Use of calcium supplements and the risk of coronary heart disease in 52–62-year-old women: The Kuopio Osteoporosis Risk Factor and Prevention Study

Background

To analyse prospectively the effect of calcium or calcium + D supplementation on coronary heart disease (CHD) in 52–62-year-old women.

Methods and results

10,555 52–62-year-old women from the population-based Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) who did not have CHD at baseline were followed for nearly 7 years in 1994–2001. Information about use of calcium supplements and health events was obtained from two repeated questionnaires in 1989 and 1994. Information about causes of death during the follow-up was obtained from the Statistics Finland. Information about CHD and other disease morbidity before and during the follow-up was obtained from the Registry of Specially Refunded Drugs of the Finnish Social Insurance Institution (SII). Cox's proportional-hazards models were used to estimate the risk of CHD morbidity related to the use of calcium supplements. At baseline, 2723 women reported current use of calcium or calcium + D supplementation. During the follow-up, CHD was diagnosed in 513 women. Compared to non-users of calcium/calcium + D supplements, the multivariate adjusted hazard ratio (HR) of CHD was 1.24 (95% CI 1.02–1.52) in women who used these supplements. The multivariate adjusted HR for CHD morbidity in postmenopausal women who used calcium/calcium + D supplements was 1.26 (95% CI 1.01–1.57).

Conclusions

Calcium or calcium + D supplementation appears to increase the risk of CHD among women before old age.     

Analysis of the seasonal pattern in suicide

BACKGROUND: Suicide has been attributed to social and psychological factors but also to geophysical effects. Of the latter, changes in solar radiation and geomagnetic activities may contribute to the frequency and the seasonal pattern of suicides. METHODS: We studied with a population-based, nationwide analysis all the individuals who committed suicide (n=27,469) in Finland during the period of 1979 to 1999. The daily data on the number of suicides, and the mean and maximum levels of geomagnetic activity were compiled and modelled with Poisson regression using the number of inhabitants in each province as the denominator. Time series analysis of monthly numbers of suicides was carried out using a seasonal-trend decomposition procedure. RESULTS: There was a strong seasonal effect on suicide occurrence (P<0.00001), the risk of suicide being greatest in spring. The seasonal effect was most pronounced when the number of suicides was relatively low. High levels of solar radiation activity were associated with the increased risk of suicide (P=0.00001), but the effect of geomagnetic activity was weak. LIMITATIONS: No individual data on alcohol consumption or mental disorders were available. CONCLUSIONS: Suicide occurrence varies markedly by season and needs attention where prevention is concerned.     

Muscle sympathetic nerve activity at rest compared to exercise tolerance

Cardiovascular autonomic function is associated with physical performance and exercise training adaptation. The association between physical performance and sympathetic regulation is not well known. We hypothesized that sympathetic nervous system activity is associated with physical performance among male runners. The study population included 26 healthy male club runners [age 33 ± 5 years, body mass index (BMI) 24 ± 1 kg/m², VO_2max 58 ± 5 ml kg⁻¹ min⁻¹; mean ± SD]. Muscle sympathetic nerve activity (MSNA) was assessed from the peroneal nerve by the microneurography technique during 5 min of supine rest. Physical performance was assessed by time to exhaustion during treadmill running. The mean resting MSNA was 20 ± 6 bursts min⁻¹ (range 6–34). The mean time to exhaustion was 1,005 ± 136 s (range 720–1260). When the study group was divided into tertiles according to their running performance (866 ± 69, 994 ± 30 and 1154 ± 71 s in time to exhaustion, P < 0.0001 between the groups), MSNA was lower (P = 0.032) in the group with the best running performance (16 ± 5 bursts min⁻¹) compared to those with the worst running performance (23 ± 7 bursts min⁻¹). In conclusion, baseline sympathetic activity, measured by a microneurography at rest, may be associated with the maximal running performance of healthy subjects.     

