J. Kennedy Cruickshank

Management of high blood pressure in children and adolescents: recommendations of the European Society of Hypertension

Hypertension in children and adolescents has gained ground in cardiovascular medicine, thanks to the progress made in several areas of pathophysiological and clinical research. These guidelines represent a consensus among specialists involved in the detection and control of high blood pressure in children and adolescents. The guidelines synthesize a considerable amount of scientific data and clinical experience and represent best clinical wisdom upon which physicians, nurses and families should base their decisions. They call attention to the burden of hypertension in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, these guidelines should encourage public policy makers, to develop a global effort to improve identification and treatment of high blood pressure among children and adolescents.

Circulating concentrations of insulin-like growth factor-I and development of glucose intolerance: A prospective observational study

BACKGROUND Results of experimental and clinical studies suggest that insulin-like growth factor-I (IGF-I) and IGF binding protein-1 (IGFBP-1) could be important determinants of glucose homoeostasis. However, experimental models might also reflect compensatory and adaptive metabolic processes. We therefore prospectively examined the associations between circulating concentrations of IGF-I and IGFBP-1 and development of glucose tolerance. METHODS Participants in this cohort study were a random sample of 615 normoglycaemic men and women aged 45-65 years. Participants underwent oral glucose tolerance testing based on WHO definitions and criteria in 1990-92 and 1994-96. At the baseline visit, we measured serum concentrations of IGF-I and IGFBP-1, and assessed the relation between these peptides and subsequent glucose intolerance. FINDINGS At 4.5 years of follow-up, 51 (8%) of 615 participants developed impaired glucose tolerance or type-2 diabetes. After adjustment for correlates of IGF-I and risk factors for glucose intolerance, the odds ratio for risk of impaired glucose tolerance or type-2 diabetes for participants with IGF-I concentrations above the median (> or = 152 microg/L) compared with those with concentrations below the median (<152 microg/L) was 0.50 (0.26-0.95). Consistent with this finding, IGF-I also showed a significant inverse association with subsequent 2-h glucose concentrations, which was independent of correlates of IGF-I and risk factors for glucose tolerance (p for linear trend=0.026). We also found that this inverse association was independently modified by IGFBP-1 (p for interaction=0.011). INTERPRETATION These data show that circulating IGF-I and its interaction with IGFBP-1 could be important determinants of glucose homoeostasis and provide further evidence for the possible protective role of IGF-I against development of glucose intolerance.

The Hyperglycemia and Adverse Pregnancy Outcome Study: Associations of GDM and obesity with pregnancy outcomes

OBJECTIVE To determine associations of gestational diabetes mellitus (GDM) and obesity with adverse pregnancy outcomes in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study. RESEARCH DESIGN AND METHODS Participants underwent a 75-g oral glucose tolerance test (OGTT) between 24 and 32 weeks. GDM was diagnosed post hoc using International Association of Diabetes and Pregnancy Study Groups criteria. Neonatal anthropometrics and cord serum C-peptide were measured. Adverse pregnancy outcomes included birth weight, newborn percent body fat, and cord C-peptide >90th percentiles, primary cesarean delivery, preeclampsia, and shoulder dystocia/birth injury. BMI was determined at the OGTT. Multiple logistic regression was used to examine associations of GDM and obesity with outcomes. RESULTS Mean maternal BMI was 27.7, 13.7% were obese (BMI ≥33.0 kg/m2), and GDM was diagnosed in 16.1%. Relative to non-GDM and nonobese women, odds ratio for birth weight >90th percentile for GDM alone was 2.19 (1.93–2.47), for obesity alone 1.73 (1.50–2.00), and for both GDM and obesity 3.62 (3.04–4.32). Results for primary cesarean delivery and preeclampsia and for cord C-peptide and newborn percent body fat >90th percentiles were similar. Odds for birth weight >90th percentile were progressively greater with both higher OGTT glucose and higher maternal BMI. There was a 339-g difference in birth weight for babies of obese GDM women, compared with babies of normal/underweight women (64.2% of all women) with normal glucose based on a composite OGTT measure of fasting plasma glucose and 1- and 2-h plasma glucose values (61.8% of all women). CONCLUSIONS Both maternal GDM and obesity are independently associated with adverse pregnancy outcomes. Their combination has a greater impact than either one alone.

Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial

Summary Background Optimal drug treatment for patients with resistant hypertension is undefined. We aimed to test the hypotheses that resistant hypertension is most often caused by excessive sodium retention, and that spironolactone would therefore be superior to non-diuretic add-on drugs at lowering blood pressure. Methods In this double-blind, placebo-controlled, crossover trial, we enrolled patients aged 18–79 years with seated clinic systolic blood pressure 140 mm Hg or greater (or ≥135 mm Hg for patients with diabetes) and home systolic blood pressure (18 readings over 4 days) 130 mm Hg or greater, despite treatment for at least 3 months with maximally tolerated doses of three drugs, from 12 secondary and two primary care sites in the UK. Patients rotated, in a preassigned, randomised order, through 12 weeks of once daily treatment with each of spironolactone (25–50 mg), bisoprolol (5–10 mg), doxazosin modified release (4–8 mg), and placebo, in addition to their baseline blood pressure drugs. Random assignment was done via a central computer system. Investigators and patients were masked to the identity of drugs, and to their sequence allocation. The dose was doubled after 6 weeks of each cycle. The hierarchical primary endpoints were the difference in averaged home systolic blood pressure between spironolactone and placebo, followed (if significant) by the difference in home systolic blood pressure between spironolactone and the average of the other two active drugs, followed by the difference in home systolic blood pressure between spironolactone and each of the other two drugs. Analysis was by intention to treat. The trial is registered with EudraCT number 2008-007149-30, and ClinicalTrials.gov number, NCT02369081. Findings Between May 15, 2009, and July 8, 2014, we screened 436 patients, of whom 335 were randomly assigned. After 21 were excluded, 285 patients received spironolactone, 282 doxazosin, 285 bisoprolol, and 274 placebo; 230 patients completed all treatment cycles. The average reduction in home systolic blood pressure by spironolactone was superior to placebo (–8·70 mm Hg [95% CI −9·72 to −7·69]; p<0·0001), superior to the mean of the other two active treatments (doxazosin and bisoprolol; −4·26 [–5·13 to −3·38]; p<0·0001), and superior when compared with the individual treatments; versus doxazosin (–4·03 [–5·04 to −3·02]; p<0·0001) and versus bisoprolol (–4·48 [–5·50 to −3·46]; p<0·0001). Spironolactone was the most effective blood pressure-lowering treatment, throughout the distribution of baseline plasma renin; but its margin of superiority and likelihood of being the best drug for the individual patient were many-fold greater in the lower than higher ends of the distribution. All treatments were well tolerated. In six of the 285 patients who received spironolactone, serum potassium exceeded 6·0 mmol/L on one occasion. Interpretation Spironolactone was the most effective add-on drug for the treatment of resistant hypertension. The superiority of spironolactone supports a primary role of sodium retention in this condition. Funding The British Heart Foundation and National Institute for Health Research.

2016 European Society of Hypertension guidelines for the management of high blood pressure in children and adolescents

Increasing prevalence of hypertension (HTN) in children and adolescents has become a significant public health issue driving a considerable amount of research. Aspects discussed in this document include advances in the definition of HTN in 16 year or older, clinical significance of isolated systolic HTN in youth, the importance of out of office and central blood pressure measurement, new risk factors for HTN, methods to assess vascular phenotypes, clustering of cardiovascular risk factors and treatment strategies among others. The recommendations of the present document synthesize a considerable amount of scientific data and clinical experience and represent the best clinical wisdom upon which physicians, nurses and families should base their decisions. In addition, as they call attention to the burden of HTN in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, these guidelines should encourage public policy makers to develop a global effort to improve identification and treatment of high blood pressure among children and adolescents.

