Clinical Evaluation of Assays for Plasma Renin Activity and Aldosterone Measurement by Liquid Chromatography-Tandem Mass Spectrometry.

BACKGROUND: Aldosterone and renin are pivotal hormones in the regulation of salt and water homeostasis and blood pressure. Measurement of renin and aldosterone in serum/plasma is essential for the investigation of primary hyperaldosteronism (PA) and monitoring of glucocorticoid replacement therapy. METHODS: We report 2 LC-MS/MS methods developed to measure aldosterone and plasma renin activity (PRA). PRA was determined by endogenous enzymatic generation of angiotensin I using 150 µL of sample. Generated angiotensin I was purified by solid phase extraction prior to chromatographic separation and mass spectrometry. Aldosterone measurement required 300 µL of sample extracted with MTBE prior to LC-MS/MS analysis. RESULTS: The PRA method was linear (1.2-193 nmol/L), sensitive (LLOQ = 1.2 nmol/L), precise (CV = 4.1%), and specific (no cross reactivity for a number of structurally similar steroids). Dilutional linearity and recovery (84%) were acceptable. Accuracy was confirmed by comparison against our current RIA method. The aldosterone method had equally acceptable performance characteristics. Reference ranges in 110 healthy normotensive subjects were: PRA 0.2-3.7 nmol/L/h and aldosterone 50-950 pmol/L. Consecutive patients (n = 62) with adrenal incidentalomas shown to have no functional adrenal disease; their post overnight 1 mg dexamethasone test values were: PRA 0.2-2.6 nmol/L/h and aldosterone 55-480 pmol/L. Serum aldosterone values after 2 liter saline suppression were-normal subjects (n = 17): 78-238 pmol/L and confirmed primary hyperaldosteronism (n = 25): 131-1080 pmol/L. CONCLUSIONS: We have developed robust assays for PRA and aldosterone with appropriate clinical evaluation. These assays are now in routine practice in the UK.

British Obesity and Metabolic Surgery Society Guidelines on perioperative and postoperative biochemical monitoring and micronutrient replacement for patients undergoing bariatric surgery-2020 update.

Bariatric surgery is recognized as the most clinically and cost-effective treatment for people with severe and complex obesity. Many people presenting for surgery have pre-existing low vitamin and mineral concentrations. The incidence of these may increase after bariatric surgery as all procedures potentially cause clinically significant micronutrient deficiencies. Therefore, preparation for surgery and long-term nutritional monitoring and follow-up are essential components of bariatric surgical care. These guidelines update the 2014 British Obesity and Metabolic Surgery Society nutritional guidelines. Since the 2014 guidelines, the working group has been expanded to include healthcare professionals working in specialist and non-specialist care as well as patient representatives. In addition, in these updated guidelines, the current evidence has been systematically reviewed for adults and adolescents undergoing the following procedures: adjustable gastric band, sleeve gastrectomy, Roux-en-Y gastric bypass and biliopancreatic diversion/duodenal switch. Using methods based on Scottish Intercollegiate Guidelines Network methodology, the levels of evidence and recommendations have been graded. These guidelines are comprehensive, encompassing preoperative and postoperative biochemical monitoring, vitamin and mineral supplementation and correction of nutrition deficiencies before, and following bariatric surgery, and make recommendations for safe clinical practice in the U.K. setting.

A global multicenter study on reference values: 2. Exploration of sources of variation across the countries.

OBJECTIVES: The intent of this study, based on a global multicenter study of reference values (RVs) for serum analytes was to explore biological sources of variation (SVs) of the RVs among 12 countries around the world. METHODS: As described in the first part of this paper, RVs of 50 major serum analytes from 13,396 healthy individuals living in 12 countries were obtained. Analyzed in this study were 23 clinical chemistry analytes and 8 analytes measured by immunoturbidimetry. Multiple regression analysis was performed for each gender, country by country, analyte by analyte, by setting four major SVs (age, BMI, and levels of drinking and smoking) as a fixed set of explanatory variables. For analytes with skewed distributions, log-transformation was applied. The association of each source of variation with RVs was expressed as the partial correlation coefficient (rp). RESULTS: Obvious gender and age-related changes in the RVs were observed in many analytes, almost consistently between countries. Compilation of age-related variations of RVs after adjusting for between-country differences revealed peculiar patterns specific to each analyte. Judged fromthe rp, BMI related changes were observed for many nutritional and inflammatory markers in almost all countries. However, the slope of linear regression of BMI vs. RV differed greatly among countries for some analytes. Alcohol and smoking-related changes were observed less conspicuously in a limited number of analytes. CONCLUSION: The features of sex, age, alcohol, and smoking-related changes in RVs of the analytes were largely comparable worldwide. The finding of differences in BMI-related changes among countries in some analytes is quite relevant to understanding ethnic differences in susceptibility to nutritionally related diseases.

