Predictors of blood pressure and hypertension in Tecumseh, Michigan

Childhood obesity and adult cardiovascular disease risk factors: a systematic review with meta-analysis

BACKGROUND

Overweight and obesity is a major public health concern that includes associations with the development of cardiovascular disease (CVD) risk factors during childhood and adolescence as well as premature mortality in adults. Despite the high prevalence of childhood and adolescent obesity as well as adult CVD, individual studies as well as previous systematic reviews examining the relationship between childhood obesity and adult CVD have yielded conflicting results. The purpose of this study was to use the aggregate data meta-analytic approach to address this gap.

METHODS

Studies were included if they met the following criteria: (1) longitudinal and cohort studies (including case-cohort), (2) childhood exposure and adult outcomes collected on the same individual over time, (3) childhood obesity, as defined by the original study authors, (4) English-language articles, (5) studies published up to June, 2015, (6) one or more of the following CVD risk factors [systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), non-high-density lipoprotein cholesterol (non-HDL), and triglycerides (TG)], (7) outcome(s) not self-reported, and (8) exposure measurements (child's adiposity) assessed by health professionals, trained investigators, or self-reported. Studies were retrieved by searching three electronic databases as well as citation tracking. Fisher's r to z score was calculated for each study for each outcome. Pooled effect sizes were calculated using random-effects models while risk of bias was assessed using the STROBE instrument. In order to try and identify sources of heterogeneity, random-effects meta-regression was also performed.

RESULTS

Of the 4840 citations reviewed, a total of 23 studies were included in the systematic review and 21 in the meta-analysis. The findings suggested that childhood obesity is significantly and positively associated with adult SBP (Zr = 0.11; 95% CI: 0.07, 0.14), DBP (Zr = 0.11; 95% CI: 0.07, 0.14), and TG (Zr =0.08; 95% CI: 0.03, 0.13), and significantly and inversely associated with adult HDL (Zr = -0.06; 95% CI: -0.10, -0.02). For those studies that adjusted for adult body mass index (BMI), associations were reversed, suggesting that adult BMI may be a potential mediator. Nine studies had more than 33% of items that placed them at an increased risk for bias.

CONCLUSIONS

The results of this study suggest that childhood obesity may be a risk factor for selected adult CVD risk factors. However, a need exists for additional, higher-quality studies that include, but are not limited to, both unadjusted and adjusted measures such as BMI before any definitive conclusions can be reached.

SYSTEMATIC REVIEW AND META-ANALYSIS

PROSPERO 2015: CRD42015019763 .

Childhood obesity and adult cardiovascular disease risk factors: a systematic review with meta-analysis

BACKGROUND

Overweight and obesity is a major public health concern that includes associations with the development of cardiovascular disease (CVD) risk factors during childhood and adolescence as well as premature mortality in adults. Despite the high prevalence of childhood and adolescent obesity as well as adult CVD, individual studies as well as previous systematic reviews examining the relationship between childhood obesity and adult CVD have yielded conflicting results. The purpose of this study was to use the aggregate data meta-analytic approach to address this gap.

METHODS

Studies were included if they met the following criteria: (1) longitudinal and cohort studies (including case-cohort), (2) childhood exposure and adult outcomes collected on the same individual over time, (3) childhood obesity, as defined by the original study authors, (4) English-language articles, (5) studies published up to June, 2015, (6) one or more of the following CVD risk factors [systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), non-high-density lipoprotein cholesterol (non-HDL), and triglycerides (TG)], (7) outcome(s) not self-reported, and (8) exposure measurements (child's adiposity) assessed by health professionals, trained investigators, or self-reported. Studies were retrieved by searching three electronic databases as well as citation tracking. Fisher's r to z score was calculated for each study for each outcome. Pooled effect sizes were calculated using random-effects models while risk of bias was assessed using the STROBE instrument. In order to try and identify sources of heterogeneity, random-effects meta-regression was also performed.

RESULTS

Of the 4840 citations reviewed, a total of 23 studies were included in the systematic review and 21 in the meta-analysis. The findings suggested that childhood obesity is significantly and positively associated with adult SBP (Zr = 0.11; 95% CI: 0.07, 0.14), DBP (Zr = 0.11; 95% CI: 0.07, 0.14), and TG (Zr =0.08; 95% CI: 0.03, 0.13), and significantly and inversely associated with adult HDL (Zr = -0.06; 95% CI: -0.10, -0.02). For those studies that adjusted for adult body mass index (BMI), associations were reversed, suggesting that adult BMI may be a potential mediator. Nine studies had more than 33% of items that placed them at an increased risk for bias.

CONCLUSIONS

The results of this study suggest that childhood obesity may be a risk factor for selected adult CVD risk factors. However, a need exists for additional, higher-quality studies that include, but are not limited to, both unadjusted and adjusted measures such as BMI before any definitive conclusions can be reached.

SYSTEMATIC REVIEW AND META-ANALYSIS

PROSPERO 2015: CRD42015019763 .

The Effect of Cardiac Cycle Phase on Reaction Time Among Individuals at Varying Risk for Hypertension

Abstract: Existing evidence suggests that baroreceptor stimulation may impair sensorimotor functioning. The purpose of this study was to determine whether the adverse effect of baroreceptor stimulation on sensorimotor functioning is more pronounced among individuals at increased risk for hypertension. A visual reaction time task was completed by 93 normotensive men and women at varying risk for hypertension, as defined by the combination of their resting systolic blood pressure and their parental history of hypertension. To correspond with natural fluctuations in baroreceptor stimulation across the cardiac cycle, stimuli were administered at one of 12 intervals after the occurrence of an electrocardiogram (ECG) R-wave (R + 50, 100, 150 . . . 600 ms). Reaction time to stimuli presented during the middle of the cardiac cycle, when baroreceptor stimulation is increased, was significantly slower than to stimuli presented earlier in the cycle, when baroreceptor stimulation is reduced. The influence of cardiac cycle phase on reaction time was similar among participants with high-normal, normal, or low-normal systolic blood pressure as well as among participants with a positive or negative parental history of hypertension. These findings suggest that baroreceptor stimulation impairs sensorimotor functioning in normotensive men and women; however, this effect is not more pronounced among individuals at increased risk for hypertension.

