Analysis of the determinants of sleep quality in a Spanish population: a study protocol for a cross-sectional study

INTRODUCTION

Sleep problems are a growing public health concern being related, among others, to an increased risk of cardiovascular diseases or worse cognitive functioning. In addition, they can affect aspects related to personal motivation and quality of life. However, very few studies have analysed the possible determinants of sleep quality in the adult population as a whole, establishing patterns based on these determinants.The objectives are to evaluate the determinants of sleep quality in a representative sample of the general adult population between 25 and 65 years old, and to establish patterns of sleep quality based on lifestyles, psychological factors, morbidities, sociodemographic variables, biological markers and other possible determinants.

METHODS AND ANALYSIS

Descriptive observational cross-sectional study. The study population will include a representative sample of 500 people between 25 and 65 years old from the cities of Salamanca and Ávila (Spain) selected by random sampling stratified by age groups and sex. A 90-minute visit will be performed, during which sleep quality will be assessed. The variables collected will be: morbidity, lifestyles (physical activity, diet, toxic habits), psychological factors (depression, stress, occupational stress and anxiety), socioeconomic and work-related variables, habitability conditions of the habitual residence and rest area, screen time, relaxation techniques and melatonin as a biological marker related to sleep quality.

DISCUSSION

With the results of this work, improved interventions for behaviour modification could be designed, as well as intervention and education programmes or other research aimed at improving sleep quality.

ETHICS AND DISSEMINATION

This study has a favourable opinion from the Ethics Committee for Drug Research of the Health Areas of Salamanca and Ávila (CEim Code: PI 2021 07 815). The results of this study will be published in international impact journals of different specialties.

TRIAL REGISTRATION NUMBER

NCT05324267.

Relationship of Different Anthropometric Indices with Vascular Ageing in an Adult Population without Cardiovascular Disease-EVA Study

The objectives of this study were to analyse the capacity of different anthropometric indices to predict vascular ageing and this association in Spanish adult population without cardiovascular disease. A total of 501 individuals without cardiovascular disease residing in the capital of Salamanca (Spain) were selected (mean age: 55.9 years, 50.3% women), through stratified random sampling by age and sex. Starting from anthropometric measurements such as weight, height, and waist circumference, hip circumference, or biochemical parameters, we could estimate different indices that reflected general obesity, abdominal obesity, and body fat distribution. Arterial stiffness was evaluated by measuring carotid-femoral pulse wave velocity (cf-PWV) using a SphygmoCor^® device. Vascular ageing was defined in three steps: Step 1: the participants with vascular injury were classified as early vascular ageing (EVA); Step 2: classification of the participants using the 10 and 90 percentiles of cf-PWV in the study population by age and sex in EVA, healthy vascular ageing (HVA) and normal vascular ageing (NVA); Step 3: re-classification of participants with arterial hypertension or type 2 diabetes mellitus included in HVA as NVA. The total prevalence of HVA and EVA was 8.4% and 21.4%, respectively. All the analysed anthropometric indices, except waist/hip ratio (WHpR), were associated with vascular ageing. Thus, as the values of the different anthropometric indices increase, the probability of being classified with NVA and as EVA increases. The capacity of the anthropometric indices to identify people with HVA showed values of area under the curve (AUC) ≥ 0.60. The capacity to identify people with EVA, in total, showed values of AUC between 0.55 and 0.60. In conclusion, as the values of the anthropometric indices increased, the probability that the subjects presented EVA increased. However, the relationship of the new anthropometric indices with vascular ageing was not stronger than that of traditional parameters. Therefore, BMI and WC can be considered to be the most useful indices in clinical practice to identify people with vascular ageing in the general population.

Prevalence of coronary atherosclerosis and reclassification of cardiovascular risk in Spanish population by coronary computed tomography angiography: EVA study

BACKGROUND

A more complete assessment of coronary artery disease (CAD) can be performed by coronary computed tomography angiography (CCTA). The aim was to assess the prevalence, distribution and characteristics of coronary artery disease (CAD) and the reclassification of cardiovascular risk by CCTA in an asymptomatic Spanish population.

DESIGN

We included, in a cross-sectional study, 501 random subjects from asymptomatic population, aged 35 and 75. Risk factors, target organ damage and cardiovascular risk were assessed. CCTA was offered to measure the coronary artery calcium score(CACS), segment involvement score(SIS) and segment stenosis score(SSS). The offer was accepted by 220 subjects (44%), with a mean age of 58 ± 14 years, 56% of them male.

