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Biomedical subjects

Stephen R Daniels

Publications and source records attributed to Stephen R Daniels.

At least 37 records · Page 2Linked to original sources
PubMed2006

Breastfeeding, introduction of complementary foods, and adiposity at 5 y of age.

BACKGROUND: Although dual-energy X-ray absorptiometry (DXA) is considered the most accurate measure of adiposity in children, it has rarely been used to examine the relation between infant feeding and adiposity during childhood. OBJECTIVE: The objective was to ascertain whether adiposity at age 5 y was related to breastfeeding, to the timing of the introduction of complementary foods during infancy, or to both. DESIGN: Body composition was measured in 313 children at age 5 y by using DXA. Data on breastfeeding, formula feeding, and the timing of the introduction of complementary foods were obtained from the mothers when the children were 3 y old. Regression analysis was used to examine the relation between infant feeding and fat mass after adjustment for lean body mass, sex, birth weight, maternal obesity, race, and other sociodemographic variables. RESULTS: Fifty-three percent of the children were boys, 80% were white, and 20% were black. There was no significant difference in adjusted fat mass between those ever breastfed and those never breastfed (x +/- SE: 4.48 +/- 0.09 and 4.76 +/- 0.17 kg, respectively; P = 0.17). Children who were breastfed for a longer duration and those who were breastfed without concurrent formula feeding did not have significantly lower fat mass than did those children who were never breastfed. Children did not differ significantly in fat mass if they were introduced to complementary foods before or after 4 mo of age (4.49 +/- 0.12 and 4.63 +/- 0.12 kg, respectively; P = 0.42). CONCLUSION: Neither breastfeeding nor the timing of the introduction of complementary foods was associated with adiposity at age 5 y.

Absorptiometry, Photon↗
PubMed2006

Dietary approaches to prevent and treat hypertension: a scientific statement from the American Heart Association.

A substantial body of evidence strongly supports the concept that multiple dietary factors affect blood pressure (BP). Well-established dietary modifications that lower BP are reduced salt intake, weight loss, and moderation of alcohol consumption (among those who drink). Over the past decade, increased potassium intake and consumption of dietary patterns based on the "DASH diet" have emerged as effective strategies that also lower BP. Of substantial public health relevance are findings related to blacks and older individuals. Specifically, blacks are especially sensitive to the BP-lowering effects of reduced salt intake, increased potassium intake, and the DASH diet. Furthermore, it is well documented that older individuals, a group at high risk for BP-related cardiovascular and renal diseases, can make and sustain dietary changes. The risk of cardiovascular disease increases progressively throughout the range of BP, beginning at 115/75 mm Hg. In view of the continuing epidemic of BP-related diseases and the increasing prevalence of hypertension, efforts to reduce BP in both nonhypertensive and hypertensive individuals are warranted. In nonhypertensive individuals, dietary changes can lower BP and prevent hypertension. In uncomplicated stage I hypertension (systolic BP of 140 to 159 mm Hg or diastolic BP of 90 to 99 mm Hg), dietary changes serve as initial treatment before drug therapy. In those hypertensive patients already on drug therapy, lifestyle modifications, particularly a reduced salt intake, can further lower BP. The current challenge to healthcare providers, researchers, government officials, and the general public is developing and implementing effective clinical and public health strategies that lead to sustained dietary changes among individuals and more broadly among whole populations.

Humans↗
PubMed2006

Self-perceived barriers to activity participation among sedentary adolescent girls.

PURPOSE: Potential barriers to activity participation were surveyed among adolescent girls and corroborated with other reported information. METHODS: Among 2379 black and white girls enrolled in the NHLBI Growth and Health Study since ages 9 or 10 yr, those reporting weekly activity frequency as "sometimes" or "rarely" were surveyed for three consecutive years from ages 16 or 17 yr. Barriers to activity were assessed using a 10-item questionnaire. Responses were cross-examined with other reported information. Race-specific longitudinal regression examined the impact of barrier scores on activity levels and also potential factors having an impact on barrier scores. RESULTS: Approximately half of the cohort was screened as "sedentary" with a trend toward an increasing proportion with age. Lack of time was cited by 60% of sedentary girls as the leading barrier to activity participation for all 3 yr. Other frequently cited barriers to activity included "I'm too tired" and "They don't interest me." No differences were seen in hours at work or in household chores between those who cited lack of time and those who did not. Barrier score was a significant predictor of habitual activity scores. For both races, body mass index and "would rather do other things than exercise" were significant predictors of barriers, but work, parental education, TV watching, and childbirth were not significant. CONCLUSION: Self-reported barriers to activity participation among sedentary girls were shown to be primarily internal and uncorrelated with other corresponding external factors.

