Streptococcal infection, Tourette syndrome, and OCD: is there a connection?

BACKGROUND

A causal relationship of common streptococcal infections and childhood neuropsychiatric disorders has been postulated.

OBJECTIVE

To test the hypothesis of an increased rate of streptococcal infections preceding the onset of neuropsychiatric disorders.

METHODS

Case-control study of a large primary care database comparing the rate of possible streptococcal infections in patients aged 2-25 years with obsessive-compulsive disorder (OCD), Tourette syndrome (TS), and tics with that in controls matched for age, gender, and practice (20 per case). We also examined the influence of sociodemographic factors.

RESULTS

There was no overall increased risk of prior possible streptococcal infection in patients with a diagnosis of OCD, TS, or tics. Subgroup analysis showed that patients with OCD had a slightly higher risk than controls of having had possible streptococcal infections without prescription of antibiotics in the 2 years prior to the onset of OCD (odds ratio 2.59, 95% confidence interval 1.18, 5.69; p = 0.02). Cases with TS or tics were not more likely to come from more affluent or urban areas, but more cases lived in areas with a greater proportion of white population (p value for trend = 0.05).

CONCLUSIONS

The present study does not support a strong relationship between streptococcal infections and neuropsychiatric syndromes such as obsessive-compulsive disorder and Tourette syndrome. However, it is possible that a weak association (or a stronger association in a small susceptible subpopulation) was not detected due to nondifferential misclassification of exposure and limited statistical power. The data are consistent with previous reports of greater rates of diagnosis of Tourette syndrome or tics in white populations.

Socio-demographic factors predict the likelihood of not returning home after hospital admission following a fall

BACKGROUND

Falls in older people result in a substantial use of resources in the NHS and care homes. One way to reduce the burden would be to identify the factors associated with the likelihood of being discharged to a care home rather than being discharged home after fall-related hospitalization. We investigate the associations between discharge destination after fall-related hospital admission with ecological factors (area deprivation, ethnicity and rurality) and individual level factors (age, gender and co-morbidities).

METHODS

We extracted data for patients aged over 50 admitted from their 'usual residence' with a fall-related diagnosis from the Hospital Episode Statistics (HES) database.

RESULTS

Increasing age, people with severe co-morbidities and people who live in less deprived, predominantly white or rural areas, were more likely to be discharged to a different residence (all P-values < 0.001). We estimated that 88.3% of people from an area classified as most deprived, urban and >5% Asian would return home, compared with 78.0% from least deprived, village/isolated and all white area.

CONCLUSION

Further research is required to examine whether these patterns reflect appropriate care or alternatively that some sub-groups of society have less access to care homes than others. These factors may have public health implications for the equitable allocation of budgets for the provision of care for elderly patients discharged from hospital after a fall.

Interleukin-18 polymorphism and physical functioning in older people: a replication study and meta-analysis

BACKGROUND

Levels of the proinflammatory cytokine interleukin-18 (IL-18) are raised in old age and are associated with reduced physical functioning. Previous studies have indicated that the C allele of the rs5744256 polymorphism in the IL-18 gene is strongly associated with reduced circulating IL-18 levels. This variant has previously been associated with improved locomotor performance in old age, but the finding requires independent replication.

METHODS

We examined the association between the IL-18 polymorphism rs5744256 and physical functioning in three cohorts with a total of 4,107 participants aged 60-85 years: the English Longitudinal Study of Ageing, Caerphilly, and Boyd Orr. We meta-analyzed (N = 6,141) the results with data from the original paper reporting this association: Iowa-Established Populations for Epidemiological Study of the Elderly and InCHIANTI cohorts. Physical functioning was assessed by timed walks or the get up and go test. As locomotor performance tests differed between the cohorts and the distributions of times to complete the test (in seconds) were positively skewed, we used the reciprocal transformation and computed study-specific z scores.

RESULTS

Based on the three new studies, the estimated linear regression coefficient per C allele was 0.011 (95% confidence interval [95% CI]: -0.04 to 0.06). A meta-analysis that pooled the data from all studies showed weak evidence of an effect, with a regression coefficient of 0.047 (95% CI: 0.010 to 0.083).

CONCLUSIONS

We did not replicate an association between the IL-18 rs5744256 polymorphism and the physical function in people aged 60-85 years. However, pooling data from all studies suggested a weak association of the C allele of the rs5744256 single nucleotide polymorphism on improving walking times in old age.

The effect of onset age on the clinical features of Parkinson's disease

Many clinicians view age at onset as an important determinant of clinical phenotype in Parkinson's disease (PD) and this has been reinforced by the identification of Mendelian genes that account for some cases of younger onset PD. A systematic review of OVID Medline for articles relevant to the relationship between clinical features and age at onset in PD published in English between 1950-2007 was performed. There are very few prospective community based studies which focus on the relationship between age at onset and the features of PD and a variety of case definitions are used in the literature. Most studies of young onset PD are based on specialist clinic referral series. The available evidence suggests that PD patients with a younger age at onset have: (i) a slower disease progression, (ii) an increased rate of dystonia at onset and during treatment, (iii) a lower rate of dementia and (iv) an increased rate of dyskinesias in response to L-DOPA treatment. The majority of the available studies do not report patient genotype data, but it is probably that the clinical heterogeneity of PD will be further refined with detailed clinico-genetic studies.

Prevalence and age of onset of Parkinson's disease in Cardiff: a community based cross sectional study and meta-analysis

BACKGROUND

Previous prevalence studies of Parkinson's disease (PD) in the UK have spanned a 40 year period and have predominantly been in the North of the country. These have presented rates by current age but have not examined this by age at disease onset.

METHODS

A community based prevalence study was undertaken which attempted to identify all clinically diagnosed cases of PD from primary and secondary care for the city of Cardiff, Wales, UK. A meta-analysis of all past studies in the UK, including our own, was also undertaken.

RESULTS

Overall, 380 cases of PD were identified from a population of 292 637 residents, giving a crude prevalence rate of 130 per 100 000 (95% CI 117 to 144) and an age standardised rate of 142 per 100 000 (95% CI 128 156), standardised to the 1997 England and Wales population. Our prevalence rates were very similar to the weighted average of previous UK studies although there was evidence of between study heterogeneity (p = 0.0006). 5.4% and 31.2% of prevalent PD patients had their disease onset below the age of 50 or 65 years, respectively.

