Biomarkers of kidney function and prediction of death from cardiovascular and other causes in the elderly: A 9-year follow-up study

BACKGROUND

Cystatin C is claimed to be superior to creatinine-based estimates of glomerular filtration rate (eGFRcr). The purpose of the study is to analyze whether cystatin C, creatinine, and/or estimated glomerular filtration rates (eGFR) predicted cardiovascular and/or non-cardiovascular deaths among Finnish elderly.

METHODS

Hazard ratios (HR) of cystatin C, creatinine and eGFRs for cardiovascular and non-cardiovascular deaths.

RESULTS

During a 9-year follow-up, 275 died, 192 deaths were a result of cardiovascular disease. In age-adjusted analyses, cystatin C predicted the risk of non-cardiovascular and cardiovascular death in men (HR for 0.1-unit increase 1.12 [95% CI, 1.04-1.19] for non-CVD deaths and 1.18 [1.09-1.28] for CVD deaths) and women (1.14 [1.07-1.21] and 1.14 [1.06-1.22], respectively). CKD-EPIcr-cyc predicted the risk of CVD deaths in men (HR for 5-unit decrease 1.17 [1.09-1.25]) and women (1.09 [1.02-1.17]) and non-CVD deaths in women (1.07 [1.01-1.14]). Also, MDRD (HR for 5-unit decrease 1.16 [1.05-1.27]) and CKD-EPI (HR for 5-unit decrease 1.15 [1.05-1.25]) predicted CVD deaths among men. After additional adjustments, predictive value of cystatin C remained significant. Also, the predictive value of CKD-EPIcr-cys remained significant in non-CVD deaths among women.

CONCLUSION

Cystatin C was clearly the best predictor for cardiovascular and non-cardiovascular deaths among Finnish elderly. Serum cystatin C is more accurate for clinical decision making than creatinine-based eGFR equations or the combined CKD-EPIcr-cys equation in persons older than 64years.

Asthma and atopic dermatitis in children born moderately and late preterm

This national register study aimed to evaluate the need of asthma medication reimbursement and hospitalization due to asthma and atopic dermatitis up to 7 years of age in moderately preterm (MP) (32-33 weeks) and late preterm (LP) (34-36 weeks) children compared to very preterm (VP) (<32 weeks) and term (≥37 weeks) children. Altogether, 1,018,302 children born in Finland between 1991 and 2008 were assessed. The MP and LP groups received asthma medication reimbursement more frequently than term controls (8.0 and 5.7 vs. 3.8 %), but less frequently than VP children (15.4 %). Hospitalization due to asthma was more common among MP (10.6 %) and LP (7.3 %) children than term children (4.8 %) but less common than in VP children (20.1 %). Hospitalization due to atopic dermatitis was more frequent among term (5.2 %) compared to MP (4.2 %) and LP (4.7 %) children. Male sex, maternal smoking, maternal diabetes, and ventilator therapy predicted asthma medication in the MP and/or LP children.

CONCLUSION

MP and LP children seem to need medication and hospitalization for asthma more often than term controls but less frequently than VP children followed by 7 years of age. Hospitalization due to atopic dermatitis becomes more common with increasing gestational age.

WHAT IS KNOWN

• MP and LP infants have an increased risk for early respiratory morbidity and to asthma. • Less is known on the occurrence of atopic dermatitis in this patient group. What is New: • Medication and hospital care due to asthma were more frequent in school-aged MP and LP than in term infants. Male sex, maternal smoking, maternal diabetes and ventilator therapy predicted asthma. • Hospitalization due to atopic dermatitis became more common with increasing gestational age.

Severe Bronchopulmonary Dysplasia, Growth, Nutrition, and Adipokines at School Age

This study evaluated nutrition and growth in relation to plasma adipokine levels in 21 very-low-birth-weight (VLBW) children with radiographic bronchopulmonary dysplasia (BPD), 19 VLBW controls, and 19 term controls with a median age of 11.3 years. We took anthropometric measurements; assessed plasma levels of adipsin, resistin, adiponectin, and leptin; and analyzed the children’s 3-day food records. Children with BPD had a smaller age-adjusted head circumference and more microcephaly but no other significant growth differences. Daily recommended nutritional intake levels were poorly met but did not differ between the groups. Leptin levels correlated positively with the body mass index standard deviation score in VLBW children. No other associations between adipokine concentrations and growth were found. There were negative correlations between leptin concentrations and fat intake, resistin levels and carbohydrate intake, and adiponectin, adipsin, and leptin levels and energy intake.

Very low birthweight bronchopulmonary dysplasia survivors show no substantial association between lung function and current inflammatory markers

AIM

The role of inflammation in the bronchopulmonary dysplasia (BPD) survivors is indistinct. We evaluated lung function in relation to inflammatory markers in plasma, exhaled breath condensate and exhaled air in school-aged very low birthweight (VLBW) survivors with and without radiographic BPD.

METHODS

Pre- and postbronchodilator impulse oscillometry were performed by 21 six to 14-year-old VLBW children with radiographic BPD, 19 VLBW children without radiographic BPD and 19 age-matched nonasthmatic term controls. Eosinophilic cationic protein, interleukins 6 and 8, adiponectin, adipsin, leptin and resistin in plasma, leukotriene B4 and 8-isoprostane in exhaled breath condensate, and bronchial and alveolar nitric oxide output were measured.

RESULTS

Abnormal lung function was found in 12.5% of the former VLBW children. Airway resistance at 5 Hz was highest in the radiographic BPD, but bronchodilator responses were most prominent in the non-BPD group. Plasma adiponectin had a modest positive correlation with obstruction and with bronchodilator responses, and alveolar nitric oxide and plasma interleukin 6 with bronchodilator responses.

CONCLUSION

Very low birthweight children with radiographic BPD had poorest lung function. The most pronounced bronchodilator responses were found in VLBW children without radiographic BPD. Current detected inflammatory markers had only a minor association with lung function in school-aged BPD survivors.

Cerebral palsy among children born moderately and late preterm

OBJECTIVE

To compare the incidence of and risk factors for cerebral palsy (CP) in moderately preterm (MP) (32(+0)-33(+6) weeks) and late preterm (LP) (34(+0)-36(+6) weeks) infants with those in very preterm (VP) (<32(+0) weeks) and term infants (≥37 weeks).

METHODS

The national register study included all live-born infants in Finland from 1991 to 2008. Infants who died before the age of 1 year, had any major congenital anomaly, or had missing data were excluded. A total of 1 018 302 infants were included in the analysis and they were analyzed in 4 subgroups (VP, MP, LP, and term) and 3 time periods (1991-1995, 1996-2001, and 2002-2008).