A Novel and Practical Screening Tool for the Detection of Silent Myocardial Infarction in Patients With Type 2 Diabetes.

OBJECTIVE: Silent myocardial infarction (MI) is a prevalent finding in patients with type 2 diabetes and is associated with significant mortality and morbidity. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is the most validated technique for detection of silent MI, but is time-consuming, costly, and requires administration of intravenous contrast. We therefore planned to develop a simple and low-cost population screening tool to identify those at highest risk of silent MI validated against the CMR reference standard. METHODS: A total of 100 asymptomatic patients with type 2 diabetes underwent electrocardiogram (ECG), echocardiography, biomarker assessment, and CMR at 3.0T including assessment of left ventricular ejection fraction and LGE. Global longitudinal strain from two- and four-chamber cines was measured using feature tracking. RESULTS: A total of 17/100 patients with no history of cardiovascular disease had silent MI defined by LGE in an infarct pattern on CMR. Only four patients with silent MI had Q waves on ECG. Patients with silent MI were older (65 vs 60, P = .05), had lower E/A ratio (0.75 vs 0.89, P = .004), lower GLS (-15.2% vs -17.7%, P = .004), and higher amino-terminal pro brain natriuretic peptide (106 ng/L vs 52 ng/L, P = .003). A combined risk score derived from these four factors had an area under the receiver operating characteristic curve of 0.823 (0.734-0.892), P < .0001. A score of more than 3/5 had 82% sensitivity and 72% specificity for silent MI. CONCLUSIONS: Using measures that can be derived in an outpatient clinic setting, we have developed a novel screening tool for the detection of silent MI in type 2 diabetes. The screening tool had significantly superior diagnostic accuracy than current ECG criteria for the detection of silent MI in asymptomatic patients.

Guidelines for the follow-up of patients undergoing bariatric surgery.

Bariatric surgery can facilitate weight loss and improvement in medical comorbidities. It has a profound impact on nutrition, and patients need access to follow-up and aftercare. NICE CG189 Obesity emphasized the importance of a minimum of 2 years follow-up in the bariatric surgical service and recommended that following discharge from the surgical service, there should be annual monitoring as part of a shared care model of chronic disease management. NHS England Obesity Clinical Reference Group commissioned a multi-professional subgroup, which included patient representatives, to develop bariatric surgery follow-up guidelines. Terms of reference and scope were agreed upon. The group members took responsibility for different sections of the guidelines depending on their areas of expertise and experience. The quality of the evidence was rated and strength graded. Four different shared care models were proposed, taking into account the variation in access to bariatric surgical services and specialist teams across the country. The common features include annual review, ability for a GP to refer back to specialist centre, submission of follow-up data to the national data base to NBSR. Clinical commissioning groups need to ensure that a shared care model is implemented as patient safety and long-term follow-up are important.

Nutritional follow-up of patients after obesity surgery: best practice.

Obesity surgery is an appropriate treatment option for patients with severe and complex obesity and helps in the improvement of comorbidities. In the first 2 years following surgery, follow-up is provided by the obesity surgery centre. Ongoing care is then usually returned to the general practitioner. Patients need access to ongoing support and monitoring otherwise may be at risk of developing nutritional deficiencies such as anaemia or protein malnutrition. The British Obesity and Metabolic Surgery Society have developed guidelines on nutritional monitoring and nutritional supplements to support both bariatric centres and general practitioners. The Royal College of General Practitioners and BOMSS have worked collaboratively to develop Ten Top Tips for the management of obesity surgery patients to aid with the long-term management in primary care. Women, planning to get pregnant, need access to preconception advice and additional monitoring during pregnancy. It is essential that long-term data are collected and inputted into the National Bariatric Surgery Register. Obesity surgery improves comorbidities; however, patients must have access to long-term nutritional monitoring.

NICE-Accredited Commissioning Guidance for Weight Assessment and Management Clinics: a Model for a Specialist Multidisciplinary Team Approach for People with Severe Obesity.

