Determinants and costs of community nursing in patients with type 2 diabetes from a community-based observational study: the Fremantle Diabetes Study

BACKGROUND

Despite widespread use, there is little information on the extent and impact of community nursing to patients with type 2 diabetes.

OBJECTIVE

To determine the incidence, predictors and costs of community nursing provision to patients with type 2 diabetes in a large community-based representative study of diabetes in an urban Australian setting.

DESIGN

Prospective observational study utilising data linkage.

SETTING

Postcode defined region in Fremantle, Australia.

PARTICIPANTS

All patients with type 2 diabetes enrolled in the Fremantle Diabetes Study between 1993 and 1996.

METHODS

Eligible patients were followed from July 1997, when home nursing data first became available, to death or census in November 2007. Home nursing data from the major community nursing service provider were linked with data from the Fremantle Diabetes Study. Cox and zero-inflated negative binomial (ZINB) regression modelling was used to identify predictors of incident home visits and visit frequency, respectively. Direct costs were estimated from the service provider's unit costs.

RESULTS

During a mean ± SD 8.6 ± 2.9 years of follow-up, 27.8% of 825 patients (aged 65.2 ± 10.3 years at study entry; 51.2% male) received 21,878 home nursing visits (median frequency 31 [interquartile range 9-85] visits, range 1-1446 visits). In Cox and ZINB models, predictors of home nursing included older age, physical disability measures and macrovascular and microvascular complications. Insulin use was an important predictor of the frequency of visits whilst ethnic and economic factors predicted lower frequency. The estimated cost of home nursing, extrapolated nationally, adds 5% to the total Australian direct health care costs of diabetes.

CONCLUSIONS

Home nursing is frequently utilized in the management of type 2 diabetes with considerable individual variation in the use of this service. Given the associated costs, further research into how home nursing can best be employed is indicated.

Severe anemia in Papua New Guinean children from a malaria-endemic area: a case-control etiologic study

BACKGROUND

There are few detailed etiologic studies of severe anemia in children from malaria-endemic areas and none in those countries with holoendemic transmission of multiple Plasmodium species.

METHODOLOGY/PRINCIPAL FINDINGS

We examined associates of severe anemia in 143 well-characterized Papua New Guinean (PNG) children aged 0.5-10 years with hemoglobin concentration <50 g/L (median [inter-quartile range] 39 [33]-[44] g/L) and 120 matched healthy children (113 [107-119] g/L) in a case-control cross-sectional study. A range of socio-demographic, behavioural, anthropometric, clinical and laboratory (including genetic) variables were incorporated in multivariate models with severe anemia as dependent variable. Consistent with a likely trophic effect of chloroquine or amodiaquine on parvovirus B19 (B19V) replication, B19V PCR/IgM positivity had the highest odds ratio (95% confidence interval) of 75.8 (15.4-526), followed by P. falciparum infection (19.4 (6.7-62.6)), vitamin A deficiency (13.5 (5.4-37.7)), body mass index-for-age z-score <2.0 (8.4 (2.7-27.0)) and incomplete vaccination (2.94 (1.3-7.2)). P. vivax infection was inversely associated (0.12 (0.02-0.47), reflecting early acquisition of immunity and/or a lack of reticulocytes for parasite invasion. After imputation of missing data, iron deficiency was a weak positive predictor (6.4% of population attributable risk).

CONCLUSIONS/SIGNIFICANCE

These data show that severe anemia is multifactorial in PNG children, strongly associated with under-nutrition and certain common infections, and potentially preventable through vitamin A supplementation and improved nutrition, completion of vaccination schedules, and intermittent preventive antimalarial treatment using non-chloroquine/amodiaquine-based regimens.

Loss-of-function mutations in IGSF1 cause an X-linked syndrome of central hypothyroidism and testicular enlargement

Congenital central hypothyroidism occurs either in isolation or in conjunction with other pituitary hormone deficits. Using exome and candidate gene sequencing, we identified 8 distinct mutations and 2 deletions in IGSF1 in males from 11 unrelated families with central hypothyroidism, testicular enlargement and variably low prolactin concentrations. IGSF1 is a membrane glycoprotein that is highly expressed in the anterior pituitary gland, and the identified mutations impair its trafficking to the cell surface in heterologous cells. Igsf1-deficient male mice show diminished pituitary and serum thyroid-stimulating hormone (TSH) concentrations, reduced pituitary thyrotropin-releasing hormone (TRH) receptor expression, decreased triiodothyronine concentrations and increased body mass. Collectively, our observations delineate a new X-linked disorder in which loss-of-function mutations in IGSF1 cause central hypothyroidism, likely secondary to an associated impairment in pituitary TRH signaling.

