Traffic noise and other determinants of blood pressure in adolescence.

Background The prevalence of hypertension in children and adolescents has increased with the rising obesity epidemic. Recent studies have found that prevalence of hypertension was higher in obese children or adolescents than in the normal weight ones. Anthropometric measurements such as body mass index (BMI), waist circumference, and skinfold thickness have been used as criteria to determine obesity in children and adolescents. Increased waist circumference has been most closely related to increased blood pressure.
 Objective To compare waist circumference, BMI, and skinfold thickness as potential risk factors for hypertension in adolescents.
 Methods This cross-sectional study was conducted in May 2014 in three senior high schools in Medan, North Sumatera, and included 253 students with normal urinalysis test. All subjects underwent blood pressure, waist circumference, tricep- and subscapular-skinfold thickness (TST and SST), body weight, and body height measurements. The study population was categorized into underweight, normoweight, overweight, and obese, according to four different criteria: waist circumference, BMI, TST, and SST; all variables were analyzed for possible correlations with systolic and diastolic blood pressure.
 Results There were significant positive correlations between systolic blood pressure and waist circumference (OR 7.933; 95%CI 2.20 to 28.65; P=0.011) as well as BMI (OR 4.137; 95%CI 1.16 to 14.75; P=0.041). There were also significant correlations between diastolic blood pressure and waist circumference (OR 3.17; 95%CI 1.83 to 5.51; P=0.002), BMI (P=0.0001; OR=3.69), TST (OR 4.73; 95%CI 2.31 to 9.69; P=0.0001), and SST (OR 3.74; 95%CI 2.35 to 5.94; P=0.0001). Multivariate analysis showed that waist circumference was a predictive factor for systolic blood pressure (OR 9.667), but not for diastolic blood pressure.
 Conclusion Waist circumference is the strongest, significant, predictive factor for elevated systolic blood pressure; meanwhile BMI, SST, and TST could be predictive factors for elevated diastolic blood pressure.

Background/Objectives:To evaluate sex and race differences in fiber intakes, which are understudied in adolescents, and to investigate whether low insoluble and soluble fiber intakes would be associated with higher risk for insulin resistance and blood pressure (BP).Subjects/Methods:A total of 754 black and white adolescents, 14 to 18 years old (49.2% blacks; 50.3% female) were previously recruited in Augusta, Georgia, the US between 2001 to 2005. Diet was assessed with four to seven independent 24-hour dietary recalls.Results:The average daily consumption of total, insoluble, and soluble fiber were 10.9, 6.7, and 4.0g, respectively. Only two adolescents met their daily fiber intake recommendation. Adjusted multiple linear regressions revealed that increasing dietary fiber intake from current averages to recommendation levels (12g to 38g in the male and 9.9g to 25g in the female), were associated with predicted decreases of 5.4 and 3.0 mg/dL fasting glucose, 7.0 and 5.0 mg/dL fasting insulin, 1.6 and 1.1 HOMA-IR, 6.3 and 3.7 mmHg SBP, and 5.2 and 3.0 mmHg DBP in the males and females, respectively (all p < 0.05). Furthermore, both insoluble and soluble fiber intakes were inversely associated with fasting insulin and HOMA-IR (p <0.05); whereas only soluble fiber intake was found to be associated with BP (p <0.05).Conclusions:Fiber consumption in adolescents is far below daily-recommended levels across all sex and race groups. Lower fiber intake of all types is associated with higher insulin level. Fiber Intake at recommendation levels may be associated with significant cardiometabolic benefits.

