Paternal age and twinning in the Jerusalem Perinatal Study

OBJECTIVE

To investigate whether incidence of twin deliveries is related to father's age, independently of mother's age, and whether it differs for same-sex or opposite-sex twin sets.

STUDY DESIGN

In a program of research on effects of paternal age, this study used data from a prospective cohort of 92,408 offspring born in Jerusalem from 1964 to 1976. Of the 91,253 deliveries in the Jerusalem Perinatal Study, 1115 were twin deliveries. The data were analyzed with General Estimate Equations to inform unconditional logistic regression.

RESULTS

After controlling for maternal age, odds ratios (ORs) and 95% confidence intervals (95% CI) associated with father's ages 25-34 and 35+ were 1.3 (1.1, 1.7) and 1.5 (1.2, 2.1) respectively, compared with fathers <25 years old. The effect of maternal age was partly explained by paternal age. The ORs for opposite-sex twin sets and male-male twin sets increased slightly with paternal age, while the OR for same-sex and female-female twin decreased.

CONCLUSION

Studies of twins are used to estimate effects of genes and environment in a variety of diseases. Our findings highlight the need to consider paternal as well as maternal age when analyzing data on twins to explore etiology of diseases.

Consanguinity and birth defects in the jerusalem perinatal study cohort

BACKGROUND

While parental consanguinity is known to increase the risk of birth defects in offspring, it is hard to quantify this risk in populations where consanguinity is prevalent.

METHODS

To support ongoing studies of cancer and of psychiatric disease, we studied relationships of consanguinity to 1,053 major birth defects in 29,815 offspring, born in 1964-1976. To adjust for confounding variables (geographic origin, social class and hospital), we constructed logistic regression models, using GEE to take into account correlations between sibs. Odds ratios (ORs) and 95% confidence limits were estimated in comparison to a reference group of offspring with grandfathers born in different countries.

RESULTS

With 10.1% of offspring having consanguineous parents, the adjusted OR for major birth defect was 1.41 (1.12-1.74). Offspring of marriages between uncles-nieces, first cousins and more distant relatives showed adjusted ORs of 2.36 (0.98-5.68), 1.59 (1.22-2.07) and 1.20 (0.89-1.59) respectively. For descendents of grandfathers born in the same country, but not known to be related, the OR was 1.05 (0.91-1.21); these showed increased risk associated with ancestries in Western Asia (1.27, 1.04-1.55, p < 0.02) or Europe (1.13, 0.79-1.80).

CONCLUSIONS

A strong association of consanguinity with poverty and low education points to the need to avoid exposure to environmental hazards in these families.

A prospective, randomised study comparing the percutaneous compression plate and the compression hip screw for the treatment of intertrochanteric fractures of the hip

Limited access surgery is thought to reduce post-operative morbidity and provide faster recovery of function. The percutaneous compression plate (PCCP) is a recently introduced device for the fixation of intertrochanteric fractures with minimal exposure. It has several potential mechanical advantages over the conventional compression hip screw (CHS). Our aim in this prospective, randomised, controlled study was to compare the outcome of patients operated on using these two devices. We randomised 104 patients with intertrochanteric fractures (AO/OTA 31.A1-A2) to surgical treatment with either the PCCP or CHS and followed them for one year postoperatively. The mean operating blood loss was 161.0 ml (8 to 450) in the PCCP group and 374.0 ml (11 to 980) in the CHS group (Student's t-test, p < 0.0001). The pain score and ability to bear weight were significantly better in the PCCP group at six weeks post-operatively. Analysis of the radiographs in a proportion of the patients revealed a reduced amount of medial displacement in the PCCP group (two patients, 4%) compared with the CHS group (10 patients, 18.9%); Fisher's exact test, p < 0.02. The PCCP device was associated with reduced intra-operative blood loss, less postoperative pain and a reduced incidence of collapse of the fracture.

