How accurate is self reported birth weight among the elderly?

The association of birthweight with age at natural menopause: a population study of women in Norway

Background

Previous studies suggest that birthweight may influence age at natural menopause, but the evidence remains inconclusive. Thus, we aimed to estimate the association of birthweight with age at natural menopause.

Methods

A retrospective population study of 164 608 women in Norway, aged 48–71 years. Data were obtained by two self-administered questionnaires among participants in BreastScreen Norway during 2006–2014. We used Cox proportional hazard models to estimate hazard ratios and logistic regression models to estimate odds ratios of menopause according to birthweight. Restricted cubic splines were applied to allow for possible non-linear associations, and adjustments were made for year and country of birth.

Results

Women with birthweight <2500 g were median 51 years at menopause (interquartile range 49–54 years), whereas women with birthweight 3500–3999 g were median 52 years at menopause (interquartile range 49–54 years). The hazard ratio of menopause decreased with increasing birthweight up until 3500 g. At birthweights >3500 g, we estimated no further decrease (P for non-linearity = 0.007). Birthweight at 2500 g increased the odds ratios of menopause before the age of 45 [1.20; 95% confidence interval (CI): 1.14–1.25] and the age of 40 (1.26; 95% CI: 1.15–1.38) compared with birthweight at 3500 g. At birthweights 4000 g and 4500 g, the odds ratio estimates were very similar to the reference group and the CIs overlapped 1.00.

Conclusions

We found a non-linear dose-relationship of birthweight with age at natural menopause, and low birthweight was associated with early natural menopause. Our findings suggest that growth restriction during fetal life may influence the timing of natural menopause.

Childhood body size and midlife mammographic breast density in foreign-born and U.S.-born women in New York City

PURPOSE

We investigated whether childhood body size is associated with midlife mammographic density, a strong risk factor for breast cancer.

METHODS

We collected interview data, including body size at age 10 years using a pictogram, and measured height and weight from 518 women, recruited at the time of screening mammography in New York City (ages 40-64 years, 71% Hispanic, 68% foreign-born). We used linear regression models to examine childhood body size in relation to percent density and areas of dense and nondense tissue, measured using a computer-assisted method from digital mammograms.

RESULTS

In models that adjusted for race/ethnicity, and age and body mass index at mammogram, the heaviest relative to leanest childhood body size was associated with 5.94% lower percent density (95% confidence interval [CI]: -9.20, -2.29), 7.69 cm² smaller dense area (95% CI: -13.94, -0.63), and 26.17 cm² larger nondense area (95% CI: 9.42, 43.58). In stratified analysis by menopausal status and nativity, the observed associations were stronger for postmenopausal and U.S.-born women although these differences did not reach statistical significance.

CONCLUSIONS

Heavy childhood body size is associated with lower mammographic density, consistent with its associations with breast cancer risk. Suggestive findings by nativity require confirmation in larger samples.

Validity of Self-Reported Birth Weight: Results from a Norwegian Twin Sample

The association between birth weight and later life outcomes is of considerable interest in life-course epidemiology. Research often relies on self-reported measures of birth weight, and its validity is consequently of importance. We assessed agreement between self-reported birth weight and official birth records for Norwegian twins born 1967–1974. The intraclass correlation between self-reported birth weight and register-based birth weight was 0.91 in our final sample of 363 twins. It could be expected that 95% of self-reported birth-weight values will deviate from official records within a maximum of +446 grams and a minimum of −478 grams — around a mean deviation of 16 grams. Self-reported birth weight had a sensitivity of 0.78–0.89 and a positive predictive value of 0.59–0.85, and an overall weighted kappa of 0.71. We further assessed agreement by conducting two linear regression models where we respectively regressed self-reported birth weight and register-based birth weight on adult body mass index, a known association. The two models were not significantly different; however, there were different levels of significance in parameter estimates that warrant some caution in using self-reported birth weight. Reliability of self-reported birth weight was also assessed, based on self-reports in another sample of twins born 1935–1960 who had reported their birth weight in two questionnaires 34 years apart. The intraclass correlation was 0.86, which indicates a high degree of reliability. In conclusion, self-reported birth weight, depending on context and age when birth weight was reported, can be cautiously used.

