Using Genetics to Inform Interventions Related to Sodium and Potassium in Hypertension.

BACKGROUND: Hypertension is a key risk factor for major adverse cardiovascular events but remains difficult to treat in many individuals. Dietary interventions are an effective approach to lower blood pressure (BP) but are not equally effective across all individuals. BP is heritable, and genetics may be a useful tool to overcome treatment response heterogeneity. We investigated whether the genetics of BP could be used to identify individuals with hypertension who may receive a particular benefit from lowering sodium intake and boosting potassium levels. METHODS: In this observational genetic study, we leveraged cross-sectional data from up to 296 475 genotyped individuals drawn from the UK Biobank cohort for whom BP and urinary electrolytes (sodium and potassium), biomarkers of sodium and potassium intake, were measured. Biologically directed genetic scores for BP were constructed specifically among pathways related to sodium and potassium biology (pharmagenic enrichment scores), as well as unannotated genome-wide scores (conventional polygenic scores). We then tested whether there was a gene-by-environment interaction between urinary electrolytes and these genetic scores on BP. RESULTS: Genetic risk and urinary electrolytes both independently correlated with BP. However, urinary sodium was associated with a larger BP increase among individuals with higher genetic risk in sodium- and potassium-related pathways than in those with comparatively lower genetic risk. For example, each SD in urinary sodium was associated with a 1.47-mm Hg increase in systolic BP for those in the top 10% of the distribution of genetic risk in sodium and potassium transport pathways versus a 0.97-mm Hg systolic BP increase in the lowest 10% (P=1.95×10-3). This interaction with urinary sodium remained when considering estimated glomerular filtration rate and indexing sodium to urinary creatinine. There was no strong evidence of an interaction between urinary sodium and a standard genome-wide polygenic score of BP. CONCLUSIONS: The data suggest that genetic risk in sodium and potassium pathways could be used in a precision medicine model to direct interventions more specifically in the management of hypertension. Intervention studies are warranted.

Persistence of Detectable Anti-Pneumococcal Antibodies 4 Years After Pneumococcal Polysaccharide Vaccination in a Randomised Controlled Trial: The Australian Study for the Prevention through Immunisation of Cardiovascular Events (AUSPICE).

AIM: Mouse models have indicated that the pneumococcal polysaccharide vaccine (PPV) can reduce atherosclerosis. This is probably through a process of molecular mimicry, where phosphorylcholine in the capsular polysaccharide of the vaccine elicits antibodies that cross-react with oxidised low-density lipoprotein and reduce plaque. We investigated whether a similar mechanism occurs in humans. METHODS: A large national blinded, randomised, placebo-controlled trial of the PPV (Australian Study for the Prevention through Immunisation of Cardiovascular Events [AUSPICE]) is underway with fatal and nonfatal cardiovascular disease (CVD) events as the primary outcome. Participants at one centre agreed to a substudy measuring a number of biomarkers and surrogates of CVD over 4 years, including anti-pneumococcal antibodies (immunoglobulin G and immunoglobulin M), C-reactive protein, carotid intima-media thickness, pulse wave velocity, insulin, fasting blood glucose, glycated haemoglobin, and hepatorenal index. RESULTS: Antipneumococcal immunoglobulin G and immunoglobulin M were both present and statistically significantly increased in the treated group compared to control at 4 years. However, there were no differences in any of the surrogate measures of CVD or metabolic markers at 4 years. CONCLUSIONS: While there were prolonged differences in anti-pneumococcal antibody titres following PPV vaccination, these did not appear to provide any cardioprotective effect, as measured by a range of markers. Final results using the fatal and nonfatal CVD events await the completion of national health record linkage next year. TRIAL REGISTRATION: ACTRN12615000536561.

Prevalence and clinical risk prediction of hypertriglyceridaemia in a community cohort.