A functional and regulatory map of asthma

The prevalence and morbidity of asthma, a chronic inflammatory airway disease, is increasing. Animal models provide a meaningful but limited view of the mechanisms of asthma in humans. A systems-level view of asthma that integrates multiple levels of molecular and functional information is needed. For this, we compiled a gene expression compendium from five publicly available mouse microarray datasets and a gene knowledge base of 4,305 gene annotation sets. Using this collection we generated a high-level map of the functional themes that characterize animal models of asthma, dominated by innate and adaptive immune response. We used Module Networks analysis to identify co-regulated gene modules. The resulting modules reflect four distinct responses to treatment, including early response, general induction, repression, and IL-13-dependent response. One module with a persistent induction in response to treatment is mainly composed of genes with suggested roles in asthma, suggesting a similar role for other module members. Analysis of IL-13-dependent response using protein interaction networks highlights a role for TGF-beta1 as a key regulator of asthma. Our analysis demonstrates the discovery potential of systems-level approaches and provides a framework for applying such approaches to asthma.

Television viewing and obesity: a prospective study in the 1958 British birth cohort

OBJECTIVE

To assess whether frequency of television viewing in adolescence (11 and 16 years) or early adulthood (23 years) affected subsequent changes in body mass index (BMI) through to mid-adulthood life, and waist-hip ratio in mid-adulthood.

SUBJECTS

The 1958 British birth cohort includes all births in 1 week in March 1958 in England, Scotland and Wales. The main analyses included at least 11 301 participants. Outcome measures included BMI at 16, 23, 33 and 45 years and waist-hip ratio at 45 years.

RESULTS

Watching television 'often' at 16 years (but not 11 years) was associated with a faster gain in BMI between 16 and 45 years in males (0.011 kg m(-2) per year, 95% confidence interval (CI) 0.003, 0.019) and females (0.013 kg m(-2) per year, 95%CI 0.003, 0.023). More frequent television viewing at 11, 16 and 23 years was associated with a faster gain in BMI between 23 and 45 years in females, but not in males. Television viewing at 23 years was associated with waist-hip ratio at 45 years: participants watching > or = 5 times per week had a waist-hip ratio 0.01 higher than those watching less often. At 45 years, those watching television for > or = 4 h day(-1) had a waist-hip ratio 0.03-0.04 higher than those watching for <1 h day(-1).

CONCLUSIONS

More frequent television viewing in adolescence and early adulthood is associated with greater BMI gains through to mid-adulthood and with central adiposity in mid-life. Television viewing may be a useful behaviour to target in strategies to prevent obesity.

Physical activity, television viewing and body mass index: a cross-sectional analysis from childhood to adulthood in the 1958 British cohort

OBJECTIVE

To investigate relationships between frequency of physical activity or television viewing and body mass index (BMI) cross-sectionally at six ages from childhood to adulthood, to better understand longitudinal relationships. To investigate how the relationships vary with age and gender and whether any relationships are due to confounding factors.

METHODS

The 1958 British birth cohort includes all births (approximately 17 000) in one week in March 1958. BMI and physical activity frequency were recorded at 11, 16, 23, 33 and 42 y and television viewing frequency at 11, 16 and 23 y. A total of 11 109 subjects provided BMI and activity data at 42 y. Relationships between BMI and (in)activity were investigated using linear regression.

RESULTS

At ages 11, 33 and 42 y in both sexes and at 23 y in female subjects, those who were more active had lower BMIs, and the relationships strengthened with age. At 42 y, the most active had a lower mean BMI than the least active, by 0.83 kg/m2 in men, and 1.03 kg/m2 in women. BMI and activity were unrelated at 16 y in female subjects, and 23 y in male subjects. At 16 y in males, the most active males had a mean BMI 0.25 kg/m2 higher than the least active. At 11 y in female subjects and 23 y in both sexes, those who watched television most frequently had higher BMIs. BMI and television viewing were unrelated at 11 y in males and at 16 y in both sexes. Relationships between BMI and activity or television viewing were largely unexplained by potential confounding factors.

CONCLUSIONS

The relationship between BMI and physical activity changes with age. In early adolescence and in adulthood, a higher activity level, or lower frequency of television viewing was associated with a lower BMI. In later adolescence (16 y), television viewing and activity were unrelated to BMI, except for an unexpected BMI-activity relationship in males. We suspect this relationship in males is primarily due to selection effects, whereby physically bigger boys, with a larger BMI, are more likely to take part in exercise activity, and possibly also to BMI being a less accurate predictor of fatness in adolescent boys.

