Genetic drivers of heterogeneity in type 2 diabetes pathophysiology

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P < 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.

Improving psychological well-being among healthcare workers during the COVID-19 pandemic with an online mindfulness intervention: A randomised waitlist-controlled trial

The high prevalence of psychological problems observed among healthcare workers (HCWs) during the COVID-19 pandemic called for interventions to safeguard their mental health. We assessed the effectiveness of a 6-week online mindfulness-based intervention in improving well-being and reducing stress among HCWs in Sri Lanka. Eighty HCWs were recruited and randomised into two groups: waitlist-control (WLC) and intervention groups. In the intervention, 1-hour online sessions were conducted at weekly intervals and participants were encouraged to do daily home practice. Stress and well-being were measured pre- and post-intervention using the Perceived Stress Scale and WHO-5 Well-being Index, respectively. One-way analysis of covariance was used to evaluate the effectiveness, in both intention-to-treat (ITT) and complete-case (CC) analyses. A significantly greater improvement in well-being occurred in the intervention arm compared to WLC on both ITT (p = .002) and CC analyses (p < .001), with medium-to-large effect sizes (partial η2  = .117-.278). However, the reduction in stress following the intervention was not significant compared to the WLC group on both ITT (p = .636) and CC analyses (p = .262). In the intervention arm, the median number of sessions attended by participants was 3. Low adherence to the intervention may have contributed to the apparent non-significant effect on stress.

Elimination of malaria from Sri Lanka and beyond; lessons for other countries in elimination phase

Elimination of malaria in 2012 was a major achievement in post-independent Sri Lanka. Sri Lanka missed a golden opportunity in 1963 when only 17 cases of malaria were reported in the country, but could not sustain the momentum resulting in a major resurgence in 1967/69. With the resurgence, the then malaria eradication programme was reverted back to a control programme that lasted for another 30 years. The WHO's Roll Back Malaria Initiative launched in 1998 provided a renewed interest in malaria control and subsequent elimination. With targeted control activities, the burden of malaria started to decrease since year 2000. Although Sri Lanka had reached pre-elimination status as early as 2004, the ongoing separatist war at that time prevented a country-wide elimination drive being implemented. With cessation of hostilities in 2009 and Global Fund financing, both of which were crucial inputs, an elimination drive was launched in September 2009 which eventually eliminated indigenous malaria in November 2012 with malaria-free certification by WHO being obtained in September 2016. Since malaria elimination, the country forged on to the prevention of re-establishment phase primarily focusing on good public practice that included intensified surveillance, both parasitological and entomological; quality assured diagnostic and treatment services; and advocacy at various level including doctors. Despite these measures, an introduced case and an induced case of malaria have been reported. A new vector of urban malaria, Anopheles stephensi, was reported in December 2016. Prevention of re-establishment of malaria should be kept in the radar of public health until malaria is eradicated.

Multi-ancestry genome-wide study in >2.5 million individuals reveals heterogeneity in mechanistic pathways of type 2 diabetes and complications

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes. To characterise the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study (GWAS) data from 2,535,601 individuals (39.7% non-European ancestry), including 428,452 T2D cases. We identify 1,289 independent association signals at genome-wide significance (P<5×10-8) that map to 611 loci, of which 145 loci are previously unreported. We define eight non-overlapping clusters of T2D signals characterised by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial, and enteroendocrine cells. We build cluster-specific partitioned genetic risk scores (GRS) in an additional 137,559 individuals of diverse ancestry, including 10,159 T2D cases, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned GRS are more strongly associated with coronary artery disease and end-stage diabetic nephropathy than an overall T2D GRS across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings demonstrate the value of integrating multi-ancestry GWAS with single-cell epigenomics to disentangle the aetiological heterogeneity driving the development and progression of T2D, which may offer a route to optimise global access to genetically-informed diabetes care.

Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis

BACKGROUND

Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.

RESULTS

To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N = 1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.

CONCLUSIONS

Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.

Reference equations for evaluation of spirometry function tests in South Asia, and among South Asians living in other countries

BACKGROUND

There are few data to support accurate interpretation of spirometry data in South Asia, a major global region with a high reported burden of chronic respiratory disease.

METHOD

We measured lung function in 7453 healthy men and women aged ≥18 years, from Bangladesh, North India, South India, Pakistan and Sri Lanka, as part of the South Asia Biobank study. First, we assessed the accuracy of existing equations for predicting normal forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC ratio. Then, we used our data to derive (n=5589) and internally validate (n=1864) new prediction equations among South Asians, with further external validation among 339 healthy South Asians living in Singapore.

RESULTS

The Global Lung Initiative (GLI) and National Health and Nutrition Examination Survey consistently overestimated expiratory volumes (best fit GLI-African American, mean±sd z-score: FEV1 -0.94±1.05, FVC -0.91±1.10; n=7453). Age, height and weight were strong predictors of lung function in our participants (p<0.001), and sex-specific reference equations using these three variables were highly accurate in both internal validation (z-scores: FEV1 0.03±0.99, FVC 0.04±0.97, FEV1/FVC -0.03±0.99) and external validation (z-scores: FEV1 0.31±0.99, FVC 0.24±0.97, FEV1/FVC 0.16±0.91). Further adjustment for study regions improves the model fit, with highest accuracy for estimation of region-specific lung function in South Asia.

CONCLUSION

We present improved equations for predicting lung function in South Asians. These offer the opportunity to enhance diagnosis and management of acute and chronic lung diseases in this major global population.

A saturated map of common genetic variants associated with human height

Common single-nucleotide polymorphisms (SNPs) are predicted to collectively explain 40-50% of phenotypic variation in human height, but identifying the specific variants and associated regions requires huge sample sizes1. Here, using data from a genome-wide association study of 5.4 million individuals of diverse ancestries, we show that 12,111 independent SNPs that are significantly associated with height account for nearly all of the common SNP-based heritability. These SNPs are clustered within 7,209 non-overlapping genomic segments with a mean size of around 90 kb, covering about 21% of the genome. The density of independent associations varies across the genome and the regions of increased density are enriched for biologically relevant genes. In out-of-sample estimation and prediction, the 12,111 SNPs (or all SNPs in the HapMap 3 panel2) account for 40% (45%) of phenotypic variance in populations of European ancestry but only around 10-20% (14-24%) in populations of other ancestries. Effect sizes, associated regions and gene prioritization are similar across ancestries, indicating that reduced prediction accuracy is likely to be explained by linkage disequilibrium and differences in allele frequency within associated regions. Finally, we show that the relevant biological pathways are detectable with smaller sample sizes than are needed to implicate causal genes and variants. Overall, this study provides a comprehensive map of specific genomic regions that contain the vast majority of common height-associated variants. Although this map is saturated for populations of European ancestry, further research is needed to achieve equivalent saturation in other ancestries.