Despite increasing prevalence of obesity, no country has successfully implemented comprehensive pathways to provide advice to all the severely obese patients that seek treatment. We aimed to formulate pathways for referral into and out of weight assessment and management clinics (WAMCs) that include internal medicine/primary care physicians as part of a multidisciplinary team that could provide specialist advice and interventions, including referral for bariatric surgery. Using a National Institute of Health and Care Excellence (NICE)-accredited process, a Guidance Development Group conducted a literature search identifying existing WAMCs. As very few examples of effective structures and clinical pathways existed, the current evidence base for optimal assessment and management of bariatric surgery patients was used to reach a consensus. The model we describe could be adopted internationally by health services to manage severely obese patients.

Obesity services: how best to develop a coherent way forward.

Obesity now affects 25% of the UK population. This volume of patients cannot be managed by current NHS services. It really needs a public health approach which encourages an environment where it is easier for the public to take healthy rather than unhealthy actions. However, there remain substantial numbers of patients who will benefit from medical intervention. This needs a joined-up service which extends from a healthy environment, linking gyms, weight loss groups, community cooking lessons, etc. with pathways connecting primary and secondary healthcare. To date, the National Health Service has not managed to develop a coherent policy that addresses obesity as a major cause of health and social care expenditure. The most important step in primary care is probably to identify the presence of obesity. The medical steps should be in the identification and management of comorbidities. The purpose of treating obesity is not weight loss alone but improving health, so the narrative needs to change from weight to blood pressure, glucose tolerance, physical fitness, etc. Many physicians believe that weight loss is an unwinnable battle but there are several well conducted studies in which primary care, supported by specialists, can deliver successful clinical weight loss. Specialist medical and surgical care for obesity will be required for complex cases and is essential for overseeing long-term postsurgical follow-up to prevent and treat nutritional and metabolic complications. Obesity management suffers from a lack of coherent national public health policies, fragmentation of care and a lack of knowledge of what successful treatment entails. Health benefits do not require a return to a healthy BMI.

Evaluation of the effect of clinical validation of out of hours critical laboratory results.

AIM: The aim of the study was to review the clinical validation process of out of hours critical biochemistry results by a clinical biochemist and its effect on primary care services. METHODS: A prospective study was conducted of all critical results for primary care patients who were analysed out of hours. The nine-month study period was conducted between June 2013 and February 2014. The data collected include patients' age, clinical details, critical results and the urgency of result communicated. The patients' subsequent attendance rate at the emergency department in the local hospital was reviewed. RESULTS: A total of 311 out of hours critical results were identified in the laboratory. After clinical validation, 110 (35.4%) results were telephoned urgently and 155 (49.8%) results were deferred to the next day. Forty-six (14.8%) results were not telephoned. Following the urgent result communication, 53/110 (48.2%) patients attended the hospital emergency department within 24 h and 17/110 (15.5%) had their repeat blood test by their general practitioner surgery within 48 h. When the result was telephoned during working hours the next day, only 15/155 (9.7%) attended the hospital acute services within 48 h and 16/155 (10.3%) had repeat blood test at their general practitioner surgery. CONCLUSION: In our practice, the clinical validation of out of hours critical results by a clinical biochemist is associated with a reduction in the number of results telephoned when compared against the critical limits list recommended by the Royal College of Pathologists and may focus out of hours clinical activity on more suitable patients.

Hepatocellular carcinoma in variegate porphyria: a case report and literature review.

Variegate porphyria is an autosomal dominant acute hepatic porphyria characterized by photosensitivity and acute neurovisceral attacks. Hepatocellular carcinoma has been described as a potential complication of variegate porphyria in case reports. We report a case of a 48-year-old woman who was diagnosed with hepatocellular carcinoma following a brief history of right upper quadrant pain which was preceded by a few months of blistering lesions in sun-exposed areas. She was biochemically diagnosed with variegate porphyria, and mutational analysis confirmed the presence of a heterozygous mutation in the protoporphyrinogen oxidase gene. Despite two hepatic resections, she developed pulmonary metastases. She responded remarkably well to Sorafenib and remains in remission 16 months after treatment. A review of the literature revealed that hepatocellular carcinoma in variegate porphyria has been described in at least eight cases. Retrospective and prospective cohort studies have suggested a plausible association between hepatocellular carcinoma and acute hepatic porphyrias. Hepatic porphyrias should be considered in the differential diagnoses of hepatocellular carcinoma of uncertain aetiology. Patients with known hepatic porphyrias may benefit from periodic monitoring for this complication.