Possible association of the human KCNE1 (minK) gene and QT interval in healthy subjects: evidence from association and linkage analyses in Israeli families

QT interval prolongation is associated with increased risk of sudden and non-sudden cardiac death. Potassium channel gene variants are associated with inherited long QT syndromes. Using linkage and association analyses, we investigated whether variants in the potassium channel subunit KCNE1 are associated with QTc intervals in an unselected population sample of 80 kindreds living in kibbutz settlements in Israel. Variance-component linkage analysis revealed weak evidence of linkage of KCNE1 polymorphisms with QTc intervals. Family-based association analysis showed a significant association between the G38S polymorphism and QTc interval. Further quantitative trait association analysis demonstrated a significant residual heritability component (h(2)= 0.33), and that the effect of the G38S variant allele is modified by gender. Estimated maximum likelihood parameters from these models indicated that male gender, age, hypertension, diabetes, hypercholesterolemia, fibrinogen and BMI were positively associated with QTc interval; level of education and cigarette smoking showed an inverse association. Both erythrocyte membrane n-6 and n-3 fatty acids showed a significant inverse association with QTc interval. While more than 15.8% of QTc variability was contributed by covariates, another 4.7% was explained by dietary factors, the G38S polymorphism explained 2.2%, and approximately 36% was explained by polygenes. An in silico analysis showed also that the novel V80 SNP, another KCNE1 synonymous variant, abolishes the recognition for a splicing enhancer, which may lead to an increased effect of the G38S mutation. These results demonstrate that, in addition to polygenic background, dietary factors and other covariables, the KCNE1 G38S variant is involved in determining QTc levels in this population-based sample of families.

Does one's own and one's spouse's education affect overall and cause-specific mortality in the elderly?

OBJECTIVES

To examine educational gradients in overall and cause-specific mortality among elderly married men and women and their spouses.

METHODS

Using the census-based Israel Longitudinal Mortality Study (1983-92), 13 573 married men and 6563 married women were identified who were aged 70-89 years at baseline. Cox proportional hazard models were used to assess the strength of the association between education and overall and cause-specific mortality.

RESULTS

Educational gradients for own and spouse's mortality varied by gender and cause of death. In particular, in relation to cardiovascular disease, men married to uneducated wives experienced elevated mortality risks [hazard ratio (HR) = 1.30; 95% confidence interval (95% CI) 1.11-1.52]. Women were generally unaffected by their husband's education, except for those who died from non-breast cancer, for whom husband's low education had a harmful effect (HR = 1.98; 95% CI 1.26-3.11).

CONCLUSIONS

Mortality among elderly married persons is associated with one's own and one's spouse's educational achievement. Research using partner's education as a proxy for one's own attainment may be omitting valuable information regarding these and other health risks.

Adolescent drinking level and adult binge drinking in a national birth cohort

AIMS

To assess (i) continuities in binge drinking across adulthood and (ii) the association between adolescent drinking level and adult binge drinking.

DESIGN

Population-based prospective birth cohort.

SETTING

England, Scotland and Wales.

PARTICIPANTS

All births during one week in March 1958 (n = 8520 in analysis).

MEASUREMENTS

Alcohol consumption reported at 16, 23, 33 and 42 years. Binge drinkers were identified by dividing number of units of alcohol consumed in the last week by usual drinking frequency, with limits of >/=10 units/occasion for men and >/=7 for women.

FINDINGS

Four in five cohort members drank alcohol at least twice a month. Prevalences of binge drinking at 23, 33 and 42 years among men were 37%, 28% and 31% and among women 18%, 13% and 14%. Most binge drinkers in adulthood changed drinking status during this period. Nevertheless, binge drinking at age 23 increased the odds of binge drinking at 42 years: odds ratio (OR) 2.10 (95% CI 1.85, 2.39) for men; OR 1.56 (95% CI 1.29,1.89) for women. Women who rarely or never drank aged 16 were less likely than light drinkers (0-2 units/week) to binge drink as adults, OR at 23 years 0.65 (95% CI 0.55, 0.77). Men who were heavier drinkers (>/=7 units/week) at 16 years were more likely than light drinkers to binge drink throughout adulthood; at 42 years, OR 1.64 (95% CI 1.33, 2.08).

