Selenoprotein P increases upon selenium and coenzyme Q10 supplementation and is associated with telomere length, quality of life and reduced inflammation and mortality.

BACKGROUND: Selenoprotein P (SELENOP) transports selenium to extrahepatic tissues and is a biomarker of selenium status. Low soil selenium leads to low dietary selenium intake. A consequence is an increased risk of cardiovascular disease. OBJECTIVE: To investigate clinical aspects associated with SELENOP deficiency, including biomarkers of inflammation, quality of life, and mortality within 12 years, and the effect of dietary selenium and coenzyme Q10 supplementation on SELENOP. METHODS: SELENOP was determined at inclusion and after four years of supplementation in 403 elderly community-living participants low in selenium receiving selenium yeast (200 µg/day) and coenzyme Q10 (200 mg/day), or placebo. Pre-intervention, the average serum selenium level was 67 µg/L. T-tests, repeated measures of variance, Cox proportional regressions analyses, Kaplan-Meier graphs and ANCOVA analyses were applied. Associations with biomarkers of inflammation, telomere length, quality of life and mortality were investigated. Benchmark modelling was used to determine the serum selenium concentration at which the saturation levels of SELENOP and GPx3 was achieved. Comparison with GPx3 and serum selenium to identify increased mortality risk was performed, and the effect of supplementation on SELENOP levels were evaluated. RESULTS: Inverse associations were observed between the level of SELENOP at inclusion and biomarkers for inflammation. At follow-up, shorter telomere lengths were seen in those with low levels of SELENOP at inclusion, whereas high levels of SELENOP were associated with better quality of life and decreased mortality. SELENOP had increased prognostic power compared to GPx3 and selenium. Saturation of SELENOP was achieved at a serum selenium level of 146 µg/L, and for GPx3 at 99 µg/L. Supplementation induced higher levels of SELENOP. CONCLUSION: Significant associations between SELENOP and inflammation, length of telomeres, quality of life, and mortality were observed. Thus, selenium supplementation improved SELENOP expression, thereby facilitating systemic selenium bioavailability and resulting in the observed positive health effects.

Relatively high mortality risk in elderly Swedish subjects with low selenium status.

BACKGROUND/OBJECTIVES: The daily dietary intake of selenium (Se), an essential trace element, is still low in Sweden in spite of decades of nutritional information campaigns and the effect of this on the public health is presently not well known. The objective of this study was to determine the serum Se levels in an elderly Swedish population and to analyze whether a low Se status had any influence on mortality. SUBJECTS/METHODS: Six-hundred sixty-eight (n=668) elderly participants were invited from a municipality and evaluated in an observational study. Individuals were followed for 6.8 years and Se levels were re-evaluated in 98 individuals after 48 months. Clinical examination of all individuals included functional classification, echocardiography, electrocardiogram and serum Se measurement. All mortality was registered and endpoints of mortality were assessed by Kaplan-Meier plots, and Cox proportional hazard ratios adjusted for potential confounding factors were calculated. RESULTS: The mean serum Se level of the study population (n=668) was 67.1 µg/l, corresponding to relatively low Se intake. After adjustment for male gender, smoking, ischemic heart disease, diabetes, chronic obstructive pulmonary disease and impaired heart function, persons with serum Se in the lowest quartile had 43% (95% confidence interval (CI): 1.02-2.00) and 56% (95% CI: 1.03-2.36) increased risk for all-cause and cardiovascular mortality, respectively. The result was not driven by inflammatory effects on Se concentration in serum. CONCLUSION: The mean serum Se concentration in an elderly Swedish population was 67.1 µg/l, which is below the physiological saturation level for several selenoprotein enzymes. This result may suggest the value of modest Se supplementation in order to improve the health of the Swedish population.

Improved Health-Related Quality of Life, and More Days out of Hospital with Supplementation with Selenium and Coenzyme Q10 Combined. Results from a Double Blind, Placebo-Controlled Prospective Study.