Rapid antigen detection tests for malaria diagnosis in severely ill Papua New Guinean children: a comparative study using Bayesian latent class models

Background

Although rapid diagnostic tests (RDTs) have practical advantages over light microscopy (LM) and good sensitivity in severe falciparum malaria in Africa, their utility where severe non-falciparum malaria occurs is unknown. LM, RDTs and polymerase chain reaction (PCR)-based methods have limitations, and thus conventional comparative malaria diagnostic studies employ imperfect gold standards. We assessed whether, using Bayesian latent class models (LCMs) which do not require a reference method, RDTs could safely direct initial anti-infective therapy in severe ill children from an area of hyperendemic transmission of both Plasmodium falciparum and P. vivax.

Methods and Findings

We studied 797 Papua New Guinean children hospitalized with well-characterized severe illness for whom LM, RDT and nested PCR (nPCR) results were available. For any severe malaria, the estimated prevalence was 47.5% with RDTs exhibiting similar sensitivity and negative predictive value (NPV) to nPCR (≥96.0%). LM was the least sensitive test (87.4%) and had the lowest NPV (89.7%), but had the highest specificity (99.1%) and positive predictive value (98.9%). For severe falciparum malaria (prevalence 42.9%), the findings were similar. For non-falciparum severe malaria (prevalence 6.9%), no test had the WHO-recommended sensitivity and specificity of >95% and >90%, respectively. RDTs were the least sensitive (69.6%) and had the lowest NPV (96.7%).

Conclusions

RDTs appear a valuable point-of-care test that is at least equivalent to LM in diagnosing severe falciparum malaria in this epidemiologic situation. None of the tests had the required sensitivity/specificity for severe non-falciparum malaria but the number of false-negative RDTs in this group was small.

Effect of continuous positive airway pressure therapy on cardiovascular risk factors in patients with type 2 diabetes and obstructive sleep apnea

CONTEXT

Few prospective intervention studies have examined the effect of continuous positive airway pressure (CPAP) therapy on cardiovascular disease (CVD) risk factors in diabetes.

OBJECTIVE

Our objective was to determine whether CPAP improves CVD risk factors in patients with type 2 diabetes and obstructive sleep apnea (OSA).

DESIGN AND SETTING

This was a randomized parallel group intervention trial in an urban Australian community.

PATIENTS

Fifty-nine participants of the Fremantle Diabetes Study Phase II at high risk for OSA consented to confirmatory polysomnography followed by randomization to a 3-month CPAP intervention initiated early (<1 wk) or late (1-2 months).

MAIN OUTCOME MEASURES

Patients were assessed before and 1 and 3 months after CPAP started. Tests for repeated measures were used to compare variables of interest over time.

RESULTS

Forty-four patients (75%) completed the study. Their mean ± sd age was 66.1 ± 8.8 yr, and 61.4% were male. Completers and noncompleters had similar age, sex, diabetes duration, apnea-hypopnea index, and Epworth Sleepiness Scale (P ≥ 0.29). There were no differences in outcome between early and late randomization, and the data were pooled. The Epworth Sleepiness Scale decreased between entry and 1 month [-4.8 (-6.5 to -3.1), P < 0.001]. Blood pressure improved between entry and 3 months (from 149 ± 23/80 ± 12 to 140 ± 18/73 ± 13 mm Hg; P ≤ 0.007). Pulse rate declined within the first month [-6 (-10 to -2) beats/min, P = 0.002]. Glycemic control and serum lipids, which were mostly within recommended target ranges at entry, did not change.

CONCLUSIONS

Three months of CPAP in community-based people with type 2 diabetes significantly decreased blood pressure and pulse rate but did not influence metabolic control.

Incidence and predictors of all-cause and site-specific cancer in type 2 diabetes: the Fremantle Diabetes Study

OBJECTIVE

To explore the relationship between diabetes and cancer.

DESIGN

The Fremantle Diabetes Study (FDS) was a community-based longitudinal observational study of 1426 subjects, 1294 of which had type 2 diabetes.

METHODS

The FDS type 2 cohort and four age-, sex- and postcode-matched controls per case were followed for cancer events from 1993 until mid-2010 and incidence rate ratios (IRRs) were calculated. Competing risks proportional hazards models generated risk factors for incident cancers in the diabetic group.

RESULTS

There were 309 first cancers over 13 051 patient-years, or 2368 (95% confidence interval (95% CI) 2111-2647)/100 000 patient-years in the diabetes patients vs 1131 over 60 324 patient-years (1875 (1769-1987)/100 000 patient-years) in the controls. For those aged ≥45 years, the risk of all-cause cancer was elevated in type 2 diabetic men (IRRs 1.23, 95% CI 1.04-1.45) and women (1.30, 1.06-1.59). The incidence of colorectal cancer was increased (1.36, 1.01-1.82), especially in diabetic men aged 75-84 years (2.14, 1.22-3.64). Age at diabetes diagnosis (sub-hazard ratio 1.05, 1.02-1.09), calcium channel blocker therapy (2.37, 1.39-4.06), recent exercise (2.11, 1.06-4.20) and serum total cholesterol (0.68, 0.52-0.88) increased colorectal cancer risk. Pancreatic cancer was also more frequent in the diabetic patients (IRR 2.26, 1.20-4.10). Diabetic men and women had similar risks of prostate and breast cancer to those of controls (0.83, 0.59-1.14 and 0.86, 0.52-1.36).

