Fatal flaw in the fetal argument

Birthweight predicts glomerular filtration rate in adult-life: population based cross sectional study

INTRODUCTION

Worldwide, there is a global progressive rise of chronic kidney disease. In parallel, children born after intra-uterine growth retardation are surviving to adult-life and beyond. This study describes the association of birthweight with and estimated glomerular filtration rate (eGFR).

METHODS

Australian Diabetes, Obesity and Lifestyle (AusDiab) study participants were asked to complete a birthweight questionnaire. The associations between birthweight and eGFR were determined.

RESULTS

A total of 4502 reported information related to their birthweight, with the other responders did not provide a value. The birthweight of the participants ranged from 0.4 to 7.0 kg with a mean-(SD) of 3.37 (0.7) kg. The mean (95%CI) birthweight was lower for females, 3.28 (0.6) kg, when compared to males, 3.5 (0.7) kg. Eight percent had a birthweight less than 2.5 kg. The eGFR was strongly and positively associated with birthweight, with people in the lowest sex-specific birthweight-quintiles having the lowest mean eGFR. This relationship persisted with adjustment for confounding factors. The OR(CI) for eGFR <10th-percentile (<61.4 ml/min for females and <73.4 for males) for people in the lowest vs. the higher birthweight-quintile was 2.19 (95%CI 1.14-4.2) for females and 2.37 (1.1-5.3) for males, after adjustment for other factors.

CONCLUSIONS

Birthweight had a positive relationship with eGFR. Possible explanations include an association of birthweight with nephron-endowment. From a global health perspective but more in developing countries and in populations in epidemiologic transition, where substantially lower birthweights coexist with recently improved infant and adult survivals, the overall impact of this phenomenon on the population health profile could be more substantial.

Birth Weight Predicts Anthropometric and Body Composition Assessment Results in Adults: A Population-Based Cross-Sectional Study

BACKGROUND

A poor intrauterine environment is associated with increased risks of hypertension, chronic kidney disease, and/or diabetes. This study evaluated relationships between birth weight and body habitus in a representative sample of the general population.

METHODS

Adult participants were asked to complete a birth weight questionnaire. Associations between various current anthropometric and body composition measurements and birth weight were investigated.

RESULTS

Of 7,157 respondents, 4,502 reported their birth weight, which ranged from 0.4 to 7.0 kg with a mean and standard deviation of 3.37±0.7 kg; of these, 384 had low birth weights (LBWs; <2.5 kg). In females, lower birth weights were associated with lower height, weight, lean body mass (LBM), total body water (TBW), fat mass (FM), fat%, and fat-free mass (FFM) than those of higher older birth weights (quintiles); however, waist circumference (WC), and hip circumference (HC) were similar across quintiles. In males, LBW was similarly associated with lower height, weight, LBM, TBW, FM, fat%, and FFM, and also with lower WC and HC. The obesity markers such as WC, WHR, and body mass index (BMI) were 47%, 61%, and 45% greater, respectively, in LBW females compared to normal birth weight females, while these associations showed non-significant trend in males with LBW.

CONCLUSION

In adult male and female respondents, LBW was associated with lower body habitus: central obesity and body fatness (BMI, FM, fat%, FFM, FM/FFM, and FM/FFM²) were more pronounced in females than males, even after taking into account current physical activity and socioeconomic status. These findings indicate LBW may contribute to high blood pressure, dysglycemia and metabolic-abnormalities in adults.

Birth weight is inversely correlated with blood pressure: population-based study

BACKGROUND AND METHOD

The current representative national cross-sectional study examines the association of birth weight and blood pressure (BP) among the adult Australian population.Questions about birth weight were added to the second round of AusDiab study. Hypertension was defined based on WHO (≥140/90), and NCEP-ATPIII (≥130/85). Both definitions were examined against the continuous birth weight and dichotomous variable of low birth weight (LBW); less than 2.5 kg, adjusting for age, BMI, physical activity, smoking, alcohol intake and socioeconomic factors.