BACKGROUND: The impact of supplementation with selenium and coenzyme Q10 (CoQ10) on health-care usage and health-related quality of life (Hr-QoL) in community-dwelling elderly people has, to our knowledge, not previously been investigated. AIM: To investigate the effect of 48 months supplementation with CoQ10 and selenium on community-dwelling elderly as regards: (I) the number of days out of hospital, and (II) the effect on Hr-QoL. METHODS: A 48-month double-blind randomized placebo-controlled trial was carried out. A total of 443 participants were given CoQ10 and organic selenium yeast combined, or a placebo. All admissions to the Department of Internal Medicine or Cardiology were evaluated. Hr-QoL were measured with the Short Form-36 (SF-36), the Cardiac Health Profile (CHP) and one item overall-quality of life (overall-QoL). RESULTS: A total of 206 participants were evaluated after 48 months. No changes were found in the number of days out of hospital or Hr-QoL. A sub-analysis of participants matched for age, gender and baseline cardiac wall tension as measured by NT-proBNP was performed. The mean number of days out of hospital was 1779 for those taking the active substance compared to 1533 for those taking the placebo (p=0.03). Those with active substance declined significantly less in the HR-QoL domains of physical role performance (p=0.001), vitality (p=0.001), physical component score (p=0.001), overall QoL (p=0.001), somatic dimension (p=0.001), conative dimension (p=0.001) and global function (p=0.001). CONCLUSION: In a match-group analysis selenium and CoQ10 increased the number of days out of hospital and slowed the deterioration in Hr-QoL.

Impaired abdominal aortic wall integrity in elderly men carrying the angiotensin-converting enzyme D allele.

OBJECTIVE: A polymorphism in the angiotensin-converting-enzyme gene (ACE I/D) has been associated with abdominal aortic aneurysm and a link between aortic aneurysm and aortic stiffness has been suggested. This study aimed to explore the links between ACE I/D polymorphism, circulating ACE and abdominal aortic wall integrity as reflected by abdominal aortic wall stiffness. MATERIAL: A total of 212 men and 194 women, aged 70-88 years, were studied. METHODS: Mechanical properties of the abdominal aorta were determined using the Wall Track System, ACE genotype using the polymerase chain reaction (PCR) and circulating ACE level by enzyme-linked immunosorbent assay (ELISA). RESULTS: In men, pulsatile diameter change differed between genotypes (II 0.70, ID 0.55 and DD 0.60 mm, P = 0.048), whereas a tendency was seen for distensibility coefficient (DC) (II 10.38, ID 7.68 and ID 8.79, P = 0.058). Using a dominant model (II vs. ID/DD), men carrying the ACE D allele had lower pulsatile diameter change (P = 0.014) and DC (P = 0.017) than II carriers. Multiple regression analyses showed additional associations between the D allele and increased stiffness ß, and reduced compliance coefficient. CONCLUSION: Men carrying the ACE D allele have stiffer abdominal aortas compared with II carriers. Deranged abdominal aortic stiffness indicates impaired vessel wall integrity, which, along with other local predisposing factors, may be important in aneurysmal disease.

Effect of estimated glomerular filtration rate on plasma concentrations of B-type natriuretic peptides measured with multiple immunoassays in elderly individuals.

OBJECTIVE: This study was designed to quantify the crude and adjusted effects of estimated glomerular filtration rate (eGFR) on N-terminal-pro-brain-natriuretic peptide (proBNP) measured with three immunoassays and brain natriuretic peptide (BNP) in elderly individuals. DESIGN: Cross-sectional study. SETTING: 474 elderly outpatients with suspected heart failure (prevalence 13%) from the primary care. MAIN OUTCOME MEASURES: The effects of eGFR on proBNP, measured with three different immunoassays (Roche Diagnostics, Oslo and Copenhagen), and BNP (Shionogi) concentrations were evaluated by multiple linear regression models. RESULTS: In univariate analyses the effect of a 10% decrease in eGFR on proBNP concentrations was a 15% (95% confidence interval 11% to 18%), 9% (5% to 13%) and 21% (14% to 28%) increase. In multivariate models the effect was a 7% (3% to 11%), 4% (2% to 6%) and 13% (4% to 20%) increase. The effect of a 10% decrease in eGFR on BNP concentrations (Shionogi) was a 10% (5% to 15%) (univariate) and a 4% (1% to 9%) (multivariate) increase. CONCLUSIONS: The effect of eGFR on proBNP measured with three different immunoassays and BNP is modest and within the same range. The effect of eGFR on proBNP and BNP concentrations is reduced substantially after adjustment for important clinical and echocardiographic confounders. These findings should be considered before renal function is offered as an explanation for increased proBNP or BNP levels.