BACKGROUND: Hypertriglyceridaemia (HTG; defined as ≥1.7 mmol/L) has a prevalence of 18-33% with significant inter-regional variation. Despite meta-analysis demonstrating its association with increased risk of cardiovascular disease, only 40% of HTG is identified in the community resulting in underutilisation of lipid-lowering therapy and specialist clinics. An increase in awareness of its clinical risk factors is needed to improve the identification and management of HTG to prevent cardiovascular risk. AIMS: To evaluate the prevalence, distribution and clinical predictors of HTG ≥1.7 mmol/L in a representative community group. METHODS: Data were obtained from the Hunter Community Study (HCS), a longitudinal cohort of community-dwelling men and women aged 55-85 years residing in Newcastle, New South Wales. Fasting triglycerides were identified based on the availability of fasting blood glucose level and categorised according to normal (<1.7 mmol/L), mild (1.7 to <2.3 mmol/L) and moderate-severe HTG (≥2.3 mmol/L). Clinical predictors of HTG were assessed using linear and logistic regression models. RESULTS: Of 2536 triglyceride levels, 2216 (87%) were in a fasting state and included in the study. Three hundred and two (13.6%) participants had mild HTG and 221 (10.0%) participants had moderate-severe HTG. Significant clinical predictors of HTG included male gender, increasing body mass index, current smoking, decreasing daily step counts, increasing fasting glucose and higher thyroid-stimulating hormone. Alcohol intake and blood pressure were not significant in either adjusted regression model. CONCLUSIONS: HTG ≥1.7 mmol/L is common, affecting 24% of the HCS. Clinical predictors identify modifiable risk factors for cardiovascular risk management. Clinician education to promote awareness is required to improve patient outcomes.

Validity of three risk prediction models for dementia or cognitive impairment in Australia.

BACKGROUND: no studies have compared the predictive validity of different dementia risk prediction models in Australia. OBJECTIVES: (i) to investigate the predictive validity of the Australian National University-Alzheimer's Disease Risk Index (ANU-ADRI), LIfestyle for BRAin Health (LIBRA) Index and cardiovascular risk factors, ageing and dementia study (CAIDE) models for predicting probable dementia/cognitive impairment in an Australian cohort. (ii) To develop and assess the predictive validity of a new hybrid model combining variables from the three models. METHODS: the Hunter Community Study (HCS) included 3,306 adults aged 55-85 years with a median follow-up of 7.1 years. Probable dementia/cognitive impairment was defined using Admitted Patient Data Collection, dispensing of cholinesterase inhibitors or memantine, or a cognitive test. Model validity was assessed by calibration and discrimination. A hybrid model was developed using deep neural network analysis, a machine learning method. RESULTS: 120 (3.6%) participants developed probable dementia/cognitive impairment. Mean calibration by ANU-ADRI, LIBRA, CAIDE and the hybrid model was 19, 0.5, 4.7 and 3.4%, respectively. The discrimination of the models was 0.65 (95% CI 0.60-0.70), 0.65 (95% CI 0.60-0.71), 0.54 (95% CI 0.49-0.58) and 0.80 (95% CI 0.78-0.83), respectively. CONCLUSION: ANU-ADRI and LIBRA were better dementia prediction tools than CAIDE for identification of high-risk individuals in this cohort. ANU-ADRI overestimated and LIBRA underestimated the risk. The new hybrid model had a higher predictive performance than the other models but it needs to be validated independently in longitudinal studies.

The effect of zinc supplementation on glucose homeostasis: a randomised double-blind placebo-controlled trial.

AIMS: The burden and health costs of Type 2 Diabetes Mellitus continue to increase globally and prevention strategies in at-risk people need to be explored. Previous work, in both animal models and humans, supports the role of zinc in improving glucose homeostasis. We, therefore, aimed to test the effectiveness of zinc supplementation on glycaemic control in pre-diabetic adults. METHODS: We conducted a randomized, double-blind, placebo-controlled trial across 10 General Practitioner (GP) practices in NSW, Australia. The trial is known as Zinc in Preventing the Progression of pre-Diabetes (ZIPPeD)Study. Pre-diabetic (haemoglobin A1c [HbA1c] 5.7-6.4%, 39-46 mmol/mol) men and women (N = 98) were all assigned to a free state government telephone health coaching service (New South Wales Get Healthy Information and Coaching Service) and then randomised to either daily 30 mg zinc gluconate or placebo. Blood tests were collected at baseline, 1, 6 and 12 months for the primary outcomes (HbA1c, fasting blood glucose (FBG)); secondary outcomes included Homeostasis Model Assessment 2 (HOMA 2) parameters, lipids, body weight, height, waist circumference, blood pressure and pulse. RESULTS: The baseline-adjusted mean group difference at 6 months, expressed as treatment-placebo, (95% CI) was -0.02 (-0.14, 0.11, p = 0.78) for HbA1c and 0.17 (-0.07, 0.42; p = 0.17) for FBG, neither of which were statistically significant. There were also no significant differences between groups in any of the secondary outcomes. Zinc was well tolerated, and compliance was high (88%). CONCLUSION: We believe our results are consistent with other Western clinical trial studies and do not support the use of supplemental zinc in populations with a Western diet. There may still be a role for supplemental zinc in the developing world where diets may be zinc deficient. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12618001120268. Registered on 6 July 2018.

