Factors associated with spontaneous vaginal birth in nulliparous women: A descriptive systematic review.

PROBLEM: Spontaneous vaginal birth (SVB) rates for nulliparous women are declining internationally. BACKGROUND: There is inadequate understanding of factors affecting this trend overall and limited large-scale responses to improve women's opportunity to birth spontaneously. AIM: To undertake a descriptive systematic review identifying factors associated with spontaneous vaginal birth at term, in nulliparous women with a singleton pregnancy. METHODS: Quantitative studies of all designs, of nulliparous women with a singleton pregnancy and cephalic presentation, who experienced a SVB at term were included. Nine databases were searched (inception to October 2022). Two reviewers undertook quality appraisal; Randomised Controlled Trials (RCTs) with high risk of bias (ROB 2.0) and other designs with (QATSDD) scoring ≤ 50% were excluded. FINDINGS: Data were abstracted from 90 studies (32 RCTs, 39 cohort, 9 cross-sectional, 4 prevalence, 5 case control, 1 quasi-experimental). SVB rates varied (13%-99%). Modifiable factors associated with SVB included addressing fear of childbirth, low impact antenatal exercise, maternal positioning during second-stage labour and midwifery led care. Complexities arising during pregnancy and regional analgesia were shown to decrease SVB and other interventions, such as routine induction of labour were equivocal. DISCUSSION: Antenatal preparation (low impact exercise, childbirth education, addressing fear of childbirth) may increase SVB, as does midwifery continuity-of-care. Intrapartum strategies to optimise labour progression emerged as promising areas for further research. CONCLUSION: Declining SVB rates may be improved through multi-factorial approaches inclusive of maternal, fetal and clinical care domains. However, the variability of SVB rates testifies to the complexity of the issue.

The Effect of High-Intensity Interval Exercise on Short-Term Glycaemic Control, Serum Level of Key Mediator in Hypoxia and Pro-Inflammatory Cytokines in Patients with Type 1 Diabetes-An Exploratory Case Study.

Type 1 diabetes (T1D) is associated with hyperglycaemia-induced hypoxia and inflammation. This study assessed the effects of a single bout of high-intensity interval exercise (HIIE) on glycaemia (BG) and serum level of pro-inflammatory cytokines, and an essential mediator of adaptive response to hypoxia in T1D patients. The macronutrient intake was also evaluated. Nine patients suffering from T1D for about 12 years and nine healthy individuals (CG) were enrolled and completed one session of HIIE at the intensity of 120% lactate threshold with a duration of 4 × 5 min intermittent with 5 min rests after each bout of exercise. Capillary and venous blood were withdrawn at rest, immediately after and at 24 h post-HIIE for analysis of BG, hypoxia-inducible factor alpha (HIF-1α), tumour necrosis factor alpha (TNF-α) and vascular-endothelial growth factor (VEGF). Pre-exercise BG was significantly higher in the T1D patients compared to the CG (p = 0.043). HIIE led to a significant decline in T1D patients' BG (p = 0.027) and a tendency for a lower BG at 24 h post-HIIE vs. pre-HIIE. HIF-1α was significantly elevated in the T1D patients compared to CG and there was a trend for HIF-1α to decline, and for VEGF and TNF-α to increase in response to HIIE in the T1D group. Both groups consumed more and less than the recommended amounts of protein and fat, respectively. In the T1D group, a tendency for a higher digestible carbohydrate intake and more frequent hyperglycaemic episodes on the day after HIIE were observed. HIIE was effective in reducing T1D patients' glycaemia and improving short-term glycaemic control. HIIE has the potential to improve adaptive response to hypoxia by elevating the serum level of VEGF. Patients' diet and level of physical activity should be screened on a regular basis, and they should be educated on the glycaemic effects of digestible carbohydrates.

Determinants of nutrition practice and food choice in UK construction workers.

The workplace is considered an effective setting for health and wellbeing interventions, including programmes focusing on nutrition, and provides opportunities to tailor programmes to meet the specific needs of industry and employees. This study explored nutrition practices amongst construction workers and managers to inform the design of a nutrition intervention. Five focus groups were conducted on three construction sites: two with managers (n = 11) and three with workers (n = 27). Construction workers and managers identified several unhealthy nutrition-related behaviours, including high consumption of convenient and fast foods, excessive coffee, alcohol, energy drinks and low fruit and vegetable intake. These behaviours were often attributed to high workloads, long working hours and physically demanding jobs. Snacking and skipping meals were repeatedly reported, attributed to short breaks and poor accessibility to food outlets. The nutritional quality of meals differed between individuals (homemade vs fast food), depending on the type of sites (temporary vs permanent) and site location. Nutrition knowledge, establishing routines, meal planning and preparation were recognized as important in sustaining healthy nutrition habits. However, meal preparation depended on the facilities available, which differed between managers and workers, highlighting the complex relationship between the workplace context and eating behaviours. Construction workers were interested in learning about nutrition and improving their eating habits through nutrition intervention. However, they highlighted that better cooking and storage facilities on site, together with fewer job demands and longer break times, would enhance the sustainability of the intervention and their ability to make healthier food choices.

