Diagnosing diabetes mellitus - Do we need new criteria?

The current classification and diagnostic criteria for diabetes mellitus were introduced by the United States National Data Group in 1979 and endorsed by the World Health Organization in 1980, with modifications in 1985 and 1994. The criteria, chosen to reflect the risk of complications, were the synthesis of considerable thought and expertise and represented a consensus which, it was hoped, would prove helpful to all those involved with diabetes practising clinician, research scientist and epidemiologist alike. The inconvenience, variability and nonphysiological nature of the oral glucose tolerance test (OGTT) are well-recognised. In spite of these limitations the 2-h post-load plasma glucose has remained the standard against which all other tests have been evaluated. This article reviews the original justification for the OGTT, and in the light of more recent epidemiological research seeks to place the current diagnostic criteria for diabetes into a pathophysiological, diagnostic and prognostic perspective.

Deriving meteorological variables across Africa for the study and control of vector-borne disease:a comparison of remote sensing and spatial interpolation of climate

This paper presents the results of an investigation into the utility of remote sensing (RS) using meteorological satellites sensors and spatial interpolation (SI) of data from meteorological stations, for the prediction of spatial variation in monthly climate across continental Africa in 1990. Information from the Advanced Very High Resolution Radiometer (AVHRR) of the National Oceanic and Atmospheric Administration's (NOAA) polar-orbiting meteorological satellites was used to estimate land surface temperature (LST) and atmospheric moisture. Cold cloud duration (CCD) data derived from the High Resolution Radiometer (HRR) onboard the European Meteorological Satellite programme's (EUMETSAT) Meteosat satellite series were also used as a RS proxy measurement of rainfall. Temperature, atmospheric moisture and rainfall surfaces were independently derived from SI of measurements from the World Meteorological Organization (WMO) member stations of Africa. These meteorological station data were then used to test the accuracy of each methodology, so that the appropriateness of the two techniques for epidemiological research could be compared. SI was a more accurate predictor of temperature, whereas RS provided a better surrogate for rainfall; both were equally accurate at predicting atmospheric moisture. The implications of these results for mapping short and long-term climate change and hence their potential for the study anti control of disease vectors are considered. Taking into account logistic and analytical problems, there were no clear conclusions regarding the optimality of either technique, but there was considerable potential for synergy.

Exploiting Human Resource Requirements to Infer Human Movement Patterns for Use in Modelling Disease Transmission Systems: An Example from Eastern Province, Zambia

In this research, an agent-based model (ABM) was developed to generate human movement routes between homes and water resources in a rural setting, given commonly available geospatial datasets on population distribution, land cover and landscape resources. ABMs are an object-oriented computational approach to modelling a system, focusing on the interactions of autonomous agents, and aiming to assess the impact of these agents and their interactions on the system as a whole. An A* pathfinding algorithm was implemented to produce walking routes, given data on the terrain in the area. A* is an extension of Dijkstra's algorithm with an enhanced time performance through the use of heuristics. In this example, it was possible to impute daily activity movement patterns to the water resource for all villages in a 75 km long study transect across the Luangwa Valley, Zambia, and the simulated human movements were statistically similar to empirical observations on travel times to the water resource (Chi-squared, 95% confidence interval). This indicates that it is possible to produce realistic data regarding human movements without costly measurement as is commonly achieved, for example, through GPS, or retrospective or real-time diaries. The approach is transferable between different geographical locations, and the product can be useful in providing an insight into human movement patterns, and therefore has use in many human exposure-related applications, specifically epidemiological research in rural areas, where spatial heterogeneity in the disease landscape, and space-time proximity of individuals, can play a crucial role in disease spread.

Traumatic brain injury and co-occurring problems in prison populations: a systematic review.