CONCLUSIONS

Binge drinking is common in British men and women throughout adulthood with continuities between the 20s and 40s. Adolescent drinking has a modest although important association with adult binge drinking.

Paula method of circular muscle exercises for urinary stress incontinence—a clinical trial

The aim of this study was to determine the efficacy of the Paula method of circular muscle training in the management of stress incontinence (SI). The theory behind this method states that activity of distant sphincters affects other muscles. In a pilot study, 59 women, mainly hospital employees, were randomly assigned to participate in exercises according to the Paula method or pelvic floor training. Efficacy was measured by reports of incontinence, quality of life (I-QOL), pad test, and pelvic floor muscle strength (assessed by perineometer and digital examination). Both the Paula exercises and pelvic floor training produced significant changes in urinary leakage compared to baseline as measured by the pad test [mean decrease of 5.4 g (p=0.002) and 9.5 g (p=0.003), respectively]. Women randomized to the Paula method reported improvement in I-QOL scores. The Paula method was found to be efficacious for SI in a population of Israeli women. Larger community-based studies will be required to confirm these results and enable evaluation of between-group differences.

Are inequalities in height narrowing? Comparing effects of social class on height in two generations

OBJECTIVE

To determine whether social inequalities in height change across generations.

METHODS

The target population was from the 1958 British birth cohort, all born 3rd-9th March 1958, followed to 1991, and the offspring of one third of this population. Main outcomes were height measured at 7, 11, 16, and 33 years (cohort members) and once at 4-18 years (offspring). Multilevel models applied to associations of social class of origin with (a) child-to-adult growth trajectory (cohort members), (b) height (offspring), and (c) generational height increment.

RESULTS

Height inequalities were observed among cohort members, with differences >2.0 cm at all ages between classes I and II, and IV and V. By adulthood, the difference in mean height had declined significantly in boys and slightly in girls. A secular trend was seen between the two generations. While male offspring had a similar mean height to their fathers in classes I and II, boys in classes IV and V gained 2.1 cm (p<0.001). Height gains of female offspring were evident in all classes, with a greater gain in classes IV and V (non-significant). The social class effect on height was weaker among offspring, with a difference between classes I and II, and IV and V of less than 1 cm.

CONCLUSIONS

Social inequalities in height observed among the cohort weakened substantially in the next generation due to a greater height gain among offspring from manual classes. Inequalities in childhood height have narrowed between the two generations in this study.

Changes in diet and physical activity in the 1990s in a large British sample (1958 birth cohort)

OBJECTIVES

To investigate whether adults studied in 1991 and 1999 (at ages 33 and 42 y) improved their diet and their physical activity level, in the direction of recommendations issued during the same period.

DESIGN

Longitudinal 1958 British birth cohort study.

SETTING

England, Scotland and Wales.

PARTICIPANTS

All births, 3rd-9th March, 1958. A minimum of 11 341 participants provided data at 33 y, 11 361 at 42 y.

MAIN OUTCOME MEASURES

Frequency of leisure time activity and consumption of (i) fried food, (ii) chips, (iii) wholemeal bread and (iv) fruit and salad/raw vegetables, at 33 and 42 y.

RESULTS

Most people changed their physical activity and dietary habits over the 8-y period. About a third of men and women increased, and a third decreased their activity frequency. Findings for fried food consumption were similar. A significantly greater proportion of cohort members decreased their chips consumption (32%), rather than increased it (17%) and increased their fruit and salad consumption (30%), rather than decreased it (25%). In all, 26% of men and 33% of women consistently ate, or switched to eating mostly wholemeal bread, while 56% of men and 48% of women consistently ate less or switched to eating less. Social gradients were seen for activity and diet in 1991, but associations between social factors or body mass index and change in activity or diet were inconsistent.

CONCLUSIONS

Lifestyle habits such as dietary intake and physical activity are slow to change. Current health promotion strategies may need to be supplemented with additional methods to affect the desired change in these habits.

Combination of low birth weight and high adult body mass index: at what age is it established and what are its determinants?

OBJECTIVE

To investigate growth trajectories and predictive factors for those with low birth weight and high adult BMI.

DESIGN

Birth cohort study.

