Left ventricular hypertrophy and ambulatory blood pressure monitoring in chronic renal failure

BACKGROUND: Left ventricular hypertrophy (LVH) is both common and an important predictor of risk of death in end-stage renal failure (ESRF). In mild to moderate chronic renal failure (CRF), the timing of onset of LVH and the factors involved in its initial development have not been fully elucidated. The present study was undertaken to examine the prevalence and potential determinants of echocardiographically determined LVH in this connection, and to compare 24-h ambulatory blood pressure (BP) recordings with BP measured at a previous clinic visit. METHODS: From a cohort of 120 non-diabetic patients who had been attending a nephrology clinic, 118 agreed to participate in the study. Of these we selected for analysis 85 stable patients (37 male). Patients with known cardiovascular disease, those with a history of poor compliance with antihypertensive medication, and those in whom such medication had been changed in the previous 3 months were excluded. Clinic BP, 24-h ambulatory BP, echocardiography, body mass index (BMI), serum creatinine (SCr), creatinine clearance (CrCl), haemoglobin (Hb), fasting cholesterol (CHOL), triglyceride TRIGL), plasma glucose, calcium (Ca), phosphate (PO4), alkaline phosphatase (ALK PHOS), parathyroid hormone (PTH) concentrations, and 24-h urinary protein were assessed in all patients. Seventy-seven per cent were on antihypertensive medication. RESULTS: LVH was detected in 16% of patients with CrCL > 30 ml/min, and 38% of patients with CrCl < 30 ml/min. By stepwise regression analysis, ambulatory systolic BP (P < 0.0001), male gender (P < 0.0001), BMI (P < 0.0002), and Hb concentration (P < 0.002) were the only independent determinants of left ventricular (LV) mass. Nocturnal systolic BP (P < 0.02) was the main determinant of LVH in the group of patients with advanced CRF. The correlation between left ventricular mass index (LVMI) and mean 24-h ambulatory systolic BP (r = 0.52, 95% confidence interval 0.50-0.54) was statistically significantly stronger than with outpatient systolic BP (r = 0.25, 95% confidence interval 0.23-0.27). The same was true for the correlation between LVMI and mean 24-h ambulatory diastolic BP (r = 0.42, 95% confidence interval 0.40-0.44), and outpatient diastolic BP (r = 0.22, 95% confidence interval 0.20-0.24). CONCLUSIONS: Twenty-four hour ambulatory BP recording and echocardiography are required for accurate diagnosis of inadequate BP control and early LVH in patients with chronic renal impairment, independent determinants of which are hypertension, male sex, BMI, and anaemia.      

Platelet cytosolic free calcium concentration and parathyroid hormone: changing relationships with haemodialysis in end-stage renal disease.

1. Twelve patients receiving haemodialysis for end-stage renal failure were studied at a single dialysis session. Platelet cytosolic calcium concentration, plasma ionized calcium concentration and serum parathyroid hormone concentration were measured before dialysis, mid-dialysis and 30 min after dialysis. 2. Plasma ionized calcium concentration increased towards dialysate calcium concentrations, falling insignificantly after cessation of dialysis. Serum parathyroid hormone concentration fell by 39% during dialysis, with incomplete recovery afterwards. There was no overall change in platelet cytosolic calcium concentration. 3. Patients were divided into two subgroups: low parathyroid hormone (serum parathyroid hormone concentration less than 10 pmol/l) and high parathyroid hormone (serum parathyroid hormone concentration greater than 10 pmol/l). Before dialysis, values of platelet cytosolic calcium concentration or plasma ionized calcium concentration were not statistically different between the subgroups, but the platelet cytosolic calcium concentration was higher in the high-parathyroid hormone subgroup during and after dialysis. 4. Before haemodialysis there was a linear correlation between plasma ionized calcium concentration and platelet cytosolic calcium concentration, which disappeared during dialysis. In contrast, there was no relationship between serum parathyroid hormone concentration and platelet cytosolic calcium concentration before dialysis, but after dialysis a hyperbolic relationship was evident. 5. These results suggest that uraemic toxins may interfere with cytosolic calcium homoeostasis, allowing passive diffusion of extracellular calcium to influence the resting concentration, and that this effect is reversible by haemodialysis.     

Sociodemographic correlates of virginity in seventh-grade black and Latino students.

