Modelling socioeconomic position as a driver of the exposome in the first 18 months of life of the NINFEA birth cohort children.

BACKGROUND: The exposome drivers are less studied than its consequences but may be crucial in identifying population subgroups with unfavourable exposures. OBJECTIVES: We used three approaches to study the socioeconomic position (SEP) as a driver of the early-life exposome in Turin children of the NINFEA cohort (Italy). METHODS: Forty-two environmental exposures, collected at 18 months of age (N = 1989), were classified in 5 groups (lifestyle, diet, meteoclimatic, traffic-related, built environment). We performed cluster analysis to identify subjects sharing similar exposures, and intra-exposome-group Principal Component Analysis (PCA) to reduce the dimensionality. SEP at childbirth was measured through the Equivalised Household Income Indicator. SEP-exposome association was evaluated using: 1) an Exposome Wide Association Study (ExWAS), a one-exposure (SEP) one-outcome (exposome) approach; 2) multinomial regression of cluster membership on SEP; 3) regressions of each intra-exposome-group PC on SEP. RESULTS: In the ExWAS, medium/low SEP children were more exposed to greenness, pet ownership, passive smoking, TV screen and sugar; less exposed to NO2, NOX, PM25abs, humidity, built environment, traffic load, unhealthy food facilities, fruit, vegetables, eggs, grain products, and childcare than high SEP children. Medium/low SEP children were more likely to belong to a cluster with poor diet, less air pollution, and to live in the suburbs than high SEP children. Medium/low SEP children were more exposed to lifestyle PC1 (unhealthy lifestyle) and diet PC2 (unhealthy diet), and less exposed to PC1s of the built environment (urbanization factors), diet (mixed diet), and traffic (air pollution) than high SEP children. CONCLUSIONS: The three approaches provided consistent and complementary results, suggesting that children with lower SEP are less exposed to urbanization factors and more exposed to unhealthy lifestyles and diet. The simplest method, the ExWAS, conveys most of the information and is more replicable in other populations. Clustering and PCA may facilitate results interpretation and communication.

Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies.

BACKGROUND: Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence. METHODS AND FINDINGS: We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries. CONCLUSIONS: This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

COVID-19-like symptoms and their relation to the SARS-CoV-2 epidemic in children and adults of an Italian birth cohort

OBJECTIVES: to estimate the population prevalence of COVID-19-like symptoms in children and adults during the first SARS-CoV-2 epidemic wave hitting Italy in the spring 2020; to assess their geographical correlation with the cumulative number of COVID-19 cases by province; to analyse their clustering within families; to estimate their sensitivity, positive predictive value (PPV) and negative predictive value (NPV) for COVID-19 diagnosis in individuals tested for SARS-CoV-2. DESIGN: cross-sectional study nested within a birth cohort. SETTING AND PARTICIPANTS: mothers participating in an Italian birth cohort (NINFEA) were invited to complete an online questionnaire on COVID-19-like symptoms in their household. MAIN OUTCOME MEASURES: population prevalence of COVID-19-like symptoms in children and adults, geographical correlation of COVID-19-like symptoms with the cumulative number of COVID-19 cases by province, clustering of COVID-19-like symptoms within families, and sensitivity, PPV and NPV of COVID-19-like symptoms for COVID-19 diagnosis in individuals tested for SARS-CoV-2. RESULTS: information was collected on 3,184 households, 6,133 adults, and 5,751 children. In the period March-April 2020, 55.4% of the NINFEA families had at least one member with at least one COVID-19-like symptom. There was a strong geographical correlation between the population cumulative incidence of COVID-19 and the prevalence of muscle pain, fatigue, low-grade fever, and breathing difficulties in adults (Spearman's rho >=0.70). Having at least one family member with a COVID-19 diagnosis, compared with none tested for SARS-CoV-2, was associated with an increased prevalence ratio (PR) of almost all COVID-19-like symptoms in adults, and only of low-grade fever (37-37.5°C; PR 4.54; 95%CI 2.20-9.40) and anosmia/dysgeusia in children. Among adults with COVID-19 diagnosis, fatigue, muscle pain, and fever had a sensitivity >=70%. In individuals tested for SARS-CoV-2, with a 16.6% prevalence of COVID-19, breathing difficulties and nausea/vomiting had the highest PPVs, with point estimates close to 60%, and with NPVs close to 90%. CONCLUSIONS: the geographical prevalence of COVID-19-like symptoms in adults may inform on local disease clusters, while certain symptoms in family members of confirmed COVID-19 cases could help identify the intra-familial spread of the virus and its further propagation in the community. Low-grade fever is frequent in children with at least one household member with COVID-19 and possibly indicates child infection.