Generation of cardio-protective antibodies after pneumococcal polysaccharide vaccine: Early results from a randomised controlled trial.

BACKGROUND AND AIMS: Observational studies have demonstrated that the pneumococcal polysaccharide vaccine (PPV) is associated with reduced risk of cardiovascular events. This may be mediated through IgM antibodies to OxLDL, which have previously been associated with cardioprotective effects. The Australian Study for the Prevention through Immunisation of Cardiovascular Events (AUSPICE) is a double-blind, randomised controlled trial (RCT) of PPV in preventing ischaemic events. Participants received PPV or placebo once at baseline and are being followed-up for incident fatal and non-fatal myocardial infarction or stroke over 6 years. METHODS: A subgroup of participants at one centre (Canberra; n = 1,001) were evaluated at 1 month and 2 years post immunisation for changes in surrogate markers of atherosclerosis, as pre-specified secondary outcomes: high-sensitive C-reactive protein (CRP), pulse wave velocity (PWV), and carotid intima-media thickness (CIMT). In addition, 100 participants were randomly selected in each of the intervention and control groups for measurement of anti-pneumococcal antibodies (IgG, IgG2, IgM) as well as anti-OxLDL antibodies (IgG and IgM to CuOxLDL, MDA-LDL, and PC-KLH). RESULTS: Concentrations of anti-pneumococcal IgG and IgG2 increased and remained high at 2 years in the PPV group compared to the placebo group, while IgM increased and then declined, but remained detectable, at 2 years. There were statistically significant increases in all anti-OxLDL IgM antibodies at 1 month, which were no longer detectable at 2 years; there was no increase in anti-OxLDL IgG antibodies. There were no significant changes in CRP, PWV or CIMT between the treatment groups at the 2-year follow-up. CONCLUSIONS: PPV engenders a long-lasting increase in anti-pneumococcal IgG, and to a lesser extent, IgM titres, as well as a transient increase in anti-OxLDL IgM antibodies. However, there were no detectable changes in surrogate markers of atherosclerosis at the 2-year follow-up. Long-term, prospective follow-up of clinical outcomes is continuing to assess if PPV reduces CVD events.

Using the AUSDRISK score to screen for pre-diabetes and diabetes in GP practices: a case-finding approach.

OBJECTIVE: To identify the optimal AUSDRISK threshold score to screen for pre-diabetes and diabetes. METHODS: A total of 406 adult patients not diagnosed with diabetes were screened in General Practices (GP) between May and October 2019. All patients received a point of care (POC) HbA1c test. HbA1c test results were categorised into diabetes (≥6.5% or ≥48 mmol/mol), pre-diabetes (5.7-6.4% or 39-47 mmol/mol), or normal (<5.7% or 39 mmol/mol). RESULTS: Of these patients, 9 (2%) had undiagnosed diabetes and 60 (15%) had pre-diabetes. A Receiver Operator Characteristic (ROC) curve was constructed to predict the presence of pre-diabetes and diabetes; the area under the ROC curve was 0.72 (95%CI 0.65-0.78) indicating modest predictive ability. The optimal threshold cut point for AUSDRISK score was 17 (sensitivity 76%, specificity 61%, + likelihood ratio (LR) 1.96, - likelihood ratio of 0.39) while the accepted cut point of 12 performed less well (sensitivity 94%, specificity 23%, +LR=1.22 -LR+0.26). CONCLUSIONS: The AUSDRISK tool has the potential to be used as a screening tool for pre-diabetes/diabetes in GP practices. A cut point of ≥17 would potentially identify 75% of all people at risk and three in 10 sent for further testing would be positive for prediabetes or diabetes. IMPLICATIONS FOR PUBLIC HEALTH: Routine case-finding in high-risk patients will enable GPs to intervene early and prevent further public health burden from the sequelae of diabetes.

Serum L-arginine and endogenous methylarginine concentrations predict irritable bowel syndrome in adults: A nested case-control study.

