Association of exposure to artificial light at night during adolescence with blood pressure in early adulthood

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Background: Although within the physiological range, overweight and obese adolescents, who are otherwise normal, have blood pressures at the higher side, whereas underweight adolescents have lower blood pressures when compared with the normal weight individuals. Aims and Objectives: (1) To assess the functional status of the cardiovascular system by measuring the heart rate (HR) and blood pressure in adolescents with different body mass indices (BMI) at rest. (2) To illustrate the response of the cardiovascular system to acute isotonic exercise by recording the HR and blood pressure in normal weight, underweight, and overweight adolescents. Materials and Methods: A total of 44 adolescents, aged between 17 and 19 years with different BMI, are the study group. Subjects are categorized into underweight, normal weight, and overweight/obese group based on their BMI. HR and blood pressure were recorded before and immediately after the acute bicycle ergometer exercise test, with three finger test and sphygmomanometer, respectively. Results: Increase in HR, systolic blood pressure (SBP), and pulse pressure (PP) in diastolic blood pressure (DBP) were observed immediately after the exercise (P = 0.000) among all the subjects. Before the exercise, SBP, DBP, and mean arterial blood pressure (P = 0.002, 0.008, and 0.003) and after the exercise, SBP and PP (P = 0.007 and 0.037) are significant among underweight, normal weight, and overweight subjects. Conclusion: Overweight/obese adolescents are having higher blood pressure at rest. SBP and PP were increased more in overweight/ obese adolescents after the exercise than the normal weight subjects.

Artificial light at night (ALAN) is a growing environmental issue associated with negative health outcomes. Yet, there is a dearth of evidence concerning its effect on blood pressure (BP), especially in Ghana. This study examined the associations between ALAN, blood pressure, and hypertension. The study used data from 13,784 participants in the 2014 Ghana Demographic and Health Survey (GDHS). VIIRS Nighttime Day/Night Band dataset within the Google Earth was used to assess ALAN. Data on BP were obtained from the 2014 GDHS. Linear and logistic mixed effects models were used to analyze the data. Findings showed that higher ALAN score was associated with higher systolic blood pressure (SBP), diastolic blood pressure (DBP), and higher odds of hypertension. We observed higher percentages of SBP, DBP, and hypertension among the majority ethnic populations compared to the minority. Public health interventions should aim to reduce ALAN exposure to benefit human health.

This clinical advisory statement from the Coordinating Committee of the National High Blood Pressure Education Program is intended to advance and clarify the recommendations of the Sixth Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI, 1997).1 The advisory addresses several interrelated issues about blood pressure (BP) that affect people approaching the later decades of life. On the basis of the wealth of currently available evidence, the committee now recommends a major paradigm shift in urging that systolic BP become the major criterion for diagnosis, staging, and therapeutic management of hypertension, particularly in middle-aged and older Americans. Several lines of strong evidence support the initiative to emphasize systolic BP. Pathophysiologically, there are strong associations among aging, increased stiffness of large arteries, increased systolic BP, increased pulse pressure, and the prevalence of cardiac and vascular disease. Epidemiologically, isolated systolic hypertension is the most common form of hypertension and is present in approximately two thirds of hypertensive individuals >60 years of age. Diagnostically, classification and staging of hypertension are more precise when systolic rather than diastolic BP is used as the principal criterion. Risk stratification for major complications of hypertension (stroke, myocardial infarction, heart failure, and kidney failure) is actually confounded by the use of diastolic BP; in older people with systolic hypertension, diastolic BP is inversely related to cardiovascular risk. Clinical benefits of treatment of isolated systolic hypertension include reductions in stroke, myocardial infarction, heart failure, kidney failure, and overall cardiovascular disease morbidity and mortality. Currently, only 1 in 4 Americans with hypertension falls below JNC VI–recommended values of 140/90 mm Hg in uncomplicated hypertension or 130/85 mm Hg in individuals with kidney disease or diabetes. Hypertension control rates are poorest in older people, primarily as a result of inadequate …

Association between perfluoroalkyl substance concentrations and blood pressure in adolescents