Ethnic differences in overweight and obesity in early adolescence in the MRC DASH study: the role of adolescent and parental lifestyle

BACKGROUND Ethnicity is a consistent correlate of excess weight in youth. We examine the influence of lifestyles on ethnic differences in excess weight in early adolescence in the UK. METHOD Data were collected from 6599 pupils, aged 11-13 years in 51 schools, on dietary practices and physical activity, parental smoking and overweight, and on overweight and obesity (using International Obesity Task Force criteria). RESULTS Skipping breakfast [girls odds ratio (OR) 1.74, 95% confidence interval (CI) 1.30-2.34; boys OR 2.06; CI 1.57-2.70], maternal smoking (girls OR 2.04, CI 1.49-2.79; boys OR 1.63, CI 1.21-2.21) and maternal overweight (girls OR 2.01, CI 1.29-3.13; boys OR 2.47, CI 1.63-3.73) were associated with obesity. Skipping breakfast, more common among girls, was associated with other poor dietary practices. Compared with White UK peers, Black Caribbeans (girls OR 1.62, CI 1.24-2.12; boys OR 1.49, CI 1.15-1.95) and Black Africans (girls OR 1.96, CI 1.52-2.53; boys OR 2.50, CI 1.92-3.27) were more likely to skip breakfast and engage in other poor dietary practices, and Indians were least likely. White Other boys reported more maternal smoking (OR 1.37, CI 1.03-1.82). All these reports were more common among those born in the UK than those born elsewhere. Black Caribbean girls were more likely to be overweight (OR 1.38, CI 1.02-1.87) and obese (OR 1.65, CI 1.05-2.58), Black African girls to be overweight (OR 1.35, CI 1.02-1.79) and White Other boys to be overweight (OR 1.37, CI 1.00-1.88) and obese (OR 1.86, CI 1.15-3.00). Adverse dietary habits and being born in the UK contributed to these patterns. CONCLUSION These findings signal a potential exacerbating effect on ethnic differences in obesity if adverse dietary habits persist. Combined adolescent and parent-focused interventions should be considered.

Impact of Statin Therapy on Central Aortic Pressures and Hemodynamics: Principal Results of the Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) Study

Background— Statins reduce the risk of cardiovascular events in people with hypertension. This benefit could arise from a beneficial effect of statins on central aortic pressures and hemodynamics. The Conduit Artery Function Evaluation–Lipid-Lowering Arm (CAFE-LLA) study, an Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) substudy, investigated this hypothesis in a prospective placebo-controlled study of treated patients with hypertension. Methods and Results— CAFE-LLA recruited 891 patients randomized to atorvastatin 10 mg/d or placebo from 5 centers in the United Kingdom and Ireland. Radial artery applanation tonometry and pulse-wave analysis were used to derive central aortic pressures and hemodynamic indices at repeated visits over 3.5 years of follow-up. Atorvastatin lowered low-density lipoprotein cholesterol by 32.4 mg/dL (95% confidence interval [CI], 28.6 to 36.3) and total cholesterol by 35.1 mg/dL (95% confidence interval, 30.9 to 39.4) relative to placebo. Time-averaged brachial blood pressure was similar in CAFE-LLA patients randomized to atorvastatin or placebo (change in brachial systolic blood pressure, −0.1 mm Hg [95% CI, −1.8 to 1.6], P=0.9; change in brachial pulse pressure, −0.02 mm Hg [95% CI, −1.6 to 1.6], P=0.9). Atorvastatin did not influence central aortic pressures (change in aortic systolic blood pressure, −0.5 mm Hg [95% CI, −2.3 to 1.2], P=0.5; change in aortic pulse pressure, −0.4 mm Hg [95% CI, −1.9 to 1.0], P=0.6) and had no influence on augmentation index (change in augmentation index, −0.4%; 95% CI, −1.7 to 0.8; P=0.5) or heart rate (change in heart rate, 0.25 bpm; 95% CI, −1.3 to 1.8; P=0.7) compared with placebo. The effect of statin or placebo therapy was not modified by the blood pressure–lowering treatment strategy in the factorial design. Conclusions— Statin therapy sufficient to significantly reduce cardiovascular events in treated hypertensive patients in ASCOT did not influence central aortic blood pressure or hemodynamics in a large representative cohort of ASCOT patients in CAFE-LLA.