Background : Hypertension in children and adolescents can be defined as Systolic Blood Pressure (TDS) / Diastolic Blood Pressure (TDD) on repeated measurements obtained from values above 95 percentiles. The incidence of hypertension in Riskesdas 2013 data for the age group 15-17 years is 5.3%. The prevalence of hypertension in adolescents in the province of Central Java in the 2013 Riskesdas data was 12.8%. Prevention of increasing the value of hypertension prevalence in adolescents can be done with aerobic exercise activities such as jogging. Objective: To determine the effect of giving aerobic exercise activities to changes in blood pressure in adolescents with hypertension. Method: Thistype of research is experimental with Randomized Control Trial Group Design. Sampling was done randomly to get 18 treatment subjects and 18 control subjects. Data collected were age, sex, weight, height, sodium intake, level of physical activity, blood pressure before and after treatment. Test the independent t-test wasused for data differences in blood pressure before and after treatment in both groups and paired t-test to determine changes in blood pressure before and after treatment, whereas the test ANOVA repeated measured is used to determine the effect of aerobic exercise (jogging)on blood pressure sample. Results: There were differences in systolic and diastolic blood pressure between the treatment and control groups (p 0.05). There is an effect of giving aerobic exercise activities to decrease systolic and diastolic blood pressure (p = 0,000 and p = 0.003) for each measurement at each meeting. Conclusion: The provision of aerobic exercise activities affects the decrease in diastolic systolic blood pressure in adolescents with hypertension.

Background: Depression and cardiovascular disease risk factors develop in childhood. The objective of this study was to investigate cross sectional and longitudinal associations between blood pressure, mood scores and tagged SNPs within the Monoamine oxidase A (MAOA) gene in the Western Australian Pregnancy Cohort (Raine) Study. Methods: Data from the five (n=1097), eight (n=1046), ten (n=1026) and fourteen (n=1124) year surveys were used. Blood pressure was measured at all surveys, anxious-depressed scores obtained from the Childhood Behavior Checklist at all surveys and depressive symptom scores from the Beck Depression Inventory for Youth at 14 years. Single nucleotide polymorphisms (SNPs) tagging the MAOA gene were identified from HapMap Phase II (CEU) data and genotyped. Cross sectional and longitudinal analyses were used to examine the association between blood pressure (outcome) and tagged SNPs within the MAOA gene and anxious/depressed scores (outcome) and tagged SNPs within the MAOA gene. Results: At 14 years, boys with the risk allele of SNP rs5905859 and rs3027396 had higher systolic blood pressure (βrs5905859=2.5; 95% CI: 0.743, 4.337 and βrs3027396=2.5; 95% CI: 0.681, 4.383 respectively) and lower mood scores (βrs5905859=-0.1; 95% CI: -0.100, -0.022 and βrs3027396=-0.2; 95% CI: -0.313,-0.045 respectively). Longitudinally, boys with the risk allele of SNPs rs5905859 (β=0.3; 95% CI: 0.026, 0.540) or rs6609257 (β= 0.3; 95% CI: 0.022, 0.521) had a higher mean systolic blood pressure trajectory compared to boys without. Conclusions: Variation within or close to the MAOA gene may explain in part the association between lower depressive symptom scores and higher systolic blood pressure in Caucasian boys within the Raine cohort.

Background: Evidence suggests that prolonged exposure to arsenic through drinking water increases the risk of hypertension in adults. However, few studies have evaluated the impact of early life arsenic exposure on blood pressure in adolescents and young adults. This study aimed to assess the association between in-utero-and-childhood arsenic exposure and prehypertension among the participants aged 11 to 22 years.Methods: The study was conducted in rural Bangladesh, Matlab. A cohort of 200 adolescents and young adults were enrolled of which 107 had in utero and first five years exposure to water arsenic concentration over 400µg/L (exposed group) and 93 had less than 10 µg/L(unexposed group). Blood pressure was measured using a standard mercury sphygmomanometer with an appropriately sized cuff. Prehypertension in adolescents was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) between the 90th and 95th percentile for age, sex and height. For the subjects 18 years and above, prehypertension was defined as SBP ranging from 120-139 mmHg and/or DBP 80-89 mmHg.Results: The overall prevalence of prehypertension was 16.5%. The high exposure group had a higher prevalence of prehypertension compared to the low exposure group (20.6% vs. 11.8%, 1-tailed p &amp;#61; 0.049). After adjustment for potential confounders, the prevalence odds ratio (POR) for prehypertension was 2.3 [95% Confidence Interval (CI): 0.78-7.1, 1-tailed p&amp;#61;0.066] in the participants exposed to arsenic &amp;gt;400 µg/L in their early life. The increased prevalence of prehypertension was only evident in females (POR&amp;#61;8.8, 95% CI: 1.05-74.1, 1-tailed p&amp;#61;0.023), and not in males (POR&amp;#61; 1.1, 95% CI: 0.26-5.1, 1-tailed p&amp;#61;0.433).Conclusions: Our result suggests a possible effect of early life arsenic exposure on increased risk of prehypertension in females. We plan to follow this unique cohort to see if the effect on blood pressure persists in females as they grow older.