Sex-specific associations of low birth weight with adult-onset diabetes and measures of glucose homeostasis: Brazilian Longitudinal Study of Adult Health

Emerging evidence suggests sex differences in the early origins of adult metabolic disease, but this has been little investigated in developing countries. We investigated sex-specific associations between low birth weight (LBW; <2.5 kg) and adult-onset diabetes in 12,525 participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Diabetes was defined by self-reported information and laboratory measurements. In confounder-adjusted analyses, LBW (vs. 2.5–4 kg) was associated with higher prevalence of diabetes in women (Prevalence Ratio (PR) 1.54, 95% CI: 1.32–1.79), not in men (PR 1.06, 95% CI: 0.91–1.25; P_{heterogeneity} = 0.003). The association was stronger among participants with maternal diabetes (PR 1.60, 95% CI: 1.35–1.91), than those without (PR 1.15, 95% CI: 0.99–1.32; P_{heterogeneity} = 0.03). When jointly stratified by sex and maternal diabetes, the association was observed for women with (PR 1.77, 95% CI: 1.37–2.29) and without (PR 1.45, 95% CI: 1.20–1.75) maternal diabetes. In contrast, in men, LBW was associated with diabetes in participants with maternal diabetes (PR 1.45, 95% CI: 1.15–1.83), but not in those without (PR 0.92, 95% CI: 0.74–1.14). These sex-specific findings extended to continuous measures of glucose homeostasis. LBW was associated with higher diabetes prevalence in Brazilian women, and in men with maternal diabetes, suggesting sex-specific intrauterine effects on adult metabolic health.

Validity of recalled v. recorded birth weight: a systematic review and meta-analysis

Low birth weight is associated with adverse health outcomes. If birth weight records are not available, studies may use recalled birth weight. It is unclear whether this is reliable. We performed a systematic review and meta-analysis of studies comparing recalled with recorded birth weights. We followed the Meta-Analyses of Observational Studies in Epidemiology (MOOSE) statement and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched MEDLINE, EMBASE and Cumulative Index to Nursing and Allied Health Literature (CINAHL) to May 2015. We included studies that reported recalled birth weight and recorded birth weight. We excluded studies investigating a clinical population. Two reviewers independently reviewed citations, extracted data, assessed risk of bias. Data were pooled in a random effects meta-analysis for correlation and mean difference. In total, 40 studies were eligible for qualitative synthesis (n=78,997 births from 78,196 parents). Agreement between recalled and recorded birth weight was high: pooled estimate of correlation in 23 samples from 19 studies (n=7406) was 0.90 [95% confidence interval (CI) 0.87–0.93]. The difference between recalled and recorded birth weight in 29 samples from 26 studies (n=29,293) was small [range −86–129 g; random effects estimate 1.4 g (95% CI −4.0–6.9 g)]. Studies were heterogeneous, with no evidence for an effect of time since birth, person reporting, recall bias, or birth order. In post-hoc subgroup analysis, recall was higher than recorded birth weight by 80 g (95% CI 57–103 g) in low and middle income countries. In conclusion, there is high agreement between recalled and recorded birth weight. If birth weight is recalled, it is suitable for use in epidemiological studies, at least in high income countries.

Sex-specific associations of birth weight with measures of adiposity in mid-to-late adulthood: the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND/OBJECTIVES

To investigate sex-specific associations of birth weight with body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) in mid-to-late adulthood.

SUBJECTS/METHODS

ELSA-Brasil is a multicenter cohort study of adults aged 35-74 years affiliated with universities or research institutions of six capital cities in Brazil. After exclusions, we investigated 11 636 participants. Socio-demographic factors and birth weight were obtained by interview. All anthropometry was directly measured at baseline. We categorized birth weight as low (⩽2.5 kg); normal (2.5-4 kg) and high (⩾4 kg). We performed analysis of covariance (ANCOVA) for continuous outcomes and ordinal logistic regression for categorical adiposity outcomes. We examined interaction on the multiplicative scale by sex and by race.

RESULTS

High birth weight uniformly predicted greater overall and central obesity in men and women. However, low (vs normal) birth weight, in ANCOVA models adjusted for participant age, family income, race, education, maternal education, and maternal and paternal history of diabetes, was associated with lower BMI, WC and WHR means for men, but not for women (Pinteraction=0.01, <0.0001 and <0.0001, respectively). In similarly adjusted ordinal logistic regression models, odds of obesity (odds ratio (OR)=0.65, 0.46-0.90) and of being in the high (vs low) tertile of WC (OR=0.66, 0.50-0.87) and of WHR (OR=0.79, 0.60-1.03) were lower for low (vs normal) birth weight men, but trended higher (BMI: OR=1.18, 0.92-1.51; WC: OR=1.21, 0.97-1.53; WHR: OR=1.44, 1.15-1.82) for low (vs normal) birth weight women.

CONCLUSIONS

In this Brazilian sample of middle-aged and elderly adults who have lived through a rapid nutritional transition, low birth weight was associated with adult adiposity in a sex-specific manner. In men, low birth weight was associated with lower overall and central adult adiposity, while in women low birth weight was generally associated with greater central adiposity.

