Identifying key factors contributing to treatment costs for snakebite envenoming in private tertiary healthcare settings in Tamil Nadu, India

BACKGROUND

India suffers ~58,000 annual deaths due to snakebites. The 'Big Four' snakes (Russell's viper, Indian cobra, common krait, and saw-scaled viper) that are responsible for most bites cause diverse clinical effects. Delayed treatment increases the risk of serious complications and treatment costs. Although government hospitals offer free treatment for snakebites in India, most patients opt for private healthcare, which is an out-of-pocket expense as they often lack health insurance coverage. This study aims to analyse snakebite treatment costs in private tertiary care hospitals in Tamil Nadu, India and identifies the key factors contributing to treatment costs.

METHODOLOGY/PRINCIPAL FINDINGS

The treatment cost details for 913 snakebite victims were collected from 10 private tertiary care hospitals across Tamil Nadu. The data were classified into hospital, pharmacy, investigation, and laboratory costs, and analysed to determine various factors that contribute to the costs. The results demonstrate that the average treatment costs vary widely for different snakes. The hospital and pharmacy costs are higher than investigation and laboratory costs for all snakebites. Notably, Russell's viper bites cost significantly more than the bites from other snakes. Overall, the type of snake, nature of complications, specialist treatments required, and arrival time to hospitals were identified as some of the key factors for higher treatment costs.

CONCLUSIONS/SIGNIFICANCE

These data demonstrate that ~80% of snakebite patients can be treated with INR 100,000 (~GBP 1000 or USD 1200) or less. This study emphasises the urgent need to improve rural medical care by providing appropriate training for healthcare professionals and essential resources to facilitate early assessment of patients, administer the initial dose of antivenom and refer the patients to tertiary care only when needed. Moreover, the outcome of this study forms a basis for developing appropriate policies to regulate snakebite treatment costs and provide affordable medical insurance for vulnerable communities.

The Effectiveness of Antibiotics in Managing Bacterial Infections on Bite Sites following Snakebite Envenomation

Snakebite envenomation (SBE) is a life-threatening medical emergency with a high mortality rate. Common secondary complications following SBE, such as wound infections, are significant due to their impact on worsening local tissue damage and causing systemic infection. Antivenoms are not effective to treat wound infections following SBE. Moreover, in several rural clinical settings, broad-spectrum antibiotics are often used without clear guidelines or based on limited laboratory data, resulting in undesirable side effects and exacerbated treatment costs. Therefore, robust antibiotic strategies should be developed to tackle this critical issue. Currently, there is limited information available on the bacterial profiles of SBE-induced infections and antibiotic susceptibility. Hence, it is essential to improve the knowledge of bacterial profiles and their antibiotic sensitivity in SBE victims to develop better treatment strategies. This study aimed to address this issue by examining the bacterial profiles of SBE victims with a specific focus on Russell's viper envenomation. The most frequently found bacteria in the bites of SBE victims were Staphylococcus aureus, Klebsiella sp., Escherichia coli, and Pseudomonas aeruginosa. Linezolid, clindamycin, colistin, meropenem, and amikacin were some of the most effective antibiotics for commonly grown bacteria in SBE victims. Similarly, ciprofloxacin, ampicillin, amoxiclave, cefixime, and tetracyclin were the least effective antibiotics for common bacteria found in the wound swabs of SBE victims. These data provide robust guidance for infection management following SBE and offer useful insights to aid in designing effective treatment protocols for SBE with serious wound infections in rural areas where laboratory facilities may not be readily available.