Systematic review of definitions of failure in revisional bariatric surgery.

BACKGROUND: There are no agreed definitions as to what constitutes a 'failure' of the primary bariatric procedure in relation to weight loss. METHODS: The MEDLINE database for primary research articles was searched using obesity [title] or bariatric [title] and revision [title] or revisional [title]. RESULTS: The MEDLINE search retrieved 174 studies. After duplicates and exclusions were removed, 60 articles underwent analysis. Fifty-one studies included inadequate weight loss or weight regain as an indication for revision: 31/51 (61 %) gave no definition of failure, 7/20 quoted <50 % of excess weight loss at 18 months and 6/20 used <25 % excess weight loss. CONCLUSIONS: The majority of published studies do not define failure of bariatric surgery, and <50 % excess weight loss at 18 months was the most frequent definition identified.

How good is the evidence base for test selection in clinical guidelines?

Clinical guidelines are ubiquitous, manifold and form an integral component of evidence-based clinical practice. Guidelines on test selection are often considered a useful adjunct to aid clinical decision-making, as test selection is a complex process that is influenced by many patient, clinician and laboratory factors. However, it is important to carefully evaluate several aspects of these guidelines, which include the context of the test in the guideline, the quality of the studies underpinning recommendations, the extent of the evaluation of effectiveness (or performance) of the specific test and in the clinical pathway, its applicability and ease of implementation. A robust evaluation of a diagnostic test should incorporate several stages including evaluation in healthy, symptomatic but unaffected and affected populations, and importantly a measurement of impact on patient outcomes. Few diagnostic studies meet these criteria, and therefore crucial aspects of test evaluation are overlooked prior to incorporation into clinical guidelines. Whilst efforts are made to standardise reporting of studies, strength of evidence and quality of guidelines, further work is required to improve the quality of the diagnostic studies that formulate these guidelines. It is important that clinicians using guidelines for test selection appreciate the limitations of the diagnostic test, and the guidelines themselves.

Cascade testing of primary care blood samples with hyperferritinaemia identifies subjects with iron overload and porphyria cutanea tarda.

INTRODUCTION: Serum ferritin is routinely used as a first line test for iron status. Testing subjects with low pre-test probability often results in unexpected abnormal results. Raised ferritin is typically found in subjects with iron overload, liver disease, malignancy or inflammation. We sought to determine whether primary care patients with high ferritin had either porphyria cutanea tarda (PCT) or hereditary haemochromatosis (HH). METHODS: Redundant serum samples were collected from consecutive specimens with high ferritin (>500 µg/L) which had been received from primary care sources. Samples were analysed for serum iron and iron-binding capacity and for porphyrins by fluorescence scanning and HPLC. RESULTS: There were 240 samples (91 females, 149 males) which represented 2.7% of total over the collection period. Serum iron was 17.3 (18.9) µmol/L (median (IQR)), TIBC 47.3 (14.2) µmol/L and transferrin saturation 35.7 (41.1) %. There were 87/240 (36%) with transferrin saturation >45% (57 males, 30 females). Of the samples 19/236 (8%) were positive for porphyrins by spectrofluorimetry and 14/15 (4 insufficient sample) had total porphyrins >11.2 nmol/L (40(63) median (IQR)) with 3/15 (1.25%) having a typical pattern for PCT. DISCUSSION: This study demonstrates the feasibility of cascading tests using laboratory protocols and confirms the ability to identify potential cases. However, further studies for HH genotype and urine and stool porphyrin analysis will be necessary to confirm the diagnoses.

Clinical biochemistry of dihydrotestosterone.

Dihydrotestosterone (DHT) is the most potent natural androgen in humans. There has been an increasing interest in this androgen and its role in the development of primary and secondary sexual characteristics as well as its potential roles in diseases ranging from prostate and breast cancer to Alzheimer's disease. Despite the range of pathologies shown to involve DHT there is little evidence for measurement of serum DHT in the management of these diseases. In this review we describe the physiology of DHT production and action, summarize current concepts in the role of DHT in the pathogenesis of various disorders of sexual development, compare current methods for the measurement of DHT and conclude on the clinical utility of DHT measurement. The clinical indications for the measurement of DHT in serum are: investigation of 5α reductase deficiency in infants with ambiguous genitalia and palpable gonads; men with delayed puberty and/or undescended testes; and to confirm the presence of active testicular tissue. Investigation is aided by the use of human chorionic gonadotrophin stimulation. Due to paucity of published data on this procedure, it is important to follow guidelines prescribed by the laboratory performing the analysis to ensure accurate interpretation.

