Does Physical Fitness Buffer the Relationship between Psychosocial Stress, Retinal Vessel Diameters, and Blood Pressure among Primary Schoolchildren?

When Much Is Too Much-Compared to Light Exercisers, Heavy Exercisers Report More Mental Health Issues and Stress, but Less Sleep Complaints

BACKGROUND

Physical inactivity has become a global somatic and mental health issue. To counterbalance, promoting regular physical activity appears plausible, above all among adults, where physical inactivity is particularly high. However, some, but sparse, research also indicates that excessive exercising might be associated with unfavorable mental health dimensions. Here, we tested the hypothesis that excessive exercising was associated with more mental health issues. To this end, we assessed mental health issues, stress, mental toughness, and sleep disturbances among heavy and light adult exercisers.

METHODS

A total of 200 adults (mean age: 35 years; 62% females) took part in the study. Of those, 100 were heavy exercisers (18-22 h/week), and 100 were light exercisers (1-6 h/week). Participants completed questionnaires covering sociodemographic information, mental health issues, perceived stress, mental toughness, and sleep disturbances.

RESULTS

Compared with light exercisers, heavy exercisers reported higher mental health issues, more stress, but also higher mental toughness scores and less sleep disturbances. Higher age, lower mental toughness scores, heavy exerciser-status, and more sleep disturbances predicted higher mental health complaints.

CONCLUSIONS

Compared with light exercising, heavy exercising might be associated with more mental health issues. As such, it appears that the association between exercise frequency, intensity, and duration and psychological well-being might be related to an optimum point, but not to a maximum point. In a similar vein, heavily exercising athletes, their coaches, parents, and representatives of sports associations should get sensitized to possible adverse psychological effects of excessive physical activity patterns.

Healthier Minds in Fitter Bodies: A Systematic Review and Meta-Analysis of the Association between Physical Fitness and Mental Health in Youth

BACKGROUND

Physical fitness is an important marker of current and future health status, yet the association between physical fitness and indicators of mental health in youth has not been systematically reviewed and meta-analyzed.

OBJECTIVE

The aim of this work was to systematically review and meta-analyze the association between physical fitness components (i.e. cardiorespiratory fitness, muscular fitness, speed-agility, flexibility and fitness composite) and mental health indicators (i.e. psychological well-being and psychological ill-being) in preschoolers, children and adolescents.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Systematic searches were conducted in PubMed, Web of Science and Scopus from database inception to May 2020.

ELIGIBILITY CRITERIA

Studies (cross-sectional, longitudinal and intervention designs) were included if they measured at least one physical fitness component and one mental health indicator in healthy youth (2-18 years).

RESULTS

A total of 58 unique studies (52 cross-sectional, 4 longitudinal and 4 intervention studies) met all eligibility criteria and were included. There was a significant positive overall association between physical fitness and mental health in children and adolescents (pooled r = 0.206, p < 0.001). We found suggestive evidence of moderation by age group, fitness components and socioeconomic status (all p < 0.08). No relevant studies focusing on preschoolers were identified. Evidence based on longitudinal and intervention studies was limited.

CONCLUSION

We observed a small to medium sized positive association between physical fitness and overall mental health in youth. However, as the majority of studies were cross-sectional, additional longitudinal and intervention studies are needed to provide evidence of causation.

TRIAL REGISTRATION

PROSPERO registration number CRD42017080005.