CONCLUSIONS

The data suggest that there are no major geographical variations in the prevalence of PD in the UK and that the age adjusted prevalence rate has remained relatively stable over the past 40 years. Although PD risk is far greater in older subjects, patients with young onset are not that uncommon in the community, and health and social care provision should reflect their needs.

Exploring the impact of patient views on 'appropriate' use of services and help seeking: a mixed method study

BACKGROUND

There are commonly-held views relating to what constitutes appropriate and inappropriate use of finite NHS resources. However, very little is known about how and why such views have an impact on consultation patterns.

AIM

To quantify the prevalence of opinion on whether people use health services unnecessarily within primary care and accident and emergency (A&E) in order to examine the impact of these views on help-seeking behaviour.

DESIGN OF STUDY

A mixed method study utilising cross-sectional questionnaire survey and semi-structured interviews.

SETTING

A primary care practice in South West England, UK.

METHOD

Responders to the questionnaire survey were drawn from a random sample of individuals, stratified by sex, selected from one practice in the UK (n = 911). The qualitative sample (n = 22) were purposefully selected from the same general practice.

RESULTS

The quantitative data suggest that the majority of people believe individuals utilise either GP or A&E services inappropriately (65.6%; 95% confidence interval [CI] = 62.4 to 68.7). However, strong views relating to this inappropriate healthcare use were not associated with reported seeking of immediate care (odds ratio [OR] = 0.98, 95% CI = 0.66 to 1.46 for 'lump' vignette). Responders tend to consider other people as time wasters, but not themselves. Individuals' generally describe clear rationales for help seeking, even for seemingly trivial symptoms and anxiety level was strongly predictive of health-seeking behaviour (OR = 2.88; 95% CI = 1.98 to 4.19 for lump vignette).

CONCLUSION

Perceptions that individuals' use health services inappropriately are unlikely to explain differences in help-seeking behaviours. The findings suggest that people do not take the decision to consult health services lightly and rationalise why their behaviour is not time wasting.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154 012 participants in 31 cohorts.† Copyright © 2009 John Wiley & Sons, Ltd.

Mothers' anxiety during pregnancy is associated with asthma in their children

BACKGROUND

Maternal stress in early life has been associated with the development of asthma in children, although it is unclear whether there are any critical periods of exposure. The association of asthma with prenatal exposure to maternal stress has not been reported.

OBJECTIVE

We tested whether prenatal and postnatal anxiety and/or depression in pregnant women predicted the risk of their offspring developing asthma in childhood.

METHODS

The Avon Longitudinal Study of Parents and Children is a population-based birth cohort recruited during pregnancy. Data were available on maternal anxiety scores and asthma at age 7(1/2) years in 5810 children. Anxiety was assessed at 18 and 32 weeks of gestation by using the validated Crown-Crisp Experiential Index. Asthma was defined at age 7(1/2) years as doctor-diagnosed asthma with current symptoms or treatment in the previous 12 months. Multivariable logistic regression was used to determine the association of prenatal anxiety with asthma (odds ratio; 95% CI).

RESULTS

Independent of postnatal anxiety and adjusted for a number of likely confounders, there was a higher likelihood of asthma at age 7(1/2) years (odds ratio, 1.64; 95% CI, 1.25-2.17) in children of mothers in the highest compared with lowest quartile of anxiety scores at 32 weeks of gestation, with evidence for a dose-response (P value for trend <0.001).

CONCLUSIONS

Maternal anxiety symptoms as an indicator of stress during fetal life may program the development of asthma during childhood.

Ethnicity, socioeconomic status, and attainment of clinical practice guideline standards in dialysis patients in the United kingdom

BACKGROUND AND OBJECTIVES

The role of socioeconomic status (SES) and its contribution to ethnic differences in standards attainment among dialysis patients is not known.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined associations between area- level SES (Townsend index) and ethnicity (white, black, South Asian) and standards attainment in 14,117 incident dialysis patients (1997-2004) in the UK.

RESULTS

Deprived patients were less likely to achieve hemoglobin (Hb) > or = 10 g/dl (trend P < 0.001) but not after controlling for patient and center characteristics (trend P = 0.1). There was no association with hemodialysis dose and parathyroid hormone (PTH) standard but deprived patients had better attainment of phosphate (PO4) <5.6 mg/dl, calcium (Ca) and Calcium-phosphate (CaPO4) standard (e.g., most deprived versus least deprived adjusted odds ratio [OR] 1.25, 95% confidence intervals [CI] 1.12, 1.38). There was no association with SES using a lower limit for PO4 (3.5 - 5.5 mg/dl). Compared with Whites, Blacks had lower attainment of Hb (adjusted OR 0.57, 95% CI 0.45, 0.71) and PTH standards (adjusted OR 0.27, 95% CI 0.22, 0.33) but better attainment of PO4 and CaPO4, while South Asians experienced better or comparable outcomes for most standards except Ca and PTH.

CONCLUSIONS

There was no evidence of socioeconomic inequity in standards attainment or a consistent pattern of inequity by ethnic group. The lower attainment of some standards in ethnic minorities may reflect biologic differences rather than ethnicity-related inequity of care.

Feasibility and cost of obtaining informed consent for essential review of medical records in large-scale health services research

Objective:

To evaluate the effectiveness and cost of obtaining consent for review of medical records within the passively observed non-intervention arm of a cluster randomized controlled trial, ‘Comparison Arm for ProtecT’.

Methods:

Two hundred and thirty men, who had been notified to the trial by cancer registries as having prostate cancer, were sent a consent form from their general practitioner or secondary care clinician. The consent rate of participants to the review of their medical records and the estimated costs of the process were evaluated.

Results:

One hundred and seventy-nine men (84%: 95% CI = 78%, 89%) consented to have their medical notes reviewed at an estimated cost of £123 (€172, $248) per person.

Conclusions:

A high consent rate for review of medical notes is achievable but at a cost. There needs to be renewed debate about the automatic need for consent to review medical records where the chance of personal harm is negligible and the purpose of the review is to provide robust evidence to save lives, prevent needless suffering, and improve the effectiveness and efficiency of health care delivery.