Premature Birth and Large for Gestational Age Are Associated with Risk of Barrett's Esophagus in Adults

BACKGROUND

Birth characteristics, including weight and gestational age, may be associated with risk of Barrett's esophagus (BE), the only known precursor for esophageal adenocarcinoma; however, data are limited.

AIMS

To examine associations between various birth characteristics and BE, and whether these associations are mediated by known risk factors for BE.

METHODS

Data were obtained from a cross-sectional study among eligible Veterans Affairs patients scheduled for an upper endoscopy, and a sample identified from primary care clinics. Participants underwent an esophagogastroduodenoscopy and completed a survey that captured information on sociodemographic and clinical factors, as well as birth information. We compared 263 patients with histologically confirmed BE to 1416 controls without BE on endoscopy. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using multivariate logistic regression.

RESULTS

Premature birth was independently associated with risk of BE after adjusted by age, sex, race, and other birth characteristics (OR 3.28, 95 % CI 1.22-8.79). On the other hand, large for gestational age was inversely associated with risk of BE (OR 0.46, 95 % CI 0.21-0.98). These effects were stronger for patients with long-segment BE than with short-segment BE. The associations were not mediated by gastroesophageal reflux disease symptoms, use of proton pump inhibitors, Helicobacter Pylori infection, waist-hip-ratio, height or the presence of hiatus hernia.

CONCLUSIONS

Premature birth and large for gestational age may be associated with risk of BE in adults. These associations do not appear to be mediated through known risk factors for BE; however, additional studies are required to confirm our findings.

Multigenerational effects of parental prenatal exposure to famine on adult offspring cognitive function

The effects of prenatal nutrition on adult cognitive function have been reported for one generation. However, human evidence for multigenerational effects is lacking. We examined whether prenatal exposure to the Chinese famine of 1959-61 affects adult cognitive function in two consecutive generations. In this retrospective family cohort study, we investigated 1062 families consisting of 2124 parents and 1215 offspring. We assessed parental and offspring cognitive performance by means of a comprehensive test battery. Generalized linear regression model analysis in the parental generation showed that prenatal exposure to famine was associated with a 8.1 (95% CI 5.8 to 10.4) second increase in trail making test part A, a 7.0 (1.5 to 12.5) second increase in trail making test part B, and a 5.5 (-7.3 to -3.7) score decrease in the Stroop color-word test in adulthood, after adjustment for potential confounders. In the offspring generation, linear mixed model analysis found no significant association between parental prenatal exposure to famine and offspring cognitive function in adulthood after adjustment for potential confounders. In conclusion, prenatal exposure to severe malnutrition is negatively associated with visual- motor skill, mental flexibility, and selective attention in adulthood. However, these associations are limited to only one generation.

Birthweight, mediating biomarkers and the development of type 2 diabetes later in life: a prospective study of multi-ethnic women

AIMS/HYPOTHESIS

The aim of this work was to investigate the prospective relationship between low birthweight (LBW) and type 2 diabetes risk later in life and the mediation effects of type 2 diabetes biomarkers linking LBW to type 2 diabetes risk.

METHODS

We measured baseline plasma concentrations of various type 2 diabetes biomarkers in 1,259 incident type 2 diabetes cases and 1,790 controls in the Women's Health Initiative-Observational Study. Self-report birthweights of the participants were recorded. The total effect of LBW on type 2 diabetes risk was partitioned into effects that were mediated by a specific biomarker and effects that were not mediated by this biomarker, using counterfactual model-based mediation analysis.

RESULTS

LBW was significantly associated with increased risk of type 2 diabetes. Compared with women with birthweight 3.63-4.54 kg, women with LBW (<2.72 kg) had a multivariable-adjusted OR of 2.15 (95% CI, 1.54, 3.00). Insulin resistance (indicated by HOMA-IR) mediated 47% of the total effect. Decreased sex hormone-binding globulin (SHBG) concentration accounted for 24%, elevated E-selectin concentration accounted for 25% and increased systolic blood pressure accounted for 8% of the total effect of LBW on type 2 diabetes risk. (Due to interactions among different mediators, the sum of each individual mediator's contribution could exceed 100%, without an upper limit.)

CONCLUSIONS/INTERPRETATION

LBW is directly predictive of higher risk of type 2 diabetes later in life. The effect of LBW on type 2 diabetes risk seems mainly mediated by insulin resistance, which is further explained by circulating levels of SHBG and E-selectin and systolic blood pressure. The study provides potential risk stratification in a population at greater risk of developing type 2 diabetes.

Ethnic differences in the relationship between birth weight and type 2 diabetes mellitus in postmenopausal women

AIM

The objective of this study is to examine the relationship between self-reported birth weight and the adult occurrence of type 2 diabetes mellitus in a large multi-ethnic population of women.