To evaluate the wave reflection characteristics in the aortic arch and common carotid artery of ex-preterm adolescents and assess their relationship to central blood pressure in a cohort followed prospectively since birth. Central blood pressures, pulse wave velocity, augmentation index, microvascular reactive hyperemia, arterial distensibility, compliance and stiffness index, and also aortic and carotid wave intensity were measured in 18-year-olds born extremely preterm at below 28 weeks' gestation (n = 76) and term-born controls (n = 42). Compared with controls, ex-preterm adolescents had higher central systolic (111 ± 11 vs. 105 ± 10 mmHg; P < 0.001) and diastolic blood pressures (73 ± 7 vs. 67 ± 7 mmHg; P < 0.001). Although conventional measures of arterial function and biomechanics such as pulse wave velocity and augmentation index were no different between groups, wave intensity analysis revealed elevated backward compression wave area (-0.39 ± 0.21 vs. -0.29 ± 0.17 W/m/s × 10; P = 0.03), backward compression wave pressure change (9.0 ± 3.5 vs. 6.6 ± 2.5 mmHg; P = 0.001) and reflection index (0.44 ± 0.15 vs. 0.32 ± 0.08; P < 0.001) in the aorta of ex-preterm adolescents compared with controls. These changes were less pronounced in the carotid artery. On multivariable analysis, forward and backward compression wave areas were the only biomechanical variables associated with central systolic pressure. Ex-preterm adolescents demonstrate elevated wave reflection indices in the aortic arch, which correlate with central systolic pressure. Wave intensity analysis may provide a sensitive novel marker of evolving vascular dysfunction in ex-preterm survivors.

The aims of this study were to examine the longitudinal association between muscular fitness (MF) and blood pressure (BP) 2years later, and to determine whether changes in MF over a 2-year period were associated with BP at follow-up, in adolescents. The sample comprised 734 youths (349 girls) aged from 12 to 18years. MF was assessed with the standing long jump and handgrip tests. Socioeconomic status, pubertal stage, waist circumference, resting BP, and cardiorespiratory fitness were measured according to standard procedures. Regression analyses showed a significant inverse association between MF at baseline and systolic BP (β= - 0.072; p = 0.032) and rate pressure product (β= - 0.124; p < 0.001) at follow-up, after adjustments for age, sex, height, pubertal stage, and socioeconomic status. However, when analyses were further adjusted for waist circumference and cardiorespiratory fitness, these associations did not remain significant. Adolescents with persistently high and increasing MF exhibited the lowest levels of diastolic BP (F(3, 721) = 3.814, p = 0.018) and systolic BP (F(3, 721) = 3.908, p = 0.014) when compared to those with persistent low MF after adjustment for age, sex, height, socioeconomic status, cardiorespiratory fitness, and waist circumference.Conclusion: This study suggests that persistent greater and increasing MF in youth are associated with lower levels of BP across the adolescence. What is Known: • Currently, there is a growing interest on the health benefits of muscular fitness. • Cross-sectional studies have identified an association between muscular fitness and blood pressure in adolescents. What is New: • Changes in muscular fitness during adolescence were associated with systolic and diastolic BP over a 2-year period. • Adolescents with persistently low muscular fitness exhibited the highest levels of diastolic and systolic BP.