Adolescent↗
PubMed2006

The consequences of childhood overweight and obesity.

Researchers are only gradually becoming aware of the gravity of the risk that overweight and obesity pose for children's health. In this article Stephen Daniels documents the heavy toll that the obesity epidemic is taking on the health of the nation's children. He discusses both the immediate risks associated with childhood obesity and the longer-term risk that obese children and adolescents will become obese adults and suffer other health problems as a result. Daniels notes that many obesity-related health conditions once thought applicable only to adults are now being seen in children and with increasing frequency. Examples include high blood pressure, early symptoms of hardening of the arteries, type 2 diabetes, nonalcoholic fatty liver disease, polycystic ovary disorder, and disordered breathing during sleep. He systematically surveys the body's systems, showing how obesity in adulthood can damage each and how childhood obesity exacerbates the damage. He explains that obesity can harm the cardiovascular system and that being overweight during childhood can accelerate the development of heart disease. The processes that lead to a heart attack or stroke start in childhood and often take decades to progress to the point of overt disease. Obesity in childhood, adolescence, and young adulthood may accelerate these processes. Daniels shows how much the same generalization applies to other obesity-related disorders-metabolic, digestive, respiratory, skeletal, and psychosocial-that are appearing in children either for the first time or with greater severity or prevalence. Daniels notes that the possibility has even been raised that the increasing prevalence and severity of childhood obesity may reverse the modern era's steady increase in life expectancy, with today's youth on average living less healthy and ultimately shorter lives than their parents-the first such reversal in lifespan in modern history. Such a possibility, he concludes, makes obesity in children an issue of utmost public health concern.

Cardiovascular Diseases↗
PubMed2006

Health-related quality of life and depressive symptoms in adolescents with extreme obesity presenting for bariatric surgery.

OBJECTIVE: We sought to document health-related quality of life (HRQoL) impairment and depressive symptomatology in adolescents with extreme obesity considering surgical weight loss. STUDY DESIGN: A retrospective review of clinical data was conducted for 33 consecutive extremely obese adolescents presenting for evaluation at a bariatric surgery program for adolescents. Adolescents completed the PedsQL and the Beck Depression Inventory. Mothers completed the parent-proxy PedsQL and the Child Behavior Checklist. RESULTS: HRQoL scores from both informants were markedly impaired relative to published norms on healthy youth. Moderate agreement was found for self-reported and parent-proxy HRQoL. Approximately 30% of youth met criteria for clinically significant depressive symptoms when based on self-report and 45% of youth when based on mother report. Only 21% of youth were currently engaged in some form of psychological treatment (eg, medication or therapy). CONCLUSIONS: The day-to-day life of adolescents with extreme obesity seeking bariatric surgery is globally and severely impaired. However, only some of these adolescents demonstrate clinically significant levels of depressive symptomatology. These data will be critical to the development of more informed patient selection criteria and more efficacious treatment paradigms for this vulnerable pediatric subgroup.

Adolescent↗
PubMed2006

Dietary recommendations for children and adolescents: a guide for practitioners.

Since the American Heart Association last presented nutrition guidelines for children, significant changes have occurred in the prevalence of cardiovascular risk factors and nutrition behaviors in children. Overweight has increased, whereas saturated fat and cholesterol intake have decreased, at least as percentage of total caloric intake. Better understanding of children's cardiovascular risk status and current diet is available from national survey data. New research on the efficacy of diet intervention in children has been published. Also, increasing attention has been paid to the importance of nutrition early in life, including the fetal milieu. This scientific statement summarizes current available information on cardiovascular nutrition in children and makes recommendations for both primordial and primary prevention of cardiovascular disease beginning at a young age.

Adolescent↗
PubMed2006

Sensitivity and specificity of pediatric lipid determinations for adult lipid status: findings from the Princeton Lipid Research Clinics Prevalence Program Follow-up Study.

OBJECTIVE: The goal was to determine the diagnostic utility of the National Cholesterol Education Program pediatric guidelines. METHODS: With the use of pediatric lipid data from the Cincinnati Clinic of the Lipid Research Clinics Prevalence Study and lipid and cardiovascular disease data collected for the same subjects as adults in the Princeton Follow-up Study, the sensitivity and specificity of the National Cholesterol Education Program pediatric guidelines were calculated overall and according to age. Furthermore, whether use of parental cardiovascular disease history during childhood influenced the sensitivity and specificity was assessed. RESULTS: Overall sensitivities were 43% to 46% and specificities were 82% to 86% for total and low-density lipoprotein cholesterol levels. There was considerable variation in sensitivities according to age, with the lowest sensitivities at ages 14 to 16 years and the highest sensitivities at ages 5 to 10 years and 17 to 19 years. Results were similar whether or not the population was restricted to children with a positive parental history of cardiovascular disease. CONCLUSIONS: Results of our analyses suggest that the sensitivity and specificity for evaluating total cholesterol or low-density lipoprotein cholesterol levels that are elevated in adulthood are not improved by selecting children with a positive parental history. These data also show the strong role that age (particularly the pubertal years between 10 and 15 years of age) plays in lipid measurements for children and adolescents. Continued prospective and longitudinal studies designed with age as well as other risk parameters are needed to determine the best guidelines for clinical screening in the future.

