressure in women during breastfeeding.

BACKGROUND AND AIMS: The benefits of breastfeeding for infants are well known. Recently data have started to emerge showing that breastfeeding may also induce positive effects in the mother. This study aimed to investigate the pattern of maternal blood pressure before, during, and after a breastfeed 2 days postpartum. Additionally, blood pressure during the following 25-week breastfeeding period was investigated. METHODS: Sixty-six primiparae with normal deliveries were consecutively recruited. Blood pressure was measured at -5, 10, 30, and 60 minutes in connection with a morning breastfeed. Thirty-three women continued to measure blood pressure before and after breastfeeding for 25 weeks. RESULTS: Blood pressure fell significantly in response to breastfeeding 2 days after birth. The fall in systolic and diastolic blood pressure amounted to 8.8 (SD = 11.00) and 7.7 (SD = 9.3) mm Hg, respectively. During the 25-week follow-up period a significant fall of basal blood pressure (systolic, df = 3, F = 7.843, p < 0.001; diastolic, df = 3, F = 5.453, p = 0.002) was observed. The total fall in systolic and diastolic blood pressure amounted to a mean of 15 (SD = 10.4) mm Hg and 10 (SD = 9.7) mm Hg, respectively. In addition, blood pressure fell significantly in response to individual breastfeeding sessions during the entire observation period. CONCLUSIONS: In conclusion, both systolic and diastolic blood pressures fall during a breastfeeding session, and pre-breastfeeding blood pressure decreases during at least the first 6 months of a breastfeeding period in a homelike environment. This study lends further support to the health-promoting effects of breastfeeding.

Post-occlusive reactive hyperemia in single nutritive capillaries of the nail fold: methodological considerations.

Endothelial function at the arterial level has been extensively assessed by a non-invasive method using flow-mediated dilatation (FMD) of the brachial artery. Early disturbances have been found in patient groups prone to later development of manifest macrovascular atherosclerosis. A possible non-invasive means of studying blood-flow regulation and function at the microcirculatory level is through videophotometric capillaroscopy. The most stable variable in such an investigation is the time-to-peak (TtP) flow after a brief arterial occlusion. The short-term reproducibility of such assessments is excellent but the coefficient of variation (CV) in long-term studies is reported to be in the order of slightly less than 20%. The aim of the present methodological study was to evaluate different sources of variations in such microcirculatory assessments in order to be able to propose design recommendations that minimize the number of patients and recordings needed to achieve sufficient statistical power in longitudinal studies. We used a symmetric design with 144 recordings of TtP after a one-minute arterial occlusion in healthy volunteers. We did six occlusions each time in the capillaries of two fingers on each occasion, and repeated the procedure three times with an interval of at least one week between each investigation. All recordings were analyzed off-line using a cross-correlation technique with the Capiflow system. Each analysis was performed at least three times, giving a total of slightly less than 500 assessments. In our material (n = 10) TtP had a mean of 6.3 s (95% confidence interval 5.2-7.4). The correlation between repeated measurements in a single capillary during a single session was r > 0.91 (CV 6%). The between-finger CV was 8% (r = 0.84). The CV of measurements between different days was about 20% when single measurements were compared. However, the CV decreased to less than 13% when the mean of at least two time-to-peak assessments on each occasion was used. In conclusion, the methodological error including day-to-day variation could be minimized using the mean of at least two repeated assessments of post-occlusive hyperemia at each time point in a longitudinal study. This finding should be taken into consideration in the design of future longitudinal studies.

N-acetylcysteine improves microcirculatory flow during smoking: new effects of an old drug with possible benefits for smokers.

BACKGROUND: Cigarette smoking provokes marked acute changes in the microcirculatory vasculature, including a reduced blood flow velocity. In accordance with the hypothesis that the reduced blood flow is due to an imbalance between pro-oxidants and oxidants, we recently showed that most of the reduction could be reversed by a high dose of vitamin C. HYPOTHESIS: In the present work we tested the hypothesis that N-acetylcysteine, a mucolyticum and an antioxidant, may have an effect on the smoking-induced changes observed by vital capillary microscopy of the nailfold. METHODS: In all, 37 healthy volunteers of both genders and with varied smoking habits were treated with N-acetylcysteine 200 mg t.i.d. for 2 weeks. In vivo investigation of the microcirculation by capillaroscopy was performed before and after treatment. RESULTS: Treatment with N-acetylcysteine significantly reduced the smoking-induced relative decrease in capillary blood flow velocity in a group of volunteers with varied smoking habits (p = 0.0016). The preventive effect was clearly significant in smokers (p = 0.003). CONCLUSION: Treatment with N-acetylcysteine has a positive impact on microcirculatory flow during smoking, particularly in habitual smokers.