METHODS

Baseline data from the Women's Health Initiative Observational Study [n=75,993] was used to examine the association between participant birth weight category and prevalent type 2 diabetes mellitus. Models were adjusted for age, ethnicity, body mass index and other pertinent risk factors. Sub-analyses were performed stratifying by ethnicity.

RESULTS

There was a strong inverse association between birth weight and type 2 diabetes mellitus with a birth weight of <6 pounds (lbs) (OR: 1.16, 95% CI: 1.01, 1.33) significantly associated with an increased risk of type 2 diabetes mellitus and a birth weight of ≥10 lbs (OR: 0.72, 95% CI: 0.57, 0.92) associated with a decreased risk of type 2 diabetes mellitus compared to women who reported their birth weight between 7 and 8 lbs 15 ounces (oz). Stratifying by ethnicity, the inverse association between birth weight and type 2 diabetes mellitus was only apparent in White women, but not Black, Hispanic or Asian women.

CONCLUSION

Lower birth weight was associated with increased T2D risk in American White and Black post-menopausal women.

Birth weight and adult cancer incidence: large prospective study and meta-analysis

BACKGROUND

Most evidence about associations between birth weight and adult cancer risk comes from studies linking birth records to cancer registration data, where information on known risk factors for cancer is generally lacking. Here, we report on associations between birth weight and cause-specific cancer risk in a large cohort of UK women, and investigate how observed associations are affected by other factors.

METHODS

A total of 453 023 women, born in the 1930s and 1940s, reported their birth weight, maternal smoking, parental heights, age at menarche, adult height, adult smoking, and many other personal characteristics. They were followed for incident cancer. Using Cox regression, relative risks by birth weight were estimated for cancers with more than 1500 incident cases, adjusting for 17 potential confounding factors, individually and simultaneously.

RESULTS

Birth weight reported in adulthood was strongly correlated with that recorded at birth (correlation coefficient = 0.78, P < 0.0001). Reported birth weight was associated with most of the potential confounding factors examined, the strongest association being with adult height. After 9.2 years follow-up per woman, 39 060 incident cancers were registered (4414 colorectal, 3175 lung, 1795 malignant melanoma, 14 542 breast, 2623 endometrial, 2009 ovarian, 1565 non-Hodgkin lymphoma, and 8937 other cancers). Associations with birth weight were null or weak and reduced after adjustment by adult height (P[trend] > 0.01 for every cancer, after adjustment). In contrast, adult height was strongly related to the risk of every cancer except lung cancer, after adjusting for birth weight and other factors (P[trend] < 0.0001 for most cancers). For lung cancer, adjusting for smoking reduced the association with birth weight. Meta-analyses were dominated by our findings.

CONCLUSION

Birth weight and adult height are correlated and likely to be markers of some aspect of growth that affects cancer risk in adulthood. However, birth weight adds little, if any, additional information to adult height as a predictor of cancer incidence in women.

Agreement between self-reported birth weight and birth certificate weights

Birth weight is emerging as a potentially important risk factor for several chronic diseases with adult onset, including breast cancer. Because participant recall is frequently used to gather data on early life exposures, it is essential that the accuracy of recall be assessed and validated. Self-reported birth weights and birth certificate weights were compared in women aged 35-51 years from the Western New York Exposures and Breast Cancer (WEB) Study, a population-based case-control study. A total of 180 participants had both birth certificate and interview data on birth weight. Participants reported birth weight to one of six categories (<5, 5-5.5, 5.6-7, 7.1-8.5, 8.6-10 and >10 lbs). The Spearman correlation for self-reported and birth certificate weights was 0.67. Sixty percent of participants reported weights with exact agreement with birth certificate; unweighted and weighted kappas (κ) were 0.39 and 0.68, respectively. Spearman correlations were similar for cases (0.67) and controls (0.68). Controls exhibited a significantly higher unweighted κ (0.51) than cases (0.27; P = 0.03), but weighted κ were not statistically different [controls, 0.73; cases, 0.64 (P = 0.32)]. Demographic and anthropometric characteristics were not different between participants who underreported, overreported, or correctly reported their birth weight for either cases or controls. Overall, the level of agreement for report of birth weight and actual birth weight was fair to moderate.

Birthweight, early life body size and adult mammographic density: a review of epidemiologic studies

PURPOSE

To evaluate the association between birth weight and early life body size with adult mammographic density in the peer-reviewed literature.

METHODS

A comprehensive literature search was conducted through January, 2014. English language articles that assessed adult mammographic density (MD) in relation to early life body size (≤18 years old), or birthweight were included.