Multifaceted community health education programs as powerful tools to mitigate snakebite-induced deaths, disabilities, and socioeconomic burden

Snakebite envenoming (SBE) predominantly affects rural impoverished communities that have limited access to immediate healthcare. These communities often hold numerous myths/misbeliefs about snakes and SBE. Moreover, healthcare professionals who practice in rural regions often work in unstable situations with limited medical infrastructure and therefore, lack sufficient knowledge/experience and confidence in the clinical management of SBE. Due to the lack of reliable statistics on the true burden of SBE, developing health policies for this condition by relevant authorities may be difficult. Hence, it is critical to improve awareness about SBE among rural communities, healthcare professionals and health authorities using robust multifaceted community health education approaches. Here, we describe the design, development, implementation, and impact of distinctive community health education approaches that we used in India and Brazil. A wide range of educational tools including information leaflets, posters, pocket guides, learning materials for healthcare professionals and short/long video documentaries were developed in local languages and used to engage with target communities through direct assemblies as well as mass/traditional and social media. Notably, we used diverse methods to determine the impact of our programs in improving awareness, treatment-seeking behaviour, and clinical practice. The people-centred approaches that we used were inclusive and highly impactful in instigating fundamental changes in the management of SBE among rural communities. The resources and approaches presented in this article can be easily adapted for wider use in other countries in order to collectively reduce SBE-induced deaths, disabilities and socioeconomic ramifications.

Russell's viper envenomation induces rectus sheath haematoma

Snakebite envenomation causes systemic and local manifestations, which result from the individual or synergistic actions of multiple venom components. The pathological hallmarks of medically important venomous snakes such as the Indian Russell's viper (Daboia russelii) are well known. Envenomation by Russell's viper is typically characterised by coagulopathies, muscular damage, nephrotoxicity, and neurotoxicity. However, recent reports have revealed several unusual complications that provide a better understanding of Russell's viper envenomation effects. To further strengthen this, here, we report a case of Russell's viper bite that induced acute abdominal pain, which was intensified on day two and conservatively treated under medical supervision. Both Fothergill and Carnett signs were positive for this patient. An ultrasound imaging revealed a dissimilar dense mass, and the abdominal computed tomography scan confirmed rectus sheath haematoma. The clinical management involved the administration of polyvalent antivenom, packed red blood cells, fresh frozen plasma, and platelets. The patient recovered gradually and was discharged from the hospital eight days after the bite. Overall, this case presentation shares an uncommon experience and adds new insights into the complex series of rare pathological events associated with Russell's viper bites in India. The scientific documentation of relatively infrequent entities based on an ongoing living assessment of medical experiences, for example, this rectus sheath haematoma, constitutes valuable guidance for an adequate diagnosis and timely treatment. Essential awareness among clinicians and further research on understanding the molecular relationship between Russell's viper venom and rectus sheath haematoma will improve patient outcomes and understanding of this condition, respectively.

Neutrophil Gelatinase-Associated Lipocalin Acts as a Robust Early Diagnostic Marker for Renal Replacement Therapy in Patients with Russell's Viper Bite-Induced Acute Kidney Injuries

Snakebite-induced acute kidney injury (AKI) is frequently observed in patients following bites from vipers such as Russell's viper (Daboia russelii) in India. Currently, the levels of serum creatinine are mainly used as a marker to determine the necessity for renal replacement therapy (RRT) (haemodialysis) in severe cases of AKI. However, it takes up to 48 h to ascertain a distinct change in creatinine levels compared to its baseline level upon admission. The time lost between admission and the 48 h timepoint significantly affects the clinical management of snakebite victims. Moreover, early diagnosis of AKI and decision on the necessity for RRT in snakebite victims is critical in saving lives, reducing long-term complications, and minimising treatment costs arising from expensive haemodialysis. Neutrophil gelatinase-associated lipocalin (NGAL) has been recently studied as a robust early marker for AKI in non-snakebite patients. However, its suitability for clinical use in snakebite victims has not been rigorously established. Here, we demonstrate the clinical significance of plasma NGAL as a robust marker for RRT following AKI using a large cohort (309) of Russell's viper victims without any pre-existing health conditions. NGAL levels upon admission are positively correlated with creatinine levels at 48 h in different stages of AKI. Overall, NGAL acts as a robust early marker to ascertain the need for RRT following Russell's viper bites. The quantification of NGAL can be recommended as a routine test in hospitals that treat snakebites to decide on RRT at early time points instead of waiting for 48 h to confirm the increase in creatinine levels. The diagnostic use of NGAL in Russell's viper victims with pre-existing comorbidities and for other vipers should be evaluated in future studies.