Moderate intensity exercise in hypoxia increases IGF-1 bioavailability and serum irisin in individuals with type 1 diabetes.

AIM: This study aimed to determine the effect of moderate intensity continuous exercise (Ex) and hypoxia (Hyp) on serum brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3), irisin and cytokines levels in patients with type 1 diabetes (T1D). METHODS: A total of 14 individuals with T1D (age: 28.7 ± 7.3 years) and 14 healthy adults (age: 27.1 ± 3.9 years) performed 40-min continuous Ex at moderate intensity (50% lactate threshold) on a cycle ergometer in normoxia (Nor) and Hyp (FiO2 = 15.1%) Biochemical factors, glucose concentrations and physiological variables were measured at rest, immediately and up to 24 h after both Ex protocols. RESULTS: Patients with T1D had significantly lower pre-Ex serum concentrations of BDNF (p < 0.05, p < 0.01), and total IGF-1 (p < 0.001, p < 0.05) and significantly higher irisin levels (p < 0.05, p < 0.01) in Nor and Hyp, compared with healthy subjects. Ex significantly increased in T1D group serum BDNF (in Nor only p < 0.05) and total IGF-1 levels in Nor and Hyp (p < 0.001 and p < 0.01, respectively). Immediately after Ex in Hyp, freeIGF-1 (p < 0.05) and irisin levels (p < 0.001) were significantly higher compared with the levels induced by Ex alone. Free IGF-1 and irisin serum levels remained elevated in 24 h post-Ex in Hyp. In T1D, significant blood glucose (BG) decrease was observed immediately after Ex in Hyp (p < 0.001) and in 24 h recovery (p < 0.001) compared with pre-Ex level. CONCLUSION: The study results suggest that moderate intensity continuous Ex has beneficial effect on BDNF and IGF-1 levels. Ex in hypoxic conditions may be more effective in increasing availability of IGF-1. The alterations in the post-Ex irisin levels and IGF-1 system may be contributing to more effective glycaemia control in patients with T1D.

Long-Term Health Outcomes Associated With an Exercise Referral Scheme: An Observational Longitudinal Follow-Up Study.

BACKGROUND: Exercise referral schemes (ERSs) support inactive adults, who have chronic health conditions, to become physically active. Uncertainty exists regarding the effectiveness of ERSs, with few studies evaluating their long-term impact. The aims of this study were to evaluate the long-term impact (12 mo) of participation in an ERS on self-reported physical activity (PA) and a range of health-related outcomes. METHODS: Data were analyzed for participants of a 24-week ERS who attended a week 52 follow-up between July 2015 and 2017. PA and health-related outcomes collected at weeks 1, 24, and 52 were analyzed using the Friedman test and Wilcoxon signed-ranks test. RESULTS: A total of 273 participants attended the week 52 follow-up. Self-reported PA significantly increased by a median of 636 MET minutes at week 52. There were also significant improvements in body mass index, systolic blood pressure, mental well-being, and health-related quality of life. CONCLUSIONS: For every 8 participants referred to this 24-week ERS, 1 participant went on to show long-term improvements in at least 1 health indicator. The evidence base requires further long-term evaluations to confirm these findings across a range of ERS providers. Changes in self-reported PA would be supported by the inclusion of device-based measurment of PA.

Effects of Hypoxia during Continuous and Intermittent Exercise on Glycaemic Control and Selected Markers of Vascular Function in Type 1 Diabetes.

OBJECTIVES: The aim of the study was to assess the effect of continuous and intermittent exercise in hypoxia on glycaemic control and selected markers of vascular function in patients with Type 1 diabetes (T1D). METHODS: 12 patients suffering from T1D for 12.1±6.0 years and 12 healthy adults performed: continuous exercise (ExC) and intermittent exercise (ExInt) in normoxia and hypoxia (FiO2=15.1%). Glycaemia and proangiogenic factors concentrations were measured at rest and immediately after exercise. RESULTS: T1D patients' glycaemia decreased in response to ExC (p<0.01) and ExInt (p<0.05) under hypoxic conditions. ExInt in normoxia (p<0.05) and hypoxia (p<0.05) reduced HIF-1α in the T1D group. A tendency for vascular endothelial growth factor to increase after ExInt in hypoxia (6.0±3.8 vs. 17.1±13.07 pg/mL) and a proinflammatory cytokine TNF-α level to decrease (33.2±19.1 vs. 25.1±14.4 pg/mL) was found in the same group. CONCLUSIONS: Combining exercise with hypoxia may allow more effective short-term glycaemic control in T1D. Intermittent exercise with hypoxia could stabilize the secretion of selected proangiogenic factors and reduce inflammation, potentially leading to improved vascular function.

