Sleep duration and its association with cardiometabolic outcomes among adolescents enrolled in the SI Program in Spain

Background

Sleep duration has been inversely associated with increased prevalence of overweight/obesity in childhood and adolescence [1, 2]. However, large studies linking over time objectively measured sleep duration and other cardiometabolic outcomes in adolescence are lacking.

Purpose

To evaluate sleep duration and its association with cardiometabolic outcomes in a large cohort of adolescents aged 12 to 16 years from the SI! Program for Secondary Schools trial in Spain [3], together with its relationship with sociodemographic variables.

Methods

Seven-day actigraphic recording was performed in 1229 adolescents at baseline (49.7% girls; 12.5 (0.4) years), 1058 at first follow-up (51.1% girls; 13.9 (0.4) years), and 895 at second follow-up (52.3% girls; 15.8 (0.4) years). Three groups were defined: very short sleep duration (<7 h), short sleep duration (7 to 8 h), and reference sleep duration (≥8 h) [4]. Overweight/obesity were determined according to BMI age- and sex-adjusted percentiles. Continuous Metabolic Syndrome (MetS) score was calculated as the sum of the age-and-gender specific z-scores of mean arterial pressure (MAP) (MAP = ((systolic BP − diastolic BP)/3) + diastolic BP), waist circumference, and fasting blood measures of high-density lipoprotein cholesterol (HDL-c) levels multiplied by −1, triglycerides, and glucose levels [5]. Associations between sleep duration and cardiometabolic outcomes were analyzed using generalized linear and Poisson distribution adjusted models.

Results

At 12 years of age, only 34.2% of the adolescents met sleep recommendations (sleep hours ≥8), and this percentage decreased with advancing age (23.4% and 19.4% at approximately 14 and 16 years of age, respectively) (Figure 1). Boys and individuals from migrant families tended to sleep shorter. Moreover, sleep duration was directly associated with sleep quality and efficiency. After adjusting for potential cofounders, very short sleepers (<7h) had a higher prevalence ratio (PR) of overweight/obesity at baseline (PR: 1.21 [95% CI: 1.16 to 1.27]) and at first follow-up (PR: 1.72 [95% CI: 1.08 to 2.74]) than the reference group (≥8 h) (Figure 2). Similarly, very short sleepers showed higher mean MetS scores at baseline (0.98 [95% CI: 0.43 to 1.54] and at first follow-up (0.76 [95% CI: 0.24 to 1.27]) as compared with the reference group. Short sleepers showed similar trends with associations of weaker magnitude, as they were the overall associations between sleep duration and cardiometabolic outcomes at second follow-up.

Conclusions

Most adolescents, and particularly those with a migrant background, did not meet sleep recommendations. Moreover, a shorter sleep duration was associated with cardiometabolic outcomes, particularly at 12 and 14 years of age and when sleeping less than 7 hours. Health promotion programs should emphasize the importance of good sleep habits.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): 1. Fundaciό la Maratό de TV3.2. SHE Foundation and “la Caixa” Foundation.

Cardiovascular health trajectories among adolescents enrolled in the SI Program in Spain: a longitudinal study

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): 1. Fondo de Investigación Sanitaria- Instituto de Salud Carlos III2. SHE Foundation and “la Caixa” Foundation.

Background

There is a paucity of data on adolescents’ cardiovascular health (CVH) profiles and longitudinal trajectories.

Purpose

To identify CVH trajectories in a large cohort of Spanish adolescents aged 12 to 16 years and their relationship with sociodemographic variables.

Methods

This study collected data at approximately 12, 14 and 16 years of age from 1078 adolescents attending 24 secondary schools enrolled in the SI! Program for Secondary Schools trial in Spain [1]. The status (non-ideal = 0 points; ideal = 1 point) of each CVH individual metric (smoking status, body mass index, physical activity, dietary habits, blood pressure, total cholesterol, and blood glucose) was determined following the criteria established by the American Heart Association [2]. An overall CVH score was constructed summing the number of ideal CVH metrics (ranged thus from 0 to 7 points), and poor, intermediate, or ideal overall CVH score was defined as ≤3, 4-5, or 6-7 ideal metrics, respectively [3]. CVH trajectories were identified using latent class trajectory modeling with the Stata command traj [4]. Next, individuals were assigned to the trajectory group they were most likely to belong based on the posterior predictive probabilities of group membership.

Results

Among 1078 adolescents with a baseline mean (SD) age of 12.5 (0.4) years, 48.5% girls, four distinct CVH trajectory groups were identified: low-stable (56 adolescents [5.0%]), low-rise (232 [21.3%]), intermediate-decline (136 [18.2%]) and intermediate-stable (654 [55.5%]) (Figure 1). Adolescents belonging to the intermediate-stable and the low-stable trajectories showed the highest and lowest overall CVH mean (SD) scores at baseline [4.8 (0.8) and 2.6 (0.9), respectively] (Figure 2). Similar differences were observed for the analysis of overall CVH score as a categorical variable (poor, intermediate, ideal). Sociodemographic differences between CVH trajectories were identified, with the highest proportion of girls, high-income and non-migrant families within the intermediate-stable trajectory.