RESULTS

By the age of 7 years, 2242 children with CP were diagnosed (0.2%). CP incidence was 8.7% in the VP, 2.4% in the MP, 0.6% in the LP, and 0.1% in the term group. The risk of CP was highest in the study period 1991-1995 in all groups. Factors predictive of an increased CP risk in the MP and LP groups included resuscitation at birth (odds ratio 1.60; 95% CI 1.01-2.53 and 1.78; 1.09-2.90), antibiotic treatment during the first hospitalization (1.63; 1.08-2.45 and 1.67; 1.13-2.44), 1-minute Apgar score <7 (1.70; 1.15-2.52 and 1.80; 1.21-2.67) and intracranial hemorrhage (7.18; 3.60-14.3 and 12.8; 5.58-29.2).

CONCLUSIONS

The incidence of CP is higher in LP and MP infants compared with term infants. There is a nonlinear decrease in incidence over time and with increasing gestational age.

A comparison of anthropometric, metabolic, and reproductive characteristics of young adult women from opposite-sex and same-sex twin pairs

BACKGROUND

Prenatal exposure to androgens has been linked to masculinization of several traits. We aimed to determine whether putative female intra-uterine exposure to androgens influences anthropometric, metabolic, and reproductive parameters using a twin design.

METHODS

Two cohorts of Finnish twins born in 1975-1979 and 1983-1987 formed the basis for the longitudinal FinnTwin16 (FT16) and FinnTwin12 (FT12) studies. Self-reported anthropometric characteristics, disease status, and reproductive history were compared between 679 same-sex (SS) and 789 opposite-sex (OS) female twins (mean age ± SD: 34 ± 1.1) from the wave 5 of data collection in FT16. Serum lipid and lipoprotein subclass concentrations measured by nuclear magnetic resonance spectroscopy were compared in 226 SS and 169 OS female twins (mean age ± SD: 24 ± 2.1) from the wave 4 of data collection in FT12 and FT16.

RESULTS

Anthropometric measures, the prevalence of hypertension and diabetes mellitus type 2 did not differ significantly between females from SS and OS twin pairs at age 34. Similarly, the prevalence of infertility, age at first pregnancy and number of induced and spontaneous abortions did not differ significantly between these two groups of women. The serum lipid and lipoprotein profile did not differ between females from SS and OS twins at age 24.

CONCLUSION

We found no evidence that androgen overexposure of the female fetus affects obesity, metabolic profile, or reproductive health in young adult females. However, these results do not exclude the possibility that prenatal androgen exposure in females could be adversely associated with these phenotypes later in life.

[Clinical research work in the community health center: obstacles and chances of success]

Research work can support the development of methods and practices and increase the appreciation of the field. Research work in the community health center requires support from the management as well as collaborative networks with the university, primary health care unit and specialized care. It is wise to select the topic so that localinterest and support will be available. Multicenter studies and collaboration between communityhealth centers ensure the collection of adequate material. At its best, research work brings enthusiasm into the functioning of community health centers, makes the personnel more committedand provides training, and promotes the adoption of evidence-based practices.

Pulse pressure and subclinical peripheral artery disease

Ankle-brachial index (ABI) measurement offers an easily available method to diagnose peripheral artery disease (PAD) and systemic atherosclerosis in early stage and thus to identify high-risk individuals for preventive interventions. The objective of this study was to assess the most practical criteria for the measurement of ABI in subjects with high cardiovascular risk. We examined 972 asymptomatic, middle-aged high-risk subjects without manifested cardiovascular disease or previously diagnosed diabetes. The prevalence of PAD (defined as ABI0.90) and borderline PAD (0.91-1.00) were 5% (95% confidence interval (CI) 4-7%) (49/972) and 20% (95% CI 18-23%) (192/972), respectively. In multivariate analysis, female gender (odds ratio (OR) 0.71 (95% CI 0.53-0.97)), current smoking (OR 2.14 (95% CI 1.47-3.11)) and pulse pressure (OR 1.03 for each increase of 1 mm Hg (95% CI 1.01-1.04)) were associated with low ABI. Measuring ABI in subjects who smoke or have pulse pressure >65 mm Hg seems to be worthwhile.

Correcting overall survival for the impact of crossover via a rank-preserving structural failure time (RPSFT) model in the RECORD-1 trial of everolimus in metastatic renal-cell carcinoma

Clinical trials in oncology often allow patients randomized to placebo to cross over to the active treatment arm after disease progression, leading to underestimation of the treatment effect on overall survival as per the intention-to-treat analysis. We illustrate the statistical aspects and practical use of the rank-preserving structural failure time (RPSFT) model with the Fleming-Harrington family of tests to estimate the crossover-corrected treatment effect, and to assess its sensitivity to various weighting schemes in the RECORD-1 trial. The results suggest that the benefit demonstrated in progression-free survival is likely to translate into a robust overall survival benefit.

Surrogates of Large Artery versus Small Artery Stiffness and Ankle-Brachial Index

Peripheral artery tonometry (PAT) is a novel method for assessing arterial stiffness of small digital arteries. Pulse pressure can be regarded as a surrogate of large artery stiffness. When ankle-brachial index (ABI) is calculated using the higher of the two ankle systolic pressures as denominator (ABI-higher), leg perfusion can be reliably estimated. However, using the lower of the ankle pressures to calculate ABI (ABI-lower) identifies more patients with isolated peripheral arterial disease (PAD) in ankle arteries. We aimed to compare the ability of PAT, pulse pressure, and different calculations of ABI to detect atherosclerotic disease in lower extremities. We examined PAT, pulse pressure, and ABI in 66 cardiovascular risk subjects in whom borderline PAD (ABI 0.91 to 1.00) was diagnosed 4 years earlier. Using ABI-lower to diagnose PAD yielded 2-fold higher prevalence of PAD than using ABI-higher. Endothelial dysfunction was diagnosed in 15/66 subjects (23%). In a bivariate correlation analysis, pulse pressure was negatively correlated with ABI-higher (r = -0.347, p = 0.004) and with ABI-lower (r = -0.424, p < 0.001). PAT hyperemic response was not significantly correlated with either ABI-higher (r = -0.148, p = 0.24) or with ABI-lower (r = -0.208, p = 0.095). Measurement of ABI using the lower of the two ankle pressures is an efficient method to identify patients with clinical or subclinical atherosclerosis and worth performing on subjects with pulse pressure above 65 mm Hg. The usefulness of PAT measurement in detecting PAD is vague.

Effects of age, sex and smoking on ankle-brachial index in a Finnish population at risk for cardiovascular disease

BACKGROUND

Smoking is a well-known risk factor for peripheral arterial disease (PAD). Data regarding differences in the prevalence of PAD between sexes are somewhat controversial. In addition, most studies indicate that the prevalence of PAD increases with age in both sexes. In the present study, the effects of sex, age and smoking on the ankle-brachial index (ABI) in a Finnish cardiovascular risk population were investigated.

OBJECTIVES

To investigate the relationship between the ankle-brachial index, and age, sex and smoking in a Finnish population at risk for cardiovascular disease.