The Exercise, Arterial Modulation and Nutrition in Youth South Africa Study (ExAMIN Youth SA)

Background: The impact of a sedentary and unhealthy lifestyle on cardiovascular health is well-documented, however the current obesity and hypertension trends among children is concerning. The ExAMIN Youth SA study aims to investigate the impact of lifestyle behaviors (physical fitness/activity, dietary intake and psychosocial factors) involved in early vascular aging among South African children. Methods: This study is an analytical, multidisciplinary, observational cohort study in a school-based setting. We aim to phenotype a cohort of ~1,000 primary school children (black and white boys and girls between ages 5-9 years) based on current clinical childhood conditions including hypertension and obesity. The primary phenotype is large artery stiffness and retinal microvascular diameters, both biomarkers of early vascular aging. The risk factors and mediators of early vascular aging and also responsible for the clinical conditions include physical inactivity, unhealthy diet, and life stress. Additionally, urinalysis and salivary analyses will be performed to identify biomarkers related to the pathophysiology of early vascular aging. Discussion: In line with the growing prevalence of obesity and hypertension responsible for the development of early vascular aging from childhood to adulthood, this study will address the critical areas in which we observe unfavorable arterial modulation related to dietary behaviors, physical inactivity, and early life stress. Implementation of novel biological markers may further contribute to our understanding of early cardiovascular adaptations in childhood, and aid in the development of primary prevention programs. Trial registration: The study was retrospectively registered on ClinicalTrials.gov on 15 August 2019 (NCT04056377).

Normative values of retinal vessel oximetry in healthy children against adults

BACKGROUND

Retinal oximetry (RO) has been established as a non-invasive method to analyse oxygen saturation in retinal vessels. The aim of our study was to compare the RO parameters of healthy children to those in adults.

METHODS

A total of 200 eyes of 104 healthy subjects were examined: 20 eyes of children aged <10 years and 62 eyes of children aged 10-19 years were compared to the eyes of adult controls from five different age groups (20-29 years:n = 24; 30-39 years:n = 32; 40-49 years:n = 15; 50-59 years:n = 20, 60-80 years:n = 27; n indicates the number of analysed eyes). The oxygen saturation was estimated with the oxygen saturation measurement tool of the Retinal Vessel Analyser (RVA; IMEDOS Systems UG, Jena, Germany). The global oxygen saturations, within 1.0-1.5 optic disc diameters from the disc margin, in the peripapillary retinal arterioles (A-SO₂ ; %) and venules (V-SO₂ ; %) were estimated and their difference (A-V SO₂ ; %) was calculated. In addition, we evaluated the mean diameter in all four major retinal arterioles (D-A; μm) and venules (D-V; μm). The ratio between venular and arterial vessel diameter (D-V/A; μm) was calculated thereafter. For statistical evaluation, anova-based linear mixed-effects models were calculated with spss^® .

RESULTS

Based on our results, younger children (<10 years) present a statistically significant lower A-SO₂ and A-V SO₂ when compared to adult subgroups. The D-A values revealed to be significantly lower in 10 + children when compared to the other groups, while the D-V values did not show significant differences.

CONCLUSION

These data indicate that the retinal oxygen metabolism changes throughout lifetime. Therefore, normative data for different age groups are mandatory.

Association between blood pressure and retinal arteriolar and venular diameters in Chinese early adolescent children, and whether the association has gender difference: a cross-sectional study

Background

To establish the independent association between blood pressure (BP) and retinal vascular caliber, especially the retinal venular caliber, in a population of 12-year-old Chinese children.

Methods

We have examined 1501 students in the 7th grade with mean age of 12.7 years. A non-mydriatic fundus camera (Canon CR-2, Tokyo, Japan) was used to capture 45⁰ fundus images of the right eyes. Retinal vascular caliber was measured using a computer-based program (IVAN). BP was measured using an automated sphygmomanometer (HEM-907, Omron, Kyoto, Japan).

Results

The mean retinal arteriolar caliber was 145.3 μm (95% confidence interval [CI], 110.6–189.6 μm) and the mean venular caliber was 212.7 μm (95% CI, 170.6–271.3 μm). After controlling for age, sex, axial length, BMI, waist, spherical equivalent, birth weight, gestational age and fellow retinal vessel caliber, children in the highest quartile of BP had significantly narrower retinal arteriolar caliber than those with lower quartiles (P for trend< 0.05). Each 10-mmHg increase in BP was associated with narrowing of the retinal arterioles by 3.00 μm (multivariable-adjusted P < 0.001), and the results were consist in three BP measurements. The association between BP measures and retinal venular caliber did not persist after adjusting for fellow arteriolar caliber. And there was no significant interaction between BP and sex, age, BMI, and birth status.