Association of genetic variation on chromosome 9p21.3 and arterial stiffness.

OBJECTIVES: Genome wide association studies have consistently reported associations between a region on chromosome 9p21.3 and a broad range of vascular diseases, such as coronary artery disease (CAD), aortic and intracranial aneurysms and type-2 diabetes (T2D). However, clear associations with intermediate phenotypes have not been described so far. To shed light on a possible influence of this chromosomal region on arterial wall integrity, we analysed associations between single nucleotide polymorphisms (SNPs) and degree of stiffness of the abdominal aorta in elderly individuals. METHODS AND RESULTS: A total of 400 subjects, 212 men and 188 women, aged 70-88 years were included. Arterial stiffness was examined at the midpoint between the renal arteries and the aortic bifurcation. Two CAD- and aneurysm-associated SNPs (rs10757274 and rs2891168) and one T2D-associated SNP (rs1081161) within the 9p21.3 region were genotyped. Aortic compliance and distensibility coefficients were higher in carriers of the rs10757274G and rs2891168G alleles in men reflecting a decrease in aortic stiffness. Adjustment for age and mean arterial pressure had no effect on these associations. The two SNPs were not associated with intima-media thickness or lumen diameter of the abdominal aorta. There were no associations between the rs10811661 SNP and any measure of aortic stiffness. CONCLUSIONS: Impaired mechanical properties of the arterial wall may explain the association between chromosome 9p21.3 polymorphisms and vascular disease.

A clinician's experience of using the Cardiac Reader NT-proBNP point-of-care assay in a clinical setting.

UNLABELLED: The evaluation of natriuretic peptides has become increasingly valuable in a clinical setting, where information is often needed promptly. OBJECTIVES: To compare the usefulness of the recently released Roche Cardiac Reader NT-proBNP assay against the Roche Elecsys NT-proBNP laboratory system in a clinical setting. DESIGN AND RESULTS: Blood samples from 440 patients, who were either admitted with acute coronary syndromes or worsening heart failure, or who were heart failure outpatients, were evaluated. The relation between the two assays was analysed and the diagnostic concordance calculated. A good correlation was found between the assays (r=0.96, 95% CI: 0.94-0.97) with a diagnostic concordance of 93%. A separate analysis was performed in the range where most clinical decisions are made (60-3000 ng/L), with a diagnostic concordance of 88%. The usefulness in a clinical setting where time is important was high. CONCLUSION: The Roche Cardiac Reader NT-proBNP assay has been evaluated in a clinical setting. The point-of-care method shows good results, although with a restricted analytical range, compared with the reference.

Depressive symptoms and six-year cardiovascular mortality in elderly patients with and without heart failure.

OBJECTIVES: To evaluate whether depressive symptoms (DS) in elderly patients with heart failure (HF) in the community is associated with increased mortality. DESIGN: A cohort of 510 elderly patients (65-82 years) in a primary healthcare setting with symptoms associated with HF underwent a clinical and echocardiographic examination. A left ventricular ejection fraction (LVEF) <40% indicated HF. The mental health index scale was used to screen for DS. Cardiovascular and all-cause mortality was registered over 6 years. RESULTS: After adjustments those with DS had an increased risk (HR) of 3.0 (CI 95% 1.6-5.5, p=0.0001) and 2.2 (CI 95% 1.3-3.7, p=0.0004) of cardiovascular and all-cause mortality, respectively. Patients with HF and DS had the highest risk of cardiovascular mortality, HR 15.7 (CI 95% 4.8-52.2) compared to patients with HF without DS and those with LVEF > or = 50% and normal left ventricular diastolic function with and without DS. CONCLUSION: DS in elderly patients with HF is independently associated with increased mortality. Screening for DS is recommended as part of the clinical routine in managing patients with HF.