RESULTS

Nine studies reported results for early life body size and %MD. Both exposure and outcome were assessed at different ages using multiple methods. In premenopausal women, findings were inconsistent; two studies reported significant, inverse associations, one reported a non-significant, inverse association, and two observed no association. Reasons for these inconsistencies were not obvious. In postmenopausal women, four of five studies supported an inverse association. Two of three studies that adjusted for menopausal status found significant, inverse associations. Birthweight and %MD was evaluated in nine studies. No association was seen in premenopausal women and two of three studies reported positive associations in postmenopausal women. Three of four studies that adjusted for menopausal status found no association.

DISCUSSION

Early life body size and birthweight appear unrelated to %MD in premenopausal women while an inverse association in postmenopausal women is more likely. Although based on limited data, birthweight and %MD appear positively associated in postmenopausal women. Given the small number of studies, the multiple methods of data collection and analysis, other methodologic issues, and lack of consistency in results, additional research is needed to clarify this complex association and develop a better understanding of the underlying biologic mechanisms.

Low birthweight and risk of albuminuria in living kidney donors

Low birthweight is linked to hypertension, chronic kidney disease and even end-stage renal disease. We hypothesized that living kidney donors born with lower birthweight may be at increased risk of hypertension, albuminuria, or reduced GFR beyond what is typical following uninephrectomy. Two hundred fifty-seven living kidney donors who donated at the University of Minnesota between 1967 and 2005 underwent iohexol GFR and urinary albumin excretion measurements. Predictors of iohexol GFR <60 mL/min/1.73 m(2), albuminuria, and hypertension were examined using logistic regression. Predictors examined include age at GFR measurement, time since donation, BMI, gender, serum creatinine level (at donation and GFR measurement), systolic and diastolic blood pressure, race, and birthweight. The latter was obtained through self-report and verified through birth certificates and family members. Older age, higher BMI, and time from donation were associated with reduced GFR. Older age and higher BMI were also associated with hypertension. Birthweight was not associated with GFR <60 mL/min/1.73 m(2): OR=0.70, 95% CI (0.28, 1.74), p = 0.45 or hypertension: OR=0.92, 95% CI (0.46, 1.84), p = 0.82 but was associated with albuminuria: OR=0.37, 95% CI (0.15, 0.92), p = 0.03. These data further strengthen the link between low birthweight and potential adverse renal outcomes.

Lifetime body size and reproductive factors: comparisons of data recorded prospectively with self reports in middle age

Background

Data on lifetime exposures are often self-reported in epidemiologic studies, sometimes many years after the relevant age. Validity of self-reported data is usually inferred from their agreement with measured values, but few studies directly quantify the likely effects of reporting errors in body size and reproductive history variables on estimates of disease-exposure associations.

Methods

The MRC National Survey of Health and Development (NSHD) and the Million Women Study (MWS) are UK population-based prospective cohorts. The NSHD recruited participants at birth in 1946 and has followed them at regular intervals since then, whereas the MWS recruited women in middle age. For 541 women who were participants in both studies, we used statistical measures of association and agreement to compare self-reported MWS data on body size throughout life and reproductive history, obtained in middle age, to NSHD data measured or reported close to the relevant ages. Likely attenuation of estimates of linear disease-exposure associations due to the combined effects of random and systematic errors was quantified using regression dilution ratios (RDRs).

Results

Data from the two studies were very strongly correlated for current height, weight and body mass index, and age at menopause (Pearson r = 0.91-0.95), strongly correlated for birth weight, parental heights, current waist and hip circumferences and waist-to-height ratio (r = 0.67-0.80), and moderately correlated for age at menarche and waist-to-hip ratio (r = 0.52-0.57). Self-reported categorical body size and clothes size data for various ages were moderately to strongly associated with anthropometry collected at the relevant times (Spearman correlations 0.51-0.79). Overall agreement between the studies was also good for most quantitative variables, although all exhibited both random and systematic reporting error. RDRs ranged from 0.66 to 0.86 for most variables (slight to moderate attenuation), except weight and body mass index (1.02 and 1.04, respectively; little or no attenuation), and age at menarche, birth weight and waist-to-hip ratio (0.44, 0.59 and 0.50, respectively; substantial attenuation).

Conclusions

This study provides some evidence that self-reported data on certain anthropometric and reproductive factors may be adequate for describing disease-exposure associations in large epidemiological studies, provided that the effects of reporting errors are quantified and the results are interpreted with caution.

Association between birth weight and visceral fat in adults

BACKGROUND

Several studies reported inverse associations between birth weight and central adiposity in adults. However, few studies investigated the contributions of different abdominal fat compartments.

OBJECTIVE

We examined associations between birth weight and adult visceral and subcutaneous abdominal fat in the population-based Fenland study.