The iHealth-T2D study: a cluster randomised trial for the prevention of type 2 diabetes amongst South Asians with central obesity and prediabetes-a statistical analysis plan

BACKGROUND

South Asians are at high risk of type 2 diabetes (T2D). Lifestyle modification is effective at preventing T2D amongst South Asians, but the approaches to screening and intervention are limited by high costs, poor scalability and thus low impact on T2D burden. An intensive family-based lifestyle modification programme for the prevention of T2D was developed. The aim of the iHealth-T2D trial is to compare the effectiveness of this programme with usual care.

METHODS

The iHealth-T2D trial is designed as a cluster randomised controlled trial (RCT) conducted at 120 sites across India, Pakistan, Sri Lanka and the UK. A total of 3682 South Asian men and women with age between 40 and 70 years without T2D but at elevated risk for T2D [defined by central obesity (waist circumference ≥ 95 cm in Sri Lanka or ≥ 100 cm in India, Pakistan and the UK) and/or prediabetes (HbA1c ≥ 6.0%)] were included in the trial. Here, we describe in detail the statistical analysis plan (SAP), which was finalised before outcomes were available to the investigators. The primary outcome will be evaluated after 3 years of follow-up after enrolment to the study and is defined as T2D incidence in the intervention arm compared to usual care. Secondary outcomes are evaluated both after 1 and 3 years of follow-up and include biochemical measurements, anthropometric measurements, behavioural components and treatment compliance.

DISCUSSION

The iHealth-T2D trial will provide evidence of whether an intensive family-based lifestyle modification programme for South Asians who are at high risk for T2D is effective in the prevention of T2D. The data from the trial will be analysed according to this pre-specified SAP.

ETHICS AND DISSEMINATION

The trial was approved by the international review board of each participating study site. Study findings will be disseminated through peer-reviewed publications and in conference presentations.

TRIAL REGISTRATION

EudraCT 2016-001,350-18 . Registered on 14 April 2016.

CLINICALTRIALS

gov NCT02949739 . Registered on 31 October 2016.

A multi-layer functional genomic analysis to understand noncoding genetic variation in lipids

A major challenge of genome-wide association studies (GWASs) is to translate phenotypic associations into biological insights. Here, we integrate a large GWAS on blood lipids involving 1.6 million individuals from five ancestries with a wide array of functional genomic datasets to discover regulatory mechanisms underlying lipid associations. We first prioritize lipid-associated genes with expression quantitative trait locus (eQTL) colocalizations and then add chromatin interaction data to narrow the search for functional genes. Polygenic enrichment analysis across 697 annotations from a host of tissues and cell types confirms the central role of the liver in lipid levels and highlights the selective enrichment of adipose-specific chromatin marks in high-density lipoprotein cholesterol and triglycerides. Overlapping transcription factor (TF) binding sites with lipid-associated loci identifies TFs relevant in lipid biology. In addition, we present an integrative framework to prioritize causal variants at GWAS loci, producing a comprehensive list of candidate causal genes and variants with multiple layers of functional evidence. We highlight two of the prioritized genes, CREBRF and RRBP1, which show convergent evidence across functional datasets supporting their roles in lipid biology.

Multi-ancestry genetic study of type 2 diabetes highlights the power of diverse populations for discovery and translation

We assembled an ancestrally diverse collection of genome-wide association studies (GWAS) of type 2 diabetes (T2D) in 180,834 affected individuals and 1,159,055 controls (48.9% non-European descent) through the Diabetes Meta-Analysis of Trans-Ethnic association studies (DIAMANTE) Consortium. Multi-ancestry GWAS meta-analysis identified 237 loci attaining stringent genome-wide significance (P < 5 × 10-9), which were delineated to 338 distinct association signals. Fine-mapping of these signals was enhanced by the increased sample size and expanded population diversity of the multi-ancestry meta-analysis, which localized 54.4% of T2D associations to a single variant with >50% posterior probability. This improved fine-mapping enabled systematic assessment of candidate causal genes and molecular mechanisms through which T2D associations are mediated, laying the foundations for functional investigations. Multi-ancestry genetic risk scores enhanced transferability of T2D prediction across diverse populations. Our study provides a step toward more effective clinical translation of T2D GWAS to improve global health for all, irrespective of genetic background.

Identification of genetic effects underlying type 2 diabetes in South Asian and European populations

South Asians are at high risk of developing type 2 diabetes (T2D). We carried out a genome-wide association meta-analysis with South Asian T2D cases (n = 16,677) and controls (n = 33,856), followed by combined analyses with Europeans (neff = 231,420). We identify 21 novel genetic loci for significant association with T2D (P = 4.7 × 10-8 to 5.2 × 10-12), to the best of our knowledge at the point of analysis. The loci are enriched for regulatory features, including DNA methylation and gene expression in relevant tissues, and highlight CHMP4B, PDHB, LRIG1 and other genes linked to adiposity and glucose metabolism. A polygenic risk score based on South Asian-derived summary statistics shows ~4-fold higher risk for T2D between the top and bottom quartile. Our results provide further insights into the genetic mechanisms underlying T2D, and highlight the opportunities for discovery from joint analysis of data from across ancestral populations.

The iHealth-T2D study, prevention of type 2 diabetes amongst South Asians with central obesity and prediabetes: study protocol for a randomised controlled trial

BACKGROUND

People from South Asia are at increased risk of type 2 diabetes (T2D). There is an urgent need to develop approaches for the prevention of T2D in South Asians that are cost-effective, generalisable and scalable across settings.

HYPOTHESIS

Compared to usual care, the risk of T2D can be reduced amongst South Asians with central obesity or raised HbA1c, through a 12-month lifestyle modification programme delivered by community health workers.

DESIGN

Cluster randomised clinical trial (1:1 allocation to intervention or usual care), carried out in India, Pakistan, Sri Lanka and the UK, with 30 sites per country (120 sites total). Target recruitment 3600 (30 participants per site) with annual follow-up for 3 years.

ENTRY CRITERIA

South Asian, men or women, age 40-70 years with (i) central obesity (waist circumference ≥ 100 cm in India and Pakistan; ≥90 cm in Sri Lanka) and/or (ii) prediabetes (HbA1c 6.0-6.4% inclusive).