IntroductionPreterm birth affects 10% of births in the United States. The nervous and cardiovascular systems undergo significant development in the third trimester. The autonomic nervous system (ANS) plays a significant role in regulating heart rate and blood pressure. Parasympathetic nervous activity (PNA) increases throughout the third trimester, and preterm birth is known to result in lower PNA during infancy. Preterm birth is known to put young adults at greater risk of cardiac autonomic dysfunction, hypertension and cardiac hypertrophy. However, little is known about the onset of these cardiovascular abnormalities. Autonomic dysfunction and high blood pressure are associated with increased risk of cardiovascular disease. The purpose of our research is to investigate the long term effects of preterm birth on autonomic function and blood pressure at rest in adolescents born preterm and age‐matched term‐born controls. We hypothesize that preterms will have lower autonomic function, as determined by heart rate variability at rest, and elevated blood pressure compared to term‐born adolescents.Methods21 children born preterm (birthweight &lt;1500 g, gestational age &lt;32 weeks) and 20 children born full term (gestational age &gt;38 weeks) were studied. Heart rate variability measurements were obtained during a 15 minute supine resting period using a 3‐lead ECG. The standard deviation of R‐R interval (SDRR) and the root mean squared of successive differences (RMSSD) were calculated using PowerLab software. Blood pressures were obtained every 2 minutes during a 10 minute supine rest period using a brachial artery cuff, and the mean arterial blood pressure (MABP), systolic blood pressure (SBP), diastolic blood pressure (DBP) were determined. The relationship between MABP and RMSSD was determined using a linear regression. Results between groups were compared using Mann‐Whitney tests.ResultsPreterms had significantly lower birthweights than the controls (1097 ± 274 v 3497 ± 366 g, respectively, p&lt;0.001) and had lower gestational age (27.86 ± 2.10 v 39.74 ± 0.87 weeks, respectively, p&lt;0.001). Preterms had significantly higher MABP (82.2 ± 3.7 v 76.4 ± 4.0 mmHg, respectively, p&lt;0.001), DBP (65.8 ± 4.7 v 59.6 ± 5.1 mmHg, p=&lt;0.001), and SBP than controls (114.8 ± 5.7 v 109.9 ± 4.8 mmHg, p=.009). Preterms had lower HRV, SDRR (69.1 ± 33.8 v 110.1 ± 33.0 ms, p=.008), and RMSSD (58.8 ± 38.2 v 101.5 ± 36.2 ms, p=.012). There was a negative relationship between RMSSD and MABP (r2=0.324, p=0.007).DiscussionOur results demonstrate that adolescents born prematurely have lower HRV and higher resting blood pressure. Both autonomic dysfunction and elevated blood pressure are known to be correlated with increased risk of cardiovascular disease. Furthermore, we found a negative relationship between HRV and blood pressure in our population. Our results suggest that preterm individuals have higher sympathetic activity, and the inverse relationship between HRV and BP suggests that higher sympathetic vascular tone due to autonomic dysfunction leads to elevated BP. The individuals in our study were free of known cardiovascular or respiratory disease, and both groups were very active. Our results suggest that otherwise healthy preterm adolescents are potentially at increased risk of developing cardiovascular disease and further study is warranted.Support or Funding InformationNIH‐NHLBI R01–HL115061This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Introduction: Low cardiorespiratory fitness (fitness) and high levels of adiposity are independently associated with higher levels of blood pressure in adolescents. However, it remains uncertain whether the associations between fitness and blood pressure are due to fitness itself or results from lower levels of adiposity. Moreover, there are no studies that have determined the extent to which adiposity, including central adiposity, moderates the association between fitness and 24-hour ambulatory blood pressure (ABP). Hypotheses: 1. Higher levels of fitness will be associated with lower levels of ambulatory systolic (SBP) and diastolic (DBP) blood pressure after adjusting for adiposity and covariates. 2. With adjustments for covariates, adiposity (body mass index [BMI], waist circumference [WC]) will modify the association between fitness and 24-hour SBP and DBP. Methods: A cross-sectional study was conducted in Houston, TX with a sample of 370 adolescents aged 11-16 years. Demographically, the sample was 54% female, 37% African American, 31% Hispanic, 29% non-Hispanic white, and 3% other ethnic/racial groups. Fitness was assessed by a height-adjusted step test and estimated by heart rate recovery, defined as the difference between peak heart rate during exercise and heart rate two minutes post-exercise. Adiposity was measured using dichotomized values for percentiles of BMI (≥ 85 th ) and WC (≥ 50 th ). Ambulatory SBP and DBP (Spacelabs model 90207) were measured every 30-60 minutes over 24 hours on a school day. Mixed-effects regression analysis was used to test the hypotheses with the following covariates: activity, location, and position at the time of each ABP measurement, height, age, sex, ethnicity, sexual maturation level, and mother’s education level. Results: Hypothesis 1: Each unit increase in fitness was associated with a decrease of SBP (-0.058 mmHg, p = 0.001) and DBP (-0.043 mmHg, p &lt; 0.0001) after adjustment for WC and covariates. Each unit increase in fitness was associated with a decrease in SBP (-0.058 mmHg, p = 0.001) and DBP (-0.045 mmHg, p &lt; 0.0001) after adjustment for BMI and covariates. Hypothesis 2: Fitness and BMI ≥ 85 th percentile (or WC ≥ 50 th percentile) interactions were not significantly associated with ambulatory SBP or DBP after adjustment for covariates. Conclusions: Our findings indicate a small but statistically significant inverse effect of fitness on 24-hour ABP in adolescents, and no evidence of a modifying effect of adiposity on this association. Further research is needed to better understand the protective role of fitness on cardiovascular health in adolescents.