DESIGN

A total of 1092 adults (437 men and 655 women) aged 30-55 y had available data on reported birth weight, standard anthropometric measures, and visceral and subcutaneous abdominal fat estimated by ultrasound. In a subgroup (n = 766), dual-energy X-ray absorptiometry assessment of total abdominal fat was performed. Linear regression models were used to analyze relations between birth weight and the various fat variables adjusted for sex, age, education, smoking, and body mass index (BMI).

RESULTS

After adjustment for adult BMI, there was an inverse association between birth weight and total abdominal fat [B (partial regression coefficient expressed as SD/1-kg change in birth weight) = -0.09, P = 0.002] and visceral fat (B = -0.07, P = 0.01) but not between birth weight and subcutaneous abdominal fat (B = -0.01, P = 0.3). Tests for interaction showed that adult BMI modified the association between birth weight and visceral fat (P for interaction = 0.01). In stratified analysis, the association between birth weight and visceral fat was apparent only in individuals with the highest BMI tertile (B = -0.08, P = 0.04).

CONCLUSIONS

The inverse association between birth weight and adult abdominal fat appeared to be specific to visceral fat. However, associations with birth weight were apparent only after adjustment for adult BMI. Therefore, we suggest that rapid postnatal weight gain, rather than birth weight alone, leads to increased visceral fat.

Validity of self-reported birth weight by adult women: sociodemographic influences and implications for life-course studies

Life-course epidemiologic studies frequently obtain data on perinatal and childhood factors through adult self-report. Data from a prospective US birth cohort of 262 women, born between 1959 and 1963 (average age at adult follow-up, 41.8 years), were used to assess the validity of self-reported birth weight category by sociodemographic characteristics. The effect of reporting error on the associations of birth weight with childhood and adult body mass index was evaluated by comparing the estimates of associations from linear regression analyses. The level of agreement between the birth weight category reported by 85% of the participants and the birth weight recorded at the time of birth was moderate to good (sensitivity = 73%, weighted kappa = 0.67). The validity varied by birth weight category (sensitivity range = 58%-81% for the lowest and highest birth weight category, respectively) and was highest for participants who were white, of lower childhood family income, and born to older mothers. Despite this moderate to good validity, the associations of birth weight with childhood and adult body mass index were attenuated and no longer statistically significant when self-reported birth weight was used. In conclusion, birth weight reported in middle adult life is measured with error, limiting its utility for detecting modest associations with health in later life periods.

The relationship between birthweight and early age-related maculopathy: the atherosclerosis risk in communities study

PURPOSE

Birthweight is a marker of fetal growth, and has been linked to future risk of chronic diseases in adults. We examined the association between birthweight and age-related maculopathy (ARM).

METHODS

We studied 9730 adults from the population-based Atherosclerosis Risk in Communities study, of whom 4744 reported their exact birthweight and an additional 4986 provided categorical birthweight data (low, medium or high). We graded retinal photographs for presence of ARM using a modification of the Wisconsin ARM Grading System.

RESULTS

Early ARM was present in 479 (4.9%) adults. Among persons with exact birthweight data, there was no association between birthweight and early ARM (OR 1.1, 95% CI 0.9-1.3, for each kg increase in birthweight). However, in Whites, greater birthweight was associated with an increased risk of early ARM (OR 1.2, 95% CI 1.0-1.4, for each kilogram increase in birthweight), after adjustment for age, sex, smoking, blood pressure and education level. In analyses including additional participants who provided categorical birthweight data, the pattern of associations were similar but not statistically significant. We did not have sufficient numbers to examine associations for late ARM (n = 12) or in African-Americans separately.

CONCLUSIONS

We found no association between birthweight and risk of early ARM in the whole population. Among the white participants, higher birthweight was associated with a slight increased risk of early ARM. These findings, if confirmed in other studies, suggest that fetal growth may be important in ARM development in white persons.

Birth weight, abdominal obesity and the risk of lower urinary tract symptoms in a population based study of Swedish men

PURPOSE

Lower urinary tract symptoms and obesity are prominent health problems. Low birth weight increases the adult risk of adiposity and insulin resistance, which may increase sympathetic activity and potentially lower urinary tract symptoms. Results of obesity and lower urinary tract symptoms studies are conflicting, and low birth weight and lower urinary tract symptoms relationships have not been investigated.

MATERIALS AND METHODS

This cross-sectional study examines lower urinary tract symptoms, body measures, activity, birth weight and lifestyle data collected by questionnaire from 1997 to 1998. Overall 27,858 men were analyzed and odds ratios calculated after excluding those with cancer, cerebrovascular accident, diabetes and incomplete information.