METHODS

All men and women between 45 and 70 years of age living in a rural town (Harjavalta, Finland; total population 7700) were invited to participate in a population survey (Harmonica study). Patients with previously diagnosed diabetes or vascular disease were excluded. In total, 2856 patients were invited to participate in the study. From these subjects, a cardiovascular risk population was screened. Complete data were available from 1028 persons. ABI (the ratio between the posterior tibial or dorsalis pedis artery and brachial artery pressures) was measured, and questionnaires were used to detect smoking status and relevant medical history. Only current smoking status was taken into account.

RESULTS

The mean ABI for the entire study population was 1.10 (range 0.56 to 1.64). Current smokers had a lower mean ABI (1.06; P<0.001). There was no statistically significant difference in ABI values among age groups, although the majority of patients with ABI values below 0.9 were older than 60 years of age. There was no statistically significant difference in ABI between sexes.

CONCLUSION

As previously reported, the present study shows the significant effect of smoking in the development of PAD. No statistically significant difference was found among age groups, but the tendency was toward lower ABIs in the oldest age groups. Sex had a minimal effect on the ABI.

High-sensitivity C-reactive protein and ankle brachial index in a finnish cardiovascular risk population

High-sensitivity C-reactive protein (hsCRP) has been previously linked to different forms of vascular disease. However, some studies have not found any relationship between hsCRP and atherosclerosis. Also, studies investigating correlation between hsCRP and ankle brachial index (ABI) are scarce. We studied hsCRP in a cardiovascular risk population with a special interest in correlation between hsCRP and ABI. All men and women aged 45 to 70 years from a rural town Harjavalta, Finland were invited to participate in a population survey. Diabetics and people with known vascular disease were excluded. Seventy-three percent (n = 2085) of the invited persons participated and 70% of the respondents (n = 1496) had at least one risk factor to cardiovascular diseases. These subjects were invited to further examinations. From them we measured ABI, hsCRP, leukocyte count, glucose tolerance, systemic coronary risk evaluation (SCORE), body mass index (BMI), and waist circumference. Mean hsCRP was 1.9 mg/L. Smokers had higher hsCRP (mean 2.2 mg/L) than nonsmokers (mean 1.8 mL/L). hsCRP in women was higher than in men (mean 2.0 mg/L versus 1.8 mg/L). Mean ABI was 1.10, and the prevalence of peripheral arterial disease was 3.1%. ABI correlated weakly with hsCRP (r = -0.077, p = 0.014), leukocyte count (r = -0.107, p = 0.001), and SCORE (r = -0.116, p = 0.001). It did not have correlation between age, weight, BMI, or waist circumference. hsCRP correlated with BMI (r = 0.208, p < 0.0001) and waist circumference (r = 0.325, p < 0.0001). When we excluded subjects with hsCRP >10 mg/L, ABI no longer correlated with hsCRP. In a cardiovascular risk population, hsCRP has only a weak correlation with ABI, and this correlation disappeared when we excluded subject with hsCRP >10 mg/L. Instead, hsCRP was correlated to the measures of obesity (waist circumference and BMI), indicating its role as a marker of adipose tissue-driven inflammation. hsCRP does not seem to be a suitable screening method for peripheral arterial disease.

Assessment of cardiovascular risk in primary health care

OBJECTIVE

This study aimed at investigating whether cardiovascular risk factors and their impact on total risk estimation differ between men and women.

DESIGN

Cross-sectional cohort study.

SUBJECTS

Finnish cardiovascular risk subjects (n = 904) without established cardiovascular disease, renal disease, or known diabetes.

MAIN OUTCOME MEASURES

Ankle-brachial index (ABI), estimated glomerular filtration rate (eGFR), oral glucose tolerance test, and total cardiovascular risk using SCORE risk charts.

RESULTS

According to the SCORE risk charts, 27.0% (95% CI 23.1-31.2) of the women and 63.1% (95% CI 58.3-67.7) of the men (p < 0.001) were classified as high-risk subjects. Of the women classified as low-risk subjects according to SCORE, 25% had either subclinical peripheral arterial disease or renal insufficiency.

CONCLUSIONS

The SCORE system does not take into account cardiovascular risk factors typical in women, and thus underestimates their total cardiovascular risk. Measurement of ABI and eGFR in primary care might improve cardiovascular risk assessment. especially in women.

Borderline peripheral arterial disease

Peripheral arterial disease (PAD), along with coronary artery disease and cerebrovascular disease, is a manifestation of systemic atherosclerosis. These cardiovascular diseases (CVDs) are the leading cause of death in the world, representing 30% of all global deaths. Although population-based studies indicate that PAD has a relatively benign course in the legs, patients with PAD show more cardiovascular comorbidity and have at least twofold risk of fatal coronary artery disease and cerebrovascular accidents compared with the general population. These studies suggest that noninvasive testing using the ankle-brachial index (ABI) is also an accurate marker of subclinical CVD and thus may hold promise for early identification of individuals at the greatest risk for major CVD events.The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) defines a cutoff ABI value of 0.90 or less for diagnosing PAD at rest. This threshold value has been reported to be 95% sensitive in detecting angiogram-positive PAD and almost 100% specific in identifying apparently healthy individuals. In persons without PAD, arterial pressures increase with greater distance from the heart, resulting in higher systolic blood pressures at the ankle than at the the brachial arteries. Thus, persons without atherosclerosis typically have an ABI greater than 1.00. But what is the significance of ABI values between 0.91 to 1.00, which are conventionally regarded as 'no disease'? The present article gives an overview of current knowledge of borderline PAD (ie, an ABI of 0.91 to 1.00).

Frequency and clinical correlates of radiographic patterns of bronchopulmonary dysplasia in very low birth weight infants by term age

Our aim was to study the frequency and clinical correlates of two radiographic patterns of bronchopulmonary dysplasia (BPD), the cystic BPD (cBPD) and the leaky lung syndrome (LLS). Radiographic findings of BPD from sixth day of life until term in a cohort of 82 very low birth weight (VLBW) infants were evaluated and scored independently by a neonatologist and a paediatric radiologist. Data on prenatal factors and events during the first hospitalisation were collected prospectively. Forty-four (53.7%) infants showed radiographic evidence of BPD, 19 (23.2%) cBPD and 25 (30.5%) LLS. In multivariate analysis, the best predictors for radiographic BPD were oxygen dependency at 28 days (odds ratio (OR) 10.2 [95% confidence interval (CI) 2.49-41.4]), more than 2 days on ventilator (OR 10.4 [95% CI 1.8-61.5]) and volume expanders in the first 2 h (OR 7.36 [95% CI 1.32-41.2]). During the first week of life, infants with radiographic BPD received less energy per kilogram (p < 0.001) and more daily fluids per kilogram of body weight (p = 0.013). Sixty-two percent of the infants with radiographic BPD were not oxygen dependent at 36 weeks postmenstrual age (PMA). Seventeen (89.5%) of the 19 infants who needed oxygen supplementation at 36 weeks PMA also had abnormal chest X-rays.