Background: A growing body of epidemiological research suggests high rates of traumatic brain injury (TBI) in prisoners. The aim of this review is to systematically explore the literature surrounding the rates of TBI and their co-occurrences in a prison population.
Methods: Six electronic databases were systematically searched for articles published between 1980 and 2014. Studies were screened for inclusion based on predetermined criteria by two researchers who independently performed data extraction. Study quality was appraised based on a modified quality assessment tool.
Results: Twenty six studies were included in this review. Quality assessment ranged from 20% (poor) to 80% (good) with an overall average of 60%. Twenty four papers included TBI prevalence rates, which ranged from 5.69%-88%. Seventeen studies explored co-occurring factors including rates of aggression (n=7), substance abuse (n=9), anxiety and depression (n=5), neurocognitive deficits (n=4), and psychiatric conditions (n=3).
Conclusions: The high degree of variation in TBI rates may be attributed to the inconsistent way in which TBI was measured with only seven studies using valid and reliable screening tools. Additionally, gaps in the literature surrounding personality outcomes in prisoners with TBI, female prisoners with TBI, and qualitative outcomes were found.

Is there a role for n-3 long-chain polyunsaturated fatty acids in the regulation of mood and behaviour? A review of the evidence to date from epidemiological studies, clinical studies and intervention trials

Selected biochemical evidence suggests a potential role for n-3 long-chain PUFA (n-3PUFA) in the regulation of mood and behaviour. The present paper reviews the relevant evidence, to date, from epidemiological studies, clinical studies and intervention trials. Most evidence is available investigating a role for n-3PUFA in depression, depressive illness and suicidal behaviour, but work is also available on anxiety and anxiety-related disorders, fatigue and fatigue-related disorders, aggression, hostility and anti-social behaviour, inattention, impulsivity and attention deficit hyperactivity disorder and schizophrenic disorders. For all these aspects of mood and behaviour, the evidence available is currently limited and highly inconsistent, both in terms of study methodology and study findings. There is a clear need for further work in this area.

Beta-blocker usage and prostate cancer survival:A nested case-control study in the UK Clinical Practice Research Datalink cohort

Background: Recent laboratory and epidemiological evidence suggests that beta-blockers could inhibit prostate cancer progression. Methods: We investigated the effect of beta-blockers on prostate cancer-specific mortality in a cohort of prostate cancer patients. Prostate cancer patients diagnosed between 1998 and 2006 were identified from the UK Clinical Practice Research Database and confirmed by cancer registries. Patients were followed up to 2011 with deaths identified by the Office of National Statistics. A nested case-control analysis compared patients dying from prostate cancer (cases) with up to three controls alive at the time of their death, matched by age and year of diagnosis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression. Results: Post-diagnostic beta-blocker use was identified in 25% of 1184 prostate cancer-specific deaths and 26% of 3531 matched controls. There was little evidence (P=0.40) of a reduction in the risk of cancer-specific death in beta-blocker users compared with non-users (OR=0.94 95% CI 0.81, 1.09). Similar results were observed after adjustments for confounders, in analyses by beta-blocker frequency, duration, type and for all-cause mortality. Conclusions: Beta-blocker usage after diagnosis was not associated with cancer-specific or all-cause mortality in prostate cancer patients in this large UK study.

Towards optimal clinical and epidemiological registration of haematological malignancies: Guidelines for recording progressions, transformations and multiple diagnoses

Haematological malignancies (HM) represent over 6% of the total cancer incidence in Europe and affect all ages, ranging between 45% of all cancers in children and 7% in the elderly. Thirty per cent of childhood cancer deaths are due to HM, 8% in the elderly. Their registration presents specific challenges, mainly because HM may transform or progress in the course of the disease into other types of HM. In the context of cancer registration decisions have to be made about classifying subsequent notifications on the same patient as the same tumour (progression), a transformation or a new tumour registration. Allocation of incidence date and method of diagnosis must also be standardised. We developed European Network of Cancer Registries (ENCR) recommendations providing specific advice for cancer registries to use haematology and molecular laboratories as data sources, conserve the original date of incidence in case of change of diagnosis, make provision for recording both the original as well as transformed tumour and to apply precise rules for recording and counting multiple diagnoses. A reference table advising on codes which reflect a potential transformation or a new tumour is included. This work will help to improve comparability of data produced by population-based cancer registries, which are indispensable for aetiological research, health care planning and clinical research, an increasing important area with the application of targeted therapies.