Medication burden and clustering in people living with HIV undergoing therapeutic drug monitoring.

AIM: People living with HIV (PLWH) have a high burden of comorbidities and concomitant medication use. The aim of this study was to analyse the prevalence, predictors and patterns of polypharmacy (PP) in a large therapeutic drug monitoring (TDM) registry. METHODS: We searched our TDM registry and categorized co-medications into 26 drug classes. We included patients with at least one medication recorded: PP and severe polypharmacy (sPP) were defined as the concomitant use of ≥5 or ≥10 nonantiretroviral/nonantitubercular drugs. Multivariable binary logistic analysis were conducted for identifying PP/sPP predictors. A hierarchical average-linkage cluster analysis was performed among drug classes. RESULTS: We included 2432 participants (1158 PLWH) aged 49.6 years (± 14.4) in the 2016-2020 period. A higher number of concomitant medications (4 vs 3.1, P < .001) and a higher prevalence of PP (26.1% vs 21.8%, P = .015) were recorded in controls. At multivariable binary logistic analysis older age, female gender and HIV-positive serostatus (P = .015) were independent predictors of PP; older age and year of inclusion were independent predictors of sPP. Cluster analysis showed that patients receiving oral drug for type 2 diabetes have a high probability of receiving several other drugs; a cluster of co-medications was observed with opioids, diuretics and central nervous system-affecting drugs. CONCLUSION: We observed a moderately high prevalence of polypharmacy in middle-aged PLWH: advanced age and female gender were associated with the greatest prevalence. The observation of co-medication clusters suggests groups of comorbidities but also identifies groups of patients at risk of similar drug-to-drug interactions.

Changes in parental smoking during pregnancy and risks of adverse birth outcomes and childhood overweight in Europe and North America: An individual participant data meta-analysis of 229,000 singleton births.

BACKGROUND: Fetal smoke exposure is a common and key avoidable risk factor for birth complications and seems to influence later risk of overweight. It is unclear whether this increased risk is also present if mothers smoke during the first trimester only or reduce the number of cigarettes during pregnancy, or when only fathers smoke. We aimed to assess the associations of parental smoking during pregnancy, specifically of quitting or reducing smoking and maternal and paternal smoking combined, with preterm birth, small size for gestational age, and childhood overweight. METHODS AND FINDINGS: We performed an individual participant data meta-analysis among 229,158 families from 28 pregnancy/birth cohorts from Europe and North America. All 28 cohorts had information on maternal smoking, and 16 also had information on paternal smoking. In total, 22 cohorts were population-based, with birth years ranging from 1991 to 2015. The mothers' median age was 30.0 years, and most mothers were medium or highly educated. We used multilevel binary logistic regression models adjusted for maternal and paternal sociodemographic and lifestyle-related characteristics. Compared with nonsmoking mothers, maternal first trimester smoking only was not associated with adverse birth outcomes but was associated with a higher risk of childhood overweight (odds ratio [OR] 1.17 [95% CI 1.02-1.35], P value = 0.030). Children from mothers who continued smoking during pregnancy had higher risks of preterm birth (OR 1.08 [95% CI 1.02-1.15], P value = 0.012), small size for gestational age (OR 2.15 [95% CI 2.07-2.23], P value < 0.001), and childhood overweight (OR 1.42 [95% CI 1.35-1.48], P value < 0.001). Mothers who reduced the number of cigarettes between the first and third trimester, without quitting, still had a higher risk of small size for gestational age. However, the corresponding risk estimates were smaller than for women who continued the same amount of cigarettes throughout pregnancy (OR 1.89 [95% CI 1.52-2.34] instead of OR 2.20 [95% CI 2.02-2.42] when reducing from 5-9 to ≤4 cigarettes/day; OR 2.79 [95% CI 2.39-3.25] and OR 1.93 [95% CI 1.46-2.57] instead of OR 2.95 [95% CI 2.75-3.15] when reducing from ≥10 to 5-9 and ≤4 cigarettes/day, respectively [P values < 0.001]). Reducing the number of cigarettes during pregnancy did not affect the risks of preterm birth and childhood overweight. Among nonsmoking mothers, paternal smoking was associated with childhood overweight (OR 1.21 [95% CI 1.16-1.27], P value < 0.001) but not with adverse birth outcomes. Limitations of this study include the self-report of parental smoking information and the possibility of residual confounding. As this study only included participants from Europe and North America, results need to be carefully interpreted regarding other populations. CONCLUSIONS: We observed that as compared to nonsmoking during pregnancy, quitting smoking in the first trimester is associated with the same risk of preterm birth and small size for gestational age, but with a higher risk of childhood overweight. Reducing the number of cigarettes, without quitting, has limited beneficial effects. Paternal smoking seems to be associated, independently of maternal smoking, with the risk of childhood overweight. Population strategies should focus on parental smoking prevention before or at the start, rather than during, pregnancy.