Repurposing Cancer Drugs Batimastat and Marimastat to Inhibit the Activity of a Group I Metalloprotease from the Venom of the Western Diamondback Rattlesnake, Crotalus atrox

Snakebite envenomation causes over 140,000 deaths every year, predominantly in developing countries. As a result, it is one of the most lethal neglected tropical diseases. It is associated with incredibly complex pathophysiology due to the vast number of unique toxins/proteins present in the venoms of diverse snake species found worldwide. Here, we report the purification and functional characteristics of a Group I (PI) metalloprotease (CAMP-2) from the venom of the western diamondback rattlesnake, Crotalus atrox. Its sensitivity to matrix metalloprotease inhibitors (batimastat and marimastat) was established using specific in vitro experiments and in silico molecular docking analysis. CAMP-2 shows high sequence homology to atroxase from the venom of Crotalus atrox and exhibits collagenolytic, fibrinogenolytic and mild haemolytic activities. It exerts a mild inhibitory effect on agonist-induced platelet aggregation in the absence of plasma proteins. Its collagenolytic activity is completely inhibited by batimastat and marimastat. Zinc chloride also inhibits the collagenolytic activity of CAMP-2 by around 75% at 50 μM, while it is partially potentiated by calcium chloride. Molecular docking studies have demonstrated that batimastat and marimastat are able to bind strongly to the active site residues of CAMP-2. This study demonstrates the impact of matrix metalloprotease inhibitors in the modulation of a purified, Group I metalloprotease activities in comparison to the whole venom. By improving our understanding of snake venom metalloproteases and their sensitivity to small molecule inhibitors, we can begin to develop novel and improved treatment strategies for snakebites.

Abstract PD5-03: Characterization of high TIL breast cancers reveals a prognostic and functionally distinct tissue-resident memory subpopulation

Background: Tumor infiltrating lymphocytes (TILs) assessed via light microscopy are prognostic and predictive in the early stage and advanced triple negative and HER2-amplified breast cancer (BC). Higher TILs can also identify patients more likely to benefit from anti-PD-1 therapy. In this study we interrogated T cell subsets that comprise high TILs to determine if distinct subpopulations are key mediators of anti-tumor immunity.

Methods: We characterised TILs with a focus on CD3+ T cells in 129 primary and metastatic BC samples using flow cytometry, bulk RNASeq on flow sorted T cell populations, multiplex immunohistochemistry and microdroplet based single cell 3' mRNA sequencing on the 10X Genomics Chromium platform. Cell type specific gene expression signatures were determined from differential expression between putative T cell subpopulations. These signatures were investigated in clinical cohorts, including trial cohorts treated with pembrolizumab.

Results: High TIL Infiltrates consisted primarily of CD3+ T cells, with both CD8 and CD4 populations. Unsupervised clustering of single cell sequencing identified 9 CD8 and CD4 subpopulations with distinct gene expression profiles. In addition to Tregs and CD8 effector memory (TEM) T cells, we found a CD8+ tissue resident memory (TRM) population expressing greater levels of T-cell checkpoints and cytotoxic markers compared to effector memory cells. In 2 primary tumours and 1 liver metastasis, bulk RNASeq of flow sorted TEM and TRM corroborated the single cell mRNASeq results. T cell receptor profiling (TCR) in the 3 samples found non-overlapping repertoires in the 2 primary tumours, but overlap in one metastatic lesion, suggesting divergent developmental origins in the breast, but the potential for nascent TRM differentiation in a metastatic niche. Clustering of these TCRs suggested differing antigen specificities between TRM and non-TRM CD8 T cells. Using Metabric data, the CD8 TRM gene expression signature was prognostic for disease free survival (DFS) in primary TNBCs (n=329, log-rank p=0.003), and was able to further stratify cases with high and low CD8A expression for DFS (log-rank p = 0.03). The CD8 TRM signature was enriched in baseline tumour samples of responders (n = 9) compared with non-responders (n=36) in 45 patients with metastatic melanoma treated with T cell checkpoint blockade (p < 0.0001). Additional single cell sequencing data with TCR sequencing will be combined with these initial results, and an independent data set of single cell mRNASeq and TCR Seq on CD3+ BC TILs will be used to confirm our findings. Cell type specific signatures will be explored in additional clinical cohorts including KEYNOTE-086, and presented at the meeting.