BACKGROUND & AIMS: Nitric oxide, a major inhibitory nonadrenergic, noncholinergic neurotransmitter that relaxes smooth muscle, may be implicated in the pathophysiology of visceral hypersensitivity in irritable bowel syndrome (IBS). Impaired bioavailability of the nitric oxide precursor molecule L-arginine and higher concentrations of methylarginines (endogenous inhibitors of nitric oxide synthesis) are known to impair nitric oxide synthesis in numerous gastrointestinal cell types. We therefore examined serum concentrations of L-arginine and the methylarginines in a nested case-control study, to assess whether these factors are associated with adult IBS. METHODS: Data on clinical characteristics, methylarginines, and L-arginine (measured using LC-MS/MS) were collected from a random population-based cohort of Australian adults (median age = 64 years; IQR = 60-70). Cases of IBS, defined according to Rome III criteria (N = 156), and controls (N = 332) were identified from within the cohort at the 5-year follow-up. RESULTS: In adjusted logistic regression analyses, L-arginine, asymmetric dimethylarginine, symmetric dimethylarginine, L-arginine/asymmetric dimethylarginine ratio, and Kessler-10 psychological distress scores were significantly associated with IBS (p < 0.05). [Correction added on 18 September 2021, after first online publication: In the preceding sentence, the value (p > 0.05) has been changed to (p < 0.05)]. Similar results were found for IBS subtypes. Higher serum L-arginine concentration had the strongest association with IBS diagnosis, with an odds ratio of 9.03 for those with serum L-arginine at the 75th (84 µmol/L) versus 25th (46 µmol/L) percentile (95% CI: 5.99-13.62). L-arginine had the best discriminative ability with a bias-adjusted area under the receiver operator characteristic curve of 0.859. CONCLUSIONS: Higher serum concentrations of L-arginine and endogenous methylarginines are strongly associated with IBS in adults.

Genetic association and causal inference converge on hyperglycaemia as a modifiable factor to improve lung function.

Measures of lung function are heritable, and thus, we sought to utilise genetics to propose drug-repurposing candidates that could improve respiratory outcomes. Lung function measures were found to be genetically correlated with seven druggable biochemical traits, with further evidence of a causal relationship between increased fasting glucose and diminished lung function. Moreover, we developed polygenic scores for lung function specifically within pathways with known drug targets and investigated their relationship with pulmonary phenotypes and gene expression in independent cohorts to prioritise individuals who may benefit from particular drug-repurposing opportunities. A transcriptome-wide association study (TWAS) of lung function was then performed which identified several drug-gene interactions with predicted lung function increasing modes of action. Drugs that regulate blood glucose were uncovered through both polygenic scoring and TWAS methodologies. In summary, we provided genetic justification for a number of novel drug-repurposing opportunities that could improve lung function.

Chronic respiratory disorders like asthma affect around 600 million people worldwide. Although these illnesses are widespread, they can have several different underlying causes, making them difficult to treat. Drugs that work well on one type of respiratory disorder may be completely ineffective on another. Understanding the biological and environmental factors that cause these illnesses will allow them to be treated more effectively by tailoring therapies to each patient. Reduced lung function is a factor in respiratory disorders and it can have many genetic causes. Studying the genes of patients with reduced lung function can reveal the genes involved, some of which may already be targets of existing drugs for other illnesses. So, could a patient's genetics be used to repurpose existing drugs to treat their respiratory disorders? Reay et al. combined three methods to link genetics and biological processes to the causes of reduced lung function. The results reveal several factors that could lead to new treatments. In one example, reduced lung function showed a link to genes associated with high blood sugar. As such, treatments used in diabetes might help improve lung function in some patients. Reay et al. also developed a scoring system that could predict the efficacy of a treatment based on a patient's genetics. The study suggests that COVID-19 infection could be affected by blood sugar levels too. Chronic respiratory disorders are a critical issue worldwide and have proven difficult to treat, but these results suggest a way to identify new therapies and target them to the right patients. The findings also support a connection between lung function and blood sugar levels. This implies that perhaps existing diabetes treatments ­ including diet and lifestyle changes aimed at reducing or limiting blood sugar ­ could be repurposed to treat respiratory disorders in some patients. The next step will be to perform clinical trials to test whether these therapies are in fact effective.