Adolescent↗
PubMed2006

Prevalence of cardiovascular disease risk factors in U.S. children and adolescents with diabetes: the SEARCH for diabetes in youth study.

OBJECTIVE: The purpose of this study was to determine the prevalence and correlates of selected cardiovascular disease (CVD) risk factors among youth aged <20 years with diabetes. RESEARCH DESIGN AND METHODS: The analysis included 1,083 girls and 1,013 boys examined as part of the SEARCH for Diabetes in Youth study, a multicenter, population-based study of youth 0-19 years of age with diabetes. Diabetes type was determined by a biochemical algorithm based on diabetes antibodies and fasting C-peptide level. CVD risk factors were defined as follows: HDL cholesterol <40 mg/dl; age- and sex-specific waist circumference >90th percentile; systolic or diastolic blood pressure >90th percentile for age, sex, and height or taking medication for high blood pressure; and triglycerides >110 mg/dl. RESULTS: The prevalence of having at least two CVD risk factors was 21%. The prevalence was 7% among children aged 3-9 years and 25% in youth aged 10-19 years (P < 0.0001), 23% among girls and 19% in boys (P = 0.04), 68% in American Indians, 37% in Asian/Pacific Islanders, 32% in African Americans, 35% in Hispanics, and 16% in non-Hispanic whites (P < 0.0001). At least two CVD risk factors were present in 92% of youth with type 2 and 14% of those with type 1A diabetes (P < 0.0001). In multivariate analyses, age, race/ethnicity, and diabetes type were independently associated with the odds of having at least two CVD risk factors (P < 0.0001). CONCLUSIONS: Many youth with diabetes have multiple CVD risk factors. Recommendations for weight, lipid, and blood pressure control in youth with diabetes need to be followed to prevent or delay the development of CVD as these youngsters mature.

Adolescent↗
PubMed2006

Interactions between noncontiguous haplotypes in the adiponectin gene ACDC are associated with plasma adiponectin.

Adiponectin, an adipocyte protein important in insulin sensitization and cardioprotection, has a strong genetic component. We hypothesized that variants in the adiponectin gene (adipocyte collagen-domain containing [ACDC]) contribute to adiponectin levels in a biracial adolescent cohort. We genotyped 11 ACDC single nucleotide polymorphisms (SNPs) in 631 non-Hispanic white and 553 African-American unrelated adolescents in grades 5-12 randomly selected from the Princeton School District Study. ACDC SNPs -11,391 (A allele), -10,068 (G allele), and +276 (T allele) were associated with higher adiponectin, adjusting for sex, puberty stage, BMI Z score, and waist Z score. Contiguous two-SNP haplotypes of promoter variants -11,391/-10,068 were significantly associated with adiponectin levels in whites and African Americans (P < 0.0001 and 0.03, respectively). Extended haplotypes from the promoter through the second intron (-11,391 to +349) strongly associated with adiponectin in whites (P = 6 x 10(-11)) and African Americans (P = 0.004), but haplotypes of first intron SNPs -4,521 to -657 did not (P > 0.2). Noncontiguous haplotypes or interactions between two-SNP (-11,391/-10,068) and three-SNP (+45, +276, and +349) haplotypes predicted adiponectin better than either region alone. Variants of ACDC are associated with adiponectin levels in whites and African Americans. Interactions between noncontiguous ACDC haplotypes strongly influence adiponectin levels, suggesting nonadditive and potentially cis relationships between these regions.

Adiponectin↗
PubMed2005

Dietary recommendations for children and adolescents: a guide for practitioners: consensus statement from the American Heart Association.

Since the American Heart Association last presented nutrition guidelines for children, significant changes have occurred in the prevalence of cardiovascular risk factors and nutrition behaviors in children. Overweight has increased, whereas saturated fat and cholesterol intake have decreased, at least as percentage of total caloric intake. Better understanding of children's cardiovascular risk status and current diet is available from national survey data. New research on the efficacy of diet intervention in children has been published. Also, increasing attention has been paid to the importance of nutrition early in life, including the fetal milieu. This scientific statement summarizes current available information on cardiovascular nutrition in children and makes recommendations for both primordial and primary prevention of cardiovascular disease beginning at a young age.