Conclusion: Using single cell profiling of the immune microenvironment in BC we demonstrate that high TIL BCs contain multiple T cell subpopulations with different functional and prognostic significance. Our approach identified a CD8 TRM population with a distinct gene expression profile and strong expression of key immune checkpoints likely representing the presence of true tumor specific immunity. This population may be a key target of immune checkpoint blockade.

Citation Format: Savas P, Virassamy B, Ye C, Salim A, Mintoff CP, Caramia F, Salgado R, Teo ZL, Dushyanthen S, Byrne A, Luen SJ, Fox SB, Speed TP, Mackay LK, Neeson PJ, Loi S. Characterization of high TIL breast cancers reveals a prognostic and functionally distinct tissue-resident memory subpopulation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD5-03.

Interferon-γ receptor-1 gene promoter polymorphisms and susceptibility for brucellosis in Makkah region

BACKGROUND

Genetic polymorphisms that affect the production levels of certain cytokines and/or their receptors may determine the risk, severity or protection in some infectious diseases like brucellosis.

OBJECTIVES

The aim of this study was to investigate the association of certain known Interferon-γ Receptor-1 (IFN-γ R1) gene promoter polymorphisms and the susceptibility to infection with Brucellosis in Saudi population.

METHODS

A cases-control association study was conducted in 69 individuals with human brucellosis and 94 healthy individuals. Genotyping of IFN-γ R1 - 56 C>T and IFN-γ R1 - 611 A>G polymorphism in both patients and healthy controls was done by PCR- restriction enzyme length polymorphisms (PCR-RFLP) and PCR- confronting two primer pairs (PCR-CTPP) methods and were assessed for potential associations with susceptibility for human brucellosis and their mode of penetrance.

RESULTS

Interestingly, we have designed a PCR-CTPP system to be used for genotyping of IFN-γ R1 - 611 A > G polymorphism. The PCR-CTPP is an accurate method for genotyping of SNPs. Moreover, it is time-saving, inexpensive and easy to perform.

CONCLUSION

Both tested polymorphisms, IFN-γ R1 - 56 C>T and IFN-γ R1 -611 A>G polymorphism had no role in genetic susceptibility to human brucellosis in the study population. The PCR-CTPP can be used for genotyping IFN-γ R1 - 611 A > G polymorphism and other types of mutation.

Is the matched extreme case-control design more powerful than the nested case-control design?

For time-to-event data, the study sample is commonly selected using the nested case-control design in which controls are selected at the event time of each case. An alternative sampling strategy is to sample all controls at the same (pre-specified) time, which can either be at the last event time or further out in time. Such controls are the long-term survivors and may therefore constitute a more 'extreme' comparison group and be more informative than controls from the nested case-control design. We investigate this potential information gain by comparing the power of various 'extreme' case-control designs with that of the nested case-control design using simulation studies. We derive an expression for the theoretical average information in a nested and extreme case-control pair for the situation of a single binary exposure. Comparisons reveal that the efficiency of the extreme case-control design increases when the controls are sampled further out in time. In an application to a study of dementia, we identified Apolipoprotein E as a risk factor using a 1:1 extreme case-control design, which provided a hazard ratio estimate with a smaller standard error than that of a 2:1 nested case-control design.

Regionalisation of trauma care in England

AIMS

We aimed to determine whether there is evidence of improved patient outcomes in Major Trauma Centres following the regionalisation of trauma care in England.