CONCLUSIONS

Type 2 diabetes is associated with a moderately increased cancer risk in well-characterised community-based patients, especially pancreatic cancer and colorectal cancer in older men. Recommended cancer screening should be considered as part of routine diabetes management.

Continuing disparities in cardiovascular risk factors and complications between aboriginal and Anglo-Celt Australians with type 2 diabetes: the Fremantle Diabetes Study

OBJECTIVE

To determine whether disparities in the nature and management of type 2 diabetes persist between Aboriginal and the majority Anglo-Celt patients in an urban Australian community.

RESEARCH DESIGN AND METHODS

Baseline data from the observational Fremantle Diabetes Study collected from 1993 to 1996 (phase I) and from 2008 to 2011 (phase II) were analyzed. Patients characterized as Aboriginal or Anglo-Celt by self-report and supporting data underwent comprehensive assessment, including questionnaires, examination, and biochemical testing in a single laboratory. Generalized linear modeling with age/sex adjustment was used to examine differences in changes in variables in the two groups between phases I and II.

RESULTS

The indigenous participants were younger at entry and at diabetes diagnosis than the Anglo-Celt participants in both phases. They were also less likely to be educated beyond primary level and were more likely to be smokers. HbA(1c) decreased in both groups over time (Aboriginal median 9.6% [interquartile range 7.8-10.7%] to 8.4% [6.6-10.6%] vs. Anglo-Celt median 7.1% [6.2-8.4%] to 6.7% [6.2-7.5%]), but the gap persisted (P = 0.65 for difference between phases I and II by ethnic group). Aboriginal patients were more likely to have microvascular disease in both phases. The prevalence of peripheral arterial disease (ankle-brachial index ≤0.90 or lower-extremity amputation) increased in Aboriginal but decreased in Anglo-Celt participants (15.8-29.7 vs. 30.7-21.5%; P = 0.055).

CONCLUSIONS

Diabetes management has improved for Aboriginal and Anglo-Celt Australian patients, but disparities in cardiovascular risk factors and complications persist.

Investigation of volatile organic biomarkers derived from Plasmodium falciparum in vitro

BACKGROUND

There remains a need for techniques that improve the sensitive detection of viable Plasmodium falciparum as part of diagnosis and therapeutic monitoring in clinical studies and usual-care management of malaria infections. A non-invasive breath test based on P. falciparum-associated specific volatile organic compounds (VOCs) could fill this gap and provide insights into parasite metabolism and pathogenicity. The aim of this study was to determine whether VOCs are present in the headspace above in vitro P. falciparum cultures.

METHODS

A novel, custom-designed apparatus was developed to enable efficient headspace sampling of infected and non-infected cultures. Conditions were optimized to support cultures of high parasitaemia (>20%) to improve the potential detection of parasite-specific VOCs. A number of techniques for VOC analysis were investigated including solid phase micro-extraction using two different polarity fibres, and purge and trap/thermal desorption, each coupled to gas chromatography-mass spectrometry. Each experiment and analysis method was performed at least on two occasions. VOCs were identified by comparing their mass spectra against commercial mass spectral libraries.

RESULTS

No unique malarial-specific VOCs could be detected relative to those in the control red blood cell cultures. This could reflect sequestration of VOCs into cell membranes and/or culture media but solvent extractions of supernatants and cell lysates using hexane, dichloromethane and ethyl acetate also showed no obvious difference compared to control non-parasitized cultures.

CONCLUSIONS

Future in vivo studies analysing the breath of patients with severe malaria who are harbouring a parasite biomass that is significantly greater than achievable in vitro may yet reveal specific clinically-useful volatile chemical biomarkers.

Simultaneous determination of primaquine and carboxyprimaquine in plasma using solid phase extraction and LC-MS assay

Sensitive bioanalytical methods are required for pharmacokinetic studies in children, due to the small volume and modest number of samples that can be obtained. We sought to develop a LC-MS assay for primaquine and its active metabolite, carboxyprimaquine, following simultaneous, solid phase extraction of both analytes from human plasma. The analysis was conducted on a single-quad LC-MS system (Shimadzu Model 2020) in ESI+ mode, with quantitation by selected ion monitoring. Primaquine, carboxyprimaquine and 8-aminoquinoline (internal standard) were separated using a mobile phase of 80:20 methanol:water with 0.1% (v/v) formic acid and a Luna C(18) HPLC column, at ambient temperature. Solid phase extraction of the analytes from plasma (0.5 mL) was achieved with Oasis(®) HLB cartridges. The retention times for primaquine, 8-aminoquinoline and carboxyprimaquine were 3.3, 5.7 and 8.5 min, respectively. The calibration curve range (2-1500 μg/L) was appropriate for the limits of quantification and detection for primaquine (2 μg/L and 1μ g/L, respectively) and carboxyprimaquine (2.5 μg/L and 1 μg/L) and the anticipated plasma concentrations of the analytes. Intra- and inter-day precision for both primaquine and carboxyprimaquine was <10% across the concentration range 5-1000 μg/L. Accuracy for both analytes was <15% (5-500 μg/L). This validated LC-MS method with solid phase extraction facilitates the simultaneous analysis of primaquine and carboxyprimaquine from small volumes of human plasma, with run time <10 min, recovery >85% and sensitivity of 1-2 μg/L.