Study of Correlation of Body Mass Index(BMI) with Blood Pressure in Adolescents

Weekend oversleep or catchup sleep is a frequent occurrence in children, but there are relatively little data concerning its impact on weight and blood pressure. The aim of this study was to assess the association between sleep duration and oversleep, and weight and blood pressure in adolescents. Sleep duration, weight and blood pressure of 327 children (51.4% boys, mean age 13.3 ± 1.7 years) who had polysomnograms performed during both exam cycles of the Tucson Children's Assessment of Sleep Apnea study (TuCASA) were analyzed. Sleep duration on school nights and non-school nights was used to compute a weighted average of child and parent reported overall sleep duration respectively. Oversleep was defined as the difference between self and parent reported weekend sleep and weekday sleep separately. Simple correlations between overall sleep duration, sleep on school and non-school nights and oversleep, and blood pressure, standardized body mass index (BMI), snoring, respiratory disturbance index (RDI) and age were calculated. Significant bivariate associations then were used to develop multivariate partial correlation models. Unadjusted negative correlations with BMI were noted for parent reported total sleep duration at the 1st exam cycle, parent and child reported total sleep and school night sleep duration, and parent reported non-school night sleep duration at the 2nd exam cycle. Additionally, for BMI, positive correlations were observed for log RDI at both exam cycles and snoring at the 2nd exam cycle. For blood pressure, there were positive associations with age, parent reported oversleep, caffeine consumption and snoring. Additionally, for blood pressure, negative relationships were observed with parent reported total sleep duration at the 1st exam cycle, and parent and child reported total sleep and school night sleep durations at the 2nd exam cycle. Partial correlations found that BMI was negatively correlated with parent reported total sleep duration at the 1st exam cycle and parent reported total sleep duration at the 2nd exam cycle, and positively correlated with snoring and log RDI at both exam cycles. Systolic blood pressure was only associated with age and snoring. Diastolic blood pressure was positively correlated with age and caffeine consumption, and negatively correlated with parent reported total and school night sleep duration. Oversleep and child reported sleep duration were not represented in any of these models. Lower amounts of sleep especially on school nights is associated with higher body weight and blood pressure. Oversleep was not associated with either body weight or blood pressure.