CSF oligoclonal band status informs prognosis in multiple sclerosis: a case control study of 100 patients

OBJECTIVE

Oligoclonal band (OCB) negative multiple sclerosis (MS) is well recognised but uncommon, studied in only a few usually small case series. These reached differing conclusions on whether its clinical features or course differ from OCB positive disease. The study hypothesis was that a definitive study would not only be of clinical and prognostic value but also potentially offer information about the possible role of CSF oligoclonal immunoglobulins in MS disease processes.

METHODS

A collaborative cohort of well documented patients in southwest England and south Wales was used to identify and analyse a large group of patients with OCB negative MS and make comparisons with age and sex matched OCB positive controls.

RESULTS

An approximate minimum 3% of patients with MS were OCB negative. They were significantly more likely to exhibit neurological or systemic clinical features atypical of MS (headaches, neuropsychiatric features and skin changes). Non-specific MRI, blood and (other) CSF abnormalities were also more common, emphasising the need for continued diagnostic vigilance, although the incautious application of McDonald diagnostic criteria in OCB negative cases renders categorisation as "definite" MS more likely. Studying the uniformly assessed Cardiff group (69 patients), we found the prognosis for neurological disability was significantly better for OCB negative cases. The age adjusted hazard ratio for OCB negative and OCB positive subjects to reach Disability Scale Status (DSS) 4 and DSS 6 was, respectively, 0.60 (95% CI 0.39 to 0.93; p = 0.02) and 0.51 (95% CI 0.27 to 0.94; p = 0.03).

CONCLUSION

There are clear clinical differences between OCB negative and OCB positive MS, in particular a better prognosis for disability. This is consistent with a secondary but nonetheless contributory role in disease process for intrathecally synthesised immunoglobulins.

Thyroid function and the natural history of depression: findings from the Caerphilly Prospective Study (CaPS) and a meta-analysis

OBJECTIVE

Low thyroid function has been associated with depression in clinical populations. We have examined whether thyroid function in the normal range is associated with minor psychiatric morbidity.

DESIGN

Prospective cohort study of 2269 middle aged men (45-59 years) with thyroid function (total T(4) only, TSH unavailable) measured between 1979 and 1983 and with repeat measures of minor psychiatric morbidity (GHQ-30) over a mean of 12.3 years follow-up. We also undertook a systematic review and meta-analysis of population-based studies examining thyroid function and mood.

RESULTS

There was a positive association between total T(4) and chronic psychiatric morbidity (odds ratio 1.21, 95% CI 1.02-1.43, P= 0.03), but this was consistent with chance after adjusting for social class, alcohol and smoking behaviours. The association with incident and recovery from psychiatric morbidity was weaker and consistent with chance. We identified seven eligible studies, from our systematic review and included six studies, including our own, in a meta-analysis. The pooled estimate showed a positive association (odds ratio 1.12, 95% CI 1.02-1.22, P-value = 0.01) between depression and T(4) and an inverse association with TSH (odds ratio 0.92, 95% CI 0.88-0.97, P= 0.0007) with no evidence of heterogeneity or publication bias.

CONCLUSION

The results from CaPS and our meta-analysis are consistent and suggest that, if anything, higher levels of thyroxine in the normal range are associated with increased risk of depression. The effects of thyroid hormone on mood may differ in normal populations and patients with clinical thyroid dysfunction.

How likely are older people to take up different falls prevention activities?

OBJECTIVE

To determine the extent to which older people are willing to engage in different falls prevention activities, and how this may vary in different sectors of the older population.

METHODS

A survey sent to patients aged over 54 in ten general practices in the Southampton, Bristol and Manchester areas of the UK in 2006 yielded 5,440 respondents. The survey assessed willingness to attend classes of strength and balance training (SBT), carry out SBT at home, or accept support to reduce home hazards. Participants were asked their gender, age, education, home tenure, ethnic group, and how often they had fallen during the past year.

RESULTS

Over 60% of the sample would consider doing SBT at home and 36.4% said they would definitely do SBT at home. Only 22.6% would definitely attend group sessions and 41.1% would definitely not attend. Older age, recent falls and lower socioeconomic status were associated with a greater willingness to carry out SBT at home (but not in classes) and accept help with home hazards.

CONCLUSIONS

Health promotion programmes should give prominence to home-based performance of SBT as a method of encouraging the entire older population to engage in falls prevention, including those most in need.

Variations in the G6PC2/ABCB11 genomic region are associated with fasting glucose levels

Identifying the genetic variants that regulate fasting glucose concentrations may further our understanding of the pathogenesis of diabetes. We therefore investigated the association of fasting glucose levels with SNPs in 2 genome-wide scans including a total of 5,088 nondiabetic individuals from Finland and Sardinia. We found a significant association between the SNP rs563694 and fasting glucose concentrations (P = 3.5 x 10(-7)). This association was further investigated in an additional 18,436 nondiabetic individuals of mixed European descent from 7 different studies. The combined P value for association in these follow-up samples was 6.9 x 10(-26), and combining results from all studies resulted in an overall P value for association of 6.4 x 10(-33). Across these studies, fasting glucose concentrations increased 0.01-0.16 mM with each copy of the major allele, accounting for approximately 1% of the total variation in fasting glucose. The rs563694 SNP is located between the genes glucose-6-phosphatase catalytic subunit 2 (G6PC2) and ATP-binding cassette, subfamily B (MDR/TAP), member 11 (ABCB11). Our results in combination with data reported in the literature suggest that G6PC2, a glucose-6-phosphatase almost exclusively expressed in pancreatic islet cells, may underlie variation in fasting glucose, though it is possible that ABCB11, which is expressed primarily in liver, may also contribute to such variation.

Immediate postnatal growth is associated with blood pressure in young adulthood: the Barry Caerphilly Growth Study

There is a consistent inverse association between birth weight and systolic blood pressure; however, few studies have been able to examine the immediate postnatal period. We have examined whether accelerated postnatal growth predicts adult systolic and diastolic blood pressure. We followed up participants from the Barry Caerphilly Growth Study. Blood pressure data were obtained on 679 of the original 951 subjects (73%) aged approximately 25 years. Both multivariable linear regression and spline models were used to examine the association among weight, length, and growth velocities with systolic blood pressure and diastolic blood pressure. Both statistical approaches showed that birth weight was inversely associated with systolic blood pressure. Only the spline models found that immediate (0 to 5 months) weight gain (beta coefficient: 1.29 mm Hg; 95% CI: 0.36 to 2.23; P=0.007) and weight gain between 1 year and 9 months to 5 years (beta coefficient: 1.44 mm Hg; 95% CI: 0.31 to 2.57; P=0.01) were independently associated with systolic blood pressure, whereas only immediate weight gain (beta coefficient: 0.74 mm Hg; 95% CI: 0.08 to 1.41; P=0.03) was associated with diastolic blood pressure. This is the first study to demonstrate that only immediate postnatal growth predicts diastolic blood pressure in term births, whereas it adds further evidence that both birth weight and postnatal growth are associated with systolic blood pressure in support of both the fetal origins and growth acceleration hypotheses.