Artificial light at night (ALAN) disrupts 24-h variability of blood pressure, but the molecular mechanisms underlying these effects are unknown. Therefore, we analysed the daily variability of pulse pressure, the maximum value of acceleration rate of aortic pressure (dP/dt(max)) measured by telemetry and protein expression in the thoracic aorta of normotensive male rats exposed to ALAN (1–2 lx) for 3 weeks. Daily, 24-h variability of pulse pressure and dP/dt(max) was observed during a regular light/dark regimen with higher values during the dark compared to the light phase of the day. ALAN suppressed 24-h variability and enhanced ultradian (<12-h) periods of pulse pressure and dP/dt(max) in duration-dependent manners. From beat-to-beat blood pressure variability, ALAN decreased low-frequency bands (a sympathetic marker) and had minimal effects on high-frequency bands. At the molecular level, ALAN decreased angiotensin II receptor type 1 expression and reduced 24-h variability. ALAN caused the appearance of 12-h oscillations in transforming growth factor β1 and fibulin 4. Expression of sarco/endoplasmic reticulum Ca2+-ATPase type 2 was increased in the middle of the light and dark phase of the day, and ALAN did not affect its daily and 12-h variability. In conclusion, ALAN suppressed 24-h variability of pulse pressure and dP/dt(max), decreased the power of low-frequency bands and differentially affected the expression of specific proteins in the rat thoracic aorta. Suppressed 24-h oscillations by ALAN underline the pulsatility of individual endocrine axes with different periods, disrupting the cardiovascular control of central blood pressure.

Elevated blood pressure in children is related to the hypertension in adults. Reducing environmental factors linked to hypertension in children is necessary to prevent hypertension in adults. To investigate the associations between outdoor artificial light at night (ALAN) and blood pressure among children. We recruited 9354 children aged 5-17 in the Seven Northeastern Cities Study between 2012 and 2013. Trained nurses measured their blood pressure with a mercury sphygmomanometer. We defined hypertension as systolic blood pressure (SBP) or diastolic blood pressure (DBP) ≥95th age-sex-height-specific percentile. We geocoded the address of each child and linked it to estimated outdoor ALAN within 500 m (ALAN-500 m) sourced from the VIIRS/DNB. We utilized generalized linear mixed-effect models to assess the associations of outdoor ALAN and blood pressure and the odds of hypertension. Effect modification by age, sex, weight status, and other potential factors was also explored. The SBP, DBP, and mean arterial pressure at quartile 4 (Q4) of outdoor ALAN-500 m against Q1 increased in 1.45 (95% CI: 0.31-2.59) mmHg, 2.09 (95% CI: 1.18-2.99) mmHg, and 1.87 (95% CI: 0.99-2.76) mmHg, respectively. The odds of hypertension increased by 30% in Q3 of outdoor ALAN-500 m compared to Q1 (OR = 1.30, 95% CI: 1.05-1.61). Furthermore, stronger effect estimates were observed among children aged ≤11 years (Q4, β = 5.07[3.28-6.85] vs β = 1.54[0.37-2.71] for DBP) and who were overweight (Q4, OR = 1.95[1.17-3.22] vs OR = 0.89[0.60-1.32] for hypertension). Living in areas with high outdoor ALAN exposure increased the odds of hypertension in children, especially in children aged ≤11 years and overweight. Reducing outdoor ALAN is important for preventing hypertension and controlling blood pressure in children. The study found a positive association between outdoor ALAN and blood pressure and hypertension.

BackgroundAlthough preterm birth predisposes for cardiovascular disease, recent studies in children indicate normal blood pressure and arterial stiffness. This prospective cohort study therefore assessed blood pressure and arterial stiffness in adolescents born very preterm due to verified fetal growth restriction (FGR).MethodsAdolescents (14 (13–17) years; 52% girls) born very preterm with FGR (preterm FGR; n = 24) and two control groups born with appropriate birth weight (AGA), one in similar gestation (preterm AGA; n = 27) and one at term (term AGA; n = 28) were included. 24-hour ambulatory blood pressure and aortic pulse wave velocity (PWV) and distensibility by magnetic resonance imaging were acquired.ResultsThere were no group differences in prevalence of hypertension or in arterial stiffness (all p ≥ 0.1). In boys, diastolic and mean arterial blood pressures increased from term AGA to preterm AGA to preterm FGR with higher daytime and 24-hour mean arterial blood pressures in the preterm FGR as compared to the term AGA group. In girls, no group differences were observed (all p ≥ 0.1).ConclusionsVery preterm birth due to FGR is associated with higher, yet normal blood pressure in adolescent boys, suggesting an existing but limited impact of very preterm birth on cardiovascular risk in adolescence, enhanced by male sex and FGR.ImpactVery preterm birth due to fetal growth restriction was associated with higher, yet normal blood pressure in adolescent boys.In adolescence, very preterm birth due to fetal growth restriction was not associated with increased thoracic aortic stiffness.In adolescence, very preterm birth in itself showed an existing but limited effect on blood pressure and thoracic aortic stiffness.Male sex and fetal growth restriction enhanced the effect of preterm birth on blood pressure in adolescence.Male sex and fetal growth restriction should be considered as additional risk factors to that of preterm birth in cardiovascular risk stratification.