EXCLUSION CRITERIA

known type 1 or 2 diabetes, normal or underweight (body mass index < 22 kg/m2); pregnant or planning pregnancy; unstable residence or planning to leave the area; and serious illness.

ENDPOINTS

The primary endpoint is new-onset T2D at 3 years, defined as (i) HbA1c ≥ 6.5% or (ii) physician diagnosis and on treatment for T2D. Secondary endpoints at 1 and 3 years are the following: (i) physical measures: waist circumference, weight and blood pressure; (ii) lifestyle measures: smoking status, alcohol intake, physical activity and dietary intake; (iii) biochemical measures: fasting glucose, insulin and lipids (total and HDL cholesterol, triglycerides); and (iv) treatment compliance.

INTERVENTION

Lifestyle intervention (60 sites) or usual care (60 sites). Lifestyle intervention was delivered by a trained community health worker over 12 months (5 one-one sessions, 4 group sessions, 13 telephone sessions) with the goal of the participants achieving a 7% reduction in body mass index and a 10-cm reduction in waist circumference through (i) improved diet and (ii) increased physical activity. Usual care comprised a single 30-min session of lifestyle modification advice from the community health worker.

RESULTS

We screened 33,212 people for inclusion into the study. We identified 10,930 people who met study entry criteria, amongst whom 3682 agreed to take part in the intervention. Study participants are 49.2% female and aged 52.8 (SD 8.2) years. Clinical characteristics are well balanced between intervention and usual care sites. More than 90% of follow-up visits are scheduled to be complete in December 2020. Based on the follow-up to end 2019, the observed incidence of T2D in the study population is in line with expectations (6.1% per annum).

CONCLUSION

The iHealth-T2D study will advance understanding of strategies for the prevention of diabetes amongst South Asians, use approaches for screening and intervention that are adapted for low-resource settings. Our study will thus inform the implementation of strategies for improving the health and well-being of this major global ethnic group.

IRB APPROVAL

16/WM/0171 TRIAL REGISTRATION: EudraCT 2016-001350-18 . Registered on 14 April 2016. ClinicalTrials.gov NCT02949739 . Registered on 31 October 2016, First posted on 31/10/2016.

The power of genetic diversity in genome-wide association studies of lipids

Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use1. Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels2, heart disease remains the leading cause of death worldwide3. Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS4-23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns24. Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine25, we anticipate that increased diversity of participants will lead to more accurate and equitable26 application of polygenic scores in clinical practice.

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 × 10-8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.

Assessing mental well-being in a Sinhala speaking Sri Lankan population: validation of the WHO-5 well-being index

Purpose

The WHO-5 well-being index is a widely used, short rating scale that measures subjective well-being. We translated the WHO-5 index into Sinhala and tested its psychometric properties including measurement invariance among diverse groups in a community sample in Sri Lanka.

Methods

The sample of 267 persons aged between 16 and 75 years was recruited from a semi-urban area. 219 completed a paper-based questionnaire and 48 responded to an online survey. Construct validity was tested for factorial validity (Confirmatory Factor Analysis -CFA), convergent validity and known group validity. Composite reliability for congeneric measures and test-retest reliability were also tested. Multi-group CFA (MG-CFA) was used to test measurement invariance.

Results

The translated Sinhala version demonstrated good content and face validity. Internal consistency reliability of the five items had a Cronbach’s alpha of 0.85 and test-retest reliability over 2 weeks was satisfactory (Pearson r = 0.72, p < 0.001, ICC = 0.82). Confirmatory factor analysis supported factorial validity with a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\chi}_5^2 $$\end{document}χ52 =4.99 (p = 0.28), a RMSEA of 0.03 (90% C.I. =0.00–0.10), a SRMR of 0.02, a TLI of 0.99 and a CFI of 0.99; factor loadings were between 0.55 and 0.89. Measurement invariance was acceptable for configural, metric and scalar invariance for gender.

WHO-5 scores were significantly negatively correlated with the Patient Health Questionnaire (PHQ-9) (Pearson’s r = − 0.45, p < 0.001) scores and the Kessler Psychological Distress Scale (K10) scores (Pearson’s r = − 0.56, p < 0.001).

Conclusion

The Sinhala translation of WHO-5 well-being index has shown acceptable psychometric properties and can be used for assessing mental well-being in the community in Sri Lanka. Further testing of the measure with larger and diverse (including different ethnic/cultural) groups are indicated to test measurement invariance of the measure.

A multi-ancestry genome-wide study incorporating gene-smoking interactions identifies multiple new loci for pulse pressure and mean arterial pressure

Elevated blood pressure (BP), a leading cause of global morbidity and mortality, is influenced by both genetic and lifestyle factors. Cigarette smoking is one such lifestyle factor. Across five ancestries, we performed a genome-wide gene-smoking interaction study of mean arterial pressure (MAP) and pulse pressure (PP) in 129 913 individuals in stage 1 and follow-up analysis in 480 178 additional individuals in stage 2. We report here 136 loci significantly associated with MAP and/or PP. Of these, 61 were previously published through main-effect analysis of BP traits, 37 were recently reported by us for systolic BP and/or diastolic BP through gene-smoking interaction analysis and 38 were newly identified (P < 5 × 10-8, false discovery rate < 0.05). We also identified nine new signals near known loci. Of the 136 loci, 8 showed significant interaction with smoking status. They include CSMD1 previously reported for insulin resistance and BP in the spontaneously hypertensive rats. Many of the 38 new loci show biologic plausibility for a role in BP regulation. SLC26A7 encodes a chloride/bicarbonate exchanger expressed in the renal outer medullary collecting duct. AVPR1A is widely expressed, including in vascular smooth muscle cells, kidney, myocardium and brain. FHAD1 is a long non-coding RNA overexpressed in heart failure. TMEM51 was associated with contractile function in cardiomyocytes. CASP9 plays a central role in cardiomyocyte apoptosis. Identified only in African ancestry were 30 novel loci. Our findings highlight the value of multi-ancestry investigations, particularly in studies of interaction with lifestyle factors, where genomic and lifestyle differences may contribute to novel findings.

Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions

A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 × 10-6) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 × 10-8 using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.