Blood loss in primary total hip arthroplasty with a short versus conventional cementless stem: a retrospective cohort study.

INTRODUCTION: To evaluate the impact of short cementless stem on several clinical and radiographic outcomes, with particular focus on blood loss, in comparison with conventional cementless stem in total hip arthroplasty (THA). MATERIALS AND METHODS: Patients undergoing THA with GTS short stem or CLS conventional stem were included. Clinical data were retrospectively collected including preoperative and postoperative day 1 value for haemoglobin (HB); rate of postoperative blood transfusions; intraoperative bone infractions; stem alignment; 5-year follow-up Harris Hip Score (HHS) and rate of stem revision at 5 years of follow-up of the short and conventional cementless stem. RESULTS: GTS and CLS stem group included 374 and 321 patients, respectively. The mean difference between the preoperative and postoperative day 1 HB value was 3.98 g/dL (SD 1.12) and 3.67 g/dL (SD 1.19) in the GTS and CLS group, respectively, which correspond to a crude effect (ß) of 0.32 (95% CI 0.15; 0.49) and adjusted effect of 0.11 (95% CI - 0.08; 0.3). GTS group reported a significantly higher number of patients with excellent results in terms of HHS (p = 0.001). The rate of intraoperative bone infractions was 1.6% and 0.3% in the GTS and CLS group, respectively (p = 0.013). At radiographic assessment, the rate of varus position of the stem was 14% in the GTS group and 6% in the CLS group (p < 0.0001). The rate of stem revision at 5 years of follow-up was 0.8% and 0.4% in the GTS and CLS group, respectively (p = 0.63). CONCLUSIONS: GTS short stem was not associated with a clinically significant lower blood loss in the immediately postoperative period. Unadjusted exploratory analyses show that GTS stem provides the same results of CLS stem in terms of HHS and rate of stem revision at 5 years of follow-up.

[Communicating data of the Italian NINFEA birth cohort]. / Comunicare i dati della coorte italiana di nuovi nati NINFEA.

"In March 2016, the website of the NINFEA project (an Internet-based cohort set up to investigate the effects of exposures acting early in life) was enriched with the section «Data¼, which reports aggregated data for selected variables of the cohort. This article discusses the rationale for this new section, available data and their possible uses are described, and some results are compared with figures accessible from surveillance studies. The Italian birth cohort NINFEA includes 7,500 pregnant women, recruited through the Internet from 2005 to June 2016, and of their children, followed up with repeated questionnaires. Thus, the «Data¼ section is based on a selected population. Currently, this new section includes information on maternal lifestyles/characteristics in pregnancy (e.g., alcohol, smoking, use of medications), child health (e.g., obesity, asthma symptoms, growth) and behaviours (e.g., sleeping patterns, being breastfed). Up to December 18th, 2017, its pages were visited 12,620 times. Prevalences for selected variables (e.g., prepregnancy body mass index, breast feeding, infant sleeping position) are similar to those reported by surveillance studies. Aggregated exposure and outcome data from large cohorts can be systematically made publicly available. These data may be of interest to the participants, to population subgroups whose characteristics are similar to the study participants, and to researchers and policy makers, whenever similar data are not available from population-based surveillance systems."