Participant-Centered Online Active Surveillance for Adverse Events Following Vaccination in a Large Clinical Trial: Feasibility and Usability Study.

BACKGROUND: Active participant monitoring of adverse events following immunization (AEFI) is a recent development to improve the speed and transparency of vaccine safety postmarketing. Vaxtracker, an online tool used to monitor vaccine safety, has successfully demonstrated its usefulness in postmarketing surveillance of newly introduced childhood vaccines. However, its use in older participants, or for monitoring patients participating in large clinical trials, has not been evaluated. OBJECTIVE: The objective of this study was to monitor AEFIs in older participants enrolled in the Australian Study for the Prevention through the Immunisation of Cardiovascular Events (AUSPICE) trial, and to evaluate the usefulness and effectiveness of Vaxtracker in this research setting. METHODS: AUSPICE is a multicenter, randomized, placebo-controlled, double-blinded trial in which participants aged 55 to 61 years were given either the pneumococcal polysaccharide vaccine (23vPPV) or 0.9% saline placebo. Vaxtracker was used to monitor AEFIs in participants in either treatment arm through the administration of two online questionnaires. A link to each questionnaire was sent to participants via email or short message service (SMS) text message 7 and 28 days following vaccination. Data were collated and analyzed in near-real time to identify any possible safety signals indicating problems with the vaccine or placebo. RESULTS: All 4725 AUSPICE participants were enrolled in Vaxtracker. Participant response rates for the first and final survey were 96.47% (n=4558) and 96.65% (n=4525), respectively. The online survey was completed by 90.23% (4083/4525) of Vaxtracker participants within 3 days of receiving the link. AEFIs were reported by 34.40% (805/2340) of 23vPPV recipients and 10.29% (240/2332) of placebo recipients in the 7 days following vaccination. Dominant symptoms for vaccine and placebo recipients were pain at the injection site (587/2340, 25.09%) and fatigue (103/2332, 4.42%), respectively. Females were more likely to report symptoms following vaccination with 23vPPV compared with males (433/1138, 38.05% versus 372/1202, 30.95%; P<.001). CONCLUSIONS: Vaxtracker is an effective tool for monitoring AEFIs in the 55 to 61 years age group. Participant response rates were high for both surveys, in both treatment arms and for each method of sending the survey. This study indicates that administration of 23vPPV was well-tolerated in this cohort. Vaxtracker has successfully demonstrated its application in the monitoring of adverse events in near-real time following vaccination in people participating in a national clinical trial. TRIAL REGISTRATION: Australian New Zealand Trial Registry Number (ACTRN) 12615000536561; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368506.

Identifying low value pathology test ordering in hospitalised patients: a retrospective cohort study across two hospitals.

The push to identify low value care has led to scrutiny of pathology test re-ordering. The objective of this study was to identify the patterns of ordering pathology tests among inpatients in teaching hospitals and model strategies to reduce unnecessary testing. This was a retrospective cohort study of all adult medical and surgical inpatients admitted to one major teaching hospital and one rural hospital in the same health district over 2 years. Obstetric, gynaecological, intensive care, elective/day procedures and dialysis admissions were excluded. Orders for electrolytes, urea and creatinine (EUC), full blood count (FBC), thyroid stimulating hormone (TSH), glycated haemoglobin (HbA1c), vitamin D, and troponin, date of order, and value of the resulting test, were obtained from a health district data warehouse. Pathology results were mapped to each inpatient day. EUC and FBC constituted over 90% of all inpatient pathology requests for these six tests. Between 40-45% of inpatients had EUC and/or FBC performed daily. After the first couple of tests, the retest interval was consistently around 24 hours, regardless of the previous value of the test, consistent with a culture of routine ordering. This was less pronounced in the rural hospital compared to the urban teaching hospital. Lockouts (applied when previous tests normal) or minimum retest intervals (applied to previously normal and abnormal tests) of various lengths were tested on the data to find optimal combinations that reduced unnecessary tests without missing too many very abnormal tests. A lockout of 48 hours for EUC and 48 hour lockout combined with a 12 hour minimum retest interval for FBC appear optimal to reduce over ordering and could save approximately AU$400/inpatient bed per year at a single teaching hospital. There is evidence of low value re-ordering of EUC and FBC pathology tests. Implementation of a computerised physician order entry system with inbuilt prompts to restrict unnecessary re-ordering of pathology tests may be a practical solution.