Survival and cause of death in multiple sclerosis: a prospective population-based study

BACKGROUND

Detailed studies of mortality in multiple sclerosis (MS) are limited. Studying death certificates in a prospective cohort of patients known to have MS is of value in establishing mortality data and can also provide important information on the accuracy and use of death certificates for epidemiological studies.

METHODS

A population-based survey performed in South Wales in 1985 identified 441 patients. Cases were flagged with the Office of Population Censuses and Surveys and death certificates collected prospectively for more than 20 years.

RESULTS

Median observed survival time was 38.0 years from symptom onset. Mean age at death was 65.3 for women and 65.2 years for men. Mean age at death in patients dying from MS-related causes was 62.5 and 69.3 years (p<0.001) for unrelated deaths. Those dying of MS-related causes had a younger age at disease onset (32.5) compared with those dying of unrelated causes (36.8 years) (p = 0.01). Cause of death was related to MS in 57.9% and unrelated in 42.1% of individuals. In 27% of patients, "MS" was absent from the death certificate. The most common cause of death was respiratory disease (47.5%). The standardised mortality ratio was 2.79 (95% CI 2.44 to 3.18) so that MS patients were almost three times more likely to die prematurely relative to the general population.

CONCLUSIONS

These results confirm a continuing trend of premature death in patients with MS. Relying on data derived from death certificates will underestimate disease prevalence. Differences were identified between those dying from MS-related causes and those dying from other causes.

The association of C-reactive protein and CRP genotype with coronary heart disease: findings from five studies with 4,610 cases amongst 18,637 participants

Background

It is unclear whether C-reactive protein (CRP) is causally related to coronary heart disease (CHD). Genetic variants that are known to be associated with CRP levels can be used to provide causal inference of the effect of CRP on CHD. Our objective was to examine the association between CRP genetic variant +1444C>T (rs1130864) and CHD risk in the largest study to date of this association.

Methods and Results

We estimated the association of CRP genetic variant +1444C>T (rs1130864) with CRP levels and with CHD in five studies and then pooled these analyses (N = 18,637 participants amongst whom there were 4,610 cases). CRP was associated with potential confounding factors (socioeconomic position, physical activity, smoking and body mass) whereas genotype (rs1130864) was not associated with these confounders. The pooled odds ratio of CHD per doubling of circulating CRP level after adjustment for age and sex was 1.13 (95%CI: 1.06, 1.21), and after further adjustment for confounding factors it was 1.07 (95%CI: 1.02, 1.13). Genotype (rs1130864) was associated with circulating CRP; the pooled ratio of geometric means of CRP level among individuals with the TT genotype compared to those with the CT/CC genotype was 1.21 (95%CI: 1.15, 1.28) and the pooled ratio of geometric means of CRP level per additional T allele was 1.14 (95%CI: 1.11, 1.18), with no strong evidence in either analyses of between study heterogeneity (I² = 0%, p>0.9 for both analyses). There was no association of genotype (rs1130864) with CHD: pooled odds ratio 1.01 (95%CI: 0.88, 1.16) comparing individuals with TT genotype to those with CT/CC genotype and 0.96 (95%CI: 0.90, 1.03) per additional T allele (I²<7.5%, p>0.6 for both meta-analyses). An instrumental variables analysis (in which the proportion of CRP levels explained by rs1130864 was related to CHD) suggested that circulating CRP was not associated with CHD: the odds ratio for a doubling of CRP level was 1.04 (95%CI: 0.61, 1.80).

Conclusions

We found no association of a genetic variant, which is known to be related to CRP levels, (rs1130864) and having CHD. These findings do not support a causal association between circulating CRP and CHD risk, but very large, extended, genetic association studies would be required to rule this out.

Effect of integration of supplemental nutrition with public health programmes in pregnancy and early childhood on cardiovascular risk in rural Indian adolescents: long term follow-up of Hyderabad nutrition trial

OBJECTIVE

To determine whether integration of nutritional supplementation with other public health programmes in early life reduces the risk of cardiovascular disease in undernourished populations.

DESIGN

Approximately 15 years' follow-up of participants born within an earlier controlled, community trial of nutritional supplementation integrated with other public health programmes.

SETTING

29 villages (15 intervention, 14 control) near Hyderabad city, south India.

PARTICIPANTS

1165 adolescents aged 13-18 years.

INTERVENTION

Balanced protein-calorie supplementation (2.51 MJ, 20 g protein) offered daily to pregnant women and preschool children aged under 6 years, coupled with integrated delivery of vertical public health programmes.

MAIN OUTCOME MEASURES

Height, adiposity, blood pressures, lipids, insulin resistance (homoeostasis model assessment (HOMA) score), and arterial stiffness (augmentation index).

RESULTS

The participants from the intervention villages were 14 mm (95% confidence interval 4 to 23; P=0.007) taller than controls but had similar body composition. The participants from the intervention villages had more favourable measures of insulin resistance and arterial stiffness: 20% (3% to 39%; P=0.02) lower HOMA score and 3.3% (1% to 5.7%; P=0.008) lower augmentation index. No strong evidence existed for differences in blood pressures and serum lipids.

CONCLUSIONS

In this undernourished population, integrated delivery of supplemental nutrition with other public health programmes in pregnancy and early childhood was associated with a more favourable profile of cardiovascular disease risk factors in adolescence. This pragmatic study provides the most robust evidence to date on this important hypothesis for which classic trials are unlikely. Improved maternal and child nutrition may have a role in reducing the burden of cardiovascular disease in low income and middle income countries.