PATIENTS AND METHODS

An observational study was undertaken using the Trauma Audit and Research Network (TARN), Hospital Episode Statistics (HES) and national death registrations. The outcome measures were indicators of the quality of trauma care, such as treatment by a senior doctor and clinical outcomes, such as mortality in hospital.

RESULTS AND CONCLUSION

A total of 20 181 major trauma cases were reported to TARN during the study period, which was 270 days before and after each hospital became a Major Trauma Centre. Following regionalisation of trauma services, all indicators of the quality of care improved, fewer patients required secondary transfer between hospitals and a greater proportion were discharged with a Glasgow Outcome Score of "good recovery". In this early post-implementation analysis, there were a number of apparent process improvements (e.g. time to CT) but no differences in either crude or adjusted mortality. The overall number of deaths following trauma in England did not change following the national reconfiguration of trauma services. Evidence from other countries that have regionalised trauma services suggests that further benefits may become apparent after a period of maturing of the trauma system. Cite this article: Bone Joint J 2016;98-B:1253-61.

An approach to forecast human cancer by profiling microRNA expressions from NGS data

BACKGROUND

microRNAs are single-stranded non-coding RNA sequences of 18 - 24 nucleotides in length. They play an important role in post-transcriptional regulation of gene expression. Evidences of microRNA acting as promoter/suppressor of several diseases including cancer are being unveiled. Recent studies have shown that microRNAs are differentially expressed in disease states when compared with that of normal states. Profiling of microRNA is a good measure to estimate the differences in expression levels, which can be further utilized to understand the progression of any associated disease.

METHODS

Machine learning techniques, when applied to microRNA expression values obtained from NGS data, could be utilized for the development of effective disease prediction system. This paper discusses an approach for microRNA expression profiling, its normalization and a Support Vector based machine learning technique to develop a Cancer Prediction System. Presently, the system has been trained with data samples of hepatocellular carcinoma, carcinomas of the bladder and lung cancer. microRNAs related to specific types of cancer were used to build the classifier.

RESULTS

When the system is trained and tested with 10 fold cross validation, the prediction accuracy obtained is 97.56% for lung cancer, 97.82% for hepatocellular carcinoma and 95.0% for carcinomas of the bladder. The system is further validated with separate test sets, which show accuracies higher than 90%. A ranking based on differential expression marks the relative significance of each microRNA in the prediction process.

CONCLUSIONS

Results from experiments proved that microRNA expression profiling is an effective mechanism for disease identification, provided sufficiently large database is available.

Quality of care for patients with a fracture of the hip in major trauma centres

Aims

In this study, we aimed to determine whether designation as a major trauma centre (MTC) affects the quality of care for patients with a fracture of the hip.

Patients and Methods

All patients in the United Kingdom National Hip Fracture Database, between April 2010 and December 2013, were included. The indicators of quality that were recorded included the time to arrival on an orthopaedic ward, to review by a geriatrician, and to operation. The clinical outcomes were the development of a pressure sore, discharge home, length of stay, in-hospital mortality, and re-operation within 30 days.

Results

There were 289 466 patients, 49 350 (17%) of whom were treated in hospitals that are now MTCs. Using multivariable logistic and generalised linear regression models, there were no significant differences in any of the indicators of the quality of care or clinical outcomes between MTCs, hospitals awaiting MTC designation and non-MTC hospitals.

Conclusion

These findings suggest that the regionalisation of major trauma in England did not improve or compromise the overall care of elderly patients with a fracture of the hip. Take home message: There is no evidence that reconfiguring major trauma services in England disrupted the treatment of older adults with a fracture of the hip. Cite this article: Bone Joint J 2016;98-B:414–19.

Insulin-dependent diabetes and serious trauma

PURPOSE

Trauma patients with diabetes mellitus (DM) represent a unique population as the acute injury and the underlying disease may both cause hyperglycemia that leads to poor outcomes. We investigated how insulin-dependent DM (IDDM) and noninsulin-dependent DM (NIDDM) impact mortality after serious trauma without brain injury.