The role of maternal anorexia nervosa and bulimia nervosa before and during pregnancy in early childhood wheezing: Findings from the NINFEA birth cohort study.

OBJECTIVE: This study evaluates associations of maternal eating disorders (bulimia nervosa, anorexia nervosa, and purging behaviors) with infant wheezing and examines the effects of eating disorders on several wheezing determinants. METHOD: We studied 5,150 singletons from the NINFEA birth cohort. Maternal bulimia nervosa and anorexia nervosa diagnoses were ascertained from the questionnaires completed in pregnancy and 6 months after delivery, and were analyzed as: ever diagnosis, only before pregnancy, and during pregnancy. Purging behaviors were assessed for 12 months before or during pregnancy. The associations with wheezing between 6 and 18 months of age were assessed in models adjusted for a priori selected confounders. RESULTS: Children born to mothers with lifetime eating disorders were at an increased risk of developing wheezing (adjusted OR 1.68; [95% CI: 1.08, 2.60]), and this risk further increased when the disorders were active during pregnancy (2.52 [1.23, 5.19]). Increased risk of offspring wheezing was observed also for purging behaviors without history of eating disorder diagnosis (1.50 [1.10, 2.04]). The observed associations were not explained by comorbid depression and/or anxiety. Bulimia nervosa and/or anorexia nervosa during pregnancy were also associated with several risk factors for wheezing, including maternal smoking, adverse pregnancy outcomes, shorter breastfeeding duration, and day-care attendance. DISCUSSION: The associations of maternal eating disorders with offspring wheezing suggest long-term adverse respiratory outcomes in children of mothers with eating disorders. A better understanding of mechanisms implicated is necessary to help reduce the respiratory disease burden in these children.

Cord Blood Metabolic Signatures of Birth Weight: A Population-Based Study.

Birth weight is an important indicator of maternal and fetal health and a predictor of health in later life. However, the determinants of variance in birth weight are still poorly understood. We aimed to identify the biological pathways, which may be perturbed by environmental exposures, that are important in determining birth weight. We applied untargeted mass-spectrometry-based metabolomics to 481 cord blood samples collected at delivery in four birth cohorts from across Europe: ENVIRONAGE (Belgium), INMA (Spain), Piccolipiu (Italy), and Rhea (Greece). We performed a metabolome-wide association scan for birth weight on over 4000 metabolic features, controlling the false discovery rate at 5%. Annotation of compounds was conducted through reference to authentic standards. We identified 68 metabolites significantly associated with birth weight, including vitamin A, progesterone, docosahexaenoic acid, indolelactic acid, and multiple acylcarnitines and phosphatidylcholines. We observed enrichment (p < 0.05) of the tryptophan metabolism, prostaglandin formation, C21-steroid hormone signaling, carnitine shuttle, and glycerophospholipid metabolism pathways. Vitamin A was associated with both maternal smoking and birth weight, suggesting a mediation pathway. Our findings shed new light on the pathways central to fetal growth and will have implications for antenatal and perinatal care and potentially for health in later life.

Prenatal influences on size, velocity and tempo of infant growth: findings from three contemporary cohorts.

BACKGROUND: Studying prenatal influences of early life growth is relevant to life-course epidemiology as some of its features have been linked to the onset of later diseases. METHODS: We studied the association between prenatal maternal characteristics (height, age, parity, education, pre-pregnancy body mass index (BMI), smoking, gestational diabetes and hypertension) and offspring weight trajectories in infancy using SuperImposition by Translation And Rotation (SITAR) models, which parameterize growth in terms of three biologically interpretable parameters: size, velocity and tempo. We used data from three contemporary cohorts based in Portugal (GXXI, n=738), Italy (NINFEA, n=2,925), and Chile (GOCS, n=959). RESULTS: Estimates were generally consistent across the cohorts for maternal height, age, parity and pre-pregnancy overweight/obesity. Some exposures only affected one growth parameter (e.g. maternal height (per cm): 0.4% increase in size (95% confidence interval (CI):0.3; 0.5)), others were either found to affect size and velocity (e.g. pre-pregnancy underweight vs normal weight: smaller size (-4.9%, 95% CI:-6.5; -3.3), greater velocity (5.9%, 95% CI:1.9;10.0)), or to additionally influence tempo (e.g. pre-pregnancy overweight/obesity vs normal weight: increased size (7.9%, 95% CI:4.9;10.8), delayed tempo (0.26 months, 95% CI:0.11;0.41), decreased velocity (-4.9%, 95% CI: -10.8;0.9)). CONCLUSIONS: By disentangling the growth parameters of size, velocity and tempo, we found that prenatal maternal characteristics, especially maternal smoking, pre-pregnancy overweight and underweight, parity and gestational hypertension, are associated with different aspects of infant weight growth. These results may offer insights into the mechanisms governing infant growth.