CONCLUSIONS

Radiographic BPD findings appeared to be common in VLBW infants. In addition to the well-known respiratory risk factors (oxygen and ventilator therapy), poor nutrition and excessive fluid administration in early life seem to be significantly associated with radiological findings of lung injury in these patients.

Effects of polarization in the presence and absence of biocides on biofilms in a simulated paper machine water

The antifouling potential of electric polarization combined and not combined with biocides was studied in nonsaline warm water with high organic content. Deinococcus geothermalis is a bacterium known for forming colored biofilms in paper machines and for its persistence against cleaning and chemical treatments. When D. geothermalis biofilms grown for 24 h in simulated paper machine water were exposed to cathodic or cathodically weighted pulsed polarization at least 60% (P < 0.05) of the biofilms were removed from stainless steel (AISI 316L). Biofilm removal by 25 ppm (effective substances 5-25 ppm) of oxidizing biocides (bromochloro-5,5-dimethylhydantoin, 2,2-dibromo-2-cyanoacetamide, peracetic acid) increased to 70% when combined with cathodically weighted pulsed polarization. Using a novel instrument that allows real-time detection of reactive oxygen species (ROS) we showed that the polarization program effective in antifouling generated ROS in a pulsed manner on the steel surface. We thus suggest that the observed added value of oxidative biocides combined with polarization depended on ROS. This suggestion was supported by the finding that a reductive biocide, methylene bisthiocyanate, counteracted the antifouling effect of polarization.

Endothelial function in a cardiovascular risk population with borderline ankle-brachial index

Introduction:

The diagnosis of peripheral arterial disease (PAD) can be made by measuring the ankle–brachial index (ABI). Traditionally ABI values > 1.00–1.40 have been considered normal and ABI ≤ 0.90 defines PAD. Recent studies, however, have shown that individuals with ABI values between 0.90–1.00 are also at risk of cardiovascular events. We studied this cardiovascular risk population subgroup in order to determine their endothelial function using peripheral arterial tonometry (PAT).

Methods:

We selected 66 individuals with cardiovascular risk and borderline ABI. They all had hypertension, newly diagnosed glucose disorder, metabolic syndrome, obesity, or a ten year risk of cardiovascular disease death of 5% or more according to the Systematic Coronary Risk Evaluation System (SCORE). Subjects with previously diagnosed diabetes or cardiovascular disease were excluded. Endothelial function was assessed by measuring the reactive hyperemia index (RHI) from fingertips using an Endo-PAT device.

Results:

The mean ABI was 0.95 and mean RHI 2.11. Endothelial dysfunction, defined as RHI < 1.67, was detected in 15/66 (23%) of the subjects. There were no statistically significant differences in RHI values between subjects with different cardiovascular risk factors. The only exception was that subjects with impaired fasting glucose (IFG) had slightly lower RHI values (mean RHI 1.91) than subjects without IFG (mean RHI 2.24) (P = 0.02).

Conclusions:

In a cardiovascular risk population with borderline ABI nearly every fourth subject had endothelial dysfunction, indicating an elevated risk of cardiovascular events. This might point out a subgroup of individuals in need of more aggressive treatment for their risk factors.

Decreased free water clearance is associated with worse respiratory outcomes in premature infants

OBJECTIVE

The goal was to elucidate predictors of decreased free water clearance (DFWC) in very low birth weight (VLBW) infants. We hypothesized that DFWC and fluid retention are linked to the severity of pulmonary problems and prolonged respiratory support, especially to nCPAP treatment.

METHODS

The investigation was carried out at Tampere University Hospital between 2001 and 2006. The study population comprised 74 VLBW infants born at 29.21 (24.57-34.14) weeks of gestation. Median birth weight was 1175 (575-1490) grams. We measured plasma and urine osmolality and 24-hour urine volume to calculate free water clearance (FWC) for each infant. If FWC was less than 30 ml/kg/day the infant was classified as having DFWC.

RESULTS

There were 38 (51.4%) infants with DFWC in the study population. The median duration of the observed DFT period was 14 (4-44) days. The gestational age at birth was lower for DFWC infants compared to infants with normal FWC (NFWC), 28.29 (24.57-32.86) vs. 30.00 (25.57-34.14) weeks (p = 0.001). DFWC infants also needed longer ventilator treatment, 2 (0-23) vs. 0.50 (0-23) days (p = 0.046), nCPAP treatment 30 (0-100) vs. 3 (0-41) days (p<0.0001) and longer oxygen supplementation 47 (0-163) vs. 22 (0-74) days (p = 0.011) than NFWC infants. All values presented here are medians with ranges.

CONCLUSIONS

DFWC appears to be frequently connected with exacerbation and prolongation of pulmonary problems in VLBW infants. Cautious fluid administration seems to be indicated in VLBW infants with prolonged respiratory problems and DFWC.

Detection and quantitation of colored deposit-forming Meiothermus spp. in paper industry processes and end products

Colored biofilms cause problems in paper industry. In this work we used real-time PCR to detect and to quantitate members of the genus Meiothermus from the process samples and end products from 24 machines manufacturing pulp, paper and board in four countries. The results obtained from 200 samples showed the importance of members of the genus Meiothermus as ubiquitous biofoulers in paper machines. This genus was the dominant biofouler in some mills. From < or =10(4) to 10(11) copies of Meiothermus 16S rRNA genes were found per gram of process deposit (wet weight). Meiothermus spp. were found in paper and board products with colored defects and connection between deposit-forming microbes and end-product spots was shown. 16S rRNA gene sequences of 29 biofilm producing bacterial isolates from different mills were determined. Based on sequence data, 25 of the isolates were assigned to the genus Meiothermus, with Meiothermus silvanus and M. ruber as the most frequent species.

Bone mineral density and lipid changes during 5 years of follow-up in a study of prevention of breast cancer with toremifene in healthy, high-risk pre- and post-menopausal women

A double-blind, randomised, placebo-controlled pilot study was initiated to evaluate the feasibility of chemoprevention with toremifene 60 mg/day in healthy women at high risk for breast cancer. Enrolment in the study was terminated earlier than planned because of slow patient accrual, although 13% of patients continued for 5 years. The revised efficacy outcomes were change in bone mineral density (BMD) from baseline at four skeletal sites, plus effects on serum lipids. In premenopausal women there was a trend for sustained increase in BMD during toremifene therapy after year 1 in lumbar spine. In postmenopausal women, toremifene had little or no effect on BMD trends. Levels of total and low-density lipoprotein (LDL) cholesterol were largely unchanged from baseline in premenopausal women treated with toremifene but were often slightly lower than in the placebo group during follow-up. Total and LDL cholesterol levels declined slightly from baseline in the postmenopausal women and were, at several points during the first 3 years, significantly lower than in the corresponding placebo group (p < 0.01). We conclude that: (a) assessment of toremifene 60 mg/day in chemoprevention will require further clinical trials; (b) toremifene 60 mg/day has no substantive negative effects on BMD in pre- or postmenopausal women and may exert a minor favourable influence (in particular, the effects of toremifene 60 mg/day on BMD in premenopausal women may make the drug an attractive alternative to tamoxifen 20 mg/day for that patient subset); (c) lipid effects of toremifene 60 mg/day are, at minimum, neutral and may be modestly favourable for reducing cardiovascular risk.