Prevalence, incidence, and prognosis of hepatobiliary disease in community-based patients with type 2 diabetes: the Fremantle Diabetes Study

CONTEXT

Few studies have examined morbidity and mortality associated with hepatobiliary disease in diabetes. Most have used administrative databases and/or have had limited/incomplete data including recognized risk factors for hepatobiliary disease.

OBJECTIVE

The objective of the study was to explore the relationship between type 2 diabetes and hepatobiliary disease in well-characterized patients with detailed risk factor data including viral hepatitis status and hemochromatosis genotype.

DESIGN

This was a community-based longitudinal observational study.

SETTING

The study was conducted in an urban Australian community.

PATIENTS

The study included 1294 patients of mean ± SD aged 64.1 ± 11.3 yr and 5156 age-, gender-, and ZIP code-matched nondiabetic controls.

MAIN OUTCOME MEASURES

Prevalent and incident hepatobiliary disease and hepatobiliary disease-related death were measured. Competing risks proportional hazard models provided independent associates of these end points.

RESULTS

During 13,705 patient-years (mean 11.5 yr), 144 patients had an initial hepatobiliary disease-related hospitalization/cancer registration vs. 403 controls during 63,937 person-years of follow-up, an incidence rate ratio of 1.66 (95% confidence interval 1.37-2.02). Incident hepatobiliary disease was associated with a lower glycosylated hemoglobin and higher urinary albumin to creatinine ratio. Nearly half of the patients (49.9%) died during follow-up [crude mortality ratio vs. nondiabetic controls 1.97 (1.16-3.32)], and 21 (3.3%) from hepatobiliary disease including two cases of cirrhosis attributable to nonalcoholic steatohepatitis. Hepatobiliary disease-related death was independently predicted by prior hepatobiliary disease, hepatitis C seropositivity, retinopathy, and peripheral neuropathy; higher educational level and higher fasting serum glucose were protective.

CONCLUSIONS

Hepatobiliary disease and associated mortality are increased in type 2 diabetes. Multiple factors including fatty infiltration, microangiopathy, and direct glucotoxicity are likely to contribute, but hospitalization and death due to cirrhosis from nonalcoholic steatohepatitis appear uncommon.

Glycemic control over 5 years in 4,900 people with type 2 diabetes: real-world diabetes therapy in a clinical trial cohort

OBJECTIVE

Glycemic control in type 2 diabetes generally worsens over time, requiring intensification of therapy. The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial provided the opportunity to observe glycemic control in a real-world setting. We assessed the adequacy of metformin, sulfonylureas, and insulin to maintain glycemic control and their effects on weight.

RESEARCH DESIGN AND METHODS

Diabetes control was measured at baseline and yearly for a median of 5 years in the 4,900 patients from the nonintervention arm of this study allocated to placebo.

RESULTS

Median HbA(1c) was 6.9% at baseline and increased by an average of 0.22% over 5 years (P < 0.001). Median weight was 86.3 kg at baseline and decreased by 0.4 kg over 5 years (P = 0.002). Baseline therapy was lifestyle measures only in 27%, oral agents without insulin in 59%, and insulin in 14% (7% also taking oral agents). Over 5 years, insulin use increased to 32% (21% also taking oral agents). Use of oral agents remained similar at 56%. Only 2% of patients at baseline and 4% after 5 years were taking oral agents other than metformin or sulfonylureas. Initiation of insulin therapy in 855 patients produced a sustained reduction of HbA(1c) from a median of 8.2 to 7.7%, with a weight gain of 4.6 kg over 5 years.

CONCLUSIONS

With intensification of traditional therapies, glycemic control deteriorated very little over 5 years in a large cohort of type 2 diabetes. However, the requirement for insulin therapy doubled, at the expense of significant weight gain and risk of hypoglycemia.

A histopathologic study of fatal paediatric cerebral malaria caused by mixed Plasmodium falciparum/Plasmodium vivax infections

Microvascular sequestration of Plasmodium falciparum underlies cerebral malaria. Despite suggestive ex vivo evidence, this phenomenon has not been convincingly demonstrated in coma complicating Plasmodium vivax malaria. Severely-ill Papua New Guinean children with mixed P. falciparum/P. vivax infections are more likely to develop cerebral malaria and die than those with P. falciparum alone, possibly reflecting P. vivax sequestration. Nested PCR was performed on post mortem brain tissue from three such children dying from cerebral malaria due to mixed-species infections. No P. vivax DNA was detected. These findings do not support the hypothesis that P. vivax sequestration occurs in human brain.