Cancer incidence in professional flight crew and air traffic control officers: disentangling the effect of occupational versus lifestyle exposures.

Flight crew are occupationally exposed to several potentially carcinogenic hazards; however, previous investigations have been hampered by lack of information on lifestyle exposures. The authors identified, through the United Kingdom Civil Aviation Authority medical records, a cohort of 16,329 flight crew and 3,165 air traffic control officers (ATCOs) and assembled data on their occupational and lifestyle exposures. Standardised incidence ratios (SIRs) were estimated to compare cancer incidence in each occupation to that of the general population; internal analyses were conducted by fitting Cox regression models. All-cancer incidence was 20-29% lower in each occupation than in the general population, mainly due to a lower incidence of smoking-related cancers [SIR (95% CI) = 0.33 (0.27-0.38) and 0.42 (0.28-0.60) for flight crew and ATCOs, respectively], consistent with their much lower prevalence of smoking. Skin melanoma rates were increased in both flight crew (SIR = 1.87; 95% CI = 1.45-2.38) and ATCOs (2.66; 1.55-4.25), with rates among the former increasing with increasing number of flight hours (p-trend = 0.02). However, internal analyses revealed no differences in skin melanoma rates between flight crew and ATCOs (hazard ratio: 0.78, 95% CI = 0.37-1.66) and identified skin that burns easily when exposed to sunlight (p = 0.001) and sunbathing to get a tan (p = 0.07) as the strongest risk predictors of skin melanoma in both occupations. The similar site-specific cancer risks between the two occupational groups argue against risks among flight crew being driven by occupation-specific exposures. The skin melanoma excess reflects sun-related behaviour rather than cosmic radiation exposure.

Cause-specific mortality in professional flight crew and air traffic control officers: findings from two UK population-based cohorts of over 20,000 subjects.

OBJECTIVE: Flight crew are exposed to several potential occupational hazards. This study compares mortality rates in UK flight crew to those in air traffic control officers (ATCOs) and the general population. METHODS: A total of 19,489 flight crew and ATCOs were identified from the UK Civil Aviation Authority medical records and followed to the end of 2006. Consented access to medical records and questionnaire data provided information on demographic, behavioral, clinical, and occupational variables. Standardized mortality ratios (SMR) were estimated for these two occupational groups using the UK general population. Adjusted mortality hazard ratios (HR) for flight crew versus ATCOs were estimated via Cox regression models. RESULTS: A total of 577 deaths occurred during follow-up. Relative to the general population, both flight crew (SMR 0.32; 95% CI 0.30, 0.35) and ATCOs (0.39; 0.32, 0.47) had lower all-cause mortality, mainly due to marked reductions in mortality from neoplasms and cardiovascular diseases, although flight crew had higher mortality from aircraft accidents (SMR 42.8; 27.9, 65.6). There were no differences in all-cause mortality (HR 0.99; 95% CI 0.79, 1.25), or in mortality from any major cause, between the two occupational groups after adjustment for health-related variables, again except for those from aircraft accidents. The latter ratios, however, declined with increasing number of hours. CONCLUSIONS: The low all-cause mortality observed in both occupational groups relative to the general population is consistent with a strong "healthy worker effect" and their low prevalence of smoking and other risk factors. Mortality among flight crew did not appear to be influenced by occupational exposures, except for a rise in mortality from aircraft accidents.

Circulating levels of coagulation and inflammation markers and cancer risks: individual participant analysis of data from three long-term cohorts.

