Search PubMed⌕ Search

Biomedical subjects

C Hertzman

Publications and source records attributed to C Hertzman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Variation by body mass index and age in waist-to-hip ratio associations with glycemic status in an aboriginal population at risk for type 2 diabetes in British Columbia, Canada.

BACKGROUND: It is unclear whether obesity and age modify or confound relations between abdominal adiposity and metabolic risk factors for type 2 diabetes. OBJECTIVE: Our objective was assess the consistency of relations between abdominal adiposity and glycemic variables across discrete categories of obesity and age. DESIGN: We performed a stratified analysis of prevalence data from a rural screening initiative in British Columbia, Canada. Subjects were Salishan Indians, all healthy relatives of individuals with type 2 diabetes [n = 151; age: 18-80 y; body mass index (BMI, in kg/m2): 17.0-48.2]. We measured waist-to-hip ratio (WHR) (2 categories); insulin, glycated hemoglobin (Hb A1c), and 2-h glucose concentrations (2 categories); and BMI (4 categories). BMI and age-specific odds ratios (ORs) and 95% CIs were calculated. RESULTS: WHR-glycemic variable relations were not consistent across BMI and age strata. Risks associated with high WHR were: for persons with BMIs from 25 to 29, elevated insulin (OR: 6.71; 95% CI: 1.41, 34.11) and Hb A1c (OR: 16.23; 95% CI: 2.04, 101.73) concentrations; for persons aged 18-34 y, elevated insulin concentrations [OR: indeterminate (+infinity); 95% CI: 1.89, +infinity]; and, for persons aged 35-49 y, elevated Hb A1c (OR: +infinity; 95% CI: 3.17, +infinity) and 2-h glucose (OR: 9.15; 95% CI: 1.74, 59.91) concentrations. CONCLUSIONS: WHR discriminates risk of type 2 diabetes in overweight but not obese individuals. Abdominal adiposity is associated with elevated insulin concentrations in younger age groups and with impaired glucose control in middle-aged groups, suggesting metabolic staging by age on a continuum from insulin resistance to impaired glucose tolerance.

Adipose Tissue↗
PubMed1999

Socioeconomic status and cardiovascular risk factors in the Czech Republic.

BACKGROUND: In western countries, prevalence of cardiovascular diseases and most risk factors is higher in lower socioeconomic groups. The social gradients in the former communist societies are less well known. Because in western countries different indicators of socioeconomic status (SES) are correlated, this gradient is found with a number of different measures of SES. We have analysed the presence and magnitude of the socioeconomic gradient in cardiovascular risk factors in a former communist country. As the relationship between material conditions and education has been much weaker than in the west, we have also attempted to separate their effects. METHODS: A cross-sectional survey examined a random sample of men and women resident in six Czech districts participating in the MONICA study in 1992. Participants completed a questionnaire, underwent anthropometric and blood pressure measurements, and provided a blood sample. Two indicators of SES were used: education and material conditions, the indicator constructed from car ownership and crowding. Linear regression was employed to analyse the relation between SES and total and high-density lipoprotein (HDL) cholesterol, body mass index (BMI), waist-hip ratio (WHR) and height. Logistic regression was used to assess the association between SES and smoking and hypertension. RESULTS: A total of 1141 men and 1212 women (overall response rate 75%) participated in the study. After controlling for age, all risk factors were associated with education, except HDL cholesterol in women and BMI in men; only smoking in both sexes and WHR in women and height in men were significantly related to material conditions. In mutually adjusted analyses, educational gradients persisted but associations with material conditions disappeared or became substantially weaker. The magnitude of the educational differences was similar to those found in western countries. CONCLUSIONS: Socioeconomic differences in cardiovascular risk factors in Czech Republic in 1992 had the same direction and similar magnitude as in Western Europe, and were strongly related to education rather than material conditions. Materialist explanations for the social differences seem unlikely in this population.

Adult↗
PubMed1999

The biological embedding of early experience and its effects on health in adulthood.

Explanations of the socioeconomic gradient in health status must account for the observations that the gradient cuts across a wide range of disease processes and is capable of replicating itself on new disease processes as they emerge in society. Understanding this pattern requires an understanding of how human organisms can become generally vulnerable or resilient to disease over time: a huge collation task across different disciplines. The hypothesis that best fits current evidence is that the gradient is an "emergent property" of the interaction between the developmental status of people and the material and psychosocial conditions they encounter over their life course. Within this broad formulation, special attention is given to child development, and the prospect that socioeconomic differences in the quality of early life experiences contribute to subsequent gradients in health status through socioeconomic differences in brain sculpting and the conditioning of host defense systems that depend on communication with the developing brain. The contribution to the gradient in health is theorized to occur through a combination of latent effects, pathway effects, and cumulative disadvantage.