METHODS

The National Trauma Data Bank (NTDB) version 7.0 was queried for all patients with moderate to severe traumatic injury [injury severity score (ISS) >9]. Patients were excluded if missing data, age <10 years, severe brain injury [head abbreviated injury scale (AIS) >3], dead on arrival or any AIS = 6. Logistic regression modeled the association between DM and mortality as well as IDDM, NIDDM and mortality.

RESULTS

Overall 166,103 trauma patients without brain injury were analyzed. Mortality was 7.6 and 4.4 % in patients with and without DM, respectively (p < 0.01). Mortality was 9.9 % for patients with IDDM and 6.7 % for NIDDM (p < 0.01). The increased mortality associated with DM was only significantly higher for DM patients in their forties (5.6 vs. 3.3 %, p < 0.01). Regression analyses demonstrated that DM (AOR 1.14, p = 0.04) and IDDM (AOR 1.46, p < 0.01) were predictors of mortality compared to no DM, but NIDDM was not (AOR 1.02, p = 0.83).

CONCLUSIONS

While DM was a predictor for higher mortality after serious trauma, this increase was only observed in IDDM and not NIDDM. Our findings suggest IDDM patients who present after serious trauma are unique and attention to their hyperglycemia and related insulin therapy may play a critical role in recovery.

Increasing intent to donate in Hispanic American high school students: results of a prospective observational study

BACKGROUND

High school students are an important target audience for organ donation education. A novel educational intervention focused on Hispanic American (HA) high school students might improve organ donation rates.

METHODS

A prospective observational study was conducted in five Los Angeles High Schools with a high percentage of HA students. A "culturally sensitive" educational program was administered to students in grades 9 to 12. Preintervention surveys that assessed awareness, knowledge, perception, and beliefs regarding donation as well as the intent to become an organ donor were compared to postintervention surveys.

RESULTS

A total of 10,146 high school students participated in the study. After exclusions, 4876 preintervention and 3182 postintervention surveys were analyzed. A significant increase in the overall knowledge, awareness, and beliefs regarding donation was observed after the intervention, as evidenced by a significant increase in the percentage of correct answers on the survey (41% pre- versus 44% postintervention, P < .0001). When specifically examining HA students, there was a significant increase in the intent to donate organs (adjusted odds ratio 1.21, 95% confidence interval: 1.09, 1.34, P = .0003).

CONCLUSION

This is the first study to demonstrate a significant increase in the intent to donate among HA high school students following an educational intervention.

The impact of meeting donor management goals on the development of delayed graft function in kidney transplant recipients

Many organ procurement organizations (OPOs) utilize preset critical care endpoints as donor management goals (DMGs) in order to standardize care and improve outcomes. The objective of this study was to determine the impact of meeting DMGs on delayed graft function (DGF) in renal transplant recipients. All eight OPOs of the United Network for Organ Sharing Region 5 prospectively implemented nine DMGs in every donor after neurologic determination of death (DNDD). "DMGs met" was defined a priori as achieving any seven of the nine DMGs and this was recorded at the time of consent for donation to reflect donor hospital ICU management, 12-18 h later, and prior to organ recovery. Multivariable analyses were performed to identify independent predictors of DGF (dialysis in the first week after transplantation) with a p<0.05. A total of 722 transplanted kidneys from 492 DNDDs were included. A total of 28% developed DGF. DMGs were met at consent in 14%, 12-18 h in 32% and prior to recovery in 38%. DGF was less common when DMGs were met at consent (17% vs. 30%, p=0.007). Independent predictors of DGF were age, Cr and cold ischemia time, while meeting DMGs at consent was significantly protective. The management of potential organ donors prior to consent affects outcomes and should remain a priority in the intensive care unit.