Cardiovascular findings in very low birthweight schoolchildren with and without bronchopulmonary dysplasia

BACKGROUND

With the introduction of new therapies in peri- and neonatology, the clinical picture of bronchopulmonary dysplasia (BPD) seems to alter. The consequences of this "new BPD" are of interest.

AIM

To evaluate cardiovascular findings during the surfactant era in very low birthweight (VLBW, birth weight < 1500 g) schoolchildren with and without BPD.

METHODS

At 7-8 years of age, 34 VLBW children with BPD born in one hospital underwent blood pressure (BP) measurement, electrocardiography (ECG), two-dimensional Doppler and M-mode echocardiography, flow-volume spirometry and whole-body plethysmography. The age- and sex-matched control groups comprised 34 VLBW children without BPD (no-BPD group) and 34 term children (term group).

RESULTS

The mean(SD) diastolic BP was significantly higher in the no-BPD than in the BPD group (65(9) vs. 59(8) mm Hg, p < 0.05). No clinically significant tricuspid regurgitations were found. The groups did not differ with respect to right ventricular systolic time intervals corrected for heart rate. The results of all M-mode measurements were within normal range. Compared to term controls, the BPD cases had lower mean(SD) forced expiratory flow in 1 s (90(14)% vs. 99(11)% of ref., p < 0.05) and more often high ratio of residual volume to total lung capacity (15(52%) vs. 4(13%), p < 0.01). No clinically significant correlations were found between current lung function and echocardiographic findings.

CONCLUSION

In the surfactant era, school-aged VLBW survivors with and without BPD do not seem to evince indirect signs of elevated pulmonary pressure. The increased pulmonary vascular resistance associated with BPD appears to resolve with time more rapidly than abnormalities in respiratory function.

Respiratory outcome in school-aged, very-low-birth-weight children in the surfactant era

AIM

To assess respiratory outcome and its predictors during the surfactant era in very-low-birth-weight (VLBW, birth weight <1500g) schoolchildren with and without bronchopulmonary dysplasia (BPD).

METHODS

At 7-8 years of age, 34 VLBW children with BPD diagnosed at a postnatal age of 28 d underwent flow-volume spirometry, metacholine challenge, bronchodilatation test, whole body plethysmography and diffusion capacity measurement. Fourteen of them had not recovered from BPD by a corrected gestational age of 36 wk (sBPD subgroup). The age- and sex-matched control groups comprised 34 VLBW cases without BPD and 34 term children.

RESULTS

Current respiratory symptoms in contact with cold air and/or upon exercise were reported in one-third of the VLBW children. Only half of the symptomatic VLBW cases without BPD had inhaled medications. Compared with term controls, the BPD cases had lower forced expiratory volume in 1 s (FEV1), higher ratio of residual volume to total lung capacity and higher airway resistance. Lower FEV1 and specific conductance were found in the sBPD subgroup compared to both control groups. Additionally, their vital capacity was lower than in term controls. A higher rate of bronchial hyper-reactivity and lower diffusion capacity of the lungs were detected in VLBW as against term cases. Low birth weight, long duration of oxygen therapy, low socio-economic status and exposure to animal dander emerged as predictors of poorer respiratory outcome.

CONCLUSION

In the surfactant era, birth weight, neonatal respiratory morbidity, as well as later environmental factors appear to affect the respiratory outcome of VLBW children. However, careful pulmonary follow-up of all VLBW children seems to be indicated regardless of the severity of neonatal respiratory problems.

Growth and adrenal androgen status at 7 years in very low birth weight survivors with and without bronchopulmonary dysplasia

AIMS

To evaluate whether 7 year old VLBW (very low birth weight, <1500 g) survivors with and without bronchopulmonary dysplasia (BPD) evince similar growth status and higher adrenal androgen (AA) levels than term controls, and whether AA levels are higher in VLBW children born small for gestational age (SGA) than in non-SGA cases.

METHODS

Assessment of height standard deviation score (SDs), body mass index (BMI), and serum androstenedione and dehydroepiandrostenedione sulphate levels in 31 VLBW children with BPD, 33 without BPD (no-BPD group), and 33 term controls.

RESULTS

Lower median (range) height SDs was found in BPD (-1.0 (-3.4 to 1.4) SD) and no-BPD (-0.9 (-2.9 to 2.2) SD) children than in term controls (0.3 (-1.5 to 1.9) SD). Low BMI (below 10th centile) was more common in both the BPD (18 (58%)) and no-BPD (16 (49%)) children compared to term cases (3 (9%)). The median (range) androstenedione levels tended to be higher in the BPD (0.8 (0 to 2.8) nmol/l) and no-BPD (0.8 (0 to 2.3) nmol/l) groups than in term controls (0.6 (0 to 1.8)). Higher median (range) dehydroepiandrostenedione sulphate levels were detected in the no-BPD compared to the term group (0.9 (0 to 4.1) v 0.3 (0 to 2.3) micro mol/l). VLBW children born SGA had higher AA levels compared to non-SGA cases.

CONCLUSIONS

At 7 years of age, VLBW children are shorter and tend to have higher AA levels than term controls, but VLBW children with and without BPD do not differ from each other in growth or AA status. Those born SGA have higher AA levels compared to non-SGA cases. The consequences of these findings to final height and to later metabolic and vascular health remain to be determined.

Isolated ultrafiltration affects dynamic vectorcardiographic ischemia monitoring parameters

AIMS

The present study was undertaken to assess the role of isolated ultrafiltration (UF phase) and hemodialysis with minimal ultrafiltration (HD phase) in changes in parameters reflecting myocardial ischemia: QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM) and ST vector magnitude (ST-VM6) registered by MIDA (myocardial infarction dynamic analysis).

PATIENTS AND METHODS

Twelve patients on maintenance hemodialysis were first ultrafiltrated for 2.5 h without dialysis (UF) followed by a 2.5-hour session of hemodialysis with minimal ultrafiltration (HD). Computerized vectorcardiography (VCG) was used for on-line dynamic analysis of ST segment and QRS complex changes. Blood volume (BV) changes were monitored non-invasively and continuously with the CRIT-LINE instrument. Whole-body bioelectric impedance analysis (BIA) was used for extracellular water (ECW) estimation.

RESULTS

During the UF phase QRS-VD and STC-VM showed a statistically significant increasing linear trend (time effect for both QRS-VD and STC-VM p < 0.0001, while no changes were noted in ST-VM6; time effect p = 0.986). During the HD phase none of these parameters changed (time effect for QRS-VD p = 0.855, for STC-VM p = 0.275 and for ST-VM6 p = 0.976). During the UF, phase changes in QRS-VD were in close relation to those in ECW.