Early life growth and hemostatic factors: the Barry Caerphilly Growth study

Associations between early life growth trajectories and a range of adult (aged approximately 25 years) hemostatic factors were assessed in the Barry Caerphilly Growth study (N = 517) in South Wales, 1974-1999. Associations of birth weight, birth length, and weight and height velocities during three periods ("immediate": 0-<5 months, "infant": 5 months-<1 year 9 months, and "childhood": 1 year 9 months-5 years) with adult levels of hemostatic factors were assessed. Birth weight was inversely associated with fibrinogen (beta per 1-unit change in z score = -0.08, 95% confidence interval (CI): -0.15, -0.02). Immediate weight velocity was inversely associated with factor VII (beta = -1.88, 95% CI: -3.84, 0.09), factor VIII (beta = -2.58, 95% CI: -4.07, -0.45), and von Willebrand factor antigen (beta = -4.07, 95% CI: -7.25, -0.89). Birth length was inversely associated with fibrinogen (beta = -0.07, 95% CI: -0.14, -0.01). Evidence was weaker for an inverse association of immediate height velocity with factor VIII (beta = -2.16, 95% CI: -4.62, 0.29) and von Willebrand factor antigen (beta = -2.85, 95% CI: -6.52, 0.81). Childhood height velocity was positively associated with D-dimer (ratio of geometric means = 1.11, 95% CI: 1.01, 1.23). Results support the view that the immediate postnatal period may be particularly important, possibly through impaired liver development and/or infection in early life, in determining cardiovascular disease risk.

Fourteen-year final report of the randomized PDRG-UK trial comparing three initial treatments in PD

BACKGROUND

Ten-year follow-up results from the Parkinson's Disease Research Group of the United Kingdom trial demonstrated that there were no long-term advantages to initiating treatment with bromocriptine compared with l-dopa in early Parkinson disease (PD). Increased mortality in patients on selegiline combined with l-dopa led to premature termination of this arm after 6 years.

METHODS

Between 1985 and 1990, 782 patients were recruited into an open pragmatic multicenter trial and were randomized to l-dopa/decarboxylase inhibitor (DDCI), l-dopa/DDCI plus selegiline, or bromocriptine. The main endpoints were mortality, disability, and motor complications. For final follow-up, health-related quality of life and mental function were also assessed.

RESULTS

Median duration of follow-up at final assessment was 14 years in the 166 (21%) surviving participants who could be contacted. After adjustment for baseline characteristics, disability scores were better in the l-dopa than in the bromocriptine arm (Webster: 16.6 vs 19.8; p = 0.03; Northwestern University Disability: 34.3 vs 30.0, p = 0.05). Physical functioning (difference 20.8; 95% CI 10.0, 31.6; p < 0.001) and physical summary scores (difference 5.2; 95% CI 0.7, 9.7; p = 0.03) on the 36-item short-form health survey were also superior on l-dopa. Differences in mortality rates and prevalence of dyskinesias, motor fluctuations, and dementia were not significantly different.

CONCLUSION

Initial treatment with the dopamine agonist bromocriptine did not reduce mortality or motor disability and the initially reduced frequency in motor complications was not sustained. We found no evidence of a long-term benefit or clinically relevant disease-modifying effect with initial dopamine agonist treatment.

Investigating Black-White differences in prostate cancer prognosis: A systematic review and meta-analysis

The case-fatality rate following a diagnosis of prostate cancer is higher for Black men compared to White men. How this elevated rate arises is uncertain, with differences in disease biology, presentation, treatment and comorbidity having been suggested. A systematic search was conducted for articles that reported ethnic differences in overall-survival, prostate cancer specific survival (PSS) or biochemical recurrence. 48 articles met the inclusion criteria. Black men had worse overall survival (risk ratio 1.35, 95% CI 1.23-1.48) but this was not due to comorbidity alone as PSS and risk of biochemical recurrence were also elevated (1.29, 95% CI 1.13-1.47 and 1.34, 95% CI 1.23-1.46, respectively). Studies adjusting for clinical predictors and socioeconomic variables no longer supported a difference in overall survival (1.01, 95% CI 0.88-1.16), but continued to find an increased risk amongst Black men for PSS (1.13, 95% CI 1.00-1.27) and biochemical recurrence (1.25, 95% CI 1.11-1.41). Similar results were seen for studies from the pre-PSA era and free-health care settings. In contrast to others, studies of metastatic cancer did not find evidence of Black-White differences (p for interaction = 0.01). In conclusion, Black men had a poorer prognosis which was not fully explained by comorbidity, PSA screening, or access to free health care, although few studies measure these factors well. Either management differences for local disease and/or biological differences may be behind Black-White differences in prostate cancer prognosis.

The risk of prostate cancer amongst South Asian men in southern England: the PROCESS cohort study

OBJECTIVE

To reinvestigate whether South Asian men in the UK are at lower risk of being diagnosed with prostate cancer in a UK-based retrospective cohort study and to examine possible reasons that may explain this.

PATIENTS AND METHODS

The catchment areas were predefined in four areas of southern England, and age- and race-specific populations for those areas taken from census data. Cases were ascertained through review of multiple hospital sources, while race, other demographic factors, and medical history were determined using questionnaires sent to the men, hospital records review and death certificates. The South Asian group included men of Indian, Bangladeshi and Pakistani origin.

RESULTS

There was modest evidence of lower prostate cancer rates in South Asian men compared with their White neighbours (age-adjusted rate ratio 0.81; 95% confidence interval 0.65-1.00). This difference did not reflect less use of prostate-specific antigen (PSA) testing or differences in clinical features at presentation.

CONCLUSION

This study provides evidence of a lower incidence of prostate cancer amongst South Asian men living in England, in comparison with their White counterparts. If anything, South Asian men presented with clinical features of earlier disease suggesting that the reduced risk is unlikely to be an artefact of poorer access to health care.

Survival in multiple system atrophy

We here report survival in patients with multiple system atrophy (MSA) in a large, prospectively studied group of patients with MSA. Eighty-five of 100 patients were known to have died. Three patients were rediagnosed as having PD. Twenty-four patients came to autopsy, which showed MSA in 22 and idiopathic Parkinson's disease in 2. The median survival time was 8.6 and 7.3 years for men and women, respectively (hazard ratio for women was 1.49, 95% CI 0.97-2.31, P = 0.07). Except for rediagnosis as PD, no predictive factors for better survival could be identified. These data confirm the relatively poor prognosis of MSA of less than 9 years on average.