RESULTS

A total of 4502 respondents reported their birth weights with a mean (SD) of 3.37 (0.7) kg. Females with LBW had significantly higher mean SBP and DBP than those with normal birth weight. This relationship persisted with adjustments for various confounding factors. Males with LBW showed a trend towards a higher SBP and DBP, though NS, than normal birth weight more than 2.5 kg. LBW individuals, less than 2.5 kg were at higher risk for having high SBP hypertension at least 140/90 mmHg and at least 130/85 mmHg compared with those with normal birth weight. Among females, for each kilogramme of birth weight, there was a predicted decrease of 1.59 (0.7, 2.5) mmHg in SBP, P = 0.001 and 0.85 (0.2, 1.5) mmHg in DBP, P = 0.001; after adjustments for age, body size, physical activity, smoking status, alcohol intake and socioeconomic factors. Among males, for each kilogramme of birth weight, there was a decrease of 1.74 (0.7, 2.8) mmHg in SBP, P = 0.002 and 1.06 (0.3, 1.9) mmHg in DBP, P = 0.008 after adjustments for all confounding factor.

CONCLUSION

This study has examined the association of birth weight and BP in a representative adult population. LBW was significantly associated with the risk of developing high BP.

Birthweight predicts adult cardiovascular disorders: Population based cross sectional survey

BACKGROUND

Cardiovascular disease (CVD) is the primary cause of death in the developed-countries and mostly in the poorer areas of the country, and in lower income-groups.

HYPOTHESIS

Birthweight predicts adult development of angina, coronary heart disease, stroke, and combination of all CVD.

METHODS

The AusDiab is a cross-sectional study of Australians aged 25 years or over. Data on age, sex, previous-CVD, smoking-status, alcohol-intake, time-spent on watching television and physical-activity, total house-income, dwelling-type and education-level were collected by interviewer- administered-questionnaires.

RESULTS

Four thousand five hundred and two had birthweights (mean (SD) of 3.4(0.7) kg). Females in the lowest birthweight-quintile were at least 1.23, 1.48, 1.65, and 1.23 times more likely to have angina, CAD, stroke, and CVS compared to the referent group ≥3.72 kg with P = .123, .09, .099, and 0.176, respectively. Similarly, males in the lowest-birthweight-quintile were 1.23, 1.30, 1.39, and 1.26 times more likely to have angina, CAD, stroke, and CVS compared to the referent-group ≥4.05 kg with P = .231, .087, .102, and .123, respectively. Females with low birth weight (LBW) were at least 1.39, 1.40, 2.30, and 1.47 times more likely to have angina, CAD, stroke and CVS compared to those ≥2.5 kg with P = .06, .19, .03, and .13, respectively. Similarly, males with LBW were 1.76, 1.48, 3.34, and 1.70 times more likely to have angina, CAD, stroke, and CVS compared to those ≥2.5 kg with P = .14, .13, .03, and .08, respectively.

CONCLUSION

there was a negative relationship between birth weight and angina, CAD, stroke, and the overall CVS. It would be prudent, to adopt policies of intensified whole of life surveillance of lower-birthweight people, anticipating this risk.