CONCLUSION

Isolated ultrafiltration leads to an increase in the VCG ischemia monitoring parameters QRS-VD and STC-VM. The increase of QRS-VD is related to changes in ECW. Hemodialysis with minimal ultrafiltration has no effect on VCG ischemia monitoring parameters.

Flavonol and flavone intake and the risk of cancer in male smokers (Finland)

OBJECTIVE

To study the associations between the intake of flavonols and flavones and the risk of cancer.

METHODS

The study cohort consisted of 27,110 male smokers, aged 50-69 years, without history of cancer. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in Finland. The men completed a validated dietary questionnaire at baseline. Incident cases of cancers were identified through national registers. During an average 6.1-year follow-up, 791 lung cancers, 226 prostate cancers, 156 urothelial cancers, 133 colorectal cancers, 111 stomach cancers, and 92 renal cell cancers were diagnosed.

RESULTS

Intake of flavonols and flavones was inversely associated with the risk of lung cancer; multivariate relative risk in the highest vs. the lowest quartile 0.56, 95% confidence interval 0.45-0.69, p for trend 0.0001. The risk was similar in all histological types of lung cancer. No association was found between flavonol and flavone intake and the risk of other cancers.

CONCLUSIONS

Intake of flavonols and flavones seemed to be inversely associated with the risk of lung cancer, but not with that of other cancers.

Heart rate adjustment of magnetic field map rotation in detection of myocardial ischemia in exercise magnetocardiography

AIMS

We studied the capability of heart rate (HR) adjusted change in multichannel magnetocardiogram (MCG) to detect exercise-induced ischemia.

METHODS AND RESULTS

The MCG and 12-lead ECG were recorded simultaneously during supine exercise testing in 17 healthy controls and 24 patients with single vessel coronary artery disease (CAD). In the MCG analysis, we plotted the orientation of the magnetic field map (MFM) against the HR in each cardiac cycle during recovery. A regression line was fitted to the data and the line slope (degrees/bpm) was determined. In the ECG, the ST-segment depression vs HR (ST/HR) slope was evaluated. The HR adjusted MFM rotation was more extensive in the pooled CAD group, and in all subgroups with different stenosed vessel, than in the control group at the ST-segment (1.5 +/- 2.1 degrees/bpm vs 0.29 +/- 0.25 degrees/bpm, p < 0.0005) and at the T-wave apex (0.95 +/- 0.81 degrees/bpm vs 0.24 +/- 0.25 degrees/bpm, p < 0.0005). Areas under the receiver operating characteristic curves of the HR adjusted MFM rotation at the ST-segment (88.5%) and the T-wave (86.0%) were higher than the ones without HR adjustment (75.5% and 68.1%, respectively), and higher than the area of ST/HR slope in the ECG (80.2%).

CONCLUSION

HR adjusted MFM rotation detects transient ischemia independent of the stenosed vessel. HR adjustment improves the performance of the MCG in ischemia detection by the analysis of the ST-segment and the T-wave. The MCG was superior to the 12-lead ECG.

ST-segment level and slope in exercise-induced myocardial ischemia evaluated with body surface potential mapping

Body surface potential mapping (BSPM) is superior to 12-lead electrocardiography for detection of acute and old myocardial infarctions (MIs). We used BSPM to examine electrocardiographic criteria for acute reversible myocardial ischemia. BSPM with 123 channels was performed in 45 patients with coronary artery disease (CAD) and 25 healthy controls during supine bicycle exercise testing. Of the 45 patients, 18 patients had anterior, 14 had posterior, and 13 had inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST amplitude was measured 60 ms after the J-point and the ST slope calculated by fitting a regression line from the J-point to 60 ms after it. The optimal locations for detecting ST depression and ST-slope decrease were identified. In the pooled CAD patient group, the optimal location for ST depression was 5 cm below standard lead V(5) (CAD group: -70 +/- 70 microV; controls: 70 +/- 80 microV, p <0.001). Using a cut-off value of -10 microV, the ST depression separated the patients with CAD from controls with a sensitivity of 84% and a specificity of 96%. The ST slope became more horizontal in the patient group than in the control group. The optimal location for ST-slope decrease was over the left side (CAD group: 20 +/- 20 microV/s; controls: 720 +/- 320 microV/s, p <0.001). Using a cut-off value of 320 microV/s, the ST slope separated patients with CAD from controls with a sensitivity of 93% at a specificity level of 88%. The area under the receiver operating characteristic curve of ST slope tended to be higher than the one of ST depression (97% vs 93%; p = 0.097). In conclusion, regions sensitive for ST depression and for ST-slope decrease could be identified in BSPM, despite variation in the location of ischemia and the presence or absence of a history of MI. ST slope is a sensitive and specific marker of transient myocardial ischemia, and might perform even better than ST depression.

Flavonol and flavone intake and the risk of cancer in male smokers (Finland)

OBJECTIVE

To study the associations between the intake of flavonols and flavones and the risk of cancer.

METHODS

The study cohort consisted of 27,110 male smokers, aged 50-69 years, without history of cancer. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in Finland. The men completed a validated dietary questionnaire at baseline. Incident cases of cancers were identified through national registers. During an average 6.1-year follow-up, 791 lung cancers, 226 prostate cancers, 156 urothelial cancers, 133 colorectal cancers, 111 stomach cancers, and 92 renal cell cancers were diagnosed.

RESULTS

Intake of flavonols and flavones was inversely associated with the risk of lung cancer; multivariate relative risk in the highest vs. the lowest quartile 0.56, 95% confidence interval 0.45-0.69, p for trend 0.0001. The risk was similar in all histological types of lung cancer. No association was found between flavonol and flavone intake and the risk of other cancers.

CONCLUSIONS

Intake of flavonols and flavones seemed to be inversely associated with the risk of lung cancer, but not with that of other cancers.

Postmyocardial infarction patients susceptible to ventricular tachycardia show increased T wave dispersion independent of delayed ventricular conduction

INTRODUCTION

Experimentally, both delayed ventricular conduction and nonhomogeneous ventricular repolarization contribute to reentrant arrhythmias. We tested the hypothesis that increased T wave dispersion is independent of delayed ventricular conduction associated with arrhythmia vulnerability in postmyocardial infarction (post-MI) patients.

METHODS AND RESULTS

We studied 32 post-MI patients with clinical or inducible monomorphic ventricular tachycardia (VT group), 28 post-MI patients without arrhythmias (MI group), and 13 healthy controls, using magnetocardiographic (MCG) mapping with signal averaging. Twelve-lead ECG was the reference. Filtered QRS duration (fQRS) and T wave peak to T wave end interval (TPE) were used as measures of ventricular conduction and nonhomogeneity in ventricular repolarization, respectively. In MCG, the VT group showed the longest fQRS (135+/-34 msec vs 114+/-22 msec in the MI group; P = 0.012). Mean TPE and maximum TPE in VT versus MI groups were 78+/-9 msec versus 70+/-6 msec (P < 0.001) and 117+/-23 msec versus 104+/-19 msec (P = 0.020), respectively. Maximum TPE did not correlate with fQRS in the VT group (r = 0.063; P = NS) but did correlate in the MI group (r = 0.396; P = 0.037). For identification of post-MI patients prone to VT, selection of cutoff values for fQRS >140 msec and mean TPE >81 msec gave sensitivity and specificity of 41% and 89%, and 31% and 96%, respectively. Their combination increased sensitivity to 63% while maintaining 89% specificity.