Multi-ancestry genome-wide gene-smoking interaction study of 387,272 individuals identifies new loci associated with serum lipids

The concentrations of high- and low-density-lipoprotein cholesterol and triglycerides are influenced by smoking, but it is unknown whether genetic associations with lipids may be modified by smoking. We conducted a multi-ancestry genome-wide gene-smoking interaction study in 133,805 individuals with follow-up in an additional 253,467 individuals. Combined meta-analyses identified 13 new loci associated with lipids, some of which were detected only because association differed by smoking status. Additionally, we demonstrate the importance of including diverse populations, particularly in studies of interactions with lifestyle factors, where genomic and lifestyle differences by ancestry may contribute to novel findings.

Novel genetic associations for blood pressure identified via gene-alcohol interaction in up to 570K individuals across multiple ancestries

Heavy alcohol consumption is an established risk factor for hypertension; the mechanism by which alcohol consumption impact blood pressure (BP) regulation remains unknown. We hypothesized that a genome-wide association study accounting for gene-alcohol consumption interaction for BP might identify additional BP loci and contribute to the understanding of alcohol-related BP regulation. We conducted a large two-stage investigation incorporating joint testing of main genetic effects and single nucleotide variant (SNV)-alcohol consumption interactions. In Stage 1, genome-wide discovery meta-analyses in ≈131K individuals across several ancestry groups yielded 3,514 SNVs (245 loci) with suggestive evidence of association (P < 1.0 x 10-5). In Stage 2, these SNVs were tested for independent external replication in ≈440K individuals across multiple ancestries. We identified and replicated (at Bonferroni correction threshold) five novel BP loci (380 SNVs in 21 genes) and 49 previously reported BP loci (2,159 SNVs in 109 genes) in European ancestry, and in multi-ancestry meta-analyses (P < 5.0 x 10-8). For African ancestry samples, we detected 18 potentially novel BP loci (P < 5.0 x 10-8) in Stage 1 that warrant further replication. Additionally, correlated meta-analysis identified eight novel BP loci (11 genes). Several genes in these loci (e.g., PINX1, GATA4, BLK, FTO and GABBR2) have been previously reported to be associated with alcohol consumption. These findings provide insights into the role of alcohol consumption in the genetic architecture of hypertension.

A Large-Scale Multi-ancestry Genome-wide Study Accounting for Smoking Behavior Identifies Multiple Significant Loci for Blood Pressure

Genome-wide association analysis advanced understanding of blood pressure (BP), a major risk factor for vascular conditions such as coronary heart disease and stroke. Accounting for smoking behavior may help identify BP loci and extend our knowledge of its genetic architecture. We performed genome-wide association meta-analyses of systolic and diastolic BP incorporating gene-smoking interactions in 610,091 individuals. Stage 1 analysis examined ∼18.8 million SNPs and small insertion/deletion variants in 129,913 individuals from four ancestries (European, African, Asian, and Hispanic) with follow-up analysis of promising variants in 480,178 additional individuals from five ancestries. We identified 15 loci that were genome-wide significant (p < 5 × 10-8) in stage 1 and formally replicated in stage 2. A combined stage 1 and 2 meta-analysis identified 66 additional genome-wide significant loci (13, 35, and 18 loci in European, African, and trans-ancestry, respectively). A total of 56 known BP loci were also identified by our results (p < 5 × 10-8). Of the newly identified loci, ten showed significant interaction with smoking status, but none of them were replicated in stage 2. Several loci were identified in African ancestry, highlighting the importance of genetic studies in diverse populations. The identified loci show strong evidence for regulatory features and support shared pathophysiology with cardiometabolic and addiction traits. They also highlight a role in BP regulation for biological candidates such as modulators of vascular structure and function (CDKN1B, BCAR1-CFDP1, PXDN, EEA1), ciliopathies (SDCCAG8, RPGRIP1L), telomere maintenance (TNKS, PINX1, AKTIP), and central dopaminergic signaling (MSRA, EBF2).

Characterising private and shared signatures of positive selection in 37 Asian populations

The Asian Diversity Project (ADP) assembled 37 cosmopolitan and ethnic minority populations in Asia that have been densely genotyped across over half a million markers to study patterns of genetic diversity and positive natural selection. We performed population structure analyses of the ADP populations and divided these populations into four major groups based on their genographic information. By applying a highly sensitive algorithm haploPS to locate genomic signatures of positive selection, 140 distinct genomic regions exhibiting evidence of positive selection in at least one population were identified. We examined the extent of signal sharing for regions that were selected in multiple populations and observed that populations clustered in a similar fashion to that of how the ancestry clades were phylogenetically defined. In particular, populations predominantly located in South Asia underwent considerably different adaptation as compared with populations from the other geographical regions. Signatures of positive selection present in multiple geographical regions were predicted to be older and have emerged prior to the separation of the populations in the different regions. In contrast, selection signals present in a single population group tended to be of lower frequencies and thus can be attributed to recent evolutionary events.

Antenatal Care Provided and its Quality in Field Clinics in Gampaha District, Sri Lanka

A descriptive cross-sectional study was carried out in the Gampaha District in Sri Lanka to assess the quality of care provided at antenatal field clinics. Checklists were used to assess the structure and process attributes of quality. An interviewer administered questionnaire assessed the quality of information provided to the clients and client satisfaction. The findings indicated that several resource components need upgrading in the district. The majority of clinics did not have adequate seating arrangements, lacked a footstool, a height measuring instrument and Vitamin C. Less than 50% of the staff were present at 8.00 a.m. in eight clinics. Health education material was substandard in nine clinics. No supervisory notes were made during the preceding year in fourteen clinics. Testing urine for sugar and albumin was substandard in 11 and eight clinics, respectively. Physical examination of pregnant females was substandard in all 20 clinics. No information was provided on some routine procedures carried out at the clinic such as blood pressure monitoring, weight gain and vaccines given. Client satisfaction exceeded 95% in all aspects except building and infrastructure and time spent at the clinic. Asia Pac J Public Health 2007; 19(3): 38-44.

Translational research for Diabetes Self-Management in Sri Lanka: A randomized controlled trial

AIMS

The study tested the hypothesis that a theory driven Diabetes Self-Management (DSM) intervention delivered by trained nurses would result in a clinically significant improvement in glycaemic control.

METHODS

Patients with an HbA1c >7.5% (58mmol/mol) and free of diabetes complications were enrolled into a randomized controlled trial (n=85). Intervention consisted of four sessions and monthly follow up for 6 months. Biochemical tests, and diet and physical activity assessments were done in both groups. Analysis of covariance was used to test the effectiveness of the intervention.

RESULTS

At 6 months, there was a significant difference (P=0.001) in HbA1c between the groups controlling for baseline values and other variables. Based on the primary outcome, 28% in the intervention group achieved the target value of 6.5% HbA1c, compared to 8% in the "usual care" group (P<0.001; η(2)=0.65). The reduction in total energy intake and increase in physical activity was significant in the intervention group between baseline and follow up.