BACKGROUND: Basic and clinical research support the hypothesis that activation of the coagulation and inflammation pathways may affect cancer onset, but there is limited epidemiological data to support this. METHODS: We examined a large range of haemostatic and inflammation markers, including fibrinogen, in 19 303 male participants from three English cohorts followed for up to 30 years. After excluding the first 3 years of follow-up, 2908 incident cancers were accrued. Competing risk models were fitted to estimate rate ratios (RRs) for cancer incidence, adjusting for age and other confounders. RESULTS: Baseline white blood cell (WBC) count and circulating levels of fibrinogen, C-reactive protein (CRP), factor VII antigen (VIIa) and prothrombin fragment F1.2 were positively associated with risk of smoking-related cancers, particularly lung cancer. The magnitude of these associations was highest for persistently raised fibrinogen levels. There was, however, substantial confounding by smoking with risk being fully (WBC, CRP and VIIa) or partially (fibrinogen) removed after adjustment. The pooled RRs (95% confidence interval) per one standard deviation increase in fibrinogen levels before and after adjustment for smoking habits were 1.23 (1.12, 1.36) and 1.12 (1.05, 1.20), respectively. The fibrinogen associations were present only among current smokers at entry. The effect of smoking on smoking-related cancers was partly mediated by fibrinogen levels. CONCLUSIONS: Our results are consistent with elevated circulating levels of fibrinogen and F1.2 being predictors of risk of smoking-related cancers. Further research is necessary to clarify whether elevated levels of fibrinogen and F1.2 are causally relevant or simply correlates of the smoking-cancer association.

Long-term association of routine blood count (Coulter) variables on fatal coronary heart disease: 30-year results from the first prospective Northwick Park Heart Study (NPHS-I).

BACKGROUND: Since evidence of a long-term association between routine blood count (Coulter) variables and coronary heart disease (CHD) is inconsistent, the authors analysed white blood cell count (WBC), red blood cell count (RBC), haemoglobin (Hgb), packed cell volume (PCV) and platelet count for their long-term associations with CHD mortality in the first Northwick Park Heart Study (NPHS-I). NPHS-I has follow-up information for >30 years on 2167 White men and 941 White women and holds entry and follow-up data on haematological variables and other known CHD risk factors. METHODS: Proportional hazards Cox models were fitted to estimate rate ratios (RRs) for the separate and joint effects of entry and follow-up Coulter variables. RESULTS: Entry RBC, PCV and Hgb were significant risk factors for CHD mortality after adjustment for gender but only PCV remained significant after adjustment for potential confounders [RR per 1 standard deviation (SD) increase = 1.17, 95% confidence interval (CI) 1.00-1.37]. This effect was partly reduced when the values of 6 years were analysed (RR per 1 SD increase = 1.10, 95% CI 0.93-1.30). No significant gender, smoking or age/time interactions were identified. PCV was the only significant predictor when all Coulter variables were studied jointly. CONCLUSION: PCV was found to predict CHD mortality even after controlling for classical risk factors. This may give some insight into possible mechanisms, such as an influence on thrombin production.

Lifestyle of UK commercial aircrews relative to air traffic controllers and the general population.

INTRODUCTION: Commercial aircrews are exposed to potential occupational hazards and, recently, epidemiological studies have examined their morbidity and mortality relative to the general population. Aircrews are, however, likely to differ from the general population in several respects which may affect the validity of such comparisons. METHODS: A cohort of 17,990 commercial aircrews was identified through the United Kingdom (UK) Civil Aviation Authority medical records and is being followed for morbidity and mortality. Demographic, lifestyle, reproductive, and medical characteristics of commercial aircrews were compared with those of: 1) UK air traffic control officers (ATCOs; N = 3386) identified in a similar way as aircrews; and 2) estimates for the UK general population. RESULTS: Aircrews and ATCOs had similar characteristics, except that sex-age-adjusted prevalences for current smoking, obesity, and hypertension were statistically significantly higher in the latter. Both aircrews and ATCOs differed considerably from the general population with, for instance, much lower sex-age-adjusted prevalences of current smoking, obesity, and hypertension but higher levels of regular physical exercise. Age-adjusted fertility rates among female aircrews and ATCOs were only one-third of those in the general population. These differences were slightly attenuated when comparisons with the general population were restricted to its highest socio-economic stratum. DISCUSSION: The differences between aircrews and the general population are consistent with a strong "healthy worker effect." Aircrews and ATCOs undergo a similar employment selection process and thus taking the latter as the reference population, in addition to the general population, will help to minimize the "healthy worker effect" and gain insight into its biases.