Conclusions

In a large cohort of adolescents, ~55% of adolescents showed an intermediate CVH score at baseline and did not decline over time. The characterization of distinct CVH trajectories and sociodemographic differences between them may help tailoring health promotion programs for adolescents.

Effects of total dietary polyphenols on plasma nitric oxide and blood pressure in a high cardiovascular risk cohort. The PREDIMED randomized trial

BACKGROUND AND AIM

Hypertension is one of the main cardiovascular risk factors in the elderly. The aims of this work were to evaluate if a one-year intervention with two Mediterranean diets (Med-diet) could decrease blood pressure (BP) due to a high polyphenol consumption, and if the decrease in BP was mediated by plasma nitric oxide (NO) production.

METHODS AND RESULTS

An intervention substudy of 200 participants at high cardiovascular risk was carried out within the PREDIMED trial. They were randomly assigned to a low-fat control diet or to two Med-diets, one supplemented with extra virgin olive oil (Med-EVOO) and the other with nuts (Med-nuts). Anthropometrics and clinical parameters were measured at baseline and after one year of intervention, as well as BP, plasma NO and total polyphenol excretion (TPE) in urine samples. Systolic and diastolic BP decreased significantly after a one-year dietary intervention with Med-EVOO and Med-nuts. These changes were associated with a significant increase in TPE and plasma NO. Additionally, a significant positive correlation was observed between changes in urinary TPE, a biomarker of TP intake, and in plasma NO (Beta = 4.84; 95% CI: 0.57-9.10).

CONCLUSIONS

TPE in spot urine sample was positively correlated with plasma NO in Med-diets supplemented with either EVOO or nuts. The statistically significant increases in plasma NO were associated with a reduction in systolic and diastolic BP levels, adding to the growing evidence that polyphenols might protect the cardiovascular system by improving the endothelial function and enhancing endothelial synthesis of NO.

Inverse association between habitual polyphenol intake and incidence of cardiovascular events in the PREDIMED study

BACKGROUND AND AIMS

Epidemiologic and biological evidence supports an inverse association between polyphenol consumption and the risk of cardiovascular disease (CVD). However, no previous studies have prospectively evaluated the relationship between polyphenol intake and the incidence of CVD in such a comprehensive way. The aim was to evaluate the association between intakes of total polyphenol and polyphenol subgroups, and the risk of major cardiovascular events (myocardial infarction, stroke or death from cardiovascular causes) in the PREDIMED study.

METHODS AND RESULTS

The present work is an observational study within the PREDIMED trial. Over an average of 4.3 years of follow-up, there were 273 confirmed cases of CVD among the 7172 participants (96.3%) who completed a validated 137-item food frequency questionnaire (FFQ) at baseline. Polyphenol consumption was calculated by matching food consumption data from the FFQ with the Phenol-Explorer database on polyphenol content of each reported food. After multivariate adjustment, a 46% reduction in risk of CVD risk was observed comparing Q5 vs. Q1 of total polyphenol intake (HR = 0.54; 95% confidence interval [CI] = 0.33-0.91; P-trend = 0.04). The polyphenols with the strongest inverse associations were flavanols (HR = 0.40; CI 0.23-0.72; P-trend = 0.003), lignans (HR = 0.51; CI 0.30-0.86; P-trend = 0.007), and hydroxybenzoic acids (HR = 0.47; CI 0.26-0.86; P-trend 0.02).

CONCLUSION

Greater intake of polyphenols, especially from lignans, flavanols, and hydroxybenzoic acids, was associated with decreased CVD risk. Clinical trials are needed to confirm this effect and establish accurate dietary recommendations.

Dietary intake and major food sources of polyphenols in a Spanish population at high cardiovascular risk: the PREDIMED study

BACKGROUND AND AIMS

Epidemiological data have shown an inverse association between the consumption of polyphenol-rich foods and the risk of cardiovascular disease or overall mortality. A comprehensive estimation of individual polyphenol intake in nutritional cohorts is needed to gain a better understanding of this association. The aim of this study was to estimate the quantitative intake of polyphenols and the major dietary sources in the PREDIMED (PREvención con DIeta MEDiterránea) cohort using individual food consumption records.

METHODS AND RESULTS

The PREDIMED study is a large, parallel-group, multicentre, randomised, controlled 5-year feeding trial aimed at assessing the effects of the Mediterranean diet on the primary prevention of cardiovascular disease. A total of 7200 participants, aged 55-80 years, completed a validated 1-year food frequency questionnaire (FFQ) at baseline. Polyphenol consumption was calculated by matching food consumption data from the FFQ with the recently developed Phenol-Explorer database on polyphenol content in foods. The mean total polyphenol intake was 820 ± 323 mg day⁻¹ (443 ± 218 mg day⁻¹ of flavonoids and 304 ± 156 mg day⁻¹ of phenolic acids). Hydroxycinnamic acids were the phenolic group with the highest consumption and 5-caffeoylquinic acid was the most abundantly ingested individual polyphenol. The consumption of olives and olive oil was a differentiating factor in the phenolic profile of this Spanish population compared with other countries.

CONCLUSION

In Mediterranean countries, such as Spain, the main dietary source of polyphenols is coffee and fruits, but the most important differentiating factor with respect to other countries is the consumption of polyphenols from olives and olive oil.