RESULTS

After adjustment for age, activity level, smoking, alcohol, coffee intake and body mass index, a significant positive association was seen between abdominal obesity (waist-to-hip ratio) and moderate to severe lower urinary tract symptoms. The risks of moderate to severe and severe lower urinary tract symptoms were 22% (95% CI 1.09-1.37) and 28% (95% CI 1.01-1.63) higher, respectively, for the top vs the lowest abdominal obesity quartile. The risk of nocturia (twice or more per night) was 1.16 (95% CI 1.02-1.33) in men in the top compared to the bottom waist-to-hip ratio quartile. Men with low birth weight (less than 2,500 gm) had a 61% (95% CI 1.12-2.30) higher risk of severe lower urinary tract symptoms compared to men with normal birth weight (2,500 to 3,999 gm). Men in the top waist-to-hip ratio quartile who had low birth weight had twice the risk of severe lower urinary tract symptoms (95% CI 1.29-3.02) compared to men with normal birth weight and in the lowest waist-to-hip ratio quartile.

CONCLUSIONS

Low birth weight and abdominal adiposity are associated with increased risk of moderate to severe lower urinary tract symptoms in adults. Further investigations are needed to determine if decreases in obesity can ameliorate lower urinary tract symptoms.

Reports of birthweight by adolescents and their mothers: comparing accuracy and identifying correlates

Birthweight is associated with health outcomes throughout the lifespan. Official birthweight records are not always available, and researchers must rely on self-reports for birthweight information. This study evaluates the accuracy of adolescent self-reports of birthweight, using medical records as a standard, and compares it with maternal reports. It also examines potential correlates of accuracy. Respondents are 17-year-old adolescents and their mothers, who participated in a follow-up study of randomly selected samples from newborn discharge lists (1983-85) of two major hospitals in south-east Michigan. Nearly one-quarter of the adolescents stated that they did not know their own birthweight, with males twice as likely as females to respond 'don't know'. In addition, self-reports of birthweight among the remaining adolescents were inaccurate, and accuracy was inversely related to birthweight. While maternal reports of offspring's birthweight are highly accurate across diverse subgroups of the population, adolescent self-reports of birthweight are unlikely to be useful in medical research.

Birth weight, components of height and coronary heart disease: evidence from the Whitehall II study

BACKGROUND

Previous studies have suggested that shorter leg length, not trunk length, may explain the inverse association between height and coronary heart disease (CHD) risk. However, investigation of the importance of birth weight for these associations has been limited. This study examines associations of measures of stature and birth weight with CHD risk factors (measures of blood pressure and lipids, 2 h glucose, waist-hip ratio and fibrinogen) and incident non-fatal coronary events in middle age.

METHODS

Data were derived mostly from the Phase 5 (1997-99) clinical screening of the Whitehall II study of British civil servants. The main cross-sectional analyses included 1084 women and 2290 men with complete data.

RESULTS

In women total height and leg length were the measures that tended to be most strongly associated with CHD risk factors, while in men leg length demonstrated the closest associations. Although associations between trunk length and CHD risk factors were weaker, trunk length was the component of height that appeared to be most closely associated with coronary events. Associations between birth weight and CHD risk factors and coronary events were generally weaker than for any measure of stature. Adjustment for birth weight had little effect on associations between components of stature and CHD risk factors or events.

CONCLUSION

Findings from this relatively privileged cohort confirmed that shorter leg length underlies the inverse association between height and CHD risk factors in middle-aged women and men. Furthermore, in this study population shorter trunk length was more closely associated with incident, non-fatal coronary events.

The relation between birth weight and intima-media thickness in middle-aged adults

BACKGROUND

Birth weight has been found to be inversely associated with the risk of coronary heart disease and stroke, although the mechanisms for this association remain unclear. Here, we investigate the relation between reported birth weight and atherosclerosis in middle age.

METHODS

We included the 9817 participants (age 44-65) in the Atherosclerosis Risk in Communities (ARIC) study who were neither a twin nor born prematurely. Carotid atherosclerosis was assessed as intima-media thickness measured by B-mode ultrasound. We studied the association with recalled exact birth weight, and for those unable to recall exact birth weight, with recalled birth weight category.

RESULTS

Mean intima-media thickness (+/- standard deviation) was 0.73 +/- 0.17 mm. Mean birth weight for the 4635 participants recalling exact birth weight was 3.49 +/- 0.71 kg. A further 4946 participants recalled birth weight category, with 4730 (96%) reporting "medium" birth weight. In univariate analysis, birth weight and intima-media thickness were positively related. However, adjustment for confounding factors reduced the association to only a 0.004 mm higher intima-media thickness (95% CI = - 0.003 to 0.011) mm per 1 kg of birth weight. The same pattern of univariate positive relationship and attenuation with adjustment was seen for birth weight category and intima-media thickness. There was no evidence of interaction between adult body mass index (BMI) and birth weight, or of interaction between category of adult BMI and birth weight category. An inverse relation between birth weight category and intima-media thickness was seen only for those in the lowest category of adult BMI (BMI <25 kg/m).