Birthweight and Lipids in Adult Life: Population-Based Cross Sectional Study

The purpose of this study was to examine the association of birthweight with lipid profile in the general adult population. Participants in the second-wave of a nationally representative cross sectional AusDiab-study were asked to complete a birthweight questionnaire. Fasting total cholesterol (TC), LDL-C, HDL-C, and triacylglycerol levels were modeled against birthweight. Four thousand five hundred and two people reported their birthweights, mean (SD) of 3.4(0.7) kg. Females with low birthweight-LBW had higher levels of TC, LDL-C, and triacylglycerols, but no difference in HDL-C, than those with normal-birthweight-NBW;≥2.5 kg. People with LBW showed a trend toward increased risk for high TC (≥5.5 mmol/L) compared to NBW. Among females with LBW, the risk for high LDL-C (≥3.5 mmol/L) was increased compared to those of NBW. The risk for low HDL-C (<0.9 mmol/L) was increased among males with LBW compared to those with NBW. Examination of the relationship on the continuum showed no differences except for high triacylglycerol levels among females with the lowest birthweight quintile compared to the higher birthweight quintile. However, the risk for various abnormalities by birthweight quintiles was similar to that when we used the traditional definition of LBW vs. NBW. Females and males with low birthweight differ in their risk for lipids abnormalities. Females had higher risk for high LDL-C, whereas males had high risk for low HDL-C (<0.9 mmol/L). In addition, females with low birthweight had the highest triacylglycerol levels. High LDL-C, low HDL-C, and high triacylglycerols are well-recognized risk factors for cardiovascular disease.

Low birthweight and subsequent emotional and behavioural outcomes in 12-year-old children in Soweto, South Africa: findings from Birth to Twenty

BACKGROUND

The fetal origins hypothesis suggests that an adverse prenatal environment, indexed by low birthweight (LBW), may increase the risk of developing later disease. Recently the hypothesis has been extended to psychological outcomes, especially depression. The aim of this analysis was to test, for the first time in a developing country setting, the association between LBW and psychological symptoms, in Soweto, South Africa.

METHODS

A sample of 1029 children was drawn from Birth to Twenty, a longitudinal cohort followed from pregnancy to young adulthood. This sample completed the Youth Self Report at age 12 years, a validated psychological measure of behavioural and emotional adjustment. Scores were compared between LBW (<2500 g) and normal birthweight children using multivariate analysis with adjustment for potential birth and life events confounding factors.

RESULTS

No associations were found between LBW and total [adjusted odds ratio (OR) 1.09, 95% confidence interval (CI) 0.69-1.74], internalizing (adjusted OR 0.81, 95% CI 0.52-1.28) or externalizing profiles (adjusted OR 0.81, 95% CI 0.49-1.36). The only difference detected was for the internalizing sub-profile of Somatic Complaints (adjusted OR 2.02, 95% CI 1.21-3.38), which on subgroup analysis was greatest among females.

CONCLUSIONS

We found no convincing evidence of an association between LBW and emotional and behavioural outcomes in 12-year olds in this sample in urban South Africa. To our knowledge, this is the first published assessment of this association in a developing world context.

Familial (shared environmental and genetic) factors and the foetal origins of cardiovascular diseases and type 2 diabetes: a review of the literature

Several researchers have argued that observed associations between birth weight and cardiovascular diseases, and type 2 diabetes, may be confounded by familial (shared environmental and genetic) factors. However, most studies have found that shared environmental factors, including socio-economic factors, do not influence the foetal origins of adult diseases. Results from two twin studies suggest that genetic factors may be of importance for the association between birth weight and risks of coronary heart disease, but findings from intergenerational studies are not consistent with genetic confounding. More studies have assessed the importance of genetic factors with respect to risk factors of coronary heart, including raised blood pressure and lipid levels. Recent findings suggest that the association between birth weight and hypertension is independent of genetic factors. In contrast, recent twin and intergenerational studies favour the hypothesis that the association between birth weight and risk of type 2 diabetes is confounded by genetic factors.

Developmental plasticity and human disease: research directions

The conceptual basis of the 'developmental origins' paradigm has converged on the role of developmental plasticity responding to signals from the early environment, with heightened risk of disease if the induced phenotype does not match the later environment. Nevertheless, numerous questions remain, including the current burden of disease that can be attributed to early environmental factors; the pathways, mechanisms and windows of plasticity; the identification of early markers of environmentally induced change; and the feasibility, costs and benefits of intervention. A focused agenda of research is needed to convince policy makers of the importance of developmental factors in human disease.