A five-year prospective study of bone mineral density in men and women with diabetes: the Fremantle Diabetes Study

To examine longitudinally the effect of diabetes on bone structure and metabolism, we measured bone mineral density (BMD) and turnover markers in 26 type 1 (mean age 49 years) and 27 type 2 (mean age 65 years) diabetic patients without known osteoporosis from a community-based sample at baseline and 5 years later. In the 17 type 1 men, BMD fell at the femoral neck (0.804 ± 0.145 vs. 0.769 ± 0.129 g/cm(2); P = 0.003) with no change at lumbar spine or forearm. In the 11 type 2 women, BMD decreased at all sites except spine (femoral neck 0.779 ± 0.119 vs. 0.742 ± 0.090 g/cm(2); P = 0.019). BMD did not fall at any site in type 1 women or type 2 men. There was an increase in serum alkaline phosphatase and trend to higher serum beta carboxyl-terminal type I collagen telopeptide concentrations in the type 1 patients, and a decrease in free testosterone in the type 1 men. These data show that the rate of demineralization at the femoral neck in type 1 men is similar to that in older post-menopausal type 2 women. Changes in biochemical markers suggest that, in type 1 men, there is ineffective bone formation associated with accelerated bone resorption and lower sex steroid bioavailability. These findings may have implications for the clinical management of young male adults with diabetes.

Predictors of acute bacterial meningitis in children from a malaria-endemic area of Papua New Guinea

Predictors of acute bacterial meningitis (ABM) were assessed in 554 children in Papua New Guinea 0.2-10 years of age who were hospitalized with culture-proven meningitis, probable meningitis, or non-meningitic illness investigated by lumbar puncture. Forty-seven (8.5%) had proven meningitis and 36 (6.5%) had probable meningitis. Neck stiffness, Kernig's and Brudzinski's signs and, in children < 18 months of age, a bulging fontanel had positive likelihood ratios (LRs) ≥ 4.3 for proven/probable ABM. Multiple seizures and deep coma were less predictive (LR = 1.5-2.1). Single seizures and malaria parasitemia had low LRs (≤ 0.5). In logistic regression including clinical variables, Kernig's sign and deep coma were positively associated with ABM, and a single seizure was negatively associated (P ≤ 0.01). In models including microscopy, neck stiffness and deep coma were positively associated with ABM and parasitemia was negatively associated with ABM (P ≤ 0.04). In young children, a bulging fontanel added to the model (P < 0.001). Simple clinical features predict ABM in children in Papua New Guinea but malaria microscopy augments diagnostic precision.

Pierre TG, Davis TME. Mathematical modeling of malaria infection with innate and adaptive immunity in individuals and agent-based communities

Background

Agent-based modeling of Plasmodium falciparum infection offers an attractive alternative to the conventional Ross-Macdonald methodology, as it allows simulation of heterogeneous communities subjected to realistic transmission (inoculation patterns).

Methodology/Principal Findings

We developed a new, agent based model that accounts for the essential in-host processes: parasite replication and its regulation by innate and adaptive immunity. The model also incorporates a simplified version of antigenic variation by Plasmodium falciparum. We calibrated the model using data from malaria-therapy (MT) studies, and developed a novel calibration procedure that accounts for a deterministic and a pseudo-random component in the observed parasite density patterns. Using the parasite density patterns of 122 MT patients, we generated a large number of calibrated parameters. The resulting data set served as a basis for constructing and simulating heterogeneous agent-based (AB) communities of MT-like hosts. We conducted several numerical experiments subjecting AB communities to realistic inoculation patterns reported from previous field studies, and compared the model output to the observed malaria prevalence in the field. There was overall consistency, supporting the potential of this agent-based methodology to represent transmission in realistic communities.

Conclusions/Significance

Our approach represents a novel, convenient and versatile method to model Plasmodium falciparum infection.

Prevalence and predictors of abnormal arterial function in statin-treated type 2 diabetes mellitus patients