Adult↗
PubMed1999

Mortality rates after cataract extraction.

Senile cataract may be a marker of generalized tissue aging. We examined this hypothesis using population-based linked health data. We hypothesized that any such association would diminish with increased use of cataract surgery. Mortality rates of those 50-95 years of age undergoing cataract surgery in British Columbia during either 1985 or 1989 were compared with the provincial population of comparable age who did not undergo cataract surgery during the study period. The 1985 cohort included 8,262 patients undergoing surgery and a comparison population of 804,303, and the 1989 cohort included 11,952 patients and a comparison population of 839,393. Using Cox regression, for the 1985 cohort, the hazard ratios for dying during follow-up were 3.2 for males 50-54.9 years of age [95% confidence limits (CL) = 2.0, 5.0] and 3.3 for females (95% CL = 1.9, 5.7). Hazard ratios for older age groups decreased with age. We also fit an additive risk model that produced excess mortalities that were less age dependent. In the 1985 analysis, these ranged from +7.1 per 1,000 (95% CL = +0.44, +13.76) to +20.3 (95% CL = +13.24, +27.36) for males and -17.5 (95% CL = -28.28, -6.72) to +2.0 (95% CL = -2.12, +6.12) for females. Findings for the 1989 analyses were similar, indicating that the association between cataracts and generalized aging remained constant despite a large increase in the use of cataract surgery.

Age Distribution↗
PubMed1998

Socioeconomic status, mortality, and the development of cataract at a young age.

It has been hypothesized that senile cataract may serve as a marker for generalised tissue aging, since structural changes occurring in the proteins of the lens during cataract formation are similar to those which occur elsewhere as part of the aging process. An earlier analysis we carried out to test this hypothesis revealed a strong age-dependent relationship between undergoing cataract surgery and subsequent mortality. Relative risks for dying over 9 yr of follow-up were particularly increased for individuals who had developed cataract requiring operation between the ages of 50-65. This finding prompted us to test the hypothesis that younger patients undergoing surgery for cataract (those in which surgery was undertaken at 50-65 yr of age) would tend disproportionately to be resident in areas of generally lower socioeconomic status. A population-based linked health data resource containing data on all hospital separations in the province of British Columbia was used to examine this hypothesis. Linkage to Canadian census data was used to assign a socioeconomic decile to the area of residence for all individuals in British Columbia who either did, or did not, undergo cataract surgery over a 3 yr period, and were aged 50-95. Relative to those who resided in the highest socioeconomic areas, odds ratios for undergoing cataract surgery between 50 and 65 yr of age were significantly greater than 1 for the four lowest socioeconomic deciles. This association was observed despite a conservative bias in our setting that favoured those of higher socioeconomic status tending to receive earlier treatment. The results of this ecologic study prompt consideration of whether factors which have the dual attributes of being correlates of socioeconomic status and implicated in the development of cataract may play a role in mediating the processes involved in the well known association of socioeconomic status and mortality.

Age Factors↗
PubMed1998

Gender, work roles and psychosocial work characteristics as determinants of health.

This paper aims to identify gender similarities and differences in psychosocial work characteristics for those in and out of paid employment, to inform research on possible health-related effects. Specifically five questions are addressed: do women report poorer work characteristics than men; are gender differences related to specific characteristics; do work characteristics differ between full- and part-time women workers and between those in paid and unpaid work; are socio-economic gradients in work characteristics similar for men and women; and, if there are gradients, do they differ between women in paid and unpaid work? Analyses are based on the 33 year follow-up of the 1958 British birth cohort. Four psychosocial work characteristics were examined: learning opportunities, monotony, pace of work, and flexibility of breaks. Women reported more negative work characteristics than men, primarily because of differences in learning opportunities (26% lacked opportunity compared with 13% of men) and monotonous work (47 and 31% respectively). Women in full-time employment reported fewer negative characteristics (27%) than part-time (39%) or home-workers (36%). Home-workers had fewer opportunities for learning (36%) and greater monotony (49%) than paid workers (21 and 22% respectively), however fewer home-workers reported inability to control the work pace (11% compared to 23%) and inflexibility of breaks (21% compared to 47%). Socio-economic gradients in work characteristics were similar among men and women, except for flexibility of break times. A socio-economic gradient in work characteristics was found for full- and part-time workers, but not among home-workers. Differences in self reported health were also examined: a social gradient was found for all employment status groups, being strongest for home-workers despite the absence of a gradient in negative work characteristics. In conclusion, these marked gender differences in psychosocial work characteristics need to be considered in future research on work and health.