Obesity and autonomic function in adolescence

Hypertension and obesity are risk factors for coronary heart diseases in adults. In turn, childhood overweight and high blood pressure increase the risk of subsequent obesity and hypertension in adulthood. Human obesity is characterized by profound alterations of hemodynamic and metabolic states. Whether these alterations involve sympathetic nervous system control on cardiac function is controversial. We report the results of our study, conducted in a sample of obese adolescents by using power spectral analysis of heart rate variability. An increase in sympathetic tone coupled with a reduction in vagal tone was found. This allowed us to hypothesize that autonomic nervous system changes depend on the time course of obesity development. It is still unclear if treatment of obesity in adolescence prevents subsequent autonomic imbalance and hypertension.

Prediction of young adult blood pressure from childhood blood pressure, height, and weight

To assess the ability of childhood blood pressure, height, and weight to predict young adult blood pressure, the authors examined data obtained over multiple visits for four years on 339 children aged 8-18 years in East Boston, Massachusetts. These subjects were again seen 8-12 years later when they were aged 20-26 years. Multivariate regression models were used to predict true blood pressure in young adulthood from observed childhood measurements closest to age 10 (n = 219), adjusting for within-person variability. Without adjusting for childhood blood pressure, childhood height, weight and body mass index were at least marginally associated with young adult systolic blood pressure in boys and girls, with similar coefficients for each gender. The strongest predictor was weight (beta = 0.6 mmHg/10 lbs for girls, and beta = 0.7 mmHg/10 lbs for boys), and height was no longer predictive with weight in the model. With childhood blood pressure included, neither childhood height nor weight were predictors of future systolic blood pressure. However, change in height and weight were predictors of future systolic blood pressure. Weight change was a stronger predictor in girls than boys with beta = 0.9 mmHg/10 lbs. For diastolic blood pressure, height and weight had limited predictive ability in these data. These models, which allow for both between- and within-person variability in young adulthood, may be used to estimate the predictive value for future high blood pressure of a child's current blood pressure, height and weight, as well as future change in height and weight. These data suggest that the effects of childhood height and weight on future blood pressure may be negligible given childhood blood pressure, but that later height and weight remain predictive.

Predictors of 7-year changes in exercise blood pressure: effects of smoking, physical fitness and pulmonary function

BACKGROUND

The health status of 1999 apparently healthy men, aged 40-59 years, was ascertained after 16 years. We found that their systolic blood pressure during an ergometer exercise test added prognostic information beyond that from their blood pressure at rest concerning total cardiovascular mortality and mortality from myocardial infarction.

OBJECTIVE

To determine predictors of the change in systolic blood pressure at rest during 7 years and of the change in the prognostically important peak exercise systolic blood pressure at 600 kilopondmetres/min during 7 years.

METHODS

Predictors of the changes in blood pressures were investigated in 1393 middle-aged men who had been healthy without drug treatment for chronic disease or hypertension for 7 years. Twelve potential independent predictors were investigated.

RESULTS

Previous blood pressures, age and body mass index were independent predictors and could explain 18% of the change in systolic blood pressure at rest over 7 years. For systolic blood pressure at 600 kilopondmetres/min also smoking was associated with a rise whereas a high body mass index, physical fitness and forced expiratory volume in 1 s (all P< 0.001) were associated with lower blood pressure, explaining 19% of the variability.

CONCLUSIONS

Beyond a relatively strong tracking of blood pressures and the expected effect of age, smoking is associated with a 7-year rise in exercise systolic blood pressure whereas relatively higher body mass, physical fitness and pulmonary function are associated with lower exercise systolic blood pressure after 7 years in middle-aged healthy men.

Reflex sympathetic activation induces acute insulin resistance in the human forearm

Inferences about the association between sympathetic overactivity and insulin resistance have been drawn from the infusion of sympathomimetic amines in supraphysiological doses. We used the isolated perfused human forearm to investigate the effect of reflex-induced sympathetic nervous system activation on the peripheral utilization of glucose in the skeletal muscles of 14 healthy men. Local hyperinsulinemia in the forearm (132 +/- 25 microunits/mL for 90 minutes) induced a significant increase in the utilization of glucose from baseline (16.4 +/- 3.1 mg.dL-1.min-1 per 100 mL forearm volume) to a plateau (85.7 +/- 15.1 mg.dL-1.min-1 per 100 mL forearm volume) between 40 and 60 minutes of insulin infusion but did not alter the utilization of oxygen. Reflex sympathetic nervous system activation was elicited by unloading of cardiopulmonary receptors with bilateral thigh cuff inflation to 40 mm Hg between 60 and 90 minutes of insulin infusion. Blood flow in the forearm was significantly decreased with inflation of thigh cuffs (average decrease of 19%, p < 0.0001). As a result of thigh cuff inflation, there was a reduction in the utilization of glucose (a decrease of 23%, p < 0.02), whereas oxygen utilization was unchanged. We find that an increase in sympathetic nervous system activation (within the normal range of physiological responses) can cause acute insulin resistance in the forearm of healthy volunteers. The reflex caused no change in oxygen utilization, but the same stimulus elicited a decrease in the utilization of glucose.(ABSTRACT TRUNCATED AT 250 WORDS)