Patients with gout often have co-morbidities such as cardiovascular disease, renal failure and metabolic syndrome components. Some studies, but not all, have suggested that hyperuricaemia and gout are associated with increased risk of myocardial infarction, renal failure and death primarily because of increased risk of cardiovascular events. Therefore, knowledge of the effects of urate-lowering therapy (ULT) on co-morbidities, in particular cardiovascular events and chronic kidney disease, is crucial. Randomized controlled trials (RCTs) have suggested that allopurinol, a xanthine oxidase inhibitor, could improve exercise capacity in patients with chronic stable angina and could decrease blood pressure in adolescents. In contrast, a well-designed RCT found no effect of allopurinol in patients with heart failure. The impact of ULT in patients with chronic kidney disease is unclear. Some RCTs found that allopurinol could slow the decline in kidney function, whereas a recent controlled trial found no benefit of febuxostat. Large randomized placebo-controlled trials are warranted to confirm or not the benefit of ULT on co-morbidities.

ABSTRACTObjectiveTo analyze the association between active commuting and blood pressure in adolescents.MethodsThis is a cross-sectional study with high school students from public education network in the state of Pernambuco, Brazil. Data from 6039 students (14 to 19 years) were collected using a questionnaire. “Physically inactive” were considered those who reported not to walk or ride a bicycle to and from school on any day of the past week, and/or those who, regardless of the weekly frequency of practice this type of activity, reported the duration of commuting to school was less than 20 minutes (round trip). The high blood pressure was obtained by Omron HEM 742 equipment. Adolescents with high blood pressure were defined as those with higher blood pressure or equal to the 95th percentile for age, sex and height. Regression logistic analyses were used to assess the association between active commuting and high blood pressure, considering adjustments for the following confounders: sex, age, overweight, total physical activity, socioeconomic level, place of residence.ResultsThe prevalence of high blood pressure was 7.3%, and 79.3% were considered insufficiently active in commuting. There was an association between high blood pressure and active commuting only among those living in rural areas (OR = 6.498; 95% CI = 1.513-27.900), and the same was not observed among those living in urban areas (OR = 1.113; 95% CI = 0.812-1.526).ConclusionActive commuting can be considered a protective factor for high blood pressure in adolescents living in rural areas.

Analysis of different anthropometric indicators in the detection of high blood pressure in school adolescents: a cross-sectional study with 8295 adolescents

Hypertension in children and adolescents is under-recognized and under-diagnosed in clinical practice. The 2017 AAP Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents provides updated recommendations that may improve hypertension identification and management. The AAP blood pressure guideline recommends annual screening for hypertension in children at preventive care visits and targeted routine screening in high-risk populations. A simplified blood pressure screening table is provided for easier recognition of blood pressures that may require attention. Normative blood pressure tables have been revised to include only data from normal-weight children as more representative of a healthy population. Classification of blood pressure in adolescents has been simplified to threshold values consistent with adult guidelines. The updated AAP blood pressure guideline has clarified and simplified recommendations for hypertension screening, diagnosis, and management based on a systematic review of current best evidence.