Adult↗
PubMed1998

Socioeconomic factors, perceived control and self-reported health in Russia. A cross-sectional survey.

Russia has the lowest life expectancy among industrialised countries, but little is known about other health outcomes and determinants of health in the Russian population. Here we report a cross-sectional study in a national sample of the Russian population of social and psychosocial determinants of two self-reported health indicators: self-rated health (shown to predict mortality in prospective studies) and physical functioning (validated against more objective health measures). A multi-stage sample of the Russian population aged 18 years and more was interviewed (n=1599, response rate 66%). The questionnaire included political attitudes, social and economic circumstances, psychosocial factors, smoking, alcohol consumption, self-rated health and physical functioning (from the SF36 instrument). Scores of perceived control over life and over one's health were calculated from 6 and 3 questions, respectively. Data were analysed in logistic regression for two dichotomised outcomes: poor self-rated health (worse than average) and low physical functioning (less than 60% of maximum). Overall, 25% of subjects rated their health as worse than average; this is substantially more than in western countries. Perceived control over life was strongly related to both outcomes; age- and sex-adjusted OR for 1 standard deviation increase in control were 0.60 (95% CI 0.52-0.69) for poor self-rated health and 0.67 (0.57-0.81) for low physical functioning. Adjustment for a battery of other factors reduced these estimates only slightly. Associations between control over one's health and both outcomes were also significant, but weaker and attenuated in multivariate models. Material deprivation was also strongly related to both outcomes. Education was inversely related to self-rated health, and unmarried men reported poor physical functioning substantially more often. Subjects not approving the economic changes reported poorer health but this association was removed by adjustment for socioeconomic factors and control. Subjects who could not rely on informal social structures when in problems reported worse health; this effect largely persisted in multivariate analyses. These results are consistent with the hypothesis that poor health status in Russia is related to dysfunction of social structures, socioeconomic deprivation, and lack of perceived control. The absence of informal social networks, vital for maintaining general welfare, seems to affect adversely self-rated health. Deprivation and low perceived control may be important mediators between the broad social environment and health in populations undergoing transition and can provide a useful framework for many biological and behavioural factors. Prospective studies are needed to address the issue of temporality and reporting bias, the major problems in interpreting these findings.

Activities of Daily Living↗
PubMed1998

Association between psychosocial factors at work and nonfatal myocardial infarction in a population-based case-control study in Czech men.

We examined the effect of decision latitude and work demand on risk of myocardial infarction in a former Soviet Bloc country and analyzed whether these factors contributed to the educational gradient in myocardial infarction in this population. We conducted a case-control study among full-time working men in the general population of five districts of the Czech Republic. Cases were 179 men 25-64 years of age with a first nonfatal myocardial infarction diagnosed in selected districts over a 1-year period, and controls were 784 men in the same age group randomly selected from the population register. We used logistic regression to estimate the odds of developing myocardial infarction in relation to self-reported work demand and decision latitude at work and the contribution of these factors as well as standard risk factors to socioeconomic differences in the risk of myocardial infarction. Cases reported lower decision latitude and lower work demand than controls. Age-adjusted odds ratios for the highest vs lowest quartiles of decision latitude and work demand were 0.43 (95% confidence interval = 0.25-0.75) and 0.54 (95% confidence interval = 0.31-0.93), respectively. Further adjustment for coronary risk factors and education did not change these estimates. Decision latitude accounted for part of the association between education and myocardial infarction, and decision latitude and risk factors jointly explained virtually all of it. The association between decision latitude at work and myocardial infarction found in our study is consistent with research in western populations and may partly explain the socioeconomic gradient in myocardial infarction.

Adult↗
PubMed1998

Fertility among a cohort of male sawmill workers exposed to chlorophenate fungicides.

The purpose of this study was to determine whether exposure to chlorophenate fungicides and their dioxin contaminants is associated with male infertility among sawmill workers. The study was conducted using fertility data compiled from 26,487 sawmill workers in 14 British Columbian sawmills. Our analysis was restricted to workers who had been employed for at least 1 continuous year between 1950 and 1985 and to live-births born at least 1 year after the initiation of employment in the period 1955-1988. We assessed fertility trends by internal comparison using Mantel-Haenszel rate ratios and by calculating standardized fertility ratios using an external and an internal reference population. We identified 19,684 births in the study period. Initially, both external and internal analyses showed that sawmill workers from mills using chlorophenates had lower fertility than workers employed in mills not using chlorophenates. After controlling for time since first hire, however, we found no inverse relation between cumulative exposure to chlorophenate fungicides and fertility. Based on the results of our study, there is little evidence for a reduction in fertility among chlorophenate-exposed sawmill workers in British Columbia. The analyses indicate the importance of time since hire as a potentially strong confounder in this type of investigation.