To assess the association between the consumption of caffeinated beverages and blood pressure in African American and white adolescents. This study was part of ongoing research examining stress-induced hemodynamic responses in adolescents. African American and white adolescents (n = 159) selected foods and beverages for a 3-day sodium-controlled diet. Caffeine in these foods was used to stratify participants into 3 categories (0-50 mg/d, >50-100 mg/d, and >100 mg/d). Before menu selection, blood pressure readings were obtained. A general linear model (multiple regression with both categorical and continuous variables) was developed to assess the effects of race, category of caffeine intake, and interaction of race and caffeine intake on systolic and diastolic blood pressure controlling for sex and body mass index (calculated as weight in kilograms divided by height in meters squared). The association between systolic blood pressure and caffeine category varied by race (P =.001). African Americans consuming more than 100 mg/d of caffeine had higher systolic blood pressure readings than the groups consuming 0 to 50 mg/d (mean difference, 6.0 mm Hg; 95% confidence interval [CI], 2.3 to 9.7) or more than 50 to 100 mg/d (mean difference, 7.1 mm Hg; 95% CI, 3.4 to 10.7). The effect on diastolic blood pressure was less pronounced (P =.08). The diastolic blood pressure of the group consuming more than 100 mg/d was 3.7 mm Hg (95% CI, 0.41 to 7.0) higher than the group consuming more than 50 to 100 mg/d and was not statistically different from the group consuming 0 to 50 mg/d (mean difference, 2.4 mm Hg; 95% CI, -0.9 to 5.8). There was no evidence that the association between diastolic blood pressure and caffeine intake varied by race (P =.80). For adolescents, especially African American adolescents, caffeine intake may increase blood pressure and thereby increase the risk of hypertension. Alternatively, caffeinated drink consumption may be a marker for dietary and lifestyle practices that together influence blood pressure. Additional research is needed owing to rising rates of adolescent hypertension and soft drink consumption.

Objective: Tobacco consumption adversely affects cardiovascular (CV) disease (CVD) and risk profile, including hypertension. The long-term effect of cigarette smoking on blood pressure (BP) in adolescents is still, however, equivocal. Thus, the current study examined the CV indices in male adolescent cigarette smokers versus nonsmokers.Method: Resting heart rate, systolic BP (SBP) and diastolic BP (DBP), mean arterial pressure (MAP), pulse pressure (PP) and rate pressure products (RPP) were examined using automatic oscillatory method, while smoking status was determined with Youth Risk Behavior Survey.Results: After controlling for cofactors, the ANCOVA showed that CV measures in the male adolescent smokers were lower (p < 0.05) than nonsmokers. Additionally, regression showed that smoking status explained 20.6% of SBP, 5.0% of DBP, 13.4% of MAP, 7.5% of PP and 13.4% of RPP.Conclusion: The results suggest that cigarette smoking lowers CV measures in adolescents. However, more studies are needed to describe the mechanism(s) for lowering CV measures and explain the relationship of adolescent smoking with adulthood CVDs.

Impacts of Artificial Light at Night (ALAN) on coastal ecosystems: A study on the herbivore Ampithoe valida with focus on sex-dependent responses.