Zinc in Preventing the Progression of pre-Diabetes (ZIPPeD Study) - study protocol for a randomised placebo-controlled trial in Australia.

BACKGROUND: Diabetes is increasing in incidence, morbidity and treatment costs globally, hence prevention strategies need to be explored. Animal studies and some human data have shown that zinc can improve glycaemic control, but the impact of this effect in a pre-diabetic population remains uncertain. This study is designed to investigate whether zinc gluconate and lifestyle coaching can improve glucose handling and ultimately reduce diabetes incidence in an at-risk pre-diabetic population in Australia. METHODS/DESIGN: The study will be a randomised, placebo-controlled, double-blind clinical trial. The study will be conducted at the Hunter New England Local Health District New South Wales (NSW), Australia. Pre-diabetic (haemoglobin A1c [HbA1c] 5.7-6.4) male and female participants (n = 410) aged 40-70 years will be recruited through the Diabetes Alliance Network, a collaboration of diabetes specialists and general practitioner practices. All participants will be given routine care to encourage healthy lifestyle changes using a telephone coaching service (Get Healthy Information and Coaching Service, NSW Health) and then randomised to receive a supplement, either zinc gluconate (equivalent to 30 mg of elemental zinc) or placebo of identical appearance for 12 months. The identity of the supplements will be blinded to both research personnel and the participants. Participants will be asked to complete medical, lifestyle and dietary surveys and will have baseline and final visits at their general practitioner practice. Primary outcomes will be HbA1c and insulin sensitivity collected at baseline and at 1, 6 and 12 months; secondary outcomes will include fasting blood glucose, fasting cholesterol, blood pressure and body mass index. The primary efficacy endpoint will be judged at 6 months. DISCUSSION: This study will generate new evidence about the potential for health coaching, with or without zinc supplementation, to improve glucose handling and ultimately to reduce progression from pre-diabetes to diabetes. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12618001120268 . Registered on 6 July 2018.

Evaluating recruitment strategies for AUSPICE, a large Australian community-based randomised controlled trial.

OBJECTIVES: To examine the effectiveness of different strategies for recruiting participants for a large Australian randomised controlled trial (RCT), the Australian Study for the Prevention through Immunisation of Cardiovascular Events (AUSPICE). DESIGN, SETTING, PARTICIPANTS: Men and women aged 55-60 years with at least two cardiovascular risk factors (hypertension, hypercholesterolaemia, overweight/obesity) were recruited for a multicentre placebo-controlled RCT assessing the effectiveness of 23-valent pneumococcal polysaccharide vaccine (23vPPV) for preventing cardiovascular events. METHODS: Invitations were mailed by the Australian Department of Human Services to people in the Medicare database aged 55-60 years; reminders were sent 2 weeks later. Invitees could respond in hard copy or electronically. Direct recruitment was supplemented by asking invitees to extend the invitation to friends and family (snowball sampling) and by Facebook advertising. MAIN OUTCOME: Proportions of invitees completing screening questionnaire and recruited for participation in the RCT. RESULTS: 21 526 of 154 992 invited people (14%) responded by completing the screening questionnaire, of whom 4725 people were eligible and recruited for the study. Despite the minimal study burden (one questionnaire, one clinic visit), the overall participation rate was 3%, or an estimated 10% of eligible persons. Only 16% of eventual participants had responded within 2 weeks of the initial invitation letter (early responders); early and late responders did not differ in their demographic or medical characteristics. Socio-economic disadvantage did not markedly influence response rates. Facebook advertising and snowball sampling did not increase recruitment. CONCLUSIONS: Trial participation rates are low, and multiple concurrent methods are needed to maximise recruitment. Social media strategies may not be successful in older age groups. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12615000536561.

Pneumococcal polysaccharide vaccine associated with reduced lengths of stay for cardiovascular events hospital admissions: Experience from the Hunter Community Study.

