Developmental origins of chronic inflammation: a review of the relationship between birth weight and C-reactive protein

Association of perinatal characteristics with biomarkers of stress and inflammation in young adults: An exploratory study

General peri- and postnatal characteristics may serve as markers linking pre- or early postnatal events to later health outcomes, which in turn are associated with altered stress- and immune system activity. Our exploratory study investigated whether A) the common perinatal measures "birth weight" and "birth mode" and B) the postnatal characteristics "breastfeeding" and "vaccination status" are associated with markers of stress systems - the hypothalamic-pituitary-adrenal (HPA) axis and autonomous nervous system (ANS) - and inflammation in healthy young adults (n = 68, females: 70.6 %, mean age: 24.21 years, SD = 4.38) exposed to psychosocial challenge, the 'Trier Social Stress Test' (TSST). Salivary cortisol, alpha-amylase (sAA) and plasma interleukin-6 (IL-6) were assessed before, during and after the TSST. Participants provided information on peri- and postnatal characteristics. Linear regressions were performed to determine whether peri-/postnatal variables predict basal and stress-response-related biomarker levels. Controlling for sex and sex hormone use as relevant confounders, we found a significant association between birth weight and cortisol recovery (p = 0.032), with higher birth weight predicting higher cortisol recovery values. There were no other significant associations between predictor and outcome variables. Our results show that, in healthy young adults of mixed gender, normal-ranged birth weight is related to the cortisol response to psychosocial stress, indicating a long-term association of this perinatal marker with HPA axis function. In contrast, birth weight was not associated with markers of the ANS stress response or inflammation in adulthood. Our results further suggest that the measures birth mode, duration of breastfeeding, and vaccination status at 4 months of age do not relate to markers of the inflammatory and stress systems in adulthood.

Birth size and the serum level of biological age markers in men

Previous studies showed that intrauterine growth restrictions, resulting in smaller body size at birth, are associated with altered development and the risk of age-related diseases in adult life. Thus, prenatal development may predict aging trajectories in humans. The study aimed to verify if body size at birth is related to biological age in adult men. The study sample consisted of 159 healthy, non-smoking men with a mean age of 35.24 (SD 3.44) years. Birth weight and length were taken from medical records. The ponderal index at birth was calculated. Biological age was evaluated based on serum levels of s-Klotho, hsCRP, DHEA/S, and oxidative stress markers. Pregnancy age at birth, lifestyle, weight, cortisol, and testosterone levels were controlled. The results showed no relationship between birth size and s-Klotho, DHEA/S level, inflammation, or oxidative stress. Also, men born as small-for-gestational-age (N = 49) and men born as appropriate-for-gestational-age (N = 110) did not differ in terms of biological age markers levels. The results were similar when controlled for pregnancy week at birth, chronological age, BMI, testosterone, or cortisol level. The results suggest that there is no relationship between intrauterine growth and biomarkers of aging in men aged 30-45 years from the affluent population.

Prenatal exposure to perfluoroalkyl substances and inflammatory biomarker concentrations

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that induce immunotoxicity in experimental studies; however, epidemiological evidence-particularly during pregnancy-is scarce. We quantified associations between first trimester plasma perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexane sulfonate (PFHxS) concentrations and third trimester concentrations of inflammatory biomarkers and determined if these associations were modified by fetal sex.

Methods

We analyzed data from 1411 participants, recruited between 2008 and 2011, in the Maternal-Infant Research on Environmental Chemicals study. Our primary outcome was a composite inflammatory index derived by summing the z-scores of eight proinflammatory biomarkers. Using multivariable linear regression models, we quantified associations between each PFAS and the inflammatory index and individual biomarkers. We quantified the effects of the PFAS mixture using weighted quantile sum regression, and evaluated effect modification using product terms and sex-stratified models.

Results

Each doubling of PFOA and PFHxS was associated with a 0.38 (95% CI, 0.09, 0.67) and 0.21 (95% CI, 0.01, 0.41) SD increase in the proinflammatory index, respectively. A one-quartile increase in the PFAS mixture was associated with a 0.40 (95% CI, 0.09, 0.71) SD increase in the proinflammatory index. In individual models, we observed positive associations between PFAS and concentrations of monocyte chemoattractant protein-1, macrophage inflammatory protein-1β, and matrix metalloproteinases-9; however, the magnitude and precision varied according to the specific PFAS. Sex-specific findings were identified in few PFAS-biomarker associations.