Arterial dysfunction (AD) in type 2 diabetes mellitus (T2DM) predicts cardiovascular events. The objective was to investigate the prevalence and predictors of AD in statin-treated T2DM patients. We measured flow-mediated (FMD) and nitrate-mediated (NMD) brachial artery dilatation in 86 statin-treated T2DM patients. Patients were classified into 2 groups: normal arterial function (FMD ≥3.7% with NMD ≥11.9%) or AD (FMD <3.7% with or without NMD <11.9%). Endothelial dysfunction without smooth muscle cell dysfunction (ED) was defined as FMD less than 3.7% with NMD of at least 11.9%, and endothelial dysfunction with smooth muscle cell dysfunction (ED/SMD) was defined as FMD less than 3.7% with NMD less than 11.9%. Predictors of arterial function were investigated using linear and logistic regression methods. The prevalence of AD was 33.7% (23.2% with ED and 10.5% with ED/SMD). In multivariate linear regression, history of hypertension (P < .01), statin dose (P < .05), and estimated glomerular filtration rate (eGFR) (P = .02) were significant predictors of FMD. Sex (P < .01) and creatinine (P = .03) or eGFR (P = .02) predicted NMD. In multivariate logistic regression, the independent predictors of AD were history of hypertension (odds ratio [OR], 8.79; 95% confidence interval, 2.14-36.12; P < .01), age (OR, 1.08; 1.01-1.17; P = .03), and statin dose (OR, 0.33; 0.12-0.87; P = .02). A history of hypertension (OR, 8.99; 1.87-43.26; P < .01) was the sole independent predictor of ED; eGFR (OR, 0.01; 0.00-0.26; P < .01) independently predicted ED/SMD. Our data suggest that one third of statin-treated diabetic patients have residual AD, mainly due to ED alone. Earlier identification and treatment of hypertension and renal impairment may improve AD and further decrease cardiovascular risk in such patients.

Bloodstream infections caused by resistant bacteria in surgical patients admitted to Modilon Hospital, Madang

In view of the dearth of information relating to antibiotic resistance in community- and hospital-acquired bacterial infections in Papua New Guinea (PNG), we carried out a prospective, hospital-based observational study of surgical patients between October 2008 and October 2009. In a sample of 115 patients (median age 30 years; 55% males) suspected of having a bloodstream infection, blood cultures were positive in 11 (10%) and a significant pathogen was isolated in 9 (8%). Staphylococcus aureus was isolated in 4 patients (44%) and 3 were methicillin resistant; all these isolates were considered community acquired because cultures were performed within 48 hours of admission. Of the remaining 5 isolates, 4 were Gram-negative organisms with at least intermediate resistance to chloramphenicol that were grown from blood taken > 48 hours post-admission and thus considered nosocomially acquired. These data suggest two distinct patterns of bacterial infection in PNG surgical inpatients that have implications for national antibiotic prescription guidelines.

Benefits and safety of long-term fenofibrate therapy in people with type 2 diabetes and renal impairment: the FIELD Study

OBJECTIVE

Diabetic patients with moderate renal impairment (estimated glomerular filtration rate [eGFR] 30-59 mL/min/1.73 m(2)) are at particular cardiovascular risk. Fenofibrate's safety in these patients is an issue because it may elevate plasma creatinine. Furthermore, guidelines regarding fenofibrate dosing in renal impairment vary internationally. We investigated fenofibrate's effects on cardiovascular and end-stage renal disease (ESRD) events, according to eGFR, in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) Study.

RESEARCH DESIGN AND METHODS

Type 2 diabetic patients (aged 50-75 years) with eGFR ≥30 mL/min/1.73 m(2) were randomly allocated to a fixed dose of fenofibrate (200 mg daily) (n = 4,895) or placebo (n = 4,900) for 5 years. Baseline renal function (Modification of Diet in Renal Disease equation) was grouped by eGFR (30-59, 60-89, and ≥90 mL/min/1.73 m(2)). The prespecified outcome was total cardiovascular events (composite of cardiovascular death, myocardial infarction, stroke, and coronary/carotid revascularization). Serious adverse events and instances of ESRD (plasma creatinine >400 μmol/L, dialysis, renal transplant, or renal death) were recorded. Analysis was by intention to treat.

RESULTS

Overall, fenofibrate reduced total cardiovascular events, compared with placebo (hazard ratio 0.89 [95% CI 0.80-0.99]; P = 0.035). This benefit was not statistically different across eGFR groupings (P = 0.2 for interaction) (eGFR 30-59 mL/min/1.73 m(2): 0.68 [0.47-0.97], P = 0.035; eGFR ≥90 mL/min/1.73 m(2): 0.85 [0.70-1.02], P = 0.08). ESRD rates were similar between treatment arms, without adverse safety signals of fenofibrate use in renal impairment.

CONCLUSIONS

Patients with type 2 diabetes and moderate renal impairment benefit from long-term fenofibrate, without excess drug-related safety concerns compared with those with no or mild renal impairment. Fenofibrate treatment should not be contraindicated in moderate renal impairment, suggesting that current guidelines may be too restrictive.

Reduced risk of Plasmodium vivax malaria in Papua New Guinean children with Southeast Asian ovalocytosis in two cohorts and a case-control study

BACKGROUND

The erythrocyte polymorphism, Southeast Asian ovalocytosis (SAO) (which results from a 27-base pair deletion in the erythrocyte band 3 gene, SLC4A1Δ27) protects against cerebral malaria caused by Plasmodium falciparum; however, it is unknown whether this polymorphism also protects against P. vivax infection and disease.

METHODS AND FINDINGS

The association between SAO and P. vivax infection was examined through genotyping of 1,975 children enrolled in three independent epidemiological studies conducted in the Madang area of Papua New Guinea. SAO was associated with a statistically significant 46% reduction in the incidence of clinical P. vivax episodes (adjusted incidence rate ratio [IRR] = 0.54, 95% CI 0.40-0.72, p<0.0001) in a cohort of infants aged 3-21 months and a significant 52% reduction in P. vivax (blood-stage) reinfection diagnosed by PCR (95% CI 22-71, p = 0.003) and 55% by light microscopy (95% CI 13-77, p = 0.014), respectively, in a cohort of children aged 5-14 years. SAO was also associated with a reduction in risk of P. vivax parasitaemia in children 3-21 months (1,111/µl versus 636/µl, p = 0.011) and prevalence of P. vivax infections in children 15-21 months (odds ratio [OR] = 0.39, 95% CI 0.23-0.67, p = 0.001). In a case-control study of children aged 0.5-10 years, no child with SAO was found among 27 cases with severe P. vivax or mixed P. falciparum/P. vivax malaria (OR = 0, 95% CI 0-1.56, p = 0.11). SAO was associated with protection against severe P. falciparum malaria (OR = 0.38, 95% CI 0.15-0.87, p = 0.014) but no effect was seen on either the risk of acquiring blood-stage infections or uncomplicated episodes with P. falciparum. Although Duffy antigen receptor expression and function were not affected on SAO erythrocytes compared to non-SAO children, high level (>90% binding inhibition) P. vivax Duffy binding protein-specific binding inhibitory antibodies were observed significantly more often in sera from SAO than non-SAO children (SAO, 22.2%; non-SAO, 6.7%; p = 0.008).

CONCLUSIONS

In three independent studies, we observed strong associations between SAO and protection against P. vivax malaria by a mechanism that is independent of the Duffy antigen. P. vivax malaria may have contributed to shaping the unique host genetic adaptations to malaria in Asian and Oceanic populations. Please see later in the article for the Editors' Summary.

Features and prognosis of severe malaria caused by Plasmodium falciparum, Plasmodium vivax and mixed Plasmodium species in Papua New Guinean children

Background

Mortality from severe pediatric falciparum malaria appears low in Oceania but Plasmodium vivax is increasingly recognized as a cause of complications and death. The features and prognosis of mixed Plasmodium species infections are poorly characterized. Detailed prospective studies that include accurate malaria diagnosis and detection of co-morbidities are lacking.

Methods and Findings

We followed 340 Papua New Guinean (PNG) children with PCR-confirmed severe malaria (77.1% P. falciparum, 7.9% P. vivax, 14.7% P. falciparum/vivax) hospitalized over a 3-year period. Bacterial cultures were performed to identify co-incident sepsis. Clinical management was under national guidelines. Of 262 children with severe falciparum malaria, 30.9%, 24.8% and 23.2% had impaired consciousness, severe anemia, and metabolic acidosis/hyperlactatemia, respectively. Two (0.8%) presented with hypoglycemia, seven (2.7%) were discharged with neurologic impairment, and one child died (0.4%). The 27 severe vivax malaria cases presented with similar phenotypic features to the falciparum malaria cases but respiratory distress was five times more common (P = 0.001); one child died (3.7%). The 50 children with P. falciparum/vivax infections shared phenotypic features of mono-species infections, but were more likely to present in deep coma and had the highest mortality (8.0%; P = 0.003 vs falciparum malaria). Overall, bacterial cultures were positive in only two non-fatal cases. 83.6% of the children had alpha-thalassemia trait and seven with coma/impaired consciousness had South Asian ovalocytosis (SAO).

Conclusions

The low mortality from severe falciparum malaria in PNG children may reflect protective genetic factors other than alpha-thalassemia trait/SAO, good nutrition, and/or infrequent co-incident sepsis. Severe vivax malaria had similar features but severe P. falciparum/vivax infections were associated with the most severe phenotype and worst prognosis.

Nuclear magnetic resonance: a tool for malaria diagnosis?

Malaria control can be improved by rapid, sensitive, low-cost detection of infection. Several such strategies are being pursued. Rapid diagnostic tests can detect infections at parasite densities above 200 μL(-1). Polymerase chain reaction methods can detect low parasite densities, but are slow and prone to contamination under field conditions. Methods that detect hemozoin presence in blood have been proposed as alternatives for rapid detection of infection. In this study, we used a benchtop nuclear magnetic resonance (NMR) device to detect hemozoin. This device could be deployed in malaria-endemic settings. We measured synthetic hemozoin in phosphate-buffered saline and malaria parasites in human blood. The NMR detected hemozoin in suspensions of 4 ng μL(-1) and parasites at densities of 8,000-10,000 μL(-1) (0.2% parasitemia). Thus, our preliminary NMR approach, although providing very rapid measurements, is unlikely to achieve the required sensitivity and specificity for malaria diagnosis, unless a preliminary concentration step is performed.

The relationship between self-monitoring of blood glucose results and glycated haemoglobin in type 2 diabetes: the fremantle diabetes study

The benefits of self-monitoring of blood glucose (SMBG) in type 2 diabetes remain contentious. If SMBG data do not accurately reflect HbA(1c), attempts to modify lifestyle/pharmacotherapy will be ineffective. We aimed to determine how well SMBG correlates with HbA(1c) and fasting serum glucose (FSG). Community-based type 2 patients using SMBG provided their highest and lowest pre- and post-prandial glucose results in the week before detailed assessment. The ability of average pre- and post-prandial SMBG to predict HbA(1c)>7.0% was determined by linear regression and receiver operating characteristic (ROC) analyses. Of 1286 patients with known SMBG status, 70% reported using SMBG. Pre-prandial SMBG data were obtained from 554 participants and post-prandial SMBG data from 418. The mean SMBG result and HbA(1c) correlated significantly (pre-prandial r(s)=0.55, post-prandial r(s)=0.47; P<0.001). Areas under the ROC curve (95% confidence limits) were 0.78 (0.74-0.83) and 0.74 (0.69-0.78) for pre- and post-prandial SMBG (P<0.04). The optimal cut-point was 6.5 mmol/L for pre-prandial SMBG (sensitivity 79.3%, specificity 64.4%). Mean pre-prandial SMBG results correlated with FSG (r(s)=0.64, P<0.001) but were on average 1.4 mmol/L lower, consistent with known whole blood vs. plasma differences. Since SMBG values reflect prevailing glycaemia, refinements in their interpretation and application may improve SMBG effectiveness.

The epidemiology and characteristics of type 2 diabetes in urban, community-based young people

As little is known about the impact of type 2 diabetes amongst Australian youth despite international increases in childhood obesity, we aimed to identify and characterize people aged<25 years with type 2 diabetes in an urban community with 60,000 people aged 10-24 years. The estimated maximum prevalence (59/100,000 persons) was lower than US estimates but higher than in Asia and Europe. In eight patients assessed in detail, obesity and related comorbidities were common, and quality of life was low.

Impact of metabolic syndrome and its components on cardiovascular disease event rates in 4900 patients with type 2 diabetes assigned to placebo in the FIELD randomised trial

Background

Patients with the metabolic syndrome are more likely to develop type 2 diabetes and may have an increased risk of cardiovascular disease (CVD) events.We aimed to establish whether CVD event rates were influenced by the metabolic syndrome as defined by the World Health Organisation (WHO), the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) and the International Diabetes Federation (IDF) and to determine which component(s) of the metabolic syndrome (MS) conferred the highest cardiovascular risk in in 4900 patients with type 2 diabetes allocated to placebo in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial.

Research design and methods

We determined the influence of MS variables, as defined by NCEP ATPIII, IDF and WHO, on CVD risk over 5 years, after adjustment for CVD, sex, HbA_1c, creatinine, and age, and interactions between the MS variables in a Cox proportional-hazards model.

Results

About 80% had hypertension, and about half had other features of the metabolic syndrome (IDF, ATPIII). There was no difference in the prevalence of metabolic syndrome variables between those with and without CVD at study entry. The WHO definition identified those at higher CVD risk across both sexes, all ages, and in those without prior CVD, while the ATPIII definition predicted risk only in those aged over 65 years and in men but not in women. Patients meeting the IDF definition did not have higher risk than those without IDF MS.

CVD risk was strongly influenced by prior CVD, sex, age (particularly in women), baseline HbA1_c, renal dysfunction, hypertension, and dyslipidemia (low HDL-c, triglycerides > 1.7 mmol/L). The combination of low HDL-c and marked hypertriglyceridemia (> 2.3 mmol/L) increased CVD risk by 41%. Baseline systolic blood pressure increased risk by 16% per 10 mmHg in those with no prior CVD, but had no effect in those with CVD. In those without prior CVD, increasing numbers of metabolic syndrome variables (excluding waist) escalated risk.

Conclusion

Absence of the metabolic syndrome (by the WHO definition) identifies diabetes patients without prior CVD, who have a lower risk of future CVD events. Hypertension and dyslipidemia increase risk.

Synthesis and antimalarial evaluation of novel isocryptolepine derivatives

A series of mono- and di-substituted analogues of isocryptolepine have been synthesized and evaluated for in vitro antimalarial activity against chloroquine sensitive (3D7) and resistant (W2mef) Plasmodium falciparum and for cytotoxicity (3T3 cells). Di-halogenated compounds were the most potent derivatives and 8-bromo-2-chloroisocryptolepine displayed the highest selectivity index (106; the ratio of cytotoxicity (IC(50)=9005 nM) to antimalarial activity (IC(50)=85 nM)). Our evaluation of novel isocryptolepine compounds has demonstrated that di-halogenated derivatives are promising antimalarial lead compounds.