Effects of exercise intensity and duration on nocturnal heart rate variability and sleep quality

Acute physical exercise may affect cardiac autonomic modulation hours or even days during the recovery phase. Although sleep is an essential recovery period, the information on nocturnal autonomic modulation indicated by heart rate variability (HRV) after different exercises is mostly lacking. Therefore, this study investigated the effects of exercise intensity and duration on nocturnal HR, HRV, HR, and HRV-based relaxation, as well as on actigraphic and subjective sleep quality. Fourteen healthy male subjects (age 36 ± 4 years, maximal oxygen uptake 49 ± 4 ml/kg/min) performed five different running exercises on separate occasions starting at 6 p.m. with HR guidance at home. The effect of intensity was studied with 30 min of exercises at intensities corresponding to HR level at 45% (easy), 60% (moderate) and 75% (vigorous) of their maximal oxygen uptake. The effect of duration was studied with 30, 60, and 90 min of moderate exercises. Increased exercise intensity elevated nocturnal HR compared to control day (p < 0.001), but it did not affect nocturnal HRV. Nocturnal HR was greater after the day with 90- than 30- or 60-min exercises (p < 0.01) or control day (p < 0.001). Nocturnal HRV was lower after the 90-min exercise day compared to control day (p < 0.01). Neither exercise intensity nor duration had any impact on actigraphic or subjective sleep quality. The results suggest that increased exercise intensity and/or duration cause delayed recovery of nocturnal cardiac autonomic modulation, although long exercise duration was needed to induce changes in nocturnal HRV. Increased exercise intensity or duration does not seem to disrupt sleep quality.     

Characterization of Water‐Dispersible n‐Type Poly(benzimidazobenzophenanthroline) Derivatives

Novel water dispersible poly(benzimidazobenzophenanthroline) polymers functionalized with poly(ethylene oxide) (BBL:PEO) have been investigated by cyclic voltammetry, in situ UV‐vis spectroscopy and atomic force microscopy. The cyclic voltammograms recorded during n‐doping indicate that the drop coated BBL:PEO films retain their properties despite functionalization. A small influence of the PEO side chains on redox properties of the investigated polymers was found, diminishing however after annealing. During spectroscopic experiments structural changes connected with polymer charging were observed (in accordance with a two electron transfer process). The functionalization of BBL with PEO side chains provided an easy processing method to obtain smooth and reproducible polymer films.

     

The incidence of stress symptoms and heart rate variability during sleep and orthostatic test

This study examined the relation of self-reported stress to cardiac autonomic modulation in real-life conditions. The participants for the study were healthy male (N = 59) and female (N = 40) employees (age 40 ± 10 years). A single-item question and a 14-item questionnaire on perceived stress were administered to the participants before the experimental night. RR-intervals (RRI) were recorded during night sleep and an orthostatic test after awakening at home. The RRI data were analyzed for heart rate (HR) and heart rate variability (HRV) in time and frequency domains. Nocturnal urinary stress hormone (cortisol, adrenal and noradrenal) secretion was also analyzed. Based on the self-reported stress, the participants were divided into either low or high stress group. The results showed that higher incidence of stress symptoms was significantly associated with lower HRV in the orthostatic test regardless of age and gender. Differences between the stress groups in HRV indices were approximately 20–50 and 30–75% in supine and standing positions, respectively. No difference was found in nocturnal HR, HRV, or stress hormone secretion between the stress groups. Higher incidence of stress symptoms was significantly associated with greater decrease of HRV from night sleep to the orthostatic test, as a response to awakening. In conclusion, the present findings support the view that autonomic modulation measured in the orthostatic test, but not during night sleep, is related to self-reported stress.     

Increased Toll-like receptor 9 expression indicates adverse prognosis in oesophageal adenocarcinoma

Kauppila J H, Takala H, Selander K S, Lehenkari P P, Saarnio J & Karttunen T J
(2011) Histopathology 59 , 643–649 Increased Toll‐like receptor 9 expression indicates adverse prognosis in oesophageal adenocarcinoma Aims: Toll‐like receptor 9 (TLR‐9) is a cellular DNA receptor that has been linked previously to invasion in various cancers. The aim of this study was to investigate TLR‐9 expression and its possible association with prognosis in oesophageal adenocarcinoma. Methods and results: Immunohistochemical TLR‐9 expression was graded in clinical specimens (n = 76) of oesophageal adenocarcinoma. The TLR‐9 immunostaining intensity was compared with tumour grade, stage and indicators of proliferation, apoptosis and tumour vascular supply. High TLR‐9 expression correlated with advanced tumour stage, tumour unresectability, poor differentiation and high proliferation. Strong immunoreactivity of TLR‐9 also indicated poor overall survival. Conclusions: High TLR‐9 expression is associated with poor differentiation, a high proliferation rate and disseminated disease. Accordingly, increased TLR‐9 expression may contribute to the growth and metastatic properties of oesophageal adenocarcinoma.     