Fish oil supplementation, resting blood flow and markers of cellular metabolism during incremental exercise.

Dietary supplementation of fish oils (n-3 PUFA) have been observed to affect insulin action and hence metabolism, affecting the ability to carry out work. Here we examine the effects of fish oil supplementation in conjunction with a glucose load during exertion, on markers of substrate utilization. A pre-test, post-test design was performed on ten healthy young males to assess the effects of 4 weeks fish oil supplementation on muscle metabolism during incremental exertion. Breath-by-breath analysis for respiratory exchange ratio (RER) along with blood lactate and blood glucose were determined at baseline, during exercise following an acute glucose bolus (10% solution at 4 mL/kg/bw), and again following supplementation of 4.2 g.day(-1) (2.2 g EPA, 1.4 g DHA). To examine the effect of fish oil on blood flow, Doppler ultrasound was used to assess femoral blood flow at rest. Following consumption of fish oils, exercising blood glucose and RER were seen to change significantly (4.66±0.44 vs. 4.58±0.31 mmol.L(-1) and 0.97±0.03 vs. 0.99±0.04; p<0.05). Resting femoral arterial blood flow was seen to increase significantly (p<0.05) pre- to post- test; 0.26±0.02-0.30±0.03 L.min(-1). Specific population groups such as those undertaking high-intensity exercise, and clinical groups such as intermittent claudicants, may benefit from the effects of fish oil supplementation.

Nutritional recommendations for competing in the Ironman triathlon.

The Ironman triathlon is an ultraendurance event that requires specific training and individually tailored nutritional practice. Carbohydrate depletion and dehydration are likely causes of fatigue, yet hyponatremia has been highlighted as a major concern during such events. As a consequence, triathletes are recommended to evaluate fluid losses during practice sessions and develop personal fluid replacement programs to ensure fluid balance. With regard to dietary preparation there are new methods of glycogen supercompensation, recommendations for improving fat oxidation while maintaining endogenous glycogen stores, and evidence aligned to the benefit of consuming combined carbohydrate intake during the race to increase exogenous carbohydrate oxidation rates. Although this review evaluates recent findings in order to make nutritional recommendations, it requires, at times, the generalization from a variety of endurance/ultraendurance studies. This highlights the need for further research within the triathlete population in order that future recommendations are sport-specific and therefore more reliable.

A comparison of pre-competition eating patterns in a group of non-elite triathletes.

A qualitative research study investigated food choice by triathletes prior to training and competition, and gauged attitudes towards nutritional management. Five focus groups were conducted with 7 male and 6 female non-elite triathletes. Sessions were semi-structured, tape recorded, and transcribed verbatim for coding and analysis. Transcripts were coded using grounded theory and higher order themes emerged including: "somatic complaints," "performance," "trust," "preferences," and "routine." Food choices, especially those of the more competitive triathletes, were made to maximize performance. Choices were based on past experience and "trial and error" rather than specialist advice. Subjects varied in nutritional knowledge, which appeared to relate to the level of competitiveness. More competitive triathletes were interested in improving performance but distrusted others making their nutritional choices. Less competitive triathletes embraced nutritional manipulation for gains in cognitive and athletic performance. "Trust" became a focus of the study and warrants further investigation, as this is a crucial component of providing nutritional advice to competitive athletes and to the general population.

The effect of nutritional manipulation on ultra-endurance performance: a case study.

The Atlantic Rowing Race requires teams of two to cover 3,000 nautical miles over 40-90 days. During this ultra-endurance event, competitors require substantial energy intake to meet metabolic requirements; therefore, sufficient physiological and nutritional support is paramount. Two highly trained males (aged 46) engaged in two 14d dietary interventions, with a 14d recovery period in between, to investigate the effect of such interventions on physiological (cardiovascular, cardiorespiratory, and blood-based measures) and performance-based (distance and split time) parameters during an ultra-endurance (2h on 2h off, for 24h) laboratory-based rowing protocol at 60% VO2max. Diet 1: high fat (HF) [60% fat, 30% carbohydrate and 10% protein] and Diet 2: high carbohydrate (HC) [20%, 70% and 10% respectively]. A greater distance was rowed by both subjects (155, 329 m and 134, 797 m vs 130, 089 m and 122, 112 m) with a concomitant reduced heart rate, volume of oxygen uptake, and respiratory exchange ratio, following the HF as opposed to HC dietary intervention. In summary, ultra-endurance performance was enhanced following a 14d HF diet, without apparent implications on liver function and overall lipid profile.