Conclusions

PFOA, PFOS, and PFHxS, individually and as a mixture, were positively associated with proinflammatory biomarkers during pregnancy.

Association between frequency of breakfast intake before and during pregnancy and infant birth weight: the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

BACKGROUND

Low birth weight is associated with an increased risk of developing chronic diseases in adulthood, with a particularly high incidence in Japan among developed countries. Maternal undernutrition is a risk factor for low birth weight, but the association between the timing of food intake and infant birth weight has not been investigated. This study aimed to examine the association between breakfast intake frequency among Japanese pregnant women and infant birth weight.

METHODS

Of all pregnant women who participated in the Tohoku Medical Megabank Project Three Generation Cohort Study, 16,820 who answered the required questions were included in the analysis. The frequency of breakfast intake from pre- to early pregnancy and from early to mid-pregnancy was classified into four groups: every day and 5-6, 3-4, and 0-2 times/week. Multivariate linear regression models were constructed to examine the association between breakfast intake frequency among pregnant women and infant birth weight.

RESULTS

The percentage of pregnant women who consumed breakfast daily was 74% in the pre- to early pregnancy period and 79% in the early to mid-pregnancy period. The average infant birth weight was 3,071 g. Compared to women who had breakfast daily from pre- to early pregnancy, those who had breakfast 0-2 times/week had lower infant birth weight (β = -38.2, 95% confidence interval [CI]: -56.5, -20.0). Similarly, compared to women who had breakfast daily from early to mid-pregnancy, those who had breakfast 0-2 times/week had lower infant birth weight (β = -41.5, 95% CI: -63.3, -19.6).

CONCLUSIONS

Less frequent breakfast intake before and mid-pregnancy was associated with lower infant birth weight.

Birth weight and cardiometabolic risk factors: a discordant twin study in the UK Biobank

One of the longstanding debates in life-course epidemiology is whether an adverse intrauterine environment, often proxied by birth weight, causally increases the future risk of cardiometabolic disease. The use of a discordant twin study design, which controls for the influence of shared genetic and environmental confounding factors, may be useful to investigate whether this relationship is causal. We conducted a discordant twin study of 120 monozygotic (MZ) and 148 dizygotic (DZ) twin pairs from the UK Biobank to explore the potential causal relationships between birth weight and a broad spectrum of later-life cardiometabolic risk factors. We used a linear mixed model to investigate the association between birth weight and later-life cardiometabolic risk factors for twins, allowing for both within-pair differences and between-pair differences in birth weight. Of primary interest is the within-pair association between differences in birth weight and cardiometabolic risk factors, which could reflect an intrauterine effect on later-life risk factors. We found no strong evidence of association in MZ twins between the within-pair differences in birth weight and most cardiometabolic risk factors in later life, except for nominal associations with C-reactive protein and insulin-like growth factor 1. However, these associations were not replicated in DZ twin pairs. Our study provided no strong evidence for intrauterine effects on later-life cardiometabolic risk factors, which is consistent with previous large-scale studies of singletons testing the potential causal relationship. It does not support the hypothesis that adverse intrauterine environments increase the risk of cardiometabolic disease in later life.

Ambient air pollution and inflammatory effects in a Canadian pregnancy cohort

Supplemental Digital Content is available in the text.

Background:

Epidemiologic studies have consistently reported associations between air pollution and pregnancy outcomes including preeclampsia and gestational diabetes. However, the biologic mechanisms underlying these relationships remain unclear as few studies have collected relevant biomarker data. We examined relationships between ambient PM_2.5 and NO₂ with markers of inflammation during pregnancy in a prospective cohort of Canadian women.