Common variation in the FTO gene alters diabetes-related metabolic traits to the extent expected given its effect on BMI

OBJECTIVE

Common variation in the FTO gene is associated with BMI and type 2 diabetes. Increased BMI is associated with diabetes risk factors, including raised insulin, glucose, and triglycerides. We aimed to test whether FTO genotype is associated with variation in these metabolic traits.

RESEARCH DESIGN AND METHODS

We tested the association between FTO genotype and 10 metabolic traits using data from 17,037 white European individuals. We compared the observed effect of FTO genotype on each trait to that expected given the FTO-BMI and BMI-trait associations.

RESULTS

Each copy of the FTO rs9939609 A allele was associated with higher fasting insulin (0.039 SD [95% CI 0.013-0.064]; P = 0.003), glucose (0.024 [0.001-0.048]; P = 0.044), and triglycerides (0.028 [0.003-0.052]; P = 0.025) and lower HDL cholesterol (0.032 [0.008-0.057]; P = 0.009). There was no evidence of these associations when adjusting for BMI. Associations with fasting alanine aminotransferase, gamma-glutamyl-transferase, LDL cholesterol, A1C, and systolic and diastolic blood pressure were in the expected direction but did not reach P < 0.05. For all metabolic traits, effect sizes were consistent with those expected for the per allele change in BMI. FTO genotype was associated with a higher odds of metabolic syndrome (odds ratio 1.17 [95% CI 1.10-1.25]; P = 3 x 10(-6)).

CONCLUSIONS

FTO genotype is associated with metabolic traits to an extent entirely consistent with its effect on BMI. Sample sizes of >12,000 individuals were needed to detect associations at P < 0.05. Our findings highlight the importance of using appropriately powered studies to assess the effects of a known diabetes or obesity variant on secondary traits correlated with these conditions.

Neurological care and risk of hospital mortality for patients with myasthenia gravis in England

BACKGROUND

Myasthenia gravis (MG) is a rare neurological disorder, which can be life threatening. Although death is a rare outcome, evidence does not exist as to whether neurological care leads to any better outcome than care by other specialties.

METHODS

A matched nested case control study sampled from all public sector hospital admissions in England with a primary diagnosis of MG from 1991 to 1999. Cases were defined as MG admissions which resulted in death and controls were other MG admissions, matched on sex, age (+/-2 years) and date of admission (+/-20 days) that were non-fatal. From a total of 18 251 finished consultant episodes with a mention of MG, we were able to create 196 matched sets with 196 fatal admissions and 788 control admissions.

RESULTS

Admission under a neurologist was associated with a 69% reduced risk of death (OR 0.31, 95% CI 0.22 to 0.44; p<0.001). This was only slightly attenuated after adjustment for a variety of patient related and hospital covariates (OR 0.37, 95% CI 0.23 to 0.62; p<0.001).

CONCLUSIONS

This is the first evidence that patients admitted with MG are far less likely to die if they are under the care of a neurologist. We cannot determine whether this is because of better management per se or because neurologists are usually based in specialist centres and may have better intensive care support, or both. Alternatively, this may be a result of "selection bias" so that neurologists select less seriously ill patients.

Ethnic differences in healthcare-seeking behaviour and management for acute chest pain: secondary analysis of the MINAP dataset 2002-2003

OBJECTIVE

To examine whether there are ethnic differences in the healthcare-seeking behaviour and management of patients with chest pain.

DESIGN

Prospective cohort of patients attending accident and emergency departments with chest pain.

SETTING

Hospitals in England and Wales from 1 January 2002 to 31 December 2003.

PARTICIPANTS

Patients with chest pain.

MAIN OUTCOME MEASURES

Whether patients arrived by ambulance, whether they received thrombolysis and the time it took from symptom onset to arrive at hospital and receive thrombolysis.

RESULTS

South Asian patients were less likely to arrive by ambulance (age and sex adjusted odds ratio 0.64, 95% CI 0.60 to 0.69, p<0.001) regardless of admission diagnosis. Overall, they were more likely to receive thrombolysis (adjusted multivariable odds ratio 1.19, 95% CI 1.10 to 1.30, p<0.001) and the difference was more marked if they had non-specific ECG changes for heart disease rather than definite evidence of a myocardial infarction. There was no evidence of an important clinical delay in South Asians receiving thrombolysis after arrival at hospital.

CONCLUSIONS

There are ethnic differences in healthcare-seeking behaviour and the way doctors manage South Asians with chest pain. The relative underuse of ambulances by South Asians may either reflect cultural differences or geographical proximity to hospitals. Doctors may have a lower threshold for giving thrombolytic therapy to South Asian men with chest pain possibly because they are aware of the increased risk of coronary heart disease in this population.

Prevalence and pattern of cognitive impairment in a community cohort of men in South Wales: methodology and findings from the Caerphilly Prospective Study

BACKGROUND/AIMS

The prevalence of dementia and cognitive impairment not dementia was investigated in the Caerphilly Prospective Study cohort (men currently aged 65-84 years).

METHODS

Of 1,633 men eligible for cognitive screening, 1,225 (75%) were seen, with those failing the screening criteria (CAMCOG <83 or decline in CAMCOG >9) being neurologically examined.

RESULTS

For dementia, diagnosed by DSM-IV criteria, the population prevalence was 5.2% rising to 6.1% in the screened population. For cognitive impairment not dementia, the prevalence in the screened population was 15.6% giving an overall prevalence of cognitive impairment of 21.8%. Prevalence rose fivefold between ages of 65 and 84 years to reach over 50%.

CONCLUSION

These figures are likely to underestimate actual prevalence in this population, and developing effective interventions should be a public health priority.