SETTING

England, Scotland, and Wales.

PARTICIPANTS

All born 3-9 March, 1958.

MAIN OUTCOME MEASURES

People at "high risk" of adult disease were defined as having a combination of lower birth weight (in the lowest third of the distribution) and high BMI (in the highest third of the distribution at age 33).

RESULTS

284 of 3462 men and 338 of 3555 women were identified as "high risk". This group was shorter than other cohort members at age 7, on average by 1.2 cm (boys) and 1.8 cm (girls), with a deficit of about 3 cm in adult height. The "high risk" group had a similar mean weight to other subjects at age 7, but were heavier thereafter through to age 23. BMI was increased at all ages in the "high risk" group. Independent predictors include paternal BMI, maternal height and smoking in pregnancy, and social class. For each SD increase in father's BMI the odds of low birth weight/high BMI increased by about 20%. For maternal height, a 1 cm increase reduced the odds of low birth weight/high BMI by about 5%. Increased ORs for "high risk" were found for those with manual social origins (1.61 for men; 1.49 for women) and for maternal smoking in pregnancy (1.79 and 2.27 respectively).

CONCLUSIONS

Maternal short stature, low social class, and smoking during pregnancy influence the development of "high risk" for adult chronic disease. The causes of high risk therefore seem to reside in utero and even earlier, in the mother's lifetime, with adverse conditions having a detrimental affect and favourable conditions protecting against high risk.

Improved neutron detection by gamma-ray spectroscopy

Most high-efficiency interactions for neutron detection are with thermal neutrons, and the detection of the prompt gamma radiation emitted as a result of thermal neutron absorption in specific materials was sometimes used. These materials are named converters, the most widespread being 10B, 113Cd or 73Ge (the last two materials are detector materials themselves for CdZnTe and HPGe detectors). However, for these materials, the main gamma-ray energies are relatively low (in the region 473-600 keV), and there are interferences from other gamma rays present in background. Different combinations of moderator-converter-detector systems were employed to optimise the system efficiency and signal-to-background ratio, using B, Cd, Gd and Cl converters and HPGe, NaI(Tl) and BGO detectors. When using a Cl converter, the 1164.7 keV peak seems to be a good choice when a HPGe spectrometer is used. A very practical material containing chlorine is PVC.

Cigarette consumption and socio-economic circumstances in adolescence as predictors of adult smoking

AIM

To investigate effects of cigarette consumption level and socio-economic circumstances during adolescence on adult smoking.

METHODS

1958 British birth cohort (all births 3-9 March 1958). Logistic regression used to predict (i) smoking at 41 years and (ii) persistent smoking (at 23, 33 and 41 years) from cigarette consumption and socio-economic circumstances at 16 years, indicated by social class and educational qualifications.

RESULTS

Of 6537 subjects with full smoking history, 30% smoked at 16 years, 23% smoked at 41 years and 19% smoked at 23, 33 and 41 years (persistent smokers). Heavier smokers at 16, 23 and 33 years were more likely to smoke at 41 years than lighter smokers. The odds ratio (OR) of smoking at 41 years was 2.5 for men and 3.0 for women who smoked >/=60 cigarettes/week at age 16, relative to <20 cigarettes/week. Subjects from manual social backgrounds and those with no qualifications had elevated risks of being a smoker at 41 years or a persistent smoker. These effects were robust to adjustment for adolescent consumption level (e.g. adjusted OR for no qualifications was 3.8). However, adolescent consumption level modified the effect of educational achievements. Among lighter adolescent smokers, those gaining higher qualifications had lower prevalence of smoking at 41 years (16%) than men with no qualifications (83%); among heavier adolescent smokers, prevalence was more similar for subjects with higher (56%) and no qualifications (69%).

CONCLUSIONS

Socio-economic background appears to influence adult smoking behaviour separately from adolescent cigarette consumption which is a recognized measure of nicotine dependence. There was some evidence that effects of early nicotine dependence are modified by educational achievements.

Probabilistic reasoning and clinical decision-making: do doctors overestimate diagnostic probabilities?

BACKGROUND

The "threshold approach" is based on a physician's assessment of the likelihood of a disease expressed as a probability. The use of Bayes' theorem to calculate disease probability in patients with and without a particular characteristic, may be hampered by the presence of subadditivity (i.e. the sum of probabilities concerning a single case scenario exceeding 100%).