CONCLUSIONS

The DSM intervention has resulted in a clinically significant impact on glycaemia, change in diet and physical activity, and has demonstrated the feasibility of using it within existing care arrangements in a developing country setting.

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.0 × 10(-21)). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10(-6)). Our results provide new evidence for the role of DNA methylation in blood pressure regulation.

Evidence-based malaria control in Timor Leste from 2006 to 2012

Background

Malaria has been a major public health problem in the newly established Democratic Republic of Timor Leste with over 200,000 cases being reported in 2006 and 2007. The National Malaria Control Programme (NMCP) was established in 2003. The progress made in malaria control in Timor Leste is reported.

Methods

Records maintained at the NMCP, the district health services, the Health Information and Management System, the National Laboratory on malaria diagnosis and entomological data of the NMCP were reviewed.

Results

There has been a 97% decrease in the reported malaria incidence from 2006 (223,002 cases) to 2012 (6,202 cases). 185,106 clinical cases reported in 2006 decreased to 2,016 in 2012 with introduction and expansion of malaria microscopy services and introduction of monovalent RDTs in 2008 and bivalent RDTs in 2010 in all parts of the country. The National Treatment Guidelines using ACT as the first-line treatment for Plasmodium falciparum infections and introduction of monovalent RDTs, led to a 42% and a 33% decrease from 2007 to 2008 in reported clinical and total malaria cases, respectively. LLINs were distributed initially to pregnant females and children under five and later per every two persons living in high-risk areas (based on microstratification at sub-district level). IRS was carried out in three districts in 2010 and extended to six districts in 2012. Anopheles barbirostris and Anopheles subpictus have been incriminated as malaria vectors. A National Laboratory, which routinely cross checks blood smears for quality assurance of microscopy was established. Malaria focal points at regional, district and sub district level, entomology surveillance staff, monitoring and evaluation officers, and quality control technicians were appointed to strengthen malaria control activities at all levels in the country.

Conclusion

The 97% decrease in the incidence of malaria in Timor Leste is due to application of evidence-based malaria control methods that included enhancing improved quality surveillance, early diagnosis and prompt treatment of cases with effective anti-malarials, targeted vector control, human resource development and deployment, commitment of staff, GFATM funding and technical assistance from WHO.

Systematic fine-mapping of association with BMI and type 2 diabetes at the FTO locus by integrating results from multiple ethnic groups

BACKGROUND/OBJECTIVE

The 16q12.2 locus in the first intron of FTO has been robustly associated with body mass index (BMI) and type 2 diabetes in genome-wide association studies (GWAS). To improve the resolution of fine-scale mapping at FTO, we performed a systematic approach consisting of two parts.

METHODS

The first part is to partition the associated variants into linkage disequilibrium (LD) clusters, followed by conditional and haplotype analyses. The second part is to filter the list of potential causal variants through trans-ethnic comparison.

RESULTS

We first examined the LD relationship between FTO SNPs showing significant association with type 2 diabetes in Japanese GWAS and between those previously reported in European GWAS. We could partition all the assayed or imputed SNPs showing significant association in the target FTO region into 7 LD clusters. Assaying 9 selected SNPs in 4 Asian-descent populations--Japanese, Vietnamese, Sri Lankan and Chinese (n≤26,109 for BMI association and n≤24,079 for type 2 diabetes association), we identified a responsible haplotype tagged by a cluster of SNPs and successfully narrowed the list of potential causal variants to 25 SNPs, which are the smallest in number among the studies conducted to date for FTO.

CONCLUSIONS

Our data support that the power to resolve the causal variants from those in strong LD increases consistently when three distant populations--Europeans, Asians and Africans--are included in the follow-up study. It has to be noted that this fine-mapping approach has the advantage of applicability to the existing GWAS data set in combination with direct genotyping of selected variants.

Genome-wide trans-ancestry meta-analysis provides insight into the genetic architecture of type 2 diabetes susceptibility

To further understanding of the genetic basis of type 2 diabetes (T2D) susceptibility, we aggregated published meta-analyses of genome-wide association studies (GWAS) including 26,488 cases and 83,964 controls of European, East Asian, South Asian, and Mexican and Mexican American ancestry. We observed significant excess in directional consistency of T2D risk alleles across ancestry groups, even at SNPs demonstrating only weak evidence of association. By following up the strongest signals of association from the trans-ethnic meta-analysis in an additional 21,491 cases and 55,647 controls of European ancestry, we identified seven novel T2D susceptibility loci. Furthermore, we observed considerable improvements in fine-mapping resolution of common variant association signals at several T2D susceptibility loci. These observations highlight the benefits of trans-ethnic GWAS for the discovery and characterisation of complex trait loci, and emphasize an exciting opportunity to extend insight into the genetic architecture and pathogenesis of human diseases across populations of diverse ancestry.

Knowledge and perceptions of filariasis in Colombo, Sri Lanka, among patients with chronic filarial lymphoedema

Knowledge of filariasis and perceptions of the disease were explored among 413 lymphoedema cases attending two filariasis clinics in the Colombo district of Sri Lanka. The information was collected in interviews based on a pre-tested, interviewer-administered questionnaire. Only 15% of the patients had initially attributed their limb swelling to filariasis. Most knew that filariasis resulted from mosquito bites (81.1%) and that the disease is transmissible (59.8%) and preventable (74.3%). The majority did not know, or were uncertain, whether filariasis causes swelling of the breasts in females (68.5%), scrotal swelling (60.7%) or dry cough/breathlessness (62.7%). Most (60%) of the interviewees wrongly believed that chronic filarial lymphoedema could be cured, primarily by long-term treatment with diethylcarbamazine. Knowledge of filariasis was significantly associated with level of education (P<0.05). Curiously, compared with the male interviewees, the females interviewed were much less likely to say that filariasis was the cause of their initial swelling (P<0.001). Those who had suffered with the disease for more than 1 year were not significantly more knowledgeable about the disease than the interviewees who had developed symptomatic filariasis more recently. Knowledge about the symptoms of filariasis was generally poor in the study population. In order to dispel several common myths about the disease, health-education programmes, that are targeted both at the community in general and at primary-care providers, are clearly needed.