CONCLUSION

Post-MI patients susceptible to VT show increased T wave dispersion independent of delayed ventricular conduction.

Magnetocardiographic intra-QRS fragmentation analysis in the identification of patients with sustained ventricular tachycardia after myocardial infarction

The aim of this study was to investigate if magnetocardiographic (MCG) analysis of cardiac micropotentials within the QRS complex can identity patients prone to ventricular arrhythmias, and to compare it to MCG time-domain, late-field analysis. The study population consisted of 136 patients with remote MI, 53 with and 83 without a history of VT. After averaging and high pass filtering of multichannel MCG signals, time-domain parameters describing the end-QRS activity and fragmentation index M and score S describing the whole QRS complex were computed. Fragmentation and time-domain parameters differed between the VT and control groups: fragmentation index M was 12 +/- 3 versus 9 +/- 2 (P <0.001), fragmentation score S was 83 +/- 42 versus 56 +/- 21 (P < 0.001), and filtered QRS duration was 144 +/- 32 versus 114 +/- 19 ms (P < 0.001) in VT and control groups, respectively. A combination of fragmentation parameters yielded 87% sensitivity and 61% specificity in VT identification. Corresponding figures for a time-domain parameter combination were 81% and 72%. Sensitivity of time-domain analysis was 88% and specificity was 75% in a subgroup with anterior MI. In multivariate analysis, fragmentation and time-domain analyses discriminated VT patients from controls independently of the extent of coronary artery disease or left ventricular dysfunction. MCG in postinfarction patients reveals pathology associated with propensity to ventricular arrhythmias inside and not only at the end of the QRS complex. MCG seems most accurate in the anterior infarct location.

Recording locations in multichannel magnetocardiography and body surface potential mapping sensitive for regional exercise-induced myocardial ischemia

INTRODUCTION

This study aimed to identify the optimal locations in multichannel magnetocardiography (MCG) and body surface potential mapping (BSPM) to detect exercise-induced myocardial ischemia.

METHODS

We studied 17 healthy controls and 24 coronary artery disease (CAD) patients with stenosis in one of the main coronary artery branches: left anterior descending (LAD) in 11 patients, right (RCA) in 7 patients, and left circumflex (LCX) in 6 patients. MCG and BSPM signals were recorded during a supine bicycle stress test. The capability of a recording location to separate the groups was quantified by subtracting the mean signal amplitude of the normal group from that of the patient group during the ST segment and at the T-wave apex, and dividing the resulting amplitude difference by the corresponding standard deviation within all subjects.

RESULTS

In MCG the optimal location for ST depression was at the right inferior grid for the RCA, at the mid-inferior grid for the LCX, and in the middle of these locations for the LAD subgroup (mean ST amplitudes: CAD -80 +/- 360fT, controls 610 +/- 660fT; p < 0.001). In BSPM it was on the left upper anterior thorax for the LAD, left lower anterior thorax for the RCA, and on the lower back for the LCX subgroup (mean ST amplitudes: CAD -39 +/- 61 microV and controls 38 +/- 38 microV; p < 0.001). In MCG the optimal site for T-wave amplitude decrease was the same as the one for the ST depression. In BSPM it was on the middle front for the LAD, on the back for the LCX and on the left abdominal area for the RCA group. In accordance with electromagnetic theory, the largest ST segment and T-wave amplitude changes took place in MCG in locations orthogonal to those in BSPM.

CONCLUSION

This study identified magnetocardiographic and BSPM recording locations which are sensitive for detecting transient myocardial ischemia by evaluation of the ST segment as well as the T-wave. These locations strongly depend on ischemic regions and are outside the conventional 12-lead ECG recording sites.

Repolarization abnormalities detected by magnetocardiography in patients with dilated cardiomyopathy and ventricular arrhythmias

INTRODUCTION

Abnormal repolarization is one of the acknowledged mechanisms leading to malignant ventricular arrhythmias. We used a novel magnetocardiographic technique to investigate the role of inhomogeneous repolarization in patients with nonischemic dilated cardiomyopathy prone to sustained ventricular arrhythmias.

METHODS AND RESULTS

Forty-nine dilated cardiomyopathy patients were studied, 18 with a history of sustained ventricular tachycardia (n = 6) or ventricular fibrillation (n = 12) and 31 with no ventricular arrhythmias. The magnetocardiogram was registered and QT apex and QT end intervals were determined by a computer algorithm. Inhomogeneity of repolarization was characterized with indices describing QT apex and QT end dispersion, and T wave end duration. In addition, time-domain late fields of the QRS complex in magnetocardiography and QT dispersion in 12-lead ECG were determined. T wave end was longer in the arrhythmia group in patients with sinus rhythm (87 +/- 15 msec vs 73 +/- 12 msec; P = 0.005) and in those not having bundle branch block. Magnetocardiographic late fields of the QRS complex were not different between groups. QT apex and end dispersion on magnetocardiography or 12-lead ECG showed no difference.

CONCLUSION

Prolongation of the end part of the T wave revealed by magnetocardiography is related to malignant ventricular arrhythmias in dilated cardiomyopathy. The results suggest that abnormal repolarization rather than delayed conduction underlies the arrhythmias in this disease.

Indoor radon concentrations caused by construction materials in 23 workplaces

The aim of this study was to compare the measured and the calculated concentrations of indoor radon caused by building materials at 23 workplaces. The measured concentrations of radon were clearly higher than the calculated radon concentrations from the building materials, which indicated that the main source of indoor radon was the soil under and around the buildings. The highest means of continuously (933 Bq m(-3)) and integrated (169 Bq m(-3)) measured and calculated (from 70 to 169 Bq m(-3)) concentrations of radon were found in hillside locations. On the other hand, the median (27 and 43 Bq m(-3)) and maximum (626 and 1002 Bq m(-3)) values of calculated indoor radon concentrations exhaled from construction materials were the highest at the ground level places. On average, only 7-19% of the radon seemed to originate from the construction materials.