The risk of cardiovascular death in elderly patients with possible heart failure. Results from a 6-year follow-up of a Swedish primary care population.

UNLABELLED: Little is known about the prognosis and clinical variables influencing the prognosis among elderly patients in primary health care with mild to moderate heart failure. AIM: To evaluate the risk of cardiovascular mortality in elderly patients with symptoms of heart failure with respect to systolic and diastolic function, and functional impairment. To evaluate prognostic determinants and to risk-stratify the patients. METHODS: A cardiologist examined 510 patients, out of 548 invited, attending primary care for symptoms of dyspnoea, fatigue and/or peripheral oedema and assessed New York Heart Association (NYHA) functional class. Examination by Doppler echocardiography was done in 454 patients, 56 patients being excluded because of, e.g., atrial fibrillation. Abnormal systolic function was defined as ejection fraction<40%. The diastolic function was evaluated using the mitral inflow and pulmonary venous flow variables. Different clinical and echocardiographic variables were analysed using a Cox regression analysis to identify those most influencing the risk of cardiovascular mortality. CONCLUSION: Abnormal systolic and/or diastolic function was found in 219 patients (48% of the 454 patients who could be echocardiographically completely investigated). The follow-up period was 6 years. Total mortality was 20%, and cardiovascular mortality was 14% (70% of total mortality). Cardiovascular mortality was high in patients with severely impaired functional capacity and ejection fraction<40% at the start of the study. Risk variables identified were male gender, diabetes mellitus, impaired functional capacity and abnormal cardiac function by echocardiography. A prognostic score model using simple clinical variables (gender, NYHA class, cardiac function) was developed to assess the risk of cardiovascular death in order to identify patients with high, moderate or low risk. In a ROC curve analysis, the AUC for clinical variables was only 0.75, whereas the AUC for clinical variables and echocardiography was 0.78, indicating that the additional prognostic information obtained by Doppler echocardiography was rather small.

Risk of cardiovascular death in elderly patients with possible heart failure. B-type natriuretic peptide (BNP) and the aminoterminal fragment of ProBNP (N-terminal proBNP) as prognostic indicators in a 6-year follow-up of a primary care population.

UNLABELLED: Heart failure is common in the elderly population and carries a serious prognosis. We evaluated EDTA-plasma B-type natriuretic peptide (brain natriuretic peptide, BNP) and the aminoterminal fragment of proBNP (N-terminal proBNP) as prognostic markers in elderly primary care patients with symptoms of heart failure. METHODS: From 474 patients attending primary care for symptoms of dyspnea, fatigue and/or peripheral edema, blood was sampled in plastic tubes containing EDTA to measure BNP by non-extraction immunoradiometric assay and N-terminal proBNP by non-extraction radioimmunoassay. Patients were evaluated with respect to history and function by NYHA classification and Doppler echocardiography. Follow-up time was 6 years. Cox regression analysis was performed to identify the weight of risk variables. CONCLUSION: Total 6-year mortality was 20% (102 patients out of 510), and cardiovascular (CV) mortality was 14% (71 patients, 70% of total mortality). BNP and N-terminal proBNP were essentially equally useful as prognostic markers. In patients with the highest quartiles of plasma concentration of BNP and N-terminal proBNP, respectively, the risk of cardiovascular mortality was 10 and 4.8 times, respectively, higher than that in those in the lowest quartile. Peptide concentrations varied widely within all functional groups including those with normal echocardiographic findings. Plasma concentrations of BNP and N-terminal proBNP give important prognostic information concerning risk of cardiovascular mortality. Cost-effective "clinical pathways" should be outlined for patients with elevated peptide concentrations.