The association of body mass index and biochemical hyperandrogenaemia in women with and without polycystic ovary syndrome.

OBJECTIVE: To investigate the association between BMI and different androgen parameters in women with PCOS and normal ovulatory women. STUDY DESIGN: A cross sectional, observational study was carried out. A total of 286 patients aged 20-44years were recruited. One hundred and sixty-five women had a diagnosis of PCOS and 121 women were ovulatory with no clinical or biochemical or ultrasound evidence of PCOS. The PCOS and non-PCOS groups were sub-divided into two subgroups based on BMI (BMI≤30kg/m(2) and BMI>30kg/m(2)). Androgen parameters measured were testosterone, androstenedione, free androgen index and sex hormone-binding globulin (SHBG). Testosterone and androstenedione were measured using tandem mass spectrometry. Free androgen index (FAI) was calculated using the formula: (testosterone/SHBG)×100. Spearman rank correlations were used to determine relationship between BMI and androgens. RESULTS: The PCOS group had a higher BMI compared with the non-PCOS group (28.9±5.8, 24.5±4.1). Total testosterone, androstenedione, and FAI were significantly higher while SHBG was lower in the PCOS group. A correlation between BMI and total testosterone was not observed in either group. Positive correlations were observed between BMI and FAI in both PCOS (p<0.001) and non-PCOS groups (p=0.02) while a positive correlation was observed between BMI and androstenedione in the PCOS group (p=0.001). SHBG correlated negatively with BMI in both groups. CONCLUSION: A strong correlation exists between BMI and FAI but not with total testosterone, possibly due to the mediation of SHBG. Hyperandrogenaemia in the form of androstenedione seems to be augmented in PCOS with increasing BMI. A direct causal relationship between BMI and androgenaemia was not established.

Hepatic metabolism and transporter gene variants enhance response to rosuvastatin in patients with acute myocardial infarction: the GEOSTAT-1 Study.

BACKGROUND: Pharmacogenetics aims to maximize benefits and minimize risks of drug treatment. Our objectives were to examine the influence of common variants of hepatic metabolism and transporter genes on the lipid-lowering response to statin therapy. METHODS AND RESULTS: The Genetic Effects On STATins (GEOSTAT-1) Study was a genetic substudy of Secondary Prevention of Acute Coronary Events-Reduction of Cholesterol to Key European Targets (SPACE ROCKET) (a randomized, controlled trial comparing 40 mg of simvastatin and 10 mg of rosuvastatin) that recruited 601 patients after myocardial infarction. We genotyped the following functional single nucleotide polymorphisms in the genes coding for the cytochrome P450 (CYP) metabolic enzymes, CYP2C9*2 (430C>T), CYP2C9*3 (1075A>C), CYP2C19*2 (681G>A), CYP3A5*1 (6986A>G), and hepatic influx and efflux transporters SLCO1B1 (521T>C) and breast cancer resistance protein (BCRP; 421C>A). We assessed 3-month LDL cholesterol levels and the proportion of patients reaching the current LDL cholesterol target of <70 mg/dL (<1.81 mmol/L). An enhanced response to rosuvastatin was seen for patients with variant genotypes of either CYP3A5 (P=0.006) or BCRP (P=0.010). Furthermore, multivariate logistic-regression analysis revealed that patients with at least 1 variant CYP3A5 and/or BCRP allele (n=186) were more likely to achieve the LDL cholesterol target (odds ratio: 2.289; 95% CI: 1.157, 4.527; P=0.017; rosuvastatin 54.0% to target vs simvastatin 33.7%). There were no differences for patients with variants of CYP2C9, CYP2C19, or SLCO1B1 in comparison with their respective wild types, nor were differential effects on statin response seen for patients with the most common genotypes for CYP3A5 and BCRP (n=415; odds ratio: 1.207; 95% CI: 0.768, 1.899; P=0.415). CONCLUSION: The LDL cholesterol target was achieved more frequently for the 1 in 3 patients with CYP3A5 and/or BCRP variant genotypes when prescribed rosuvastatin 10 mg, compared with simvastatin 40 mg. Clinical Trial Registration- URL: http://isrctn.org. Unique identifier: ISRCTN 89508434.

What is the evidence for gender differences in ferritin and haemoglobin?