RESULTS

The mean CACS was 119.6 ± 381.7 (median (IQR) (0 (0-61.55))), with higher scores in males (191.9 ± 493.1) than females (26.1 ± 73.3; P < .01). CCTA revealed coronary atherosclerosis in 89 cases, 40% (CI95%:34%-46%) in global, 51% in male and 25% in female, of which 13 had obstructive lesions (5.9%). Mean SIS was 1.5 ± 2.5 and SSS 1.2 ± 3.1. When the CACS was included in the CAD risk scale, there was a reclassification of 24%, and when using the SIS percentile, it was 38%, with a 9% increase in risk in both cases.

CONCLUSIONS

The prevalence of CAD in asymptomatic Spanish population was 40%, with greater proportion among males. The incorporation of CACS and SIS in the assessment of cardiovascular risk allows reclassifying subjects who are at low or moderate risk and thus identify those with high cardiovascular risk and also the other way.

Vascular and cognitive effects of cocoa-rich chocolate in postmenopausal women: a study protocol for a randomised clinical trial

INTRODUCTION

The intake of polyphenols has certain health benefits. This study will aim to assess the effect of adding a daily amount of chocolate high in cocoa content and polyphenols to the normal diet on blood pressure, vascular function, cognitive performance, quality of life and body composition in postmenopausal women.

METHODS AND ANALYSIS

Here we plan a randomised clinical trial with two parallel groups involving a total of 140 women between 50 and 64 years in the postmenopausal period, defined by amenorrhoea of ​​at least 12 consecutive months. The main variable will be the change in blood pressure. Secondary variables will be changes in vascular function, quality of life, cognitive performance and body composition. The intervention group will be given chocolate containing 99% cocoa, with instructions to add 10 g daily to their normal diet for 6 months. The daily nutritional contribution of this amount of chocolate is 59 kcal and 65.4 mg of polyphenols. There will be no intervention in the control group. All variables will be measured at the baseline visit and 3 and 6 months after randomisation, except cognitive performance and quality of life, which will only be assessed at baseline and at 6 months. Recruitment is scheduled to begin on 1 June 2018, and the study will continue until 31 May 2019.

ETHICS AND DISSEMINATION

This study was approved by the Clinical Research Ethics Committee of the Health Area of Salamanca, Spain ('CREC of Health Area of Salamanca'), in February 2018. A SPIRIT checklist is available for this protocol. The clinical trial has been registered at ClinicalTrials.gov provided by the US National Library of Medicine, number NCT03492983. The results will be disseminated through open access peer-reviewed journals, conference presentations, broadcast media and a presentation to stakeholders.

Postprandial effects of breakfast glycaemic index on cognitive performance among young, healthy adults: A crossover clinical trial

Objective: To evaluate the postprandial effects of high and low glycaemic index (GI) breakfasts on cognitive performance in young, healthy adults.Methods: A crossover clinical trial including 40 young, healthy adults (aged 20-40 years, 50% females) recruited from primary healthcare centres in Salamanca, Spain. Verbal memory, phonological fluency, attention, and executive functions were examined 0, 60, and 120 minutes after consuming a low GI (LGI), high GI (HGI), or water breakfast. Every subject tried each breakfast variant, in a randomized order, separated by a washout period of 7 days, for a total of 3 weeks.Results: A significant interaction between the type of breakfast consumed and immediate verbal memory was identified (P<.05). We observed a trend towards better performance in verbal memory (delayed and immediate), attention, and phonological fluency following an LGI breakfast.Discussion: Cognitive performance during the postprandial phase in young, healthy adults was minimally affected by the GI of breakfast. The potential for breakfast's GI modulation to improve short- and long-term cognitive functioning requires further research.

Effectiveness of an intensive intervention to improve lifestyles in people with intermediate cardiovascular risk (DATE study): Study protocol for a randomized controlled trial

AIM

The aim of this study was to evaluate the effectiveness of an intensive intervention led by primary care nurses for lifestyle modification among people with intermediate cardiovascular risk.

BACKGROUND

Cardiovascular diseases may be prevented by adopting healthy lifestyles. Interventions focused on populations at risk are more efficient than those aimed at the general population. More than 50 per cent of cardiovascular events occur in people with intermediate cardiovascular risk, but only a few studies have targeted this population.

DESIGN

A randomized controlled trial approved in January 2017.

METHODS

We will recruit 208 participants aged 35-74 years who have intermediate cardiovascular risk. They will be selected by consecutive sampling and will be randomized into a control group or intervention group. Individual standardized brief counselling on healthy lifestyles will be provided to both groups. Additionally, individuals from the intervention group will receive four weekly group sessions focusing on cardiovascular risk, healthy diet, moderation in alcohol consumption, daily physical activity, stress management and smoking cessation and two motivational follow-up calls. The primary outcome will be the lifestyle modification measured by total steps recorded by a pedometer, total score on the Mediterranean Diet Adherence Screener and percentage of current smokers.