Methods:

We analyzed data from 1170 women enrolled in the Maternal-Infant Research on Environmental Chemicals study. Daily residential PM_2.5 and NO₂ exposures during pregnancy were estimated using satellite-based and land-use regression models and used to create 14-day and 30-day exposure windows before blood-draw. Inflammatory markers C-reactive protein, interleukin-6, interleukin-8, and tumor necrosis factor-α were measured in third trimester plasma samples. Multivariable linear regression was used to estimate associations for an interquartile range (IQR) increase in PM_2.5 and NO₂ and markers of inflammation, while adjusting for individual-level confounders.

Results:

Fourteen-day (IQR: 6.85 µg/m³) and 30-day (IQR: 6.15 µg/m³) average PM_2.5 exposures before blood-draw were positively associated with C-reactive protein after adjustment for covariates (24.6% [95% CI = 9.4, 41.9] and 17.4% [95% CI = 1.0, 35.0] increases, respectively). This association was found to be robust in several sensitivity analyses. Neither PM_2.5 nor NO₂ exposures were associated with interleukin-6, interleukin-8, or tumor necrosis factor-α.

Conclusion:

Exposure to ambient PM_2.5 is positively associated with maternal inflammatory pathways in late pregnancy. This may contribute to positive associations between ambient PM_2.5 and risk of adverse pregnancy outcomes.

The Effect of Prickly Pear, Pumpkin, and Linseed Oils on Biological Mediators of Acute Inflammation and Oxidative Stress Markers

Medicinal plants have been used as a source of effective and safe alternative therapeutic agents for various ailments including inflammation. In fact, the aim of this study is to assess the topical anti-inflammatory and antioxidative potential effects of Cucurbita pepo (pumpkin), Linum usitatissimum (linseed), and Opuntia ficus indica (prickly pear) oils on acute inflammation using carrageenan-induced paw edema model. The study was conducted on 36 rats splitted in 6 groups: a normal control group and 5 carrageenan-treated groups (1%), each treated with either a normal saline, the reference drug (“Inflocine®” 2 mg/paw), pumpkin, linseed, or prickly pear oils (25 μl/paw). The response to these treatments was mainly assessed by the measuring of edema paw size, hematological and biochemical analysis, oxidative stress testing, and histological study. All the studied seed oils especially prickly pear oil proved to be efficient in treating acute inflammation. The oil-treated groups revealed a significant (p < 0.05) decrease in the clinical signs of inflammation, hematological parameters (white blood cells and platelets), concentrations of CRP and fibrinogen, and congestion compared to the normal saline-treated group. The results also showed that the tested oils, endowed with a radical scavenging ability, could significantly increase the activities of SOD, CAT, and GPx in carrageenan-treated skin by reducing the lipid peroxidation and protein oxidation (TBARS, AOPP). The anti-inflammatory effect of the tested oils was closely related to both their antioxidant properties as well as their bioactive compounds (polyunsaturated fatty acids, vitamin E, and phytosterols). For the first time, the findings of the current study highlight the “in vivo” anti-inflammatory property of pumpkin, linseed, and prickly pear oils on carrageenan-induced acute inflammation by regulating inflammatory mediators and oxidative stress markers.

Childhood socioeconomic conditions are associated with increased chronic low-grade inflammation over adolescence: findings from the EPITeen cohort study

OBJECTIVE

Early life adversity has been associated with increased risk of inflammation and inflammation-related diseases in adulthood. This study aimed to examine the association of childhood socioeconomic conditions with chronic low-grade inflammation over adolescence.

METHODS

We used information on 2942 members (1507 girls and 1435 boys) of the EPITeen (Epidemiological Health Investigation of Teenagers in Porto) cohort that was established in 2003 in Porto, Portugal, and included 13-year-old adolescents were further evaluated at 17 and 21 years. Mother' and father's education and occupation were used as indicators of childhood socioeconomic conditions. High-sensitivity C reactive protein (hs-CRP) was measured at three points in time (13, 17 and 21 years). hs-CRP levels were categorised in tertiles separately for each wave; chronic low-grade inflammation in adolescence was defined as having hs-CRP levels in the highest tertile in at least two waves and never in the lowest tertile.