Adolescent↗
PubMed2005

Cardiac and vascular adaptation in pediatric patients with chronic kidney disease: role of calcium-phosphorus metabolism.

In children, cardiac abnormalities such as increased left ventricular mass (LVM) and diastolic dysfunction develop at the time of mild to moderate chronic renal insufficiency (CRI) and progress as renal function deteriorates. It was hypothesized that in this age group, vascular abnormalities develop early in the course of chronic kidney disease (CKD) in parallel with cardiac abnormalities and become more severe as end-stage disease is reached. Echocardiography and ultrasound of the carotid artery were performed on 44 patients with CKD stages 2 to 4 (CRI group), 16 patients who were on maintenance dialysis, and 35 healthy individuals. Carotid artery intima-media thickness (cIMT) was measured and distensibility and stiffness were calculated to assess carotid artery structure and function. Both the CRI and dialysis groups had greater cIMT, higher LVM index, and poorer diastolic function than the control subjects (P < 0.0001). Children who were on dialysis had greater cIMT and higher LVM index than those with CRI (P < 0.001) and greater arterial stiffness than both CRI patients and control subjects (P < 0.001). Arterial compliance was similar in CRI and control subjects. In all patients with CKD (CRI and dialysis), increased calcium-phosphorus product predicted increased cIMT. Increased serum phosphorus and intact parathyroid hormone predicted increased arterial stiffness. Elevated intact parathyroid hormone was a predictor of increased LVM index and poor diastolic function. In dialysis patients, the cumulative dose of phosphate binders and calcitriol predicted abnormal vascular structure and function. It is concluded that vascular abnormalities are already present in children and adolescents during early stages of CKD; they are more severe in children who are on maintenance dialysis and are related to abnormal calcium-phosphorus metabolism.

Adaptation, Physiological↗
PubMed2005

Regulation of body mass and management of childhood overweight.

Obesity has become an increasingly important public health problem. Recent evidence suggests that obesity has become a close second to tobacco use as a preventable cause of death in the United States. During the past decade an increase in the prevalence of type 2 diabetes in adolescents has been observed. The association of type 2 diabetes and obesity is well established and most adolescents with type 2 diabetes have body mass index (BMI) in a range that would already be considered obese in an adult. Childhood overweight is also associated with the atherosclerotic process. In the Bogalusa autopsy study, Berenson et al. found that the extent of fatty streaks and fibrous plaques in the aorta and coronary arteries was associated with BMI. There are three modalities currently available for the treatment of overweight in children and adolescents, including behavioral approaches, pharmacologic approaches, and surgical approaches. Surgical intervention may be considered if the BMI > or = 40 kg/m2 and a severe medical comorbidity including type 2 diabetes, obstructive sleep apnea or pseudotumor cerebri, or if the BMI is > or = 50 kg/m2 and comorbid conditions such as hypertension, dyslipidemia, or the metabolic syndrome are present. Behavioral intervention is usually made by a psychologist, behavioral therapist, dietician, or exercise physiologist. There is evidence that the effect of behavioral therapy for weight loss in childhood will be longer lasting than that seen in adults.

Behavior Therapy↗
PubMed2005

The relationships of adiponectin with insulin and lipids are strengthened with increasing adiposity.

CONTEXT: Adipose tissue inflammation has been implicated in the pathogenesis of obesity-related comorbidities. Adiponectin, an antiinflammatory protein, improves insulin sensitivity and lipid levels systemically. Because adiponectin is secreted by adipocytes, it may also act locally to counteract insulin resistance and dyslipidemia worsened by inflammation. OBJECTIVE: The aim of this study was to determine whether associations between adiponectin and insulin sensitivity and lipids are stronger with increasing adiposity. DESIGN: This cross-sectional study involved participants in The Princeton School District Study. SETTING: The study was conducted in the Princeton City schools (Cincinnati, OH) during the 2001-2002 school year. PARTICIPANTS: A total of 1196 non-Hispanic White and Black students in grades 5-12 participated. MAIN OUTCOME MEASURE: The relationships between adiponectin and high-density lipoprotein, triglycerides, and insulin were measured. To test our hypothesis, we: 1) compared correlation and regression coefficients of lean and nonlean individuals, and 2) incorporated an adiponectin by adiposity interaction in regression models. RESULTS: For high-density lipoprotein and triglycerides, the relationship with adiponectin, although present among lean adolescents, strengthened with increasing adiposity. However, with insulin, a relationship with adiponectin was only present among nonlean adolescents. CONCLUSIONS: These analyses suggest that adiponectin's relationship with insulin and lipids strengthens with increasing adiposity, such that heavier adolescents have a greater benefit from high levels of adiponectin than their lean counterparts.