Abstract P2-11-06: Mortality among offspring of women diagnosed with breast cancer; a population based study

Introduction: Survival after breast cancer has improved substantially over the past decades. As a result, an increasing number of breast cancer survivors is starting or extending their family post-diagnosis. We evaluated mortality risks of offspring from women with a history of breast cancer.

Methods: From the Swedish Multi-Generation Register and the Cancer Register we identified all 63,205 children whose mother had ever been diagnosed with invasive breast cancer. For these children, we calculated relative mortality risks as compared to the background population (Standardized Mortality Ratios [SMRs]). We compared SMRs according to the mother's parity status at diagnosis and timing of birth in relation to time of diagnosis, i.e. before (&gt;1 year before), around (between 1 year before and 1 year after) and after (&gt;1 year after) diagnosis.

Results: Children born around their mother's breast cancer diagnosis had an increased mortality risk as compared to the background population (SMR 2.70 95% CI [1.64–4.44]). This risk was particularly high for first-born children (SMR 11.07 (95% CI [2.09–27.13]), who had an absolute excess risk of 6.4% to die before the age of 5 years. Children born more than one year before or after their mother's breast cancer diagnosis had similar mortality risks as the background population.

Conclusion: Children born around their mother's breast cancer diagnosis have significantly increased mortality risks. Offspring of nulliparous women have a particularly high relative mortality risk, suggesting that pregnant breast cancer patients may be keen to keep their first child in spite of potential treatment toxicity.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-11-06.

KCNQ1 SNPS and susceptibility to diabetic nephropathy in East Asians with type 2 diabetes

AIMS/HYPOTHESIS

A Japanese study had earlier reported that KCNQ1 single-nucleotide polymorphisms (SNPs) may be associated with diabetic nephropathy. To further investigate this finding, we analysed three SNPs, rs2237895, rs2237897 and rs2283228, within the KCNQ1 locus for association with albuminuria among Chinese type 2 diabetic patients residing in Singapore. Albuminuria was analysed as both categorical (micro- and macroalbuminuria) and continuous traits (log(e) albumin/creatinine ratio [ACR]).

METHODS

A total of 752 Chinese patients with type 2 diabetes were included in the study. Albuminuria was determined by ACR using spot urine samples, and renal function was approximated using estimated GFR. Genotyping was performed using invader and Taqman assays as appropriate. Multivariate regression analyses were used to analyse the associations between SNPs and renal traits.

RESULTS

Significant associations were detected between rs2283228 and macroalbuminuria (p < 0.001, corrected p < 0.01), as well as log(e) ACR (p = 0.004, corrected p = 0.036) after multiple hypothesis testing and adjustment for potential confounding. A trend of increasing OR was observed with increasing severity of diabetic nephropathy (low and high microalbuminuria, macroalbuminuria). rs2237897, previously implicated in the earlier Japanese study, was also associated with macroalbuminuria, but this finding did not remain significant after correction for multiple testing. Meta-analyses of the Chinese and Japanese studies revealed both SNPs to be significantly associated with macroalbuminuria.

CONCLUSIONS/INTERPRETATION

Together with the previous Japanese study, our findings support the hypothesis that, in addition to KCNQ1 being an established type 2 diabetes gene, genetic variation in this gene may contribute to susceptibility to diabetic nephropathy in East Asians.

Ethnicity modifies the relation between fasting plasma glucose and HbA1c in Indians, Malays and Chinese

AIMS

To study whether HbA(1c) , and its relationship with fasting plasma glucose, was significantly different among Chinese, Malays and Indians in Singapore.

METHODS

A sample of 3895 individuals without known diabetes underwent detailed interview and health examination, including anthropometric and biochemical evaluation, between 2004 and 2007. Pearson's correlation, analysis of variance and multiple linear regression analyses were used to examine the influence of ethnicity on HbA(1c) .