RESULTS

Prevalence of chronic low-grade inflammation during adolescence was significantly higher among participants with low parental socioeconomic position. Low parental socioeconomic position was associated with chronic low-grade inflammation in adolescence, after adjustment for sex, perinatal and physical environment factors, health-related behaviours and health status in adolescence OR=1.6; 95% CI: 1.1 to 2.4 for lowest versus highest mother's education and OR=1.6; 95% CI: 1.1 to 2.3 for lowest versus highest father's occupation.

CONCLUSION

Low childhood socioeconomic conditions are associated with chronic low-grade inflammation during adolescence. Our results suggest that the early life socioeconomic environment has an impact on inflammatory processes over adolescence.

Detecting the Effects of Early-Life Exposures: Why Fecundity Matters

Prenatal exposures have meaningful effects on health across the lifecourse. Innovations in causal inference have shed new light on these effects. Here, we motivate the importance of innovation in the characterization of fecundity, and prenatal selection in particular. We argue that such innovation is crucial for expanding knowledge of the fetal origins of later life health. Pregnancy loss is common, responsive to environmental factors, and closely related to maternal and fetal health outcomes. As a result, selection into live birth is driven by many of the same exposures that shape the health trajectories of survivors. Lifecourse effects that are inferred without accounting for these dynamics may be significantly distorted by survival bias. We use a set of Monte Carlo simulations with realistic parameters to examine the implications of prenatal survival bias. We find that even in conservatively specified scenarios, true fetal origin effects can be underestimated by 50% or more. In contrast, effects of exposures that reduce the probability of prenatal survival but improve the health of survivors will be overestimated. The absolute magnitude of survival bias can even exceed small effect sizes, resulting in inferences that beneficial exposures are harmful or vice-versa. We also find reason for concern that moderately sized true effects, underestimated due to failure to account for selective survival, are missing from scientific knowledge because they do not clear statistical significance filters. This bias has potential real-world costs; policy decisions about interventions to improve maternal and infant health will be affected by underestimated program impact.

Anti-Inflammatory and Anti-Hyperuricemic Functions of Two Synthetic Hybrid Drugs with Dual Biological Active Sites

The present study aimed to test the anti-inflammatory and xanthine oxidase inhibitory activities of two synthesized molecules and compare them to routinely prescribed nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac and the serum urate-lowering drug, allopurinol. The anti-inflammatory effects of the designed compounds (A and B) were evaluated in carrageenan (CAR)-induced paw edema in mice. The levels of nitric oxide and myeloperoxidase activity were measured in paw skin using biochemical methods. Additionally, prostaglandin E2 (PGE2), C-reactive protein (CRP), cyclooxygenase-2 (Cox-2), tumor necrosis factor-α (TNFα), interleukin (IL)-1β, IL-2 and IL-10, and monocyte chemoattractant protein-1 (MCP1) were assessed by enzyme-linked immunosorbent assay (ELISA). The expression of inflammation-related genes was confirmed by real-time qPCR. The expression of inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-κB) were estimated using immunohistochemistry, and xanthine oxidase inhibitory activity was evaluated using an in vitro assay. The results revealed that compounds A and B decreased inflammation, as was observed by a reduction in the elevation of all the tested markers. In addition, the tested compounds markedly decreased paw swelling, mobilization of inflammatory cells, iNOS-, and NF-κB-immunoreactive cells in a mouse model of paw edema. Interestingly, both compounds were potent xanthine oxidase inhibitors as well as Cox inhibitors with higher activity in favor of compound B providing potential dual acting series of anti-hyperuricemic and anti-inflammatory therapeutic agents.

Iron Dysregulation and Dormant Microbes as Causative Agents for Impaired Blood Rheology and Pathological Clotting in Alzheimer's Type Dementia