PURPOSE: To examine rates of virginity in seventh-grade black and Latino students and assess the extent to which various sociodemographic factors are correlated with virginity. METHODS: A total of 523 seventh-grade students from five junior high schools and one middle school in the District of Columbia completed an anonymous self-administered questionnaire. Students responded to questions about age at first intercourse, demographics, grades, educational expectations, and risk behaviors. Multivariate analysis was used to determine the independent strength of the association of these variables with virginity. RESULTS: Eighty-one percent of girls and 44% of boys reported never having had sexual intercourse, i.e., being virgins. Black and Latino students were equally as likely to report being virgins. Younger age and absence of other risk behaviors, including smoking and alcohol use, were associated with virginity for males and females. For boys, reporting high academic achievement and living with both parents was significantly correlated with virginity and appeared to be protective. CONCLUSIONS: Although prevalent particularly in seventh-grade black and Latino boys, sexual activity was clearly associated with other risk behaviors in both boys and girls. Sociodemographic correlates of virginity were gender-specific. School-based efforts to delay the onset of initiation of sexual activity in high-risk populations should be targeted at boys 12 years and younger with interventions which are gender-specific. This study underscores a need to examine correlates of virginity to generate practical approaches to prevention of early sexual activity.     

The development of measures of community capacity for community-based funding programs in Canada

Improving community capacity for influencing actions on the determinants of health is an immediate outcome of many Public Health Agency of Canada-funding community-based programs. Despite the importance of this outcome, it has been difficult to measure and describe the contribution of funding programs to improving community capacity. This paper reports on a study conducted to develop and establish the psychometric properties of scales that measure community capacity to address health issues in the context of federally funded community-based programs. A literature review and national think tank with 21 experts informed the development of the first draft of the scales that outlined nine key domains of community capacity. Two focus groups with community practitioners provided information on the face and content validity and general usability of this draft instrument. The revised instrument was sent for pilot testing to 114 community organizations. Qualitative and quantitative analyses were performed to assess the validity, reliability and usability of the instrument. Twenty-nine organizations returned a completed instrument (25% response rate). Principal Component Analysis confirmed scale unidimensionality for eight multi-item scales: all of the component loadings were considered good with all scales loading between 0.60 and 0.92. Scale internal consistency was also considered high with alphas between 0.72 and 0.86 for six of these eight scales. Spearman's correlations were significant for the remaining two multi-item scales (composed of two items each), indicating that the two items for each scale were significantly correlated to each other. One scale could not be analyzed quantitatively, as it contained only a single item. Triangulation of qualitative and quantitative results found consistency in interpretations of scale response sets. Feedback on the instrument indicated interest in using it for project planning and evaluation. Psychometric analyses and triangulation provided evidence of the construct validity and reliability of the instrument. The final instrument covers 9 domains and has a total of 26 items, each with a four-point rating scale and a section for qualitative contextual comments. The instrument provides quantitative and qualitative information on community capacity within the context and scope of community-based funding programs.     

Quality assurance and the role of infection control: a retrospective study of hospital-acquired infection in a District General Hospital based on three sites, 1978-1988.

A retrospective study of hospital-acquired infection surveillance data from 1978 to 1988 showed a reduction in the incidence rate from 7.6 to 3.9% respectively, while simultaneously there was a 25% increase in throughput of patients. The reduction in the incidence of hospital-acquired infection is considered to be multifactorial. Since the rates of infection appear to be significantly altered by staff awareness and infection control programmes, they could be used as an outcome measure to reflect the quality of care in hospitals.     

Food insecurity of low-income lone mothers and their children in Atlantic Canada

OBJECTIVE: To examine the occurrence and predictors of hunger and food insecurity over the past year and month among low-income mother-led households in Atlantic Canada. METHOD: The Cornell-Radimer Questionnaire to Estimate the Prevalence of Hunger and Food Insecurity was administered weekly for a month, with modifications, to a community sample of 141 lone mothers who took part in a larger dietary intake study. Eligible women included those living alone with at least two children under the age of 14 years in the four Atlantic Provinces and having an annual income less than or equal to Statistics Canada's low-income cut-off. RESULTS: Food insecurity over the past year occurred in 96.5% of households. Child hunger was similar to maternal hunger over the one-month study period (23%), however, it was lower than maternal hunger over the past year. On multiple logistic regression analysis, maternal hunger over the past year was predicted by maternal age over 35 years (p < 0.0005), and Nova Scotia residence (p = 0.03). Child hunger over the past year was also predicted by maternal age over 35 years (p = 0.009). Families from New Brunswick experienced less food insecurity over the past month at both the household (p = 0.01) and maternal levels (p < 0.0005). DISCUSSION: Provincial policies that might contribute to the regular occurrence of food insecurity in these families should be investigated.     