RESULTS

As fasting plasma glucose increased, HbA(1c) increased more in Malays and Indians compared with Chinese after adjustment for age, gender, waist circumference, serum cholesterol, serum triglyceride and homeostasis model assessment of insulin resistance (P-interaction < 0.001). This translates to an HbA(1c) difference of 1.1 mmol/mol (0.1%, Indians vs. Chinese), and 0.9 mmol/mol (0.08%, Malays vs. Chinese) at fasting plasma glucose 5.6 mmol/l (the American Diabetes Association criterion for impaired fasting glycaemia); and 2.1 mmol/mol (0.19%, Indians vs. Chinese) and 2.6 mmol/mol (0.24%, Malays vs. Chinese) at fasting plasma glucose 7.0 mmol/l, the diagnostic criterion for diabetes mellitus.

CONCLUSIONS

Using HbA(1c) in place of fasting plasma glucose will reclassify different proportions of the population in different ethnic groups. This may have implications in interpretation of HbA(1c) results across ethnic groups and the use of HbA(1c) for diagnosing diabetes mellitus.

An observational study of the Baska® mask: a novel supraglottic airway

The Baska mask is a novel supraglottic airway device. We conducted an initial observational study to assess this device in 30 low-risk female patients. All Baska masks were inserted by a single investigator. The overall success rate for device insertion was 96.7% (95% CI 82.8-99.9%), while the success rate for the first insertion attempt was 76.7% (95% CI 57.7-90.1%). The device was easy to insert, with a mean (SD) difficulty score of 0.9 (1.6) on a 10-cm scale. The mean (SD) airway leak pressure was 35.7 (13.3) cmH(2) O. The incidence of throat pain, dysphonia and dysphagia was low. We conclude that the Baska mask demonstrates a level of utility as an alternative supraglottic airway that is worthy of further clinical study.

A metabolomic study of low estimated GFR in non-proteinuric type 2 diabetes mellitus

AIMS/HYPOTHESIS

We carried out a urinary metabolomic study to gain insight into low estimated GFR (eGFR) in patients with non-proteinuric type 2 diabetes.

METHODS

Patients were identified as being non-proteinuric using multiple urinalyses. Cases (n = 44) with low eGFR and controls (n = 46) had eGFR values <60 and ≥60 ml min(-1) 1.73 m(-2), respectively, as calculated using the Modification of Diet in Renal Disease formula. Urine samples were analysed by liquid chromatography/mass spectrometry (LC/MS) and GC/MS. False discovery rates were used to adjust for multiple hypotheses testing, and selection of metabolites that best predicted low eGFR status was achieved using least absolute shrinkage and selection operator logistic regression.

RESULTS

Eleven GC/MS metabolites were strongly associated with low eGFR after correction for multiple hypotheses testing (smallest adjusted p value = 2.62 × 10(-14), largest adjusted p value = 3.84 × 10(-2)). In regression analysis, octanol, oxalic acid, phosphoric acid, benzamide, creatinine, 3,5-dimethoxymandelic amide and N-acetylglutamine were selected as the best subset for prediction and allowed excellent classification of low eGFR (AUC = 0.996). In LC/MS, 19 metabolites remained significant after multiple hypotheses testing had been taken into account (smallest adjusted p value = 2.04 × 10(-4), largest adjusted p value = 4.48 × 10(-2)), and several metabolites showed stronger evidence of association relative to the uraemic toxin, indoxyl sulphate (adjusted p value = 3.03 × 10(-2)). The potential effect of confounding on the association between metabolites was excluded.

CONCLUSIONS/INTERPRETATION

Our study has yielded substantial new insight into low eGFR and provided a collection of potential urinary biomarkers for its detection.

Estimating the number of true discoveries in genome-wide association studies

Recent genome-wide association studies have reported the discoveries of genetic variants of small to moderate effects. However, most studies of complex diseases face a great challenge because the number of significant variants is less than what is required to explain the disease heritability. A new approach is needed to recognize all potential discoveries in the data. In this paper, we present a practical model-free procedure to estimate the number of true discoveries as a function of the number of top-ranking SNPs together with the confidence bounds. This approach allows a practical methodology of general utility and produces relevant statistical quantities with simple interpretation.