Alzheimer’s disease and other similar dementias are debilitating neurodegenerative disorders whose etiology and pathogenesis remain largely unknown, even after decades of research. With the anticipated increase in prevalence of Alzheimer’s type dementias among the more susceptible aging population, the need for disease-modifying treatments is urgent. While various hypotheses have been put forward over the last few decades, we suggest that Alzheimer’s type dementias are triggered by external environmental factors, co-expressing in individuals with specific genetic susceptibilities. These external stressors are defined in the Iron Dysregulation and Dormant Microbes (IDDM) hypothesis, previously put forward. This hypothesis is consistent with current literature in which serum ferritin levels of individuals diagnosed with Alzheimer’s disease are significantly higher compared those of age- and gender-matched controls. While iron dysregulation contributes to oxidative stress, it also causes microbial reactivation and virulence of the so-called dormant blood (and tissue) microbiome. Dysbiosis (changes in the microbiome) or previous infections can contribute to the dormant blood microbiome (atopobiosis¹), and also directly promotes systemic inflammation via the amyloidogenic formation and shedding of potent inflammagens such as lipopolysaccharides. The simultaneous iron dysregulation and microbial aberrations affect the hematological system, promoting fibrin amylodiogenesis, and pathological clotting. Systemic inflammation and oxidative stress can contribute to blood brain barrier permeability and the ensuing neuro-inflammation, characteristic of Alzheimer’s type dementias. While large inter-individual variability exists, especially concerning disease pathogenesis, the IDDM hypothesis acknowledges primary causative factors which can be targeted for early diagnosis and/or for prevention of disease progression.

No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases

Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.

Maternal pregnancy C-reactive protein predicts offspring birth size and body composition in metropolitan Cebu, Philippines

The gestational milieu is an important influence on fetal development and long-term disease risk. Here we assess relationships between maternal pregnancy inflammation, indicated by C-reactive protein (CRP), and offspring anthropometric outcomes measured soon after birth. Data come from female participants (n=327, age 24.4-30.2 years) in a longitudinal study located in Metropolitan Cebu, Philippines. Between 2009 and 2014, pregnancy interviews (n=429) were conducted during which questionnaire and anthropometric data were obtained along with dried blood spot cards for CRP measurement. Offspring body weight, length, head circumference and five skinfold thickness measures were obtained soon after birth. Maternal pregnancy CRP was borderline (-1.11±0.64 days/log-mg/l; P<0.1) inversely related to gestational age at delivery, but did not increase the likelihood of preterm delivery. After adjusting for maternal pre-pregnancy body mass index, height, pregnancy adiposity, age, parity and other covariates, CRP was significantly, inversely related to offspring body weight (-0.047±0.017 kg/log-mg/l), length (-0.259±0.092 cm/log-mg/l) and sum of skinfolds (-0.520±0.190 mm/log-mg/l) (all P<0.05), and borderline inversely related to offspring head circumference (-0.102±0.068 cm/log-mg/l; P<0.1). Notably, relationships were continuous across the full CRP range, and not limited to unusually high levels of inflammation. These findings point to an important role of maternal non-specific immune activation as a predictor of offspring birth outcomes. In light of evidence that early life microbial, nutritional and stress experiences influence adult inflammatory regulation, these findings point to inflammation as a potential pathway for the intergenerational transmission of maternal experience to offspring health.

Perinatal complications, lipid peroxidation, and mental health problems in a large community pediatric sample

Replicated evidence indicates that perinatal complications are associated with increased markers of oxidative stress and with mental health problems in children. However, there are fewer reports on the impact of perinatal complications in later phases of development. We aimed to investigate the estimated effects of perinatal complications on levels of lipid peroxidation and on psychopathology in children and adolescents. The study is part of the High Risk Cohort Study for Psychiatric Disorders; the population was composed by 554 students, 6-14 years of age. Serum levels of malondialdehyde, a product of lipid peroxidation, were measured by the TBARS method. A household interview with parents and caregivers was conducted and included inquiries about perinatal history, the Child Behavior Checklist (CBCL), and parent's evaluation, using the Mini International Psychiatric Interview (MINI). We created a cumulative risk index, conceptualized as each individual's cumulative exposure to perinatal complications. Results indicate that perinatal complications were associated with higher levels of TBARS. After adjusting for age, gender, socio-economic status, CBCL total problems score, parental psychopathology, and childhood maltreatment, children exposed to 3 or more perinatal complications had an 26.9% (95% CI 9.9%, 46.6%) increase in TBARS levels, relative to the unexposed group. Exploratory mediation analysis indicated that TBARS levels partially mediated the association between perinatal complications and externalizing problems. In conclusion, an adverse intrauterine and/or early life environment, as proxied by the cumulative exposure to perinatal complications, was independently associated with higher levels of lipid peroxidation in children and adolescents.