Community mobilization and household level waste management for dengue vector control in Gampaha district of Sri Lanka; an intervention study

Introduction

Waste management through community mobilization to reduce breeding places at household level could be an effective and sustainable dengue vector control strategy in areas where vector breeding takes place in small discarded water containers. The objective of this study was to assess the validity of this assumption.

Methods

An intervention study was conducted from February 2009 to February 2010 in the populous Gampaha District of Sri Lanka. Eight neighborhoods (clusters) with roughly 200 houses each were selected randomly from high and low dengue endemic areas; 4 of them were allocated to the intervention arm (2 in the high and 2 in the low endemicity areas) and in the same way 4 clusters to the control arm. A baseline household survey was conducted and entomological and sociological surveys were carried out simultaneously at baseline, at 3 months, at 9 months and at 15 months after the start of the intervention. The intervention programme in the treatment clusters consisted of building partnerships of local stakeholders, waste management at household level, the promotion of composting biodegradable household waste, raising awareness on the importance of solid waste management in dengue control and improving garbage collection with the assistance of local government authorities.

Results

The intervention and control clusters were very similar and there were no significant differences in pupal and larval indices of Aedes mosquitoes. The establishment of partnerships among local authorities was well accepted and sustainable; the involvement of communities and households was successful. Waste management with the elimination of the most productive water container types (bowls, tins, bottles) led to a significant reduction of pupal indices as a proxy for adult vector densities.

Conclusion

The coordination of local authorities along with increased household responsibility for targeted vector interventions (in our case solid waste management due to the type of preferred vector breeding places) is vital for effective and sustained dengue control.

The burden of diabetes mellitus and impaired fasting glucose in an urban population of Sri Lanka

AIMS

To describe the burden of diabetes mellitus and impaired fasting glucose in middle-aged residents (35-64 years) in an urban area of Sri Lanka.

METHODS

A cross-sectional survey was conducted in the Ragama Medical Officer of Health area, from which 2986 participants (1349 men and 1637 women) were randomly selected from the electoral registry between January and December 2007. The participants underwent a physical examination and had their height, weight, waist and hip circumferences and blood pressure measured by trained personnel. Fasting blood samples were taken for measurement of glucose, HbA(1c) and lipids. The prevalence of diabetes (fasting plasma glucose > 7 mmol/l) and impaired fasting glycaemia (fasting plasma glucose 5.6-6.9 mmol/l) and major predictors of diabetes in Sri Lanka were estimated from the population-based data.

RESULTS

Age-adjusted prevalence of diabetes mellitus in this urban population was 20.3% in men and 19.8% in women. Through the present screening, 263 patients with diabetes and 1262 with impaired fasting glucose levels were identified. The prevalence of newly detected diabetes was 35.7% of all patients with diabetes. Among patients with diabetes, only 23.8% were optimally controlled. In the regression models, high BMI, high waist circumference, high blood pressure and hypercholesterolaemia increased the fasting plasma glucose concentration, independent of age, sex and a family history of diabetes.

CONCLUSIONS

Our data demonstrate the heavy burden of diabetes in this urban population. Short- and long-term control strategies are required, not only for optimal therapy among those affected, but also for nationwide primary prevention of diabetes.

Capacity building in environmental and occupational health in Sri Lanka

BACKGROUND

Although environmental and occupational health (EOH) research and services in Sri Lanka have a long history, policies related to EOH are outdated.

METHODS

We review the International Training and Research in Environmental and Occupational Health (ITREOH) program in Sri Lanka that commenced in 2006 as a collaboration between the University of Alabama at Birmingham and the Faculty of Medicine of the University of Kelaniya, Sri Lanka.

RESULTS

The program has trained over 20 scientists in conducting EOH research. New pioneering research in EOH was initiated. The program was instrumental in furthering the training and research in EOH by initiating a MPH degree program, the first in the country.

CONCLUSIONS

The program has established North-South, South-South and in-country collaborations between institutions and scientists, increasing the visibility of EOH in the future.

Biomass fuel use for cooking in Sri Lanka: analysis of data from national demographic health surveys

BACKGROUND

Biomass cooking fuel is the main source of indoor air pollution in the majority of households in the developing world. Sri Lanka is an island of about 20 million population with urban, rural, and estate population of 14.6%, 80.0%, and 5.4%, respectively. This study describes biomass fuel use for cooking in Sri Lanka.

METHODS

We analyzed data from two national Demographic Health Surveys (2000 and 2007) to identify the use and determinants of cooking fuels in Sri Lankan households. The results are based on a sample of 8,169 households in 2000 and 19,862 households in 2007.

RESULTS

Wood was the principal cooking fuel used in 78.3% and 78.5% of households in 2000 and 2007, respectively. In 2007, 96.3% of estate sector households used firewood as compared to 84.2% in the rural and 34.6% in the urban sectors. Similar trends were noted in 2000 as well.

CONCLUSIONS

The shift from firewood to cleaner fuels in Sri Lanka is negligible from 2000 to 2007. Improving the quality of life of the population does not necessarily predict a shift towards the use of cleaner cooking fuels in Sri Lanka.

Musculoskeletal pain in four occupational populations in Sri Lanka

BACKGROUND

Factors influencing work-related musculoskeletal disorders might differ in developing and developed countries.

AIMS

To assess the prevalence and determinants of musculoskeletal pain in four occupational populations in Sri Lanka.

METHODS

As part of the international Cultural and Psychosocial Influences on Disability study, samples of postal workers, sewing machinists, nurses and computer operators were interviewed about pain at each of six anatomical sites in the past month, and about possible physical and psychosocial risk factors. Associations with prevalent pain were assessed by binomial regression.

RESULTS

Analysis was based on 852 participants (86% response rate). Overall, the lower back was the most common site of pain, with 1-month prevalence ranging from 12% in computer operators to 30% in nurses. Postal workers had the highest prevalence of shoulder pain (23%), but pain in the wrist/hand was relatively uncommon in all four occupational groups (prevalence rates ranged from 8% to 9%). Low mood and tendency to somatize were consistently associated with pain at all six sites. After adjustment for psychosocial risk factors, there was a higher rate of low back pain in nurses and postal workers than in computer operators, a higher rate of shoulder pain in postal workers than in the other occupational populations, and a relatively low rate of knee pain in computer operators.

CONCLUSIONS

Rates of regional pain, especially at the wrist/hand, were lower than have been reported in Western countries. As elsewhere, pain was strongly associated with low mood and somatizing tendency. Differences in patterns of pain by occupation may reflect differences in physical activities.