Background: Identifying the best marker for appropriate screening of risk factors of chronic diseases seems necessary in any society. Objectives: This study aimed at performing a comparative evaluation of anthropometric indices to determine a better marker for prediction of high blood pressure in adolescents. Methods: This cross-sectional study was done during 2013 on 1046 students, aged 11 to 19 year old in Kashan, who were chosen by cluster and class sampling method. Height, waist circumference (WC), waist-to-hip ratio (WHR), waist-to-high ratio (WHtR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) of the subjects were measured. Blood pressure of all subjects, who had their blood pressures measured during the first visit, was measured during the second and third visit again, and the three measured blood pressure averages was considered as subjects' blood pressure. Results: This study showed a significant positive correlation between BP and body mass index (BMI), WC, WHR, and WHtR indices (P < 0.001). Receiver operating characteristic curve (ROC) analysis was performed. Area under the curve (AUC) was obtained for BMI (0.62 to 0.73), WC (0.67 to 0.76), WHR (0.57 to 0.67), and WHtR (0.63 to 0.77) in diastolic blood pressure and BMI (0.66 to 0.76), WC (0.68 to 0.78), WHR (0.57 to 0.67) and WHtR (0.67 to 0.77) in systolic blood pressure. The WHtR in adolescents had better distinguishing power than other anthropometric indices. Conclusions: The WHtR, as a relatively simple, inexpensive, and convenient measurement method is the best anthropometric index for determination of blood pressure in these subjects.

The increasing prevalence of cardiovascular risk factors in children and adolescents has been largely, but not entirely, related to the childhood obesity epidemic. Among the noted risk factors detectable in children is elevated blood pressure. Emerging findings indicate that in addition to overweight and obesity, sodium intake is associated with elevated blood pressure in youth. Moreover, dietary sodium intake is quite high and well above recommended levels throughout childhood. In adults, the relationship of sodium consumption with hypertension is well established, and there is evidence from both population and clinical studies that potassium intake is also associated with blood pressure. Higher potassium intake is associated with lower blood pressure; and potassium deficit leads to an increase in blood pressure. Findings on relationships of potassium intake with blood pressure in childhood are sparse. There are some reports that provide evidence that a dietary pattern that includes potassium-rich foods is associated with lower blood pressure and may also lower blood pressure in adolescents with elevated blood pressure. Considering the secular changes in dietary patterns throughout childhood, it is prudent to encourage a diet for children that is high in potassium-rich foods.

The number of visits and blood pressure measurements influence the prevalence of high blood pressure in adolescents

Introduction: Greater dietary fiber intake has shown cardiometabolic benefits in adults. Previously, we have shown that dietary fiber intake is inversely associated with adiposity and inflammation in youth. However, evidence of the relations of fiber intake to insulin resistance and blood pressure in adolescents is lacking. Hypothesis: We hypothesized that greater daily dietary fiber intake would be associated with lower insulin resistance and blood pressure. Additionally, insulin resistance may mediate the relationship between fiber intake and blood pressure. Methods: Seven hundred and sixty-six Southeastern US adolescents from age 14 to 18 were recruited (50.3% females; 49.2% African-Americans). Diet was assessed via four to seven independent 24-hour recalls. Seated systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured five times at 1 minute intervals after 10 minute rest and the last three measurements were averaged. Percent body fat (%BF) was measured by dual-energy x-ray absorptiometry. Fasting blood samples were measured for fasting glucose and fasting insulin. Homeostatic Model Assessment for insulin resistance (HOMA-IR) was then calculated. Results: Multiple linear regressions with bootstrapping, adjusting for age, sex, race, Tanner stage, %BF, and energy intake, revealed that dietary total fiber intake was negatively associated with HOMA-IR, SBP, and DBP (standardized β = -0.22, β = -0.09, and β = -0.12; all p &lt; 0.05). Subcategorizing fiber into soluble and insoluble fiber revealed that both types were negatively associated with HOMA-IR ( p &lt; 0.01). However, only soluble fiber intake was negatively associated with both SBP and DBP (all p &lt; 0.01). No significant race and gender interactions with fiber were identified. Furthermore, a mediation test identified HOMA-IR as a mediator between soluble fiber intake and SBP and DBP (95% CI: -0.34; -0.04; 95% CI: -0.15; -0.01 respectively). Conclusions: Our data suggest that greater consumption of fiber may reduce insulin resistance and blood pressure in adolescents. Furthermore, insulin resistance may mediate the relationship between soluble fiber intake and blood pressure.