BACKGROUND: The pneumococcal polysaccharide vaccine (PPV) has been associated with reduced risk of cardiovascular events in human observational studies. Animal studies suggest that the phosphorylcholine epitope in the Streptococcus pneumoniae cell wall is structurally similar to oxidized low-density lipoprotein (oxLDL), hence PPV induces the production of antibodies that cross-react with anti-oxLDL and may cause regression of atherosclerotic plaque. We set out to determine the strength of association between PPV administration and reduction in cardiovascular events. METHODS: A longitudinal, population-based cohort study of older Australians, from the Hunter Community Study, with up to 11 years of follow-up. We included participants aged ≥ 65 years at baseline (2004-2008), without a history of cardiovascular disease (CVD). History of PPV administration at baseline was the main exposure of interest. "Total number of hospital bed-days with CVD primary diagnosis" was one of the main outcomes measured. Models were adjusted for age, diabetes, alcohol intake, and smoking status. Influenza vaccine was the control exposure used and fracture bed-days was the control outcome used, to investigate the potential for residual confounding. RESULTS: 91 of the total 1074 participants (mean age = 72, male = 45%) experienced a CVD event during follow-up. PPV (regardless of influenza vaccine) was associated with a significant reduction in CVD bed-day, (n = 863, incident rate ratio, IRR = 0.65, 95%CI: 0.45-0.94, p = 0.02), but influenza vaccine (regardless of PPV) was not (n = 864, IRR = 0.86, 95%CI: 0.54-1.35, p = 0.51). Furthermore, PPV adjusted for influenza vaccine remained associated with CVD bed-days (IRR = 0.64, 95%CI: 0.43-0.96, p = 0.03) but was not associated with fracture bed-days (IRR = 0.75, 95%CI: 0.28-2.00, p = 0.56). CONCLUSION: PPV demonstrated a 35% reduction in CVD bed-days. This finding was robust to residual confounding, using a control exposure and a control outcome, eliminating the concern for healthy-user bias. A large double-blinded placebo-controlled RCT is underway to confirm our finding and to explore the proposed mechanism of action (ACTRN12615000536561).

The effect of inhaled corticosteroids on bone mineral density measured by quantitative ultrasonography in an older population.

INTRODUCTION: Prolonged use of systemic corticosteroids leads to reduced bone mineral density and osteoporosis, in turn increasing the risk of minimal trauma fractures with their associated morbidity and mortality in elderly populations. However, the effect of inhaled corticosteroids on bone mineral density has been debated in the medical literature. OBJECTIVES: We aimed to determine the effect of inhaled corticosteroids on bone mineral density measured using calcaneal quantitative ultrasonography in a cohort of older Australians. METHODS: Data was collected from the Hunter Community Study, a longitudinal cohort of Australians aged 55-85. Simple and multiple linear regression methods were used to test the cross-sectional association between inhaled corticosteroids and calcaneal bone mineral density measured with quantitative ultrasound at baseline. A causal diagram was used to determine the minimally sufficient number of co-variates necessary to determine the unconfounded effect of inhaled corticosteroids on bone mineral density; these included gender, body mass index, smoking, asthma, alcohol use, age, physical activity, and diet. RESULTS: There were 152 (6.8%) patients on inhaled corticosteroids and 2098 (93%) controls. Simple and multiple linear regression methods showed a non-significant effect of inhaled steroids on BMD with slight decrease of BMD -0.010 g/cm2 (95% CI -0.042 to 0.022, P = .55) and -0.013 g/cm2 (95% CI -0.062 to 0.036, P = .61) respectively. Age, gender, body mass index, and smoking were stronger predictors of BMD. CONCLUSIONS: No statistically significant relationship was detected between the use of inhaled corticosteroids and reduced bone mineral density in this observational study of a cohort of older Australians.

A quantitative analysis of the quality and content of the health advice in popular Australian magazines.

OBJECTIVE: To examine how health advice is provided in popular magazines and the quality of that advice. METHODS: A prospective quantitative analysis of the quality of health advice provided in Australian magazines between July and December 2011 was conducted. A rating instrument was adapted from the Media Doctor Australia rating tool used to assess quality of health news reporting. Criteria included: recommends seeing a doctor; advice based on reliable evidence; advice clear and easily applied; benefits presented meaningfully; potential harms mentioned; evidence of disease mongering; availability and cost of treatments; obvious advertising; vested interest, and anecdotal evidence. RESULTS: 163 health advice articles were rated showing a wide variation in the quality of advice presented between magazines. Magazines with 'health' in the title, rated most poorly with only 36% (26/73) of these articles presenting clear and meaningful advice and 52% (38/73) giving advice based on reliable evidence. CONCLUSIONS: Australian magazines, especially those with health in the title, generally presented poor quality, unreliable health advice. Teen magazine Dolly provided the highest quality advice. IMPLICATIONS: Consumers need to be aware of this when making health choices.