Insulin-like growth factor binding protein 5 and type-1 insulin-like growth factor receptor are differentially regulated during apoptosis in cerebellar granule cells

Neuronal apoptosis is considered to play a significant role in several neuropathological conditions. However, the molecular mechanisms underlying neuronal apoptosis are poorly understood. Insulin-like growth factor (IGF) signalling is considered to be an important regulator of neuronal differentiation, survival and apoptosis. We have examined the expression of two members of the IGF system, insulin-like growth factor binding protein 5 (IGFBP-5) and the type-1 IGF receptor (IGF1R), during apoptosis of rat cerebellar granule cells (CGCs) in vitro. We describe a prominent downregulation of IGFBP-5 mRNA and protein expression. We also show that IGF-I increases IGFBP-5 expression in CGCs and that the downregulation of IGFBP-5 mRNA can be suppressed by inhibiting mRNA synthesis with actinomycin D. The expression of IGF1R mRNA showed a transient upregulation during potassium chloride (KCl) deprivation induced apoptosis, in contrast to the IGF1R protein level, which was downregulated during KCl deprivation. Our results provide insight into the expression of IGF-related genes during neuronal apoptosis, and indicate that they mediate a protective response to the withdrawal of trophic stimulation. It seems that the expression of IGFBP-5 and IGF1R is regulated to maximize the availability of IGF and the activity of IGF-triggered survival signalling.

Effects of cardiovascular autonomic function tests on QT dispersion in the 12-lead electrocardiogram of healthy patients

Changes in autonomic tone modulate QT interval duration. How cardiovascular autonomic reflexes affect QT dispersion, a suggested marker of arrhythmia risk, is not well established. We studied 10 healthy young adult volunteer men during quiet and deep breathing, the Valsalva maneuver, sustained handgrip, hyperventilation, the cold pressor test, and mental stress. An automated method was used for measurement of QT-peak and QT-end intervals, and QT dispersion was defined as maximum-minimum of the measured intervals. QT-peak dispersion was greater on deep expiration than deep inspiration (49 +/- 20 ms vs 37 +/- 14 ms, P < .05). QT-end dispersion decreased in the tachycardia phase of the Valsalva maneuver (45 +/- 23 ms vs 35 +/- 21 ms, P < .05), but QT dispersion did not change during the other interventions. Rapid cardiovascular autonomic reflex adjustment does not change QT dispersion in healthy young adult men. However, large intrathoracic volume and intrathoracic pressure changes during forced respiratory movements might confound QT dispersion measurements.

Magnetocardiographic QT dispersion during cardiovascular autonomic function tests

QT dispersion is considered to reflect nonhomogeneity of ventricular repolarization. The autonomic nervous system modulates QT interval duration, but the effect may not be spatially homogenous. Magnetocardiography (MCG) registers the weak magnetic fields generated by myocardial electric currents with high localizing accuracy. We studied the effects of rapid cardiovascular autonomic nervous adjustment on QT dispersion in MCG. Ten healthy male volunteers were monitored during deep breathing, the Valsalva maneuver, sustained handgrip, hyperventilation, the cold pressor test and mental stress. 67 MCG channels and 12 ECG leads were recorded simultaneously. A computer algorithm was used for QT interval measurements. QT dispersion was defined as maximum - minimum or standard deviation of the QTpeak and QTend intervals. In MCG the QT(end) dispersion increased during deep inspiration compared with deep expiration (96+/-19 ms v. 73+/-27 ms, p = 0.05). Magnetic QT dispersion tended to increase during the bradycardia phase of the Valsalva maneuver, but the change was obvious only for QT(end) (55+/-26 ms v. 76+/-29 ms, p<0.05). Other tests had no significant effect on QT dispersion, not even the cold pressor test, although it causes strong sympathetic activation. Magnetic and electric QT(peak) and QT(end) intervals correlated closely (r = 0.93 and 0.91), whereas the QT dispersion measures showed no correlation. In conclusion, magnetic QT dispersion is not modified by rapid changes in autonomic tone, but maneuvers involving deep respiratory efforts and changes in ventricular loading affect QT dispersion measurements.

Intake of flavonoids, carotenoids, vitamins C and E, and risk of stroke in male smokers

BACKGROUND AND PURPOSE

Antioxidants may protect against atherosclerosis and thus prevent cerebrovascular disease. We studied the association between dietary antioxidants and subtypes of stroke.

METHODS

The study cohort consisted of 26 593 male smokers, aged 50 to 69 years, without a history of stroke. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in Finland. The men completed a validated dietary questionnaire at baseline. Incident cases were identified through national registers.

RESULTS

During a 6.1-year follow-up, 736 cerebral infarctions, 83 subarachnoid hemorrhages, and 95 intracerebral hemorrhages occurred. Neither dietary flavonols and flavones nor vitamin E were associated with risk for stroke. The dietary intake of beta-carotene was inversely associated with the risk for cerebral infarction (relative risk [RR] of highest versus lowest quartile 0.74, 95% CI 0.60 to 0. 91), lutein plus zeaxanthin with risk for subarachnoid hemorrhage (RR 0.47, 95% CI 0.24 to 0.93), and lycopene with risks of cerebral infarction (RR 0.74, 95% CI 0.59 to 0.92) and intracerebral hemorrhage (RR 0.45, 95% CI 0.24 to 0.86). Vitamin C intake was inversely associated with the risk for intracerebral hemorrhage (RR 0.39, 95% CI 0.21 to 0.74). After simultaneous modeling of the antioxidants, a significant association remained only between beta-carotene intake and risk for cerebral infarction (RR 0.77, 95% CI 0.61 to 0.99).

CONCLUSIONS

Dietary intake of beta-carotene was inversely associated with the risk for cerebral infarction. No association was detected between other dietary antioxidants and risk for stroke.

Hemodialysis causes changes in dynamic vectorcardiographic ischemia monitoring parameters

AIMS

The aim of this study was to establish whether changes in parameters reflecting myocardial ischemia QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM) and ST vector magnitude (ST-VM6) during hemodialysis (HD) registered by MIDA (myocardial infarction dynamic analysis) are related to changes in blood volume (BV), extracellular water (ECW) and blood biochemistry.

PATIENTS AND METHODS

Fifteen hemodialysis (HD) patients were studied. Computerized vectorcardiography was used for on-line dynamic analysis of ST segment and QRS complex changes. BV changes were monitored non-invasively and continuously with the CRIT-LINE instrument. Bioelectric impedance analysis (BIA) was used for ECW estimation. Blood samples were taken before and after hemodialysis for hemoglobin (B-Hb), hematocrit (B-Hcr), sodium (P-Na), chloride (P-Cl), magnesium (P-Mg), potassium (P-K), ionized calcium (P-iCa), phosphate (P-Pi) and astrup measurement.

RESULTS

During dialysis treatment QRS-VD, ST-VM6 and STC-VM did not change in parallel. According to the linear mixed model, no statistically significant changes were noted in ST-VM6 during dialysis (time effect p = 0.5635). On the other hand, QRS-VD and STC-VM showed a statistically significant linear trend (time effect for QRS-VD p = 0.0001 and for STC-VM p = 0.0004). Changes in both ECW and BV affected the change in QRS-VD and in STC-VM.

CONCLUSION

During HD treatment changes in the vectorcardiographic ischemia monitoring parameters QRS-VD and STC-VM are mostly related to ECW and BV changes and may give a false positive impression of myocardial ischemia. The ST-VM6 trend is less markedly influenced by volume changes.