Adult↗
PubMed1997

Social and biological pathways linking early life and adult disease.

Evidence is presented for a pathways model linking early life factors and adult disease, which takes account of the inter-relationships between social and biological risks throughout the lifecourse. Few studies, if any, have yet recorded adequate birth to death information which could be used to quantify the effects of different factors and their timing. Hence, there is only limited understanding of the extent to which biological and social risks experienced at different life stages combine to influence adult disease. However, some of the pathways between early and later life are suggested when evidence from earlier stages of the lifecourse is linked to that from studies at older ages, in which adult disease risk factors have been established. Further support for pathway effects is provided by studies showing that health outcomes of early biological insults can depend on the subsequent social and biological environment. Thus, it is argued that adult disease will be more fully understood when account is taken of the combined effects of social and biological risk occurring at different life stages.

Adolescent↗
PubMed1997

Searching for the biological pathways between stress and health.

Population-based, person-specific health surveys, with concomitant biological measures, should provide important information about the processes by which socioeconomic and psychosocial factors embed themselves in human health. Questionnaire responses allow for assessment of the perceived psychosocial environment, but biological measurements will measure the status of the psychoneuroimmunology/ psychoneuroendocrinology (PNI/PNE) pathways and may allow us to identify people who have "adapted" to their stress because of experience, expectations, stoicism, etc. This review sets criteria to evaluate potential physiological markers of chronic stress. Because population health surveys involve a massive number of samples, special consideration must be given to the laboratory analysis method and transportation time of the markers chosen. We reviewed five areas: glycosylated proteins, the immune system, hemostasis peripheral benzodiazepine receptors, and the waist-hip ratio.

Biomarkers↗
PubMed1997

Mortality and cancer incidence among sawmill workers exposed to chlorophenate wood preservatives.

OBJECTIVES: This study examined the association between exposure to chlorophenates and the risk of soft tissue sarcoma; non-Hodgkin's lymphoma; Hodgkin's disease; and cancers of the lung, nose, and nasopharynx. METHODS: A retrospective cohort study was conducted of 26487 workers employed for at least 1 year between 1950 and 1985 in 11 chlorophenate-using and 3 non-using sawmills in British Columbia, Canada. Exposures by job were ascertained with interviews of senior employees. RESULTS: Probabilistic record linkage to the Canadian Mortality Data Base and the British Columbia Cancer Registry found 4710 deaths between 1950 and 1990, and 1547 incident cases of cancer between 1969 and 1989. None of the cancers of interest had elevated mortality related to chlorophenate exposure. Non-Hodgkin's lymphoma incidence (n = 65) increased with increasing chlorophenate exposure hours, yielding the following standardized incidence ratios: less than 120 hours 0.68; 120 to 1999 hours, 0.59; 2000 to 3999 hours, 1.04; 4000 to 9999 hours, 1.02; and 10000 or more hours, 1.30. CONCLUSIONS: These results are consistent with the borderline positive associations seen in other recently reported studies of chlorophenate-exposed workforces.

British Columbia↗
PubMed1997

Social differences in health: life-cycle effects between ages 23 and 33 in the 1958 British birth cohort.

OBJECTIVES: The purpose of this study was to determine whether social differences in health persist or widen during early adulthood. METHODS: A longitudinal follow-up of the 1958 British birth cohort was investigated, using social class at birth and six health measures at ages 23 and 33. A slope of inequality was estimated to represent social differences in health. RESULTS: Social gradients in health were evident by age 23: the prevalence of poor health increased with decreasing social position. This was observed for several but not all health indicators. Social gradients persisted to age 33. The slope of inequality was greatest for malaise (odds ratio [OR] = 3.37 for men, 3.21 for women) and obesity (OR = 4.80 for men and 2.84 for women), both at age 23, and for self-rated health in women at age 23 (OR = 2.94) and age 33 (OR = 3.22). Inequality increased significantly between ages 23 and 33 for limiting illness in men, and lessened, although not significantly, for malaise, overweight, and obesity; social gradients remained constant for self-rated health, respiratory symptoms, and asthma or wheezing. CONCLUSIONS: Social gradients in health evident in this sample by age 23 persisted to age 33. Inequalities did not appear to widen consistently, but variable findings for several health measures suggest that inequalities reproduce through different pathways.