Physical, psychological, and social aspects of quality of life in filarial lymphedema patients in Colombo, Sri Lanka

Quality of life (QOL) was assessed in 141 filarial lymphedema patients and 128 healthy people in the Colombo district, Sri Lanka, by administering modified, translated, and validated (in Sri Lanka) versions of the Short Form 36 health survey questionnaire (SF-36) and the 30-item General Health questionnaire (GHQ-30). The GHQ-30 assesses the current mental health status. The SF-36 measures health on 8 multi-item dimensions covering functional state, well-being, and overall evaluation of health (physical functioning, role limitations resulting from physical health problems, role limitations resulting from emotional problems, energy/fatigue, emotional well-being, social functioning, pain and general health). By SF-36, patients experienced poorer physical functioning, more role limitations resulting from physical health conditions, less emotional well-being, poorer social functioning, and more pain than healthy individuals. By GHQ-30, mental well-being of healthy controls was significantly better than that of patients. The significant difference in the QOL as perceived by filarial lymphedema patients and healthy individuals reiterates the importance of morbidity control in patients affected by this disease.

Air pollution and health in Sri Lanka: a review of epidemiologic studies

BACKGROUND

Air pollution is increasingly documented as a threat to public health in most developing countries. Evaluation of current air quality levels, regulatory standards and scientific literature on outdoor and indoor air pollution, and health effects are important to identify the burden, develop and implement interventions and to fill knowledge gaps in Sri Lanka.

METHODS

PUBMED and Medline databases, local journals and conference proceedings were searched for epidemiologic studies pertaining to air pollution and health effects in Sri Lanka. All the studies pertaining to air pollution and health effects were considered.

RESULTS

Sixteen studies investigated the association between exposure to ambient or indoor air pollution (IAP) and various health outcomes ranging from respiratory symptoms, low birth weight and lung cancers. Of the sixteen, three used a case control design. Half of the studies collected exposure data only through questionnaires. There were positive associations between air pollution and adverse health effects in all studies. Methodological limitations in most of the studies resulted in poor quantification of risk estimates.

CONCLUSION

A limited number of epidemiological studies in Sri Lanka have investigated the health effects of air pollution. Based on findings of studies and reported air quality levels, air pollution may be considered a neglected public health problem in Sri Lanka.

Hospitalisation trends due to selected non-communicable diseases in Sri Lanka, 2005–2010

OBJECTIVES

To project hospitalisation trends due to selected non-communicable diseases (NCD) from 2005 to 2010.

DESIGN

Morbidity data, maintained at the Medical Statistics Unit of the Ministry of Health, from 1981 to 2000, were used to model trends of hospitalisation due to diabetes mellitus, hypertensive disease and ischaemic heart disease. Linear and quadratic trends were used to model morbidity trends.

RESULTS

For all three diseases considered, the increase in the incidence of hospitalisation is exponential. An increase is estimated in the incidence of hospitalisation by 36%, 40% and 29% due to diabetes mellitus, hypertensive disease and ischaemic heart disease, respectively, in 2010 as compared to 2005. The greatest burden and the largest increase in the rate of hospitalisation will be due to hypertensive disease.

CONCLUSIONS

There will be an exponential increase in hospitalisation due to diabetes, hypertension and ischaemic heart disease. The health sector should provide additional resources to meet the demand.

Anti-tuberculosis drug inducd hepatitis – a Sri Lankan experience

OBJECTIVE

To assess the incidence of anti-tuberculosis (TB) drug induced hepatitis (AIH) in Sri Lankan patients, determine risk factors of AIH, and to address management options in AIH.

DESIGN

A prospective study.

SETTING

Chest Hospital, Welisara, Sri Lanka, from April 2001 to April 2002.

PATIENTS

Seven hundred and eighty three patients with a confirmed diagnosis of TB and resident in the Colombo and Gampaha districts who presented to Chest Hospital, Welisara, Sri Lanka.

METHODS

WHO recommended treatment was commenced in all cases. AIH was diagnosed when patients complained of decreased appetite with nausea or vomiting and elevated serum bilirubin (SB; >1.1 mg/dL) or elevated serum alanine transferase (ALT; > 3 times upper limit of normal).

RESULTS

Of 783 enrolled patients, 74 (9.5%) developed AIH, the majority (58%) developing AIH within the first 2 weeks of the intensive phase of treatment. AIH was more common among patients over 60 years (p = 0.018), who developed pulmonary TB (p = 0.028), and in patients weighing 33-55 kg (p = 0.004). Age, weight and rifampicin overdosage were significant predictors of AIH. Of the 74 AIH patients, standard treatment was restarted in 60, treatment modified in six, two defaulted and six died.

CONCLUSIONS

The incidence of AIH in Sri Lanka is 9.5% in treated patients. AIH was associated with age, low body weight and rifampicin overdosage.

Costs and effectiveness of application of Poecilia reticulata (guppy) and temephos in anopheline mosquito control in river basins below the major dams of Sri Lanka

In this study we examined the costs and effectiveness of using larvivorous fish, Poecilia reticulata, and a chemical larvicide, temephos, in anopheline mosquito control in the riverbeds below the major dams in Sri Lanka. Five riverbeds below the dams, namely Laxapana, Kotmale 1, Kotmale 2, Nilambe, Rantembe and Victoria, were selected. Riverbed pools in Laxapana and Kotmale 1 were treated with P. reticulata; Rantembe and Victoria were treated with temephos; and Kotmale 2 and Nilambe were kept as controls. In each area, the anopheline larval density, before and after application of fish/temephos, was estimated. The cost of application of fish/temephos was estimated by activities involved for each treatment. After intervention, there was a significant reduction in anopheline larval density in the fish-treated areas compared with the temephos-treated and control areas. Application of P. reticulata was 2.67 times less costly than that of temephos. The cost of fish application can be further reduced if the community is involved in the application.

Efficacy of a limb-care regime in preventing acute adenolymphangitis in patients with lymphoedema caused by bancroftian filariasis, in Colombo, Sri Lanka

The efficacy of a programme of community home-based care (CHBC) for lymphoedematous limbs was evaluated among 163 lymphoedema patients attending two filariasis clinics in Colombo. Each patient was interviewed and examined and his or her lymphoedema was graded during a baseline assessment, before the CHBC programme, and again, during a post-intervention assessment, after the patient had been in the programme for 1 year. The number of patients having entry lesions was 24% lower at the post-intervention assessment than at the baseline (P<0.001), with a reduction in the frequency of each type of entry lesion investigated. In the year the patients were in the CHBC programme, 30% fewer of them experienced at least one attack of adenolymphangitis (ADL; P<0.001), the mean number of ADL attacks/patient was lower (P<0.001), and the mean duration of each ADL attack suffered was slightly shorter (5.70 v. 5.84 days; P>0.05) than in the year before the baseline assessment. The reduction in the incidence of ADL attacks was greatest in the patients with the higher grades of lymphoedema. Approximately 66% of the patients perceived an improvement in their swollen limb post-intervention. Eleven patients had grade-II lymphoedema at baseline but only grade-I lymphoedema after being on the CHBC programme for a year (P=0.012). The programme appeared to increase the frequencies with which patients followed each of the limb-care measures considered and most of the measures for the home management of ADL attacks that were investigated. It is recommended that the CHBC programme be implemented as a national programme in Sri Lanka.