AIM

To assess the presence of subadditivity in physicians' estimations of probabilities and the degree of concordance among doctors in their probability assessments.

DESIGN

Prospective questionnaire.

METHODS

Residents and trained physicians in Family Medicine, Internal Medicine and Cardiology (n = 84) were asked to estimate the probability of each component of the differential diagnosis in a case scenario describing a patient with chest pain.

RESULTS

Subadditivity was exhibited in 65% of the participants. The total sum of probabilities given by each participant ranged from 44% to 290% (mean 137%). There was wide variability in the assignment of probabilities for each diagnostic possibility (SD 16-21%).

DISCUSSION

The finding of substantial subadditivity, coupled with the marked discordance in probability estimates, questions the applicability of the threshold approach. Physicians need guidance, explicit tools and formal training in probability estimation to optimize the use of this approach in clinical practice.

Infant feeding and obesity through the lifecourse

In the 1958 British birth cohort (n = 12,857 at age 7), breast feeding and BMI were unrelated in childhood. Breast feeding was protective against increased BMI at ages 16 and 33 years in females, and at 33 years in males, but this effect was markedly reduced and no longer significant after adjustment for confounding factors.

Child to adult socioeconomic conditions and obesity in a national cohort

OBJECTIVE

Critical stages in childhood are suspected for adult obesity. We sought to identify (i) whether risk of adult obesity is influenced by childhood socioeconomic conditions in addition to those in adulthood; and (ii) whether conditions in childhood act independently or through their association with education or parental obesity.

DESIGN

Longitudinal, 1958 British birth cohort.

SUBJECTS

A total of 11 405 men and women followed to age 33 y.

MEASUREMENTS

Social class at birth and ages 7, 11, 16, 23 and 33 y. Obesity (BMI> or =30) at age 33 y.

RESULTS

Social class was related to obesity, cross-sectionally at ages 16 (women), 23 and 33 y, but not at younger ages. In analysis of adult obesity (age 33 y) and social class at five life stages, class at age 7 y significantly predicted obesity for women (adjusted odds ratio (OR)=1.31, that is, the odds increased by 31% for each decrease in social class). For men, class at birth and age 23 y predicted adult obesity (adjusted OR=1.19 and 1.16, respectively). Education was also associated with adult obesity, increasing the odds by 30% (men) and 35% (women) for each decrease in qualification level. Adjustment for education level and parental BMI did not abolish the effect on adult obesity of class at age 7 y among women, nor of class at birth among men, while class at age 23 y reduced to borderline significance.

CONCLUSIONS

Cross-sectional associations for social class and obesity can be misleading and obscure effects of childhood socioeconomic conditions. Influences around birth to age 7 y have a long-lasting impact on the risk of adult obesity.

Industry-sponsored research on the potential health and environmental effects of selected brominated flame retardants

Modern fire-fighting techniques, equipment and fire-resistant building design has lead to less destruction than in the previous centuries. However, a high fuel load in either a residence or a commercial building can overwhelm even the best firefighters or building construction, and factors affecting the fuel load have changed in recent decades. The fire load in a typical home has doubled over the last 50 years, furnishings typically include those made of petrochemicals that can behave as if containing built-in accelerant, and modern energy-efficient buildings are less able to disperse heat in the event of a fire. Flame retardant chemicals (FRs) are one means used to reduce the risk of fire. FRs are typically added or incorporated chemically into a polymer to slow or hinder the ignition or growth of a fire in low-to-moderate cost commodity polymers. One type of FR contains bromine atoms as the active moiety. The FR industry, either as individual companies or as consortia, has conducted a broad range of studies on the commercial deca-, octa- and pentabromodiphenyl oxide/ether, tetrabromobisphenol A and hexabromocyclododecane products. These five products have data in excess of the OECD Screening Informational Data Set (SIDS) and the U.S. High Production Volume (HPV) program, and sufficient data for the performance of formal EU risk assessments. The objective of this paper is to present the range of data developed by industry consortia and to provide sources for the information. We hope to facilitate further research by assembling references to industry consortia-sponsored research here.