DISCUSSION

This study will allow us to investigate whether an intensive intervention based on a multifactorial group approach is more effective in lifestyle modification than individual standardized brief counseling among adults with intermediate cardiovascular risk. Our results could lead to the establishment of new strategies for cardiovascular risk management.

Postprandial Effects of Breakfast Glycemic Index on Vascular Function among Young Healthy Adults: A Crossover Clinical Trial

This study aimed to evaluate the postprandial effects of high and low glycemic index (GI) breakfasts on vascular function. It was a crossover trial that included 40 young healthy adults (50% women), aged 20-40 years, who were recruited at primary care settings. They consumed three experimental breakfasts in randomized order, each one separated by a 1-week washout period: (1) control conditions (only water); (2) low GI (LGI) breakfast (29.4 GI and 1489 KJ energy); and (3) high GI (HGI) breakfast (64.0 GI and 1318 KJ energy). Blood samples were collected at 60 and 120 min after each breakfast to determine glucose and insulin levels. Vascular parameters were measured at 15 min intervals. Augmentation index (AIx) was studied as a primary outcome. Secondary outcomes comprised glucose, insulin, heart rate (HR) and pulse pressures (PPs). We found a trend toward increased AIx, HR and PPs for the HGI versus the LGI breakfast. A significant interaction between the type of breakfast consumed and all measured parameters was identified (p < 0.05) except for central PP. Stratifying data by sex, this interaction remained significant for AIx and augmentation pressure only in males (p < 0.05). In conclusion, breakfast GI could affect postprandial vascular responses in young healthy adults.

Postprandial effect of breakfast glycaemic index on vascular function, glycaemic control and cognitive performance (BGI study): study protocol for a randomised crossover trial

Background

Postprandial glycaemic response affects cognitive and vascular function. The acute effect of breakfast glycaemic index on vascular parameters is not sufficiently known. Also, the influence of breakfasts with different glycaemic index on cognitive performance has been mostly studied in children and adolescents with varying results. Therefore, the purpose of this study is to analyse the postprandial effect of high and low glycaemic index breakfasts on vascular function and cognitive performance and their relationship with postprandial glycaemic response in healthy young adults.

Methods/design

This is a crossover clinical trial targeting adults (aged 20–40 years, free from cardiovascular disease) selected by consecutive sampling at urban primary care health clinics in Salamanca (Spain). Each subject will complete three interventions with a washout period of one week: a control condition (consisting of water); a low glycaemic index breakfast (consisting of dark chocolate, walnuts, yogurt and an apple, with an overall glycaemic index of 29.4 and an energy contribution of 1489 kJ); and a high glycaemic index breakfast (consisting of bread, grape juice and strawberry jam, with an overall glycaemic index of 64.0 and an energy contribution of 1318 kJ). The postprandial effect will be assessed at 60 and 120 minutes from each breakfast including blood sampling and cognitive performance evaluations. Measurements of arterial stiffness and central haemodynamic parameters will be taken at –10, 0, 15, 30, 45, 60, 75, 90, 105 and 120 minutes.

Discussion

The differences in postprandial glycaemic response due to breakfast glycaemic index could affect vascular parameters and cognitive performance with important applications and implications for the general population. This could provide necessary information for the establishment of new strategies in terms of nutritional education and work performance improvement.

Trial registration

ClinicalTrials.gov: NCT02616276. Registered on 19 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1649-x) contains supplementary material, which is available to authorized users.

Dietary glycemic index and retinal microvasculature in adults: a cross-sectional study

Objective

To analyze the relationship between dietary glycemic index (GI) and retinal microvasculature in adults.

Methods

This was a cross-sectional study of 300 subjects from the EVIDENT II study. Dietary GI was calculated using a validated, semi-quantitative food frequency questionnaire. Retinal photographs were digitized, temporal vessels were measured in an area 0.5–1 disc diameter from the optic disc and arteriolar-venular index (AVI) was estimated with semi-automated software.

Results

AVI showed a significant difference between the tertiles of GI, after adjusting for potential confounders. The lowest AVI values were observed among subjects in the highest tertile of GI, whereas the greatest were found among those in the lowest tertile (estimated marginal mean of 0.738 vs. 0.768, p = 0.014).

Conclusions

In adults, high dietary GI implies lowering AVI values regardless of age, gender and other confounding variables.

Trial registration

Clinical Trials.gov Identifier: NCT02016014. Registered 9 December 2013.