Adult↗
PubMed1996

Reliability of retrospective chlorophenol exposure estimates over five decades.

For a cohort study of chlorophenate-exposed sawmill workers, historical exposures from the 1940s to the 1980s were estimated by teams of 9-20 employees (each interviewed individually). The mill histories were divided into eras when jobs and exposures were relatively stable. Raters with at least 5 years of work experience in an era were asked to estimate the frequency and duration of exposure for each job in the mill. Reliability measures for these estimates were calculated for each of the 39 mill and time period combinations, using the individual intraclass correlation coefficient (ICCind) to assess agreement between raters and the group intraclass correlation coefficient (ICCgroup) to assess the stability of the mean estimates of exposure. ICCind were low, with means that increased from 0.24 to 0.35 over the five decades. ICCgroup were considerably higher (means increasing from 0.78 to 0.88 over time), indicating that the number of raters used in this study was sufficient to produce stable average estimates of exposure throughout the study period. These data confirm the intuitive expectation that reliability of exposure estimates decreases when reconstruction of conditions in the distant past is required, and therefore that the random component of exposure misclassification is a greater threat to validity in these earlier time periods.

Analysis of Variance↗
PubMed1996

Child development and long-term outcomes: a population health perspective and summary of successful interventions.

Studies of socioeconomic gradients in mortality in wealthy societies reveal that they have been persist, and included most of the principal causes of death, even during the era when these principal causes of death have entirely changed. This observation has led to an interest in the ways in which the diversity of conditions of life, unfolding over the life cycle, can become embedded in human biology and subsequently affect health status and vitality. There is evidence that childhood experiences affect subsequent health status (as well as well-being and competence) in profound and long-lasting ways. Conflicting explanatory models of the impact of childhood experiences have been advanced, whose conflicts are political in nature, in that the reflect divergent beliefs about how human potential expresses itself, and, also, about the nature of the obligations which members of society have to one another. Notwithstanding these conflicts, a body of evidence derived from intervention studies in the post-neonatal, preschool, and school age periods suggest that performance in two basic domains of child development, the cognitive and the social-emotional, can be modified in ways which improve health, well-being, and competence in the long-term.

Child↗
PubMed1996

Pharmacokinetic model of dioxin and furan levels in adipose tissue from sawmill work involving chlorophenate fungicides.

Sawmill workers in British Columbia (B.C.), Canada, have been exposed to chlorophenate fungicides which are known to be contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Due to concern about the potential of these workers to have significant body burdens of PCDD/Fs, and the absence of measurements in these workers, a single-compartment pharmacokinetic model was developed to estimate the concentration of PCDD/Fs in the fat tissue of the sawmill workers. Data from a large cohort of B.C. sawmill workers and literature-based data on chlorophenate exposures and PCDD/F concentrations in chlorophenates were used in Monte Carlo simulations to predict a PCDD/F body burden distribution. The median concentrations of HxCDF and HpCDF predicted using the model for the B.C. sawmill worker population exceeded the range measured in unexposed populations. PeCDF and OCDF concentrations exceeded the range measured in unexposed populations at the 70th percentile of the model-predicted distribution, and PeCDD at the 90th percentile. The primary limitation of the model was the scarcity of input data about actual dermal and inhalation exposures to chlorophenates.

Adipose Tissue↗
PubMed1996

Reproductive effects of paternal exposure to chlorophenate wood preservatives in the sawmill industry.

OBJECTIVES: The purpose of the study was to determine whether paternal occupational exposure to dioxincontaminated chlorophenols is associated with an increased risk of congenital anomalies or other adverse reproductive outcomes in offspring. METHODS: As a result of a multistep linkage, 19675 births between 1952 and 1988 were identified as children of a cohort of 9512 fathers who had worked at least one year in British Columbia sawmills where chlorophenate wood preservatives had been used. A nested case-referent analysis was applied, using conditional logistic regression, with five referents matched per case according to year of birth and gender. Chlorophenate exposure was based on expert raters' estimations of hours of exposure applied to specific time windows prior to birth. RESULTS: The offspring of male sawmill workers were at increased risk for developing congenital anomalies of the eye, particularly congenital cataracts; elevated risks for developing anencephaly or spina bifida and congenital anomalies of genital organs were shown according to specific windows of exposure. No associations were found for low birthweight, prematurity, stillbirths, or neonatal deaths. CONCLUSIONS: The study adds further support to the hypothesis of male-mediated developmental toxicity. Paternal exposure to chlorophenates was associated with the development of certain congenital anomalies in offspring.

Abnormalities, Drug-Induced↗