Mitochondrial changes and associated alterations induced in mice by streptozotocin administered in vivo and in vitro.

Isolated mouse liver mitochondria incubated with streptozotocin showed decreased rate and extent of Ca2+ uptake, and, dependent on the concentration of streptozotocin and the addition of alpha-ketoglutarate, glutamate, fluorocitrate or guanosine 5'-triphosphate, the retention of Ca2+ was either increased or decreased. Similar observations were made in liver mitochondria incubated with succinyl-CoA. In mitochondria isolated from the kidneys and islets of mice injected with streptozotocin, with and without additional injections of glucose and/or glucagon, the rate and extent of Ca2+ uptake were reduced and the release of accumulated Ca2+ was stimulated. Electron microscopy and X-ray microanalysis showed dislocation of Ca2+-containing precipitates from the mitochondria to the cytosol, and stereology disclosed increased mitochondrial volume in the B cells of streptozotocin-treated mice. State 3 and state 4 respiration with NAD-linked substrates was inhibited, but succinate oxidation was unaffected, in mitochondria isolated from the kidneys of mice treated with streptozotocin. In the kidneys of streptozotocin-injected mice, the concentration of succinyl-CoA was increased, that of citrate and guanosine 5'-triphosphate was decreased, that of glucose 6-phosphate, fructose 6-phosphate and fructose 1,6-diphosphate was unaffected, and the metabolite concentration ratios suggested increased mitochondrial [NAD+]/[NADH] ratio and decreased cytoplasmic [NAD+]/[NADH] ratio. It is suggested as a new hypothesis that the cytotoxicity and the diabetogenicity of streptozotocin are dependent on inhibited citric acid cycle enzyme activity (primarily that of succinyl-CoA synthetase and citrate synthetase) with altered metabolite concentrations, leading to impairment of the mitochondrial uptake of Ca2+ and the activation of the pyruvate, isocitrate and alpha-ketoglutarate dehydrogenases.

Ca2+ transport in isolated mouse liver mitochondria; role of reductive carboxylation and citrate?

The uptake of Ca2+ in isolated mouse liver mitochondria respiring on succinate in the presence of rotenone and added Pi, was inhibited by dibucaine, fluorocitrate, p-hydroxymercuribenzoate (PMB), malonate, palmitoyl-CoA, succinyl-CoA and trifluoroperazine. The release of accumulated Ca2+ was stimulated by arsenite, malonate, PMB, palmitoyl-CoA and succinyl-CoA, whereas the release was inhibited by dibucaine, fluorocitrate, trifluoroperazine, and by oligomycin, especially in the presence of ADP. The pyridine nucleotides were oxidized in mitochondria incubated with PMB. The observations suggest a possible contributory role of reductive carboxylation for the uptake of Ca2+, and a possible role of citrate for the retention of Ca2+ in isolated mouse liver mitochondria.

Osteopenia in mice with genetic diabetes.

Bone mass and growth were studied in mice with genetic diabetes (db/db) characterized by obesity, hyperinsulinemia and hyperglycemia, in their lean litter mates (db/+) and in non-diabetic mice of the same strain (+/+). No significant difference was observed between db/+ and +/+ mice. The length, bone mass, bone mineral mass, bone mineral density and content of moisture of the tibia of the db/db mice were significantly decreased compared with the db/+ and +/+ mice. Microradiographs of the distal femur diaphysis of the db/db mice showed a significant reduction of the spongious bone area and of the number and thickness of bone trabeculae with a normal mineralization. The amount of osteoid was significantly increased in the db/db mice. The area of cortical bone of the tibia epiphysis of the db/db mice was significantly decreased compared with the db/+ and +/+ mice. The data suggest the occurrence of osteopenia due to decreased mineralization in mice with genetic diabetes.