CONCLUSIONS

We found no evidence of a clinically significant relation between birth weight and carotid atherosclerosis.

Parents’ Growth in Childhood and the Birth Weight of Their Offspring

BACKGROUND

A person's birth weight is inversely related to both their own and their parents' cardiovascular disease mortality risk, but mechanisms underlying such transgenerational associations are unclear. We investigated the influence of the childhood growth of the mother or father on the birth weight of their first-born offspring.

METHODS

We used data from the long-term follow up (in 1997-1998) of 4999 children from 1352 families who participated in the Boyd Orr Survey of Diet and Health in Pre-War Britain (1937-1939). Complete information on childhood height, potential confounding variables, and the birth weight of first-born offspring was available for 637 subjects.

RESULTS

Mother's height in childhood was positively associated with her offspring's birth weight. Leg length, but not trunk length, was the component of maternal height associated with offspring birth weight. For each unit increase in z-score for maternal childhood leg length, there was a 96-g (95% confidence interval = 6-186) increase in offspring birth weight after controlling for childhood socioeconomic variables and adult height. There were weaker positive associations of paternal height and leg length in childhood with offspring birth weight. Associations were not confounded by maternal birth weight or midgrandparental height.

CONCLUSIONS

Our findings are consistent with the hypothesis that maternal growth during childhood influences offspring birth weight, independently of maternal birth weight, final attained height, or midgrandparental height. Because leg length is a sensitive marker of adverse nutritional and social exposures during childhood, these results suggest a key role for a mother's early environmental exposures as a determinant of her child's subsequent health.

Relationship between birthweight and blood lipid concentrations in later life: evidence from the existing literature

BACKGROUND

It has been suggested that there is a link between fetal growth and chronic diseases later in life. Several studies have shown a negative association between birthweight and cardiovascular diseases, as well as cardiovascular disease risk factors, such as blood pressure and type 2 diabetes. Far fewer studies have focused on the association between size at birth and blood lipid concentrations. We have conducted a qualitative assessment of the direction and consistency of the relationship between size at birth and blood lipid concentrations to see whether the suggested relationship between intrauterine growth and cardiovascular diseases is mediated by lipid metabolism.

METHODS

A literature search covering the period January 1966 to January 2003 was performed using Medline, Embase, and Web of Science. All papers written in English and reporting the relationship between size at birth and lipid levels in humans were assessed. Bibliographies were searched for further publications.

RESULTS

From an initial screen of 1198 references, 39 papers were included involving 28 578 individuals. There was no consistent relationship between size at birth and blood lipid levels; the one exception being triglyceride concentration, which showed statistically significant negative or U-shaped, but not positive, relationships with birthweight.

CONCLUSION

This review does not strongly support a link between birthweight and blood lipid levels in later life. However, the research in this area is limited and in order to make any definitive conclusions, longitudinal studies with sufficient power, data, and prospective follow-up are needed.

Life course influences on insulin resistance: findings from the British Women's Heart and Health Study

OBJECTIVE

To assess the independent associations of a broad range of early life risk factors and adult obesity with adult insulin resistance.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study of 1,394 women, aged 60-79 years, from 23 British towns.

RESULTS

There was a strong (independent of confounding factors, other early life factors, and adult waist-to-hip ratio) inverse association between birth weight and insulin resistance in women in the highest third of BMI (>28.77 kg/m2): -0.12 (95% CI -0.19 to -0.04) log homeostasis model assessment (HOMA) score per 1 SD birth weight, but no association between birth weight and insulin resistance in women in the two lowest thirds of BMI (P for interaction = 0.04). Offspring birth weight, own leg length, and childhood manual social class did not interact with adult obesity and were all independently inversely associated with insulin resistance: -0.05 (-0.09 to -0.01) log HOMA score per 1 SD offspring birth weight, -0.09 (-0.12 to -0.06) log HOMA score per 1 SD leg length, and a -0.07 (-0.14 to 0.00) difference in log HOMA score between manual and nonmanual childhood social class. Childhood manual social class and shorter leg length were both independently associated with adverse lipid profiles. BMI and waist-to-hip ratio were independently positively associated with insulin resistance and with all other components of the insulin resistance syndrome.

CONCLUSIONS

Insulin resistance is an important risk factor for type 2 diabetes and coronary heart disease. Our results suggest that genetic factors, intrauterine environment, early childhood, and adult environmental factors are all relevant in determining adult insulin resistance.