Corrie Macdonald-Wallis

Cohort Profile: The Avon Longitudinal Study of Parents and Children: ALSPAC mothers cohort

Summary The Avon Longitudinal Study of Children and Parents (ALSPAC) was established to understand how genetic and environmental characteristics influence health and development in parents and children. All pregnant women resident in a defined area in the South West of England, with an expected date of delivery between 1st April 1991 and 31st December 1992, were eligible and 13 761 women (contributing 13 867 pregnancies) were recruited. These women have been followed over the last 19–22 years and have completed up to 20 questionnaires, have had detailed data abstracted from their medical records and have information on any cancer diagnoses and deaths through record linkage. A follow-up assessment was completed 17–18 years postnatal at which anthropometry, blood pressure, fat, lean and bone mass and carotid intima media thickness were assessed, and a fasting blood sample taken. The second follow-up clinic, which additionally measures cognitive function, physical capability, physical activity (with accelerometer) and wrist bone architecture, is underway and two further assessments with similar measurements will take place over the next 5 years. There is a detailed biobank that includes DNA, with genome-wide data available on >10 000, stored serum and plasma taken repeatedly since pregnancy and other samples; a wide range of data on completed biospecimen assays are available. Details of how to access these data are provided in this cohort profile.

Association of Maternal Weight Gain in Pregnancy With Offspring Obesity and Metabolic and Vascular Traits in Childhood

Background— We sought to examine the association of gestational weight gain (GWG) and prepregnancy weight with offspring adiposity and cardiovascular risk factors. Methods and Results— Data from 5154 (for adiposity and blood pressure) and 3457 (for blood assays) mother-offspring pairs from a UK prospective pregnancy cohort were used. Random-effects multilevel models were used to assess incremental GWG (median and range of repeat weight measures per woman: 10 [1, 17]). Women who exceeded the 2009 Institute of Medicine-recommended GWG were more likely to have offspring with greater body mass index, waist, fat mass, leptin, systolic blood pressure, C-reactive protein, and interleukin-6 levels and lower high-density lipoprotein cholesterol and apolipoprotein A1 levels. Children of women who gained less than the recommended amounts had lower levels of adiposity, but other cardiovascular risk factors tended to be similar in this group to those of offspring of women gaining recommended amounts. When examined in more detail, greater prepregnancy weight was associated with greater offspring adiposity and more adverse cardiovascular risk factors at age 9 years. GWG in early pregnancy (0 to 14 weeks) was positively associated with offspring adiposity across the entire distribution but strengthened in women gaining >500 g/wk. By contrast, between 14 and 36 weeks, GWG was only associated with offspring adiposity in women gaining >500 g/wk. GWG between 14 and 36 weeks was positively and linearly associated with adverse lipid and inflammatory profiles, with these associations largely mediated by the associations with offspring adiposity. Conclusions— Greater maternal prepregnancy weight and GWG up to 36 weeks of gestation are associated with greater offspring adiposity and adverse cardiovascular risk factors. Before any GWG recommendations are implemented, the balance of risks and benefits of attempts to control GWG for short- and long-term outcomes in mother and child should be ascertained.

Associations of Pregnancy Complications With Calculated Cardiovascular Disease Risk and Cardiovascular Risk Factors in Middle Age The Avon Longitudinal Study of Parents and Children

Background— The nature and contribution of different pregnancy-related complications to future cardiovascular disease (CVD) and its risk factors and the mechanisms underlying these associations remain unclear. Methods and Results— We studied associations of pregnancy diabetes mellitus, hypertensive disorders of pregnancy, preterm delivery, and size for gestational age with calculated 10-year CVD risk (based on the Framingham score) and a wide range of cardiovascular risk factors measured 18 years after pregnancy (mean age at outcome assessment, 48 years) in a prospective cohort of 3416 women. Gestational diabetes mellitus was positively associated with fasting glucose and insulin, even after adjustment for potential confounders, whereas hypertensive disorders of pregnancy were associated with body mass index, waist circumference, blood pressure, lipids, and insulin. Large for gestational age was associated with greater waist circumference and glucose concentrations, whereas small for gestational age and preterm delivery were associated with higher blood pressure. The association with the calculated 10-year CVD risk based on the Framingham prediction score was odds ratio 1.31 (95 confidence interval, 1.11–1.53) for preeclampsia and 1.26 (95 confidence interval, 0.95–1.68) for gestational diabetes mellitus compared with women without preeclampsia and without gestational diabetes mellitus, respectively. Conclusions— Hypertensive disorders of pregnancy and pregnancy diabetes mellitus are independently associated with an increased calculated 10-year CVD risk. Preeclampsia may be the better predictor of future CVD because it was associated with a wider range of cardiovascular risk factors. Our results suggest that pregnancy may be an important opportunity for early identification of women at increased risk of CVD later in life.