Reference ranges for haemoglobin and ferritin in women of reproductive age are widely reported showing values that are lower than equivalent aged males. Similar values would be expected in the absence of different biological requirements. While reference ranges have been derived from data on large populations, it is likely that these populations have included significant numbers of women who are iron deficient in view of menstrual blood loss and poor dietary intake. Populations with a daily iron intake in excess of 100mg have shown that iron deficiency in females is rare. Studies reporting bone marrow with iron stains from 50 years ago pointed out that significant numbers of women were iron deficient and more recently serum ferritin studies have confirmed this. However, a large number of women in the Western world spend a significant part of their lives in a negative iron balance due to a combination of poor diet and menstrual blood loss. The presence of haem iron in the diet of humans enhances non-haem iron absorption but dietary surveys consistently report that women's diet is deficient in iron. Furthermore, the typical Western diet contains many common foods that limit iron absorption. It appears that lower haemoglobin and ferritin values in menstruating women have been accepted as normal rather than possibly representing widespread iron deficiency. Reference ranges should be re-evaluated in populations proven to be iron replete.

Defining hyperandrogenism in polycystic ovary syndrome: measurement of testosterone and androstenedione by liquid chromatography-tandem mass spectrometry and analysis by receiver operator characteristic plots.

OBJECTIVE: Hyperandrogenism is one of the diagnostic criteria for the polycystic ovary syndrome (PCOS) despite no agreed definition of hyperandrogenism. In part, this is due to the quality of testosterone immunoassays. We have developed liquid chromatography-tandem mass spectrometry methods for analysing testosterone and androstenedione (Ad) to study their reference ranges and diagnostic utility in PCOS. DESIGN, SETTING AND SUBJECTS: A consecutive series of 122 women attending a reproductive medicine clinic. METHODS: Blood samples were taken during the early follicular phase for measurement of LH, FSH, oestradiol, Ad, testosterone and sex hormone-binding globulin (SHBG). Retrospective case note analysis was used to determine the clinical features and ultrasound findings. RESULTS: The incidence of PCOS was 13.9%. The reference interval for testosterone was <1.8 nmol/l and for Ad was 1.4-7.4 nmol/l. There were significant differences in total testosterone (P=0.001), Ad (P<0.05) and free androgen index (FAI; P<0.0001) between the women with and without PCOS. Diagnostic performance using receiver operator characteristic plots showed area under the curve (AUC) for FAI 0.81, testosterone 0.75 and Ad 0.66. The AUC for the LH:FSH ratio was 0.72. CONCLUSIONS: Our analysis of a consecutive series of women attending a reproductive clinic has provided an appropriate series on which to construct reference ranges for key androgens in women. Secondly, it has allowed us to conclude that early follicular serum testosterone measured using tandem mass spectrometry, FAI and the LH:FSH ratio are valuable laboratory tests in the diagnosis of PCOS.

Vitamin D receptor gene polymorphisms, serum 25-hydroxyvitamin D levels, and melanoma: UK case-control comparisons and a meta-analysis of published VDR data.

We have carried out melanoma case-control comparisons for six vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) and serum 25-hydroxyvitamin D(3) levels in order to investigate the role of vitamin D in melanoma susceptibility. There was no significant evidence of an association between any VDR SNP and risk in 1028 population-ascertained cases and 402 controls from Leeds, UK. In a second Leeds case-control study (299 cases and 560 controls) the FokI T allele was associated with increased melanoma risk (odds ratio (OR) 1.42, 95% confidence interval (CI) 1.06-1.91, p=0.02). In a meta-analysis in conjunction with published data from other smaller data sets (total 3769 cases and 3636 controls), the FokI T allele was associated with increased melanoma risk (OR 1.19, 95% CI 1.05-1.35), and the BsmI A allele was associated with a reduced risk (OR 0.81, 95% CI 0.72-0.92), in each instance under a parsimonious dominant model. In the first Leeds case-control comparison cases were more likely to have a higher body mass index (BMI) than controls (p=0.007 for linear trend). There was no evidence of a case-control difference in serum 25-hydroxyvitamin D(3) levels. In 1043 incident cases from the first Leeds case-control study, a single estimation of serum 25-hydroxyvitamin D(3) level taken at recruitment was inversely correlated with Breslow thickness (p=0.03 for linear trend). These data provide evidence to support the view that vitamin D and VDR may have a small but potentially important role in melanoma susceptibility, and putatively a greater role in disease progression.