Newly identified loci that influence lipid concentrations and risk of coronary artery disease

To identify genetic variants influencing plasma lipid concentrations, we first used genotype imputation and meta-analysis to combine three genome-wide scans totaling 8,816 individuals and comprising 6,068 individuals specific to our study (1,874 individuals from the FUSION study of type 2 diabetes and 4,184 individuals from the SardiNIA study of aging-associated variables) and 2,758 individuals from the Diabetes Genetics Initiative, reported in a companion study in this issue. We subsequently examined promising signals in 11,569 additional individuals. Overall, we identify strongly associated variants in eleven loci previously implicated in lipid metabolism (ABCA1, the APOA5-APOA4-APOC3-APOA1 and APOE-APOC clusters, APOB, CETP, GCKR, LDLR, LPL, LIPC, LIPG and PCSK9) and also in several newly identified loci (near MVK-MMAB and GALNT2, with variants primarily associated with high-density lipoprotein (HDL) cholesterol; near SORT1, with variants primarily associated with low-density lipoprotein (LDL) cholesterol; near TRIB1, MLXIPL and ANGPTL3, with variants primarily associated with triglycerides; and a locus encompassing several genes near NCAN, with variants strongly associated with both triglycerides and LDL cholesterol). Notably, the 11 independent variants associated with increased LDL cholesterol concentrations in our study also showed increased frequency in a sample of coronary artery disease cases versus controls.

Birth weight; postnatal, infant, and childhood growth; and obesity in young adulthood: evidence from the Barry Caerphilly Growth Study

BACKGROUND

Birth weight has been shown to be positively associated with adult obesity, but relatively few studies have examined the associations with growth in specific periods of early childhood.

OBJECTIVE

The objective was to assess the association of measures of growth between birth and 5 y of age with adult measures of adiposity.

DESIGN

We conducted a longitudinal study of young adults from Barry and Caerphilly, United Kingdom, who had previously taken part between 1972 and 1974 in a randomized controlled trial of milk supplementation. We reexamined 679 men and women (72% of the target population) to measure body mass index (BMI; in kg/m(2)), waist-to-hip ratio, sagittal abdominal diameter, and waist circumference.

RESULTS

An increase in weight velocity from 1 y and 9 mo to 5 y of age was the most important predictor of BMI, waist circumference, and sagittal abdominal diameter. A z-score increase in weight gain in this period was associated with an increase in BMI of 1.13 (95% CI: 0.69, 1.57; P < 0.001). Infant weight gain from 5 mo to 1 y and 9 mo was the strongest predictor of waist-to-hip ratio (0.51; 95% CI: 0.00, 1.02; P = 0.05).

CONCLUSIONS

Birth weight does not predict adiposity on the basis of weight gain in childhood. The association between adult adiposity and weight gain in different periods is variable and depends on the measure of adiposity that is used. It remains unclear whether early childhood is the optimum period in the life course for the primary prevention of adult adiposity.

The Emerging Risk Factors Collaboration: analysis of individual data on lipid, inflammatory and other markers in over 1.1 million participants in 104 prospective studies of cardiovascular diseases

Many long-term prospective studies have reported on associations of cardiovascular diseases with circulating lipid markers and/or inflammatory markers. Studies have not, however, generally been designed to provide reliable estimates under different circumstances and to correct for within-person variability. The Emerging Risk Factors Collaboration has established a central database on over 1.1 million participants from 104 prospective population-based studies, in which subsets have information on lipid and inflammatory markers, other characteristics, as well as major cardiovascular morbidity and cause-specific mortality. Information on repeat measurements on relevant characteristics has been collected in approximately 340,000 participants to enable estimation of and correction for within-person variability. Re-analysis of individual data will yield up to approximately 69,000 incident fatal or nonfatal first ever major cardiovascular outcomes recorded during about 11.7 million person years at risk. The primary analyses will involve age-specific regression models in people without known baseline cardiovascular disease in relation to fatal or nonfatal first ever coronary heart disease outcomes. This initiative will characterize more precisely and in greater detail than has previously been possible the shape and strength of the age- and sex-specific associations of several lipid and inflammatory markers with incident coronary heart disease outcomes (and, secondarily, with other incident cardiovascular outcomes) under a wide range of circumstances. It will, therefore, help to determine to what extent such associations are independent from possible confounding factors and to what extent such markers (separately and in combination) provide incremental predictive value.

Relationship of early childhood illness with adult cortisol in the Barry Caerphilly Growth (BCG) cohort

BACKGROUND

The developmental origins hypothesis suggests that pre- and postnatal exposures may influence vulnerability to later disease. The hypothalamic-pituitary-adrenal (HPA) axis is one pathway by which this may occur. Analyses were conducted in the Barry Caerphilly Growth (BCG) cohort to explore whether the postnatal exposure of childhood infections was related to HPA axis activity in adulthood.

METHODS

Detailed data on type and frequency of illnesses were collected in the first 5 years of life. At the recent follow-up of this cohort (N=566; mean age of participants=25 years) three salivary cortisol samples were taken: two fasting samples in the morning (within 30 min of arrival at the study site and after venesection and cognitive test procedures) and one evening sample (2200 h). These data were transformed to provide AUCi and AUCg (indices reflecting axis reactivity and total hormonal output, respectively).

FINDINGS

Negative associations were evident between number of upper respiratory illnesses and adult cortisol (as captured by the second morning sample, evening sample and AUCg). These relationships remained after controlling for other potential prenatal, postnatal and adult determinants. These associations were not observed for gastrointestinal illnesses suggesting that confounding by socioeconomic factors is unlikely to be the explanation.

CONCLUSIONS

Childhood respiratory illnesses were associated with reduced HPA axis activity in adulthood. Further follow-ups will determine whether this pattern of activity influences vulnerability to diseases associated with HPA regulation.

A coronary heart disease risk model for predicting the effect of potent antiretroviral therapy in HIV-1 infected men

BACKGROUND

Many HIV-infected patients on highly active antiretroviral therapy (HAART) experience metabolic complications including dyslipidaemia and insulin resistance, which may increase their coronary heart disease (CHD) risk. We developed a prognostic model for CHD tailored to the changes in risk factors observed in patients starting HAART.

METHODS

Data from five cohort studies (British Regional Heart Study, Caerphilly and Speedwell Studies, Framingham Offspring Study, Whitehall II) on 13,100 men aged 40-70 and 114,443 years of follow up were used. CHD was defined as myocardial infarction or death from CHD. Model fit was assessed using the Akaike Information Criterion; generalizability across cohorts was examined using internal-external cross-validation.

RESULTS

A parametric model based on the Gompertz distribution generalized best. Variables included in the model were systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, triglyceride, glucose, diabetes mellitus, body mass index and smoking status. Compared with patients not on HAART, the estimated CHD hazard ratio (HR) for patients on HAART was 1.46 (95% CI 1.15-1.86) for moderate and 2.48 (95% CI 1.76-3.51) for severe metabolic complications.