Hypertension after renal transplantation. A comparison of cyclosporine and conventional immunosuppression

Hypertension is a common complication after renal transplantation and is associated with increased mortality. Cyclosporine is known to be nephrotoxic and raises blood pressure in recipients of cardiac and bone marrow transplants, but there is conflicting data on the role of cyclosporine after renal transplantation. We have examined this question in patients entered into the second Oxford prospective randomized comparison of short-term cyclosporine treatment alone with conversion to azathioprine and prednisolone at 90 days (CsA group), and conventional therapy with azathioprine and prednisolone throughout (AP group). Blood pressure and antihypertensive medication were similar in the CsA and AP treatment groups during the first 90 days. Following conversion from cyclosporine, mean blood pressure fell from 155/94 to 142/81 within 7 days, and this fall correlated with the change in plasma creatinine over the same period (r = 0.44, P less than 0.05). Blood pressure was subsequently lower in the converted patients than in those treated with AP throughout. Six months after transplantation patients converted from cyclosporine not only had lower blood pressure but also required fewer antihypertensive drugs than AP patients. This study demonstrates that cyclosporine may elevate the blood pressure in recipients of renal transplants. This effect may either be direct or mediated through the effect of cyclosporine on renal function. Administration of corticosteroids during the first three months after transplantation is implicated as a possible cause of persisting high blood pressure.     

The Cognitive,Affective, and Somatic Empathy Scales (CASES) for Children

Although the assessment of empathy has moved from general empathy to differentiating between cognitive and affective empathy, no instruments have assessed somatic (motor) empathy, and none have separated positive from negative affect empathy. The main objective of this study was to develop a 30-item self-report cognitive, affective, and somatic empathy scale (CASES) with positive and negative affect components for use with children and adolescents. A community sample of 428 male and female 11-year-olds completed the CASES together with validity questionnaires and were assessed on IQ. Caregivers reported on callous-unemotional traits, behavior problems, social adversity, and paternal criminality. Confirmatory factor analysis provided support for a 3-factor cognitive—affective—somatic structure of CASES and support for a broader 6-factor model of empathy. Configural and metric factor invariance across genders was established. Good internal consistency was obtained for the main scales. Criterion validity was established by lower empathy in callous-unemotional children. Incremental and predictive validity was documented by empathy at baseline predicting 12 months later to callous-unemotional traits after controlling for baseline callous-unemotional traits. Discriminant validity was documented by empathy being unrelated to internalizing behavior problems and differentially related to proactive and reactive forms of aggression. Construct validity was documented by lower empathy being associated with lower IQ, being male, more externalizing behavior problems, and criminality in the biological parent. Results provide initial support for a brief but multidimensional empathy scale with good sampling and face validity that can be used with children and adolescents.     

The effect of a supplementary (‘gist-based’) information leaflet on colorectal cancer knowledge and screening intention: a randomized controlled trial

Guided by Fuzzy Trace Theory, this study examined the impact of a ‘Gist-based’ leaflet on colorectal cancer screening knowledge and intentions; and tested the interaction with participants’ numerical ability. Adults aged 45–59 years from four UK general practices were randomly assigned to receive standard information (‘The Facts’, n = 2,216) versus standard information plus ‘The Gist’ leaflet (Gist + Facts, n = 2,236). Questionnaires were returned by 964/4,452 individuals (22 %). 82 % of respondents reported having read the information, but those with poor numeracy were less likely (74 vs. 88 %, p < .001). The ‘Gist + Facts’ group were more likely to reach the criterion for adequate knowledge (95 vs. 91 %; p < .01), but this was not moderated by numeracy. Most respondents (98 %) intended to participate in screening, with no group differences and no interaction with numeracy. The improved levels of knowledge and self-reported reading suggest ‘The Gist’ leaflet may increase engagement with colorectal cancer screening, but ceiling effects reduced the likelihood that screening intentions would be affected.     

White matter microstructure is associated with cognitive control in children

Cognitive control, which involves the ability to pay attention and suppress interference, is important for learning and achievement during childhood. The white matter tracts related to control during childhood are not well known. We examined the relationship between white matter microstructure and cognitive control in 61 children aged 7–9 years using diffusion tensor imaging (DTI). This technique enables an in vivo characterization of microstructural properties of white matter based on properties of diffusion. Such properties include fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity, measures thought to reflect specific biological properties of white matter integrity. Our results suggest that children with higher estimates of white matter integrity in the corona radiata, superior longitudinal fasciculus, posterior thalamic radiation, and cerebral peduncle were more accurate during incongruent (> > < > >, < < > < <) and neutral (-->--, --<--) trials of a task of cognitive control. Importantly, less interference during the task (i.e., incongruent and neutral difference scores) was associated with greater white matter microstructure in the posterior thalamic radiation and cerebral peduncle. Fiber tracts in a frontal–parietal–striatal–motor circuit seem to play a role in cognitive control in children.