Zinc supplementation for improving glucose handling in pre-diabetes: A double blind randomized placebo controlled pilot study.

AIMS: There are a number of studies showing that zinc supplementation may improve glucose handling in people with established diabetes. We sought to investigate whether this zinc-dependent improvement in glucose handling could potentially be harnessed to prevent the progression of pre-diabetes to diabetes. In this double-blind randomized placebo-controlled trial, we determined participants' fasting blood glucose levels, (FBG) and Homeostasis Model Assessment (HOMA) parameters (beta cell function, insulin sensitivity and insulin resistance) at baseline and after 6 months of zinc supplementation. METHODS: The Bangladesh Institute of Health Sciences Hospital (BIHS) (Mirpur, Dhaka, Bangladesh) database was used to identify 224 patients with prediabetes, of whom 55 met the inclusion criteria and agreed to participate. The participants were randomized either to the intervention or control group using block randomization. The groups received either 30mg zinc sulphate dispersible tablet or placebo, once daily for six months. RESULTS: After six months, the intervention group significantly improved their FBG concentration compared to the placebo group (5.37±0.20mmol/L vs 5.69±0.26, p<0.001) as well as compared to their own baseline (5.37±0.20mmol/L vs 5.8±0.09, p<0.001). Beta cell function, insulin sensitivity and insulin resistance all showed a statistically significant improvement as well. CONCLUSION: To our knowledge this is the first trial to show an improvement in glucose handling using HOMA parameters in participants with prediabetes. Larger randomized controlled trials are warranted to confirm these findings and to explore clinical endpoints.

Rationale and design of a randomized controlled trial of pneumococcal polysaccharide vaccine for prevention of cardiovascular events: The Australian Study for the Prevention through Immunization of Cardiovascular Events (AUSPICE).

BACKGROUND: Research has shown that vaccination with Streptococcus pneumoniae reduced the extent of atherosclerosis in experimental animal models. It is thought that phosphorylcholine lipid antigens in the S. pneumoniae cell wall induce the production of antibodies that cross-react with oxidized low-density lipoprotein, a component of atherosclerotic plaques. These antibodies may bind to and facilitate the regression of the plaques. Available data provide evidence that similar mechanisms also occur in humans, leading to the possibility that pneumococcal vaccination protects against atherosclerosis. A systematic review and meta-analysis, including 8 observational human studies, of adult pneumococcal polysaccharide vaccination for preventing cardiovascular disease in people older than 65 years, showed a 17% reduction in the odds (odds ratio 0.83, 95% CI 0.71-0.97) of having an acute coronary syndrome event. METHODS/DESIGN: The AUSPICE is a multicenter, randomized, placebo-controlled, double-blind, clinical trial to formally test whether vaccination with the pneumococcal polysaccharide vaccine protects against cardiovascular events (fatal and nonfatal acute coronary syndromes and ischemic strokes). Cardiovascular outcomes will be obtained during 4 to 5 years of follow-up, through health record linkage with state and national administrative data sets. CONCLUSION: This is the first registered randomized controlled trial (on US, World Health Organization, Australia and New Zealand trial registries) to be conducted to test whether vaccination with the pneumococcal polysaccharide vaccine will reduce cardiovascular events. If successful, vaccination can be readily extended to at-risk groups to reduce the risk of cardiovascular diseases.

Prevalence of and associations with excessive daytime sleepiness in an Australian older population.

The aim of this research is to estimate the prevalence of excessive daytime sleepiness in an older population and associations with sociodemographic, health, and lifestyle factors using a cross-sectional, population-based study. Participants were men (1560) and women (1759), aged 55 to 85 years, enrolled in the Hunter Community Study, a longitudinal study of aging. Measurements were self-reported questionnaires, biochemical measures, and clinical measures. Of the 3319 participants, 3053 participants completed the Epworth Sleepiness Scale questionnaire. The prevalence of excessive daytime sleepiness was 15.3% overall and this was higher in males. In adjusted multivariate analysis, gender, working full time, body mass index, high-density and low-density lipoprotein cholesterol, Center for Epidemiologic Studies-Depression scale score, and Kessler psychological distress score were associated with excessive daytime sleepiness. Given the high prevalence of excessive daytime sleepiness observed in this study, further investigation and/or interventions to reduce adverse health outcomes, especially in males is warranted.