Associations of gestational weight gain with maternal body mass index, waist circumference, and blood pressure measured 16 y after pregnancy: the Avon Longitudinal Study of Parents and Children (ALSPAC)

Background: Little is known about associations of gestational weight gain (GWG) with long-term maternal health. Objective: We aimed to examine associations of prepregnancy weight and GWG with maternal body mass index (BMI; in kg/m2), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) 16 y after pregnancy. Design: This is a prospective study in 2356 mothers from the Avon Longitudinal Study of Parents and Children (ALSPAC)—a population-based pregnancy cohort. Results: Women with low GWG by Institute of Medicine recommendations had a lower mean BMI (−1.56; 95% CI: −2.12, −1.00) and WC (−3.37 cm; −4.91, −1.83 cm) than did women who gained weight as recommended. Women with a high GWG had a greater mean BMI (2.90; 2.27, 3.52), WC (5.84 cm; 4.15, 7.54 cm), SBP (2.87 mm Hg; 1.22, 4.52 mm Hg), and DBP (1.00 mm Hg; −0.02, 2.01 mm Hg). Analyses were adjusted for age, offspring sex, social class, parity, smoking, physical activity and diet in pregnancy, mode of delivery, and breastfeeding. Women with a high GWG had 3-fold increased odds of overweight and central adiposity. On the basis of estimates from random-effects multilevel models, prepregnancy weight was positively associated with all outcomes. GWG in all stages of pregnancy was positively associated with later BMI, WC, increased odds of overweight or obesity, and central adiposity. GWG in midpregnancy (19–28 wk) was associated with later greater SBP, DBP, and central adiposity but only in women with a normal prepregnancy BMI. Conclusions: Results support initiatives aimed at optimizing prepregnancy weight. Recommendations on optimal GWG need to balance contrasting associations with different outcomes in both mothers and offspring.

Neurofilament light chain: A prognostic biomarker in amyotrophic lateral sclerosis.

Objective: To test blood and CSF neurofilament light chain (NfL) levels in relation to disease progression and survival in amyotrophic lateral sclerosis (ALS). Methods: Using an electrochemiluminescence immunoassay, NfL levels were measured in samples from 2 cohorts of patients with sporadic ALS and healthy controls, recruited in London (ALS/control, plasma: n = 103/42) and Oxford (ALS/control, serum: n = 64/36; paired CSF: n = 38/20). NfL levels in patients were measured at regular intervals for up to 3 years. Change in ALS Functional Rating Scale–Revised score was used to assess disease progression. Survival was evaluated using Cox regression and Kaplan–Meier analysis. Results: CSF, serum, and plasma NfL discriminated patients with ALS from healthy controls with high sensitivity (97%, 89%, 90%, respectively) and specificity (95%, 75%, 71%, respectively). CSF NfL was highly correlated with serum levels (r = 0.78, p < 0.0001). Blood NfL levels were approximately 4 times as high in patients with ALS compared with controls in both cohorts, and maintained a relatively constant expression during follow-up. Blood NfL levels at recruitment were strong, independent predictors of survival. The highest tertile of blood NfL at baseline had a mortality hazard ratio of 3.91 (95% confidence interval 1.98–7.94, p < 0.001). Conclusion: Blood-derived NfL level is an easily accessible biomarker with prognostic value in ALS. The individually relatively stable levels longitudinally offer potential for NfL as a pharmacodynamic biomarker in future therapeutic trials. Classification of evidence: This report provides Class III evidence that the NfL electrochemiluminescence immunoassay accurately distinguishes patients with sporadic ALS from healthy controls.

Cardiovascular biomarkers and vascular function during childhood in the offspring of mothers with hypertensive disorders of pregnancy: findings from the Avon Longitudinal Study of Parents and Children

Aims It is uncertain if the higher blood pressure (BP) observed in the offspring of hypertensive pregnancies is an isolated abnormality or one that is accompanied by impaired vascular function and alterations in lipid and inflammation markers that would be indicative of a more general cardiometabolic disturbance of the type observed in the mother during pre-eclampsia. Methods and results In a large UK cohort of maternal-offspring pairs (n = 3537–4654), assessed at age 9–12 years, we examined the associations of maternal gestational hypertension and pre-eclampsia with offspring BP, endothelial function assessed by brachial artery flow-mediated dilatation; arterial stiffness assessed by carotid to radial pulse wave velocity; brachial artery distensibility and BP (vascular outcomes); as well as markers of inflammation, lipids and apolipoproteins A1 and B. Offspring of women with pre-eclampsia or gestational hypertension had higher systolic blood pressure by 2.04 mmHg (95% CI: 1.33, 2.76) and 1.82 mmHg (95% CI: 0.03, 3.62), respectively, and higher diastolic blood pressure by 1.10 mmHg (95% CI: 0.47, 1.73) and 1.26 mmHg (95% CI: −0.32, 2.85), respectively, in analyses adjusted for maternal and offspring body mass index (BMI), offspring dietary sodium intake and other potential confounders. However, we found no associations of