Genetic evidence for the presence of two distinct hantaviruses associated with Apodemus mice in Croatia and analysis of local strains

In Europe, Dobrava-Belgrade (DOBV), Saaremaa (SAAV), and Puumala (PUUV) viruses are known to cause hemorrhagic fever with renal syndrome (HFRS). All three hantaviruses are now found in Croatia. Lung tissue samples of 315 Apodemus mice trapped in 2003-2004 were screened for the presence of hantaviral N-Ag and 20 mice (6.3%) were found either strongly positive or weak/suspected-positive. Partial sequences of hantavirus M and S segments were recovered by RT-PCR from six mice and subjected to (phylo)genetic analysis that revealed the presence of four novel strains of DOBV and one of SAAV. Curiously, one of the newly described DOBV strains was found in Apodemus agrarius mouse, that is, not in the traditional host, A. flavicollis mice, suggesting a spillover event. S segment sequences recovered previously from HFRS cases [Markoti? et al., 2002] were confirmed as DOBV sequences; one of which appeared particularly close to the prototype Slovenian DOBV isolate. Taken together with earlier data on PUUV in Croatia, these results show a co-circulation of three European hantavirus pathogens in this country. So far, not a single SAAV sequence has been recovered from HFRS patients either in Croatia or neighboring Slovenia and Hungary nor in Slovakia suggesting a somewhat lower fequency of acute SAAV infection in humans in this part of Europe than for example in the Baltics.     

Immune responses to borrelial VlsE IR6 peptide variants

Laboratory confirmation of Lyme borreliosis (LB) relies mainly on the demonstration of anti-borrelial antibodies. In recent studies, a novel VlsE protein IR₆ peptide-based assay has been introduced. Our aim was to evaluate the IR₆ peptides from three Borrelia burgdorferi sensu lato genospecies in the serodiagnosis of European and North American patients. Five VlsE protein IR₆ peptide variants representing sequences from B. burgdorferi sensu stricto, B. garinii, and B. afzelii were used as antigens in both IgG and IgM enzyme-linked immunosorbent assays (ELISA). Serum antibodies of 187 patients at different stages of LB from Europe and the United States were evaluated for serodiagnosis. For comparison samples were tested with one of the commercial IR₆ ELISAs. Three B. afzelii IR₆ variant peptides revealed antibodies that were concordant with each other. B. burgdorferi sensu stricto peptide antibodies mostly paralleled B. afzelii peptide antibodies, and positive values were also obtained in the majority of European sera. For several sera, B. garinii IR₆ peptide antibodies were discordant to B. afzelii peptide antibodies. The commercial IR₆ peptide antibody assay (C6 ELISA) results correlated better with B. burgdorferi sensu stricto IR₆ than with B. garinii IR₆ peptide IgG results, especially in sera from patients with facial palsy. Thus, antibody specificity to IR₆ peptides may vary according to the infecting Borrelia species. In some manifestations of the disease, C6 ELISA may not cover all LB cases. Evidently, the methodological aspects in ELISA design for peptide antibody measurements are important as well as the amino acids sequence of the antigen.     

Increased fMRI responses during encoding in mild cognitive impairment

Structural and functional magnetic resonance imaging (fMRI) was performed on 21 healthy elderly controls, 14 subjects with mild cognitive impairment (MCI) and 15 patients with mild Alzheimer's disease (AD) to investigate changes in fMRI activation in relation to underlying structural atrophy. The fMRI paradigm consisted of associative encoding of novel picture-word pairs. Structural analysis of the brain was performed using voxel-based morphometry (VBM) and hippocampal volumetry. Compared to controls, the MCI subjects exhibited increased fMRI responses in the posterior hippocampal, parahippocampal and fusiform regions, while VBM revealed more atrophy in MCI in the anterior parts of the left hippocampus. Furthermore, the hippocampal volume and parahippocampal activation were negatively correlated in MCI, but not in controls or in AD. We suggest that the increased fMRI activation in MCI in the posterior medial temporal and closely connected fusiform regions is compensatory due to the incipient atrophy in the anterior medial temporal lobe.