Conclusions

In a large population of adolescent Chinese children, higher BP was found to be associated with narrower retinal arterioles, but not with retinal venules. Sex and other confounding factors had no effect on the relationship of BP and retinal vessel diameter.

Obesity, Blood Pressure, and Retinal Vessels: A Meta-analysis

CONTEXT

Retinal vessel imaging is a noninvasive diagnostic tool used to evaluate cardiovascular risk. Childhood obesity and elevated blood pressure (BP) are associated with retinal microvascular alterations.

OBJECTIVE

To systematically review and meta-analyze associations between obesity, BP, and physical activity with retinal vessel diameters in children.

DATA SOURCES

We conducted a literature search through the databases of PubMed, Embase, Ovid, Web of Science, and the Cochrane Register of Controlled Trials.

STUDY SELECTION

School- and population-based cross-sectional data.

DATA EXTRACTION

General information, study design, participants, exposure, and outcomes.

RESULTS

A total of 1751 studies were found, and 30 full-text articles were analyzed for eligibility. Twenty-two articles (18 865 children and adolescents) were used for further assessment and reflection. Eleven articles were finally included in the meta-analysis. We found that a higher BMI is associated with narrower retinal arteriolar (pooled estimate effect size -0.37 [95% confidence interval (CI): -0.50 to -0.24]) and wider venular diameters (0.35 [95% CI: 0.07 to 0.63]). Systolic and diastolic BP are associated with retinal arteriolar narrowing (systolic BP: -0.63 [95% CI: -0.92 to -0.34]; diastolic BP: -0.60 [95% CI -0.95 to -0.25]). Increased physical activity and fitness are associated with favorable retinal vessel diameters.

LIMITATIONS

Long-term studies are needed to substantiate the prognostic relevance of retinal vessel diameters for cardiovascular risk in children.

CONCLUSIONS

Our results indicate that childhood obesity, BP, and physical inactivity are associated with retinal microvascular abnormalities. Retinal vessel diameters seem to be sensitive microvascular biomarkers for cardiovascular risk stratification in children.

Longitudinal association between psychosocial stress and retinal microvasculature in children and adolescents

BACKGROUND

Retinal microvessels provides a window to assess the microcirculation of heart and brain, and might reflect cardio- or cerebrovascular disease risk. Limited information exist on the relation between psychosocial stress and the microcirculation, even though psychosocial stress might trigger vascular diseases. This study investigates whether childhood psychosocial stress is a predictor of retinal microvasculature.

METHODS

We followed-up 182 Belgian children, aged 5.7-11.3 years at baseline (53.3% boys). Information about psychosocial stress was obtained using emotional, behavioral and negative life events questionnaires and hair cortisol, an objective stress marker. Retinal photographs were used to calculate vessel diameters, bifurcation angles and optimality deviation with semiautomated software. Cross-sectional and longitudinal associations were explored using multivariable regression analysis with retinal parameters in 2015 as outcome, while adjusting for age, sex, socioeconomic status, cardiovascular parameters and lifestyle factors.

RESULTS

Feelings of happiness, sadness and negative life events were associated with retinal vascular diameter, but behavior and hair cortisol were not. High stress levels over a 4-year time period (less happy, sadder and higher total negative emotions) were associated with larger venules (β = 0.21-0.43) and children who experienced more negative life events had smaller arterioles (β = -0.15). No consistent patterns were seen with bifurcation angles and optimality deviation.

CONCLUSION

Based on the results, we conclude that high levels of childhood psychosocial stress unfavorably affect the retinal vascular diameters, potentially reflecting the microvasculature of the heart and brain. It seems this might even be independent of lifestyle and BMI, but further research on mechanisms is necessary.