This study was intended to clarify the relation between fasting insulin, lipids, and blood pressure in adolescents before the onset of hypertension and to examine the association of these data with similar data obtained in their parents. The participants in this study were 183 adolescents 14 to 18 years old (96 girls) completing a 4-year intervention trial and their parents (164 mothers, 122 fathers). Blood pressure was measured twice on the right arm in a seated position using a random-zero sphygmomanometer. Fasting blood samples were obtained for lipid and insulin analyses. Fasting insulin was significantly correlated with systolic blood pressure in the adolescents and also in the parents before and after adjustment for body mass index. Fasting insulin was correlated significantly with levels of cholesterol, triglycerides, and HDL and LDL cholesterol in the adolescents. It was correlated only with triglycerides and HDL-cholesterol in mothers and fathers. After adjustment for body mass index, the correlations between fasting insulin and lipids in the children were not significant. A significant relation was shown between children's systolic blood pressure and mothers' fasting insulin and systolic blood pressure. Significant correlations were found between the children's and fathers' triglycerides and HDL-cholesterol, whereas significant correlations were found for fasting insulin and all lipids between mothers and children, and these remained significant after adjustment for body mass index. These results show (1) a significant relation between fasting insulin and both lipids and systolic blood pressure in adolescents and (2) a significant relation for these factors between adolescents and their parents. Although weight appears to play an important role in this relation during adolescence, genetic and environmental factors other than those mediated via weight may control insulin metabolism within families. The data support a role for studies during early biological development to address these issues.

This study investigates sexual maturity as a predictor of resting blood pressures independent of other known predictors, in 179 boys and 204 girls 11-16 years of age from the Heartfelt Study. The sample included youth of African (n = 140), Mexican (n = 117), and European and "other" (n = 126) backgrounds. Sexual maturity was assessed during clinical examination of three standard indicators for each sex. Systolic and diastolic blood pressures were higher in children of maturity stages IV and V, compared to stages I-III, in each gender/ethnic group (P < 0.01 in almost all groups). Boys and girls advanced in sexual maturity for their age group, had significantly higher systolic blood pressures (but not diastolic) than the less advanced in linear models that included height, body mass index (BMI), ethnicity, and age as co-predictors. Diastolic blood pressures were predicted by height in boys and by age and the BMI in girls. This analysis, using a very conservative approach, suggests that sexual maturity provides important and independent information on systolic blood pressure in adolescents. Further investigation of its role in 24-hr blood pressures and in blood pressures taken during physical and emotional stress, is recommended.

This study investigates sexual maturity as a predictor of resting blood pressures independent of other known predictors, in 179 boys and 204 girls 11-16 years of age from the Heartfelt Study. The sample included youth of African (n = 140), Mexican (n = 117), and European and “other” (n = 126) backgrounds. Sexual maturity was assessed during clinical examination of three standard indicators for each sex. Systolic and diastolic blood pressures were higher in children of maturity stages IV and V, compared to stages I–III, in each gender/ethnic group (P < 0.01 in almost all groups). Boys and girls advanced in sexual maturity for their age group, had significantly higher systolic blood pressures (but not diastolic) than the less advanced in linear models that included height, body mass index (BMI), ethnicity, and age as co-predictors. Diastolic blood pressures were predicted by height in boys and by age and the BMI in girls. This analysis, using a very conservative approach, suggests that sexual maturity provides important and independent information on systolic blood pressure in adolescents. Further investigation of its role in 24-hr blood pressures and in blood pressures taken during physical and emotional stress, is recommended. Am. J. Hum. Biol. 13:227–234, 2001. © 2001 Wiley-Liss, Inc.

Artificial light at night (ALAN) is linked to negative behavioural and physiological consequences in animals. A potential mechanism for these adverse effects is artificial light at night’s inhibition of melatonin synthesis, a zeitgeber for cellular processes and a powerful antioxidant. Accordingly, melatonin supplementation can ameliorate artificial light at night-linked pathologies. Most studies expose animals to artificial light at night across their whole lifespan or a single life stage, but many nocturnal species experience variable exposure across heterogeneously lit landscapes. We investigated the effects of artificial light at night during both early- and late-juvenile development on adult reproduction in the Pacific field cricket Teleogryllus oceanicus, and whether dietary melatonin supplementation could mitigate these effects. We found life-stage-specific developmental effects of artificial light at night. Lifelong artificial light at night exposure accelerated juvenile development, yet did not affect late-juvenile development, total development time or adult body mass. Moreover, we confirm the potential for melatonin supplementation to rescue male sperm viability and daily egg production by females. The degree of ‘rescue’ was sex, and potentially age specific, which may be explained by the differential effect of artificial light at night on early-juvenile development. Critically, this effect would have been masked had we not partitioned this early life stage, underscoring the importance of considering life-stage-specific artificial light at night exposure when evaluating ecological and physiological consequences.