Adiponectin↗
PubMed2005

Blood pressure and total peripheral resistance in children with chronic kidney disease.

We performed a study to assess cardiac output (CO) and total peripheral resistance (TPR) at rest and during peak exercise with the goal to better define the role of these parameters in the development of hypertension in children with chronic kidney disease (CKD) stage 2-4. Fifty-two pediatric patients with CKD (mean age 12.7+/-3.7 years) and 28 healthy individuals of comparable age and sex participated in the study. At rest, children with CKD had a significantly higher systolic and diastolic blood pressure (BP) and calculated mean arterial pressure (MAP) than healthy controls. Total peripheral resistance was significantly higher in children with CKD than in controls (1627.7+/-534.6 vs 1354.6+/-338.9 dynexsxcm(-5), p =0.02). There was no significant difference in heart rate or CO between the two groups. Children taking antihypertensive medications had lower TPR than children without BP medications (1514.6+/-439.6 vs 1788.2+/-505.4 dynexsxcm(-5), respectively, p =0.06). At peak exercise, children with CKD had a significant increase in MAP, heart rate and CO and had a significant decrease in TPR (difference between rest and peak exercise: -782.4+/-375.9 dynexsxcm(-5), p <0.001). Children taking BP medications had blunted MAP and CO responses when compared to controls (Delta CO: 6.2+/-2.8 l/min vs 9.8+/-4.5 l/min, respectively, p =0.01; MAP: 13.9+/-10.2 mmHg vs 21.5+/-11.7 mmHg, respectively, p =0.01). Children without BP medications had a similar to controls response to exercise in respect to CO, MAP and TPR. We conclude that increased TPR is a major contributor to elevated blood pressure in children with CKD and suggest that BP medications decreasing vascular resistance should be used as a first line of antihypertensive therapy in these patients.

Adolescent↗
PubMed2005

Overweight in children and adolescents: pathophysiology, consequences, prevention, and treatment.

The prevalence of overweight among children and adolescents has dramatically increased. There may be vulnerable periods for weight gain during childhood and adolescence that also offer opportunities for prevention of overweight. Overweight in children and adolescents can result in a variety of adverse health outcomes, including type 2 diabetes, obstructive sleep apnea, hypertension, dyslipidemia, and the metabolic syndrome. The best approach to this problem is prevention of abnormal weight gain. Several strategies for prevention are presented. In addition, treatment approaches are presented, including behavioral, pharmacological, and surgical treatment. Childhood and adolescent overweight is one of the most important current public health concerns.

Adolescent↗
PubMed2005

Factor analysis of clustered cardiovascular risks in adolescence: obesity is the predominant correlate of risk among youth.

BACKGROUND: Clustering of cardiovascular (CV) risks begins in childhood, yet studies of the factor structure underlying this clustering have focused on adults. The increasing rates of obesity and type 2 diabetes and the growing importance of metabolic syndrome among adolescents make assessment of CV risk clustering even more urgent in this age group. METHODS AND RESULTS: Exploratory factor analysis (principal components analysis) was performed with data from 1578 healthy seventh to 12th graders from the Princeton School District Study, a school-based study in Cincinnati, Ohio. Measured CV risks included cholesterol, triglycerides, fasting insulin and glucose, body mass index (BMI), waist circumference, fibrinogen, and blood pressure. Factor analysis yielded 4 uncorrelated factors (adiposity [BMI, waist, fibrinogen, insulin], cholesterol [LDL and total cholesterol], carbohydrate-metabolic [glucose, insulin, HDL cholesterol, triglycerides], and blood pressure [systolic and diastolic blood pressure]). These factors explained approximately 67% of the total variance. A summary cumulative risk scale was derived from factor scores, and high risk was defined as scoring in the top 5%. Although insulin loaded onto both the adiposity and carbohydrate-metabolic factors, obesity was a much stronger correlate of high cumulative risk (odds ratio=19.2; 95% CI, 7.6 to 48.5) than hyperinsulinemia (odds ratio=3.5; 95% CI, 1.8 to 6.8). A sizable proportion (18.5%; n=12) of those who were at high cumulative risk were not at high risk for any of the individual factors. CONCLUSIONS: The patterning of CV risk clustering seen among adults is present in healthy adolescents. Among youth, obesity is the predominant correlate of cumulative risk.

Adolescent↗