An indigenous case of Plasmodium ovale infection in Sri Lanka

Plasmodium ovale, which is generally prevalent only in the African region, has been emerging in the Asian and southeast Asian regions. It has not been reported in Sri Lanka. We report, to our knowledge, an indigenous case of P. ovale infection in Sri Lanka. This patient, who was diagnosed by a polymerase chain reaction, had no history of travel overseas or receipt of a transfusion of blood or any blood products, which makes this a likely case of indigenous transmission. This incidental finding of a P. ovale infection has implications for malaria control in the country and highlights the need to rigorously monitor malaria incidence, as well as prevalent Plasmodium species, with newer and more reliable diagnostics.

Physical disability and psychosocial impact due to chronic filarial lymphoedema in Sri Lanka

Background

Information on the physical and psychosocial disability of lymphatic filariasis in Sri Lanka is scarce. Therefore this study was carried out to describe the physical disability and psychosocial impact associated with chronic lymphoedema in patients attending filariasis clinics in the Colombo district, Sri Lanka.

Methods

Four hundred and thirteen patients with lymphoedema of limbs attending filariasis clinics in Werahera and Dehiwala in the Colombo district were enrolled in the study after obtaining informed written consent. Data were collected using a pre-tested, interviewer-administered questionnaire and analyzed using SPSS.

Results

Majority (95%) of patients had lower limbs affected and there was a significant association with difficulty in walking (p = 0.023). The swollen limb affected the work of 87 (52 %) of employed patients and 26 persons reported loss of job. Approximately 25 % and 6 % reported having problems interacting with the community and family, respectively and 8.7 % felt that they were rejected by society. The swollen limb was perceived as a major problem by 36.8 % of patients. Of the married persons, 5.7 % and 6.2 % reported sexual and marital problems respectively, due to their swollen limb/s. Of those who had marital problems, 77.3% reported sexual problems as well (p < 0.001).

Conclusion

Lymphoedema significantly affects physical, psychological and social functioning in affected individuals. Morbidity control, in addition to control of physical disability, should target the psychosocial consequences.

Evaluation of the effectiveness of the national vitamin A supplementation programme among school children in Sri Lanka

The Ministry of Health in Sri Lanka commenced a vitamin A supplementation programme of school children with a megadose of 105 micromol (100,000 IU) vitamin A in school years 1, 4 and 7 (approximately 5-, 9- and 12-year-olds, respectively) in 2001. We evaluated the vitamin A supplementation programme of school children in a rural area of Sri Lanka. A cross-sectional study was conducted among children supplemented with an oral megadose of vitamin A (105 micromol; n 452) and children not supplemented (controls; n 294) in Grades 1-5. Children were clinically examined and a sample of blood was taken for serum vitamin A concentration estimation by HPLC. Socio-demographic information was obtained from children or mothers. Supplemented children had a higher proportion of males and stunted children, were younger and lived under poorer conditions as compared to controls. There was no difference in the prevalences of eye signs and symptoms of vitamin A deficiency in the two groups. Supplemented children had higher serum vitamin A concentrations than controls (1.4 (SD 0.49) micromol/l v. 1.2 (SD 0.52) micromol/l). The serum vitamin A concentrations were 1.6 (SD 0.45), 1.4 (SD 0.50), 1.3 (SD 0.44) and 1.1 (SD 0.43) micromol/l in children supplemented within 1, 1-6, 7-12 and 13-18 months of supplementation, respectively. Vitamin A concentrations were significantly greater than controls if supplementation was carried out within 6 months after adjustment. The oral megadose of 105 micromol vitamin A maintained serum vitamin A concentrations for 6 months in school children.

Toxicity due to organophosphorus compounds: what about chronic exposure?

The inappropriate use of toxic chemicals is common in developing countries, where it leads to excessive exposure and high risks of unintentional poisoning. The risks are particularly high with the pesticides used in agriculture, where poor rural populations live and work in close proximity to these compounds, which are often stored in and around the home. It is estimated that 99% of all deaths from pesticide poisoning occur in developing countries. Whilst the acute toxicity of pesticides has been well documented, there is still relatively little known of the effects on health of chronic pesticide exposure. Organophosphate insecticides have been extensively used in agriculture in developing countries, with little protection for the communities and individuals thus exposed. Given the indisputable chronic exposure of vulnerable groups to organophosphate compounds, including pregnant women, the fetus and young children, the potential for widespread adverse effects is considerable. Thus, whilst there is some evidence that chronic exposure may have adverse effects on health, there is an urgent need for high-quality observational and interventional studies of both occupational and environmental exposure to these compounds.

Anopheline breeding in river bed pools below major dams in Sri Lanka

Anopheline mosquito larval surveys were carried out from September 2000 to August 2002 in Mahaweli and Kelani river beds, below five major dams in the wet and intermediate zones of Sri Lanka, to study the prevalence of anopheline species in these areas. In each study site, all permanent and semi-permanent pools were surveyed fortnightly by dipping at 6 dips/m(2) surface area of water. Larvae were collected in separate containers, staged and identified at their third and fourth stages. During each survey, the surface area and depth of pools were recorded and each reading was considered as an individual observation. River bed pools below the dams contained stagnant clean water with a little or no aquatic vegetation. The majority of pools were < or =1m(2) in surface area and < or =75 cm in depth. Anopheline mosquito breeding was seen throughout the year in each study site. The average percentage of pools positive for anopheline larvae, the number of larvae per 100 pools and 100 dips were 14.85%, 32.34 and 9.29, respectively. Thirteen anopheline species, including 10 potential vectors, namely, An. barbirostris, An. culicifacies, An. jamesii, An. maculatus, An. nigerrimus, An. peditaeniatus, An. subpictus, An. tessellatus, An. vagus and An. varuna were found breeding in the river bed pools.