Cord blood lipoproteins and prenatal influences

Purpose of review Blood lipoprotein profiles in early life are known to be related to and predictive of those in adulthood, but little is known about their determinants. Genetic and environmental influences affect cord blood lipoproteins, but how this occurs and the relative contribution of these influences to the overall profile in healthy newborns remains uncertain. Recent findings This review discusses findings from a range of earlier and more recent studies, and summarizes the key influences on cord blood lipoproteins. In particular, we review the potential contribution of maternal blood total cholesterol levels during pregnancy and the increased maternal transmission in newborns of mothers with diabetes. Summary In cord blood, cholesterol levels are lower than in adults and the relative proportion present in HDL as opposed to LDL is much higher. The currently available evidence suggests that several factors influence the composition of cord blood lipoproteins. Although inheritance of major monogenic disorders can affect cord lipids in general, the genetic contribution appears to be minimal, although effects of the proprotein convertase subtilisin/kexine type 9 gene (PCSK9) need fuller exploration in this regard in certain ethnic groups. Evidence is summarized that maternal lipoprotein levels, particularly those due to diet or induced by pregnancy, influence cord lipid levels. Placental insufficiency and other conditions affecting fetal growth and the mode of delivery may also influence cord lipoprotein concentrations. How maternal glucose tolerance during pregnancy affects cord blood lipoproteins remains unclear. In view of increasing evidence that cardiovascular risk may have prenatal antecedents, this would seem to be an important area for further investigation.

Hyperglycemia and Adverse Pregnancy Outcome Study: Neonatal Glycemia

OBJECTIVE: The goal was to describe the temporal pattern of neonatal plasma glucose levels and associations with maternal glucose levels, cord serum C-peptide levels, and neonatal size and adiposity. METHODS: A total of 17 094 mothers and infants were included in the Hyperglycemia and Adverse Pregnancy Outcome Study (15 centers in 9 countries). Mothers underwent a 75-g, 2-hour, oral glucose tolerance test (OGTT) at 24 to 32 weeks of gestation. Cord blood and neonatal blood samples were collected. Biochemical neonatal hypoglycemia was defined as glucose levels of <10th percentile (2.2 mmol/L). Clinically identified hypoglycemia was ascertained through medical record review and associations were assessed. RESULTS: Plasma glucose concentrations were stable during the first 5 hours after birth. Maternal glucose levels were weakly positively associated with biochemical neonatal hypoglycemia (odds ratios: 1.07–1.14 for 1-SD higher OGTT glucose levels). Frequency of neonatal hypoglycemia was higher with higher cord C-peptide levels (odds ratio: 11.6 for highest versus lowest C-peptide category). Larger and/or fatter infants were more likely to have hypoglycemia (P < .001), and infants with hypoglycemia tended to have a higher frequency of cord C-peptide levels of >90th percentile. CONCLUSIONS: Mean neonatal plasma glucose concentrations varied little in the first 5 hours after birth, which suggests normal postnatal adjustment. Biochemical and clinical hypoglycemia were weakly related to maternal OGTT glucose measurements but were strongly associated with elevated cord serum C-peptide levels. Larger and/or fatter infants were more likely to develop hypoglycemia and hyperinsulinemia. These relationships suggest physiologic relationships between maternal glycemia and fetal insulin production.

Characterizing the elastic properties of tissues

The quality of life of ageing populations is increasingly determined by age-related changes to the mechanical properties of numerous biological tissues. Degradation and mechanical failure of these tissues has a profound effect on human morbidity and mortality. Soft tissues have complex and intricate structures and, similar to engineering materials, their mechanical properties are controlled by their microstructure. Thus age-relate changes in mechanical behavior are determined by changes in the properties and relative quantities of microstructural tissue components. This review focuses on the cardiovascular system; it discusses the techniques used both in vivo and ex vivo to determine the age-related changes in the mechanical properties of arteries.