CONCLUSIONS

The change in the risk of CHD in HIV-infected men starting HAART can be estimated based on typical changes in risk factors, assuming that HRs estimated using data from non-infected men are applicable to HIV-infected men. Based on this model the risk of CHD is likely to increase, but increases may often be modest, and could be offset by lifestyle changes.

Type 2 diabetes TCF7L2 risk genotypes alter birth weight: a study of 24,053 individuals

The role of genes in normal birth-weight variation is poorly understood, and it has been suggested that the genetic component of fetal growth is small. Type 2 diabetes genes may influence birth weight through maternal genotype, by increasing maternal glycemia in pregnancy, or through fetal genotype, by altering fetal insulin secretion. We aimed to assess the role of the recently described type 2 diabetes gene TCF7L2 in birth weight. We genotyped the polymorphism rs7903146 in 15,709 individuals whose birth weight was available from six studies and in 8,344 mothers from three studies. Each fetal copy of the predisposing allele was associated with an 18-g (95% confidence interval [CI] 7-29 g) increase in birth weight (P=.001) and each maternal copy with a 30-g (95% CI 15-45 g) increase in offspring birth weight (P=2.8x10-5). Stratification by fetal genotype suggested that the association was driven by maternal genotype (31-g [95% CI 9-48 g] increase per allele; corrected P=.003). Analysis of diabetes-related traits in 10,314 nondiabetic individuals suggested the most likely mechanism is that the risk allele reduces maternal insulin secretion (disposition index reduced by ~0.15 standard deviation; P=1x10-4), which results in increased maternal glycemia in pregnancy and hence increased offspring birth weight. We combined information with the other common variant known to alter fetal growth, the -30G-->A polymorphism of glucokinase (rs1799884). The 4% of offspring born to mothers carrying three or four risk alleles were 119 g (95% CI 62-172 g) heavier than were the 32% born to mothers with none (for overall trend, P=2x10-7), comparable to the impact of maternal smoking during pregnancy. In conclusion, we have identified the first type 2 diabetes-susceptibility allele to be reproducibly associated with birth weight. Common gene variants can substantially influence normal birth-weight variation.

A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity

Obesity is a serious international health problem that increases the risk of several common diseases. The genetic factors predisposing to obesity are poorly understood. A genome-wide search for type 2 diabetes-susceptibility genes identified a common variant in the FTO (fat mass and obesity associated) gene that predisposes to diabetes through an effect on body mass index (BMI). An additive association of the variant with BMI was replicated in 13 cohorts with 38,759 participants. The 16% of adults who are homozygous for the risk allele weighed about 3 kilograms more and had 1.67-fold increased odds of obesity when compared with those not inheriting a risk allele. This association was observed from age 7 years upward and reflects a specific increase in fat mass.

The Etiopathogenesis of Parkinson Disease and Suggestions for Future Research. Part II

We are at a critical juncture in our knowledge of the etiology and pathogenesis of Parkinson disease (PD). It is clear that PD is not a single entity simply resulting from a dopaminergic deficit; rather it is most likely caused by a combination of genetic and environmental factors. Although there is extensive new information on the etiology and pathogenesis of PD, which may advance its treatment, new syntheses of this information are needed. The second part of this two-part, state-of-the-art review by leaders in PD research critically examines the research field to identify areas for which new knowledge and ideas might be helpful for treatment purposes. Topics reviewed in Part II are genetics, animal models, and oxidative stress.

The risk of prostate cancer amongst black men in the United Kingdom: the PROCESS cohort study

OBJECTIVES

It is known that African American men have a greater risk of prostate cancer than white men. We investigated whether this was true for first-generation black Caribbean and black African men in the United Kingdom.

METHODS

A clinical cohort study design recruiting all cases of prostate cancer diagnosed over a 5-yr period and residing in defined areas of London and Bristol. We calculated the age-standardised incidence rates and relative risk for all black men, and black Caribbean and black African men versus white men.

RESULTS

Black men had higher age-adjusted rates of prostate cancer (166 per 100,000, 95% confidence interval [95%CI], 151-180 per 100,000) than white men (56.4 per 100,000, 95%CI, 53.3-59.5 per 100,000). The relative risks for all black, black Caribbean, and black African men were 3.09 (95%CI, 2.79-3.43; p<0.0001), 3.19 (95%CI, 2.85-3.56; p<0.0001) and 2.87 (95%CI, 2.34-3.53; p<0.0001), respectively. There was no strong evidence that the rates for black Caribbean differed from black African men. The higher risk in black men compared with white men was more apparent in younger age groups (p value for interaction<0.001).

CONCLUSIONS

Black men in the United Kingdom have substantially greater risk of developing prostate cancer compared with white men, although this risk is lower than that of black men in the United States. The similar rates in black Caribbean and black African men suggest a common genetic aetiology, although migration may be associated with an increased risk attributable to a gene-environment interaction.

Risk and presenting features of prostate cancer amongst African-Caribbean, South Asian and European men in North-east London

OBJECTIVE

To determine whether there are ethnic differences in the incidence and presenting features of all patients with prostate cancer presenting in North-east London, UK.

PATIENTS AND METHODS

All newly diagnosed men with prostate cancer between 1999 and 2000 who were resident in the East London and City Health Authority were identified from various sources. Key clinical features were extracted from hospital records. The age-adjusted incidence rates for European, South Asian and African-Caribbean patients were calculated using census denominator data.

RESULTS

For men aged >50 years the annual age-adjusted incidence rates (95% confidence interval) were 213 (186-240), 647 (504-789) and 199 (85-310) for the European, African-Caribbean and South Asian patients, respectively. African-Caribbean men had a three times greater risk (risk ratio 3.07, 2.40-3.93, P < 0.001) than European men. South Asian men had a lower risk of prostate cancer but this could have been compatible with chance. There was no evidence of marked ethnic differences for prostate-specific antigen levels, clinical staging and Gleason scores.

CONCLUSION

The greater risk of prostate cancer for African-Caribbean men in South-east England is consistent with data from the USA and the Caribbean. Future work needs to determine whether this risk differs according to country of origin, and which genetic and/or environmental risk factors might be important in explaining these observations.