Breastfeeding, overweight status, and inflammation

Research documents a host of health benefits of breastfeeding for infants and children, including long-term health conditions arising from inflammation. Here, we provide new evidence about this association, focusing on the link between breastfeeding in infancy and inflammation in early adulthood. Our study is based on the National Longitudinal Study of Adolescent to Adult Health (Add Health) which allows us investigate a potentially important mediating pathway - overweight status from early adolescence into young adulthood. Results from pathway analyses in a structural equation modeling framework indicate that, in addition to a direct pathway linking breastfeeding and inflammation, an indirect pathway through overweight status across adolescence into young adulthood partially explains the association between breastfeeding and inflammation. Overweight status, moreover, links breastfeeding to inflammation not only through proximal timing of overweight status, but also through an indirect cascading process of overweight status over the life course that is evident in adolescence. Overall, this study highlights the importance of considering breastfeeding, overweight status and inflammation as dynamic life course processes that contribute to development of health inequalities.

Association of serum interleukin-6 with mental health problems in children exposed to perinatal complications and social disadvantage

There is consistent evidence that inflammation is involved in mental disorders pathogenesis. Herein, using data from the High Risk Cohort Study for Psychiatric Disorders, we investigated the relationship between parental mood disorders (PMD), environmental factors, serum interleukin-6 (IL6) and mental health problems in children aged 6-12. We measured the serum levels of IL6 in 567 children. Information related to socio-demographic characteristics, mental health problems and multiple risk factors, as well as parent's psychiatric diagnosis, was captured. We evaluated two groups of environmental risk factors (i.e. perinatal complications and social disadvantage) using a cumulative risk model. Results showed that higher serum levels of IL6 were associated with PMD (RR=1.072, p=0.001), perinatal complications (RR=1.022, p=0.013) and social disadvantage (RR=1.024, p=0.021). There was an interaction between PMD and social disadvantage (RR=1.141, p=0.021), as the effect of PMD on IL6 was significantly higher in children exposed to higher levels of social disadvantage. Moreover, there was a positive correlation between IL6 and mental health problems (RR=1.099, p=0.026), which was moderated by exposure to perinatal complications or social disadvantage (RR=1.273, p=0.015 and RR=1.179, p=0.048, respectively). In conclusions, there is evidence of a differential inflammatory activation in children with PMD and exposure to environmental risk factors, when compared to matched peers. Systemic inflammation may be involved in the pathway linking familial risk and mental health problems.

Early Life Factors Associated with Adult-Onset Systemic Lupus Erythematosus in Women

Background

Exposure early in life can influence adult disease and immunity, but the role of early life exposures in risk of systemic lupus erythematosus (SLE) is not established.

Methods

Women in a national cohort (ages 35–74) provided data on perinatal, maternal, and sociodemographic factors, longest residence to age 14, and residential farm history of at least 12 months to age 18. Cases (N = 124) reported SLE diagnosed age 16 years or older with use of disease modifying antirheumatic drugs. Non-cases (N = 50,465) did not report lupus. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression adjusting for age and race/ethnicity.

Results

SLE was associated with low birthweight (data on 84 cases and 36,477 non-cases; <2,500 versus 3,000 to <3,500 g OR = 2.2; 95%CI 1.2, 3.9) and preterm birth (57 cases and 22,784 non-cases; ≥1 month early versus full-term OR = 3.4; 95%CI 1.6, 7.4). Considering longest childhood residence to age 14, SLE was associated with more frequent pesticide use (e.g., at least monthly OR = 2.3; 95%CI 1.3, 4.1). SLE was associated with having an early and extended childhood farm residence (i.e., prenatal/maternal farm exposure and longest childhood farm residence OR = 1.8; 95%CI 1.1, 3.0 versus neither). In those with a childhood-only farm residence of 12+ months, agricultural pesticide use was associated with SLE, with the strongest associations for direct personal exposures.

Conclusion

The association of SLE with preterm birth is consistent with studies in other populations and with an observed association with low birthweight. The associations of SLE with childhood exposure to residential and agricultural pesticides warrant further study.