Digital pathology and image analysis in tissue biomarker research

Digital pathology and the adoption of image analysis have grown rapidly in the last few years. This is largely due to the implementation of whole slide scanning, advances in software and computer processing capacity and the increasing importance of tissue-based research for biomarker discovery and stratified medicine. This review sets out the key application areas for digital pathology and image analysis, with a particular focus on research and biomarker discovery. A variety of image analysis applications are reviewed including nuclear morphometry and tissue architecture analysis, but with emphasis on immunohistochemistry and fluorescence analysis of tissue biomarkers. Digital pathology and image analysis have important roles across the drug/companion diagnostic development pipeline including biobanking, molecular pathology, tissue microarray analysis, molecular profiling of tissue and these important developments are reviewed. Underpinning all of these important developments is the need for high quality tissue samples and the impact of pre-analytical variables on tissue research is discussed. This requirement is combined with practical advice on setting up and running a digital pathology laboratory. Finally, we discuss the need to integrate digital image analysis data with epidemiological, clinical and genomic data in order to fully understand the relationship between genotype and phenotype and to drive discovery and the delivery of personalized medicine.

β-Blocker usage and colorectal cancer mortality:a nested case-control study in the UK Clinical Practice Research Datalink cohort

BACKGROUND: Epidemiological and laboratory studies suggest that β-blockers may reduce cancer progression in various cancer sites. The aim of this study was to conduct the first epidemiological investigation of the effect of post-diagnostic β-blocker usage on colorectal cancer-specific mortality in a large population-based colorectal cancer patient cohort.

PATIENTS AND METHODS: A nested case-control analysis was conducted within a cohort of 4794 colorectal cancer patients diagnosed between 1998 and 2007. Patients were identified from the UK Clinical Practice Research Datalink and confirmed using cancer registry data. Patients with a colorectal cancer- specific death (data from the Office of National Statistics death registration system) were matched to five controls. Conditional logistic regression was applied to calculate odds ratios (OR) and 95% confidence intervals (95% CIs) according to β-blocker usage (data from GP-prescribing records).

RESULTS: Post-diagnostic β-blocker use was identified in 21.4% of 1559 colorectal cancer-specific deaths and 23.7% of their 7531 matched controls, with little evidence of an association (OR = 0.89 95% CI 0.78-1.02). Similar associations were found when analysing drug frequency, β-blocker type or specific drugs such as propranolol. There was some evidence of a weak reduction in all-cause mortality in β-blocker users (adjusted OR = 0.88; 95% CI 0.77-1.00; P = 0.04) which was in part due to the marked effect of atenolol on cardiovascular mortality (adjusted OR = 0.62; 95% CI 0.40-0.97; P = 0.04).

CONCLUSIONS: In this novel, large UK population-based cohort of colorectal cancer patients, there was no evidence of an association between post-diagnostic β-blocker use and colorectal cancer-specific mortality.

CLINICAL TRIALS NUMBER: NCT00888797.

Aflatoxin Exposure and Associated Human Health Effects, a Review of Epidemiological Studies

flatoxins are fungal toxins that possess acute life threatening toxicity, carcinogenic properties and other potential chronic adverse effects. Dietary exposure to aflatoxins is considered a major public health concern, especially for subsistence farming communities in sub-Saharan Africa and South Asia, where dietary staple food crops such as groundnuts and maize are often highly contaminated with aflatoxin due to hot and humid climates and poor storage, together with low awareness of risk and lack of enforcement of regulatory limits. Biomarkers have been developed and applied in many epidemiological studies assessing aflatoxin exposure and the associated health effects in these high-risk population groups. This review discusses the recent epidemiological evidence for aflatoxin exposure, co-exposure with other mycotoxins and associated health effects in order to provide evidence on risk assessment, and highlight areas where further research is necessary. Aflatoxin exposure can occur at any stage of life and is a major risk factor for hepatocellular carcinoma, especially when hepatitis B infection is present. Recent evidence suggests that aflatoxin may be an underlying determinant of stunted child growth, and may lower cell-mediated immunity, thereby increasing disease susceptibility. However, a causal relationship between aflatoxin exposure and these latter adverse health outcomes has not been established, and the biological mechanisms for these have not been elucidated, prompting further research. Furthermore, there is a dearth of information regarding the health effects of co-exposure to aflatoxin with other mycotoxins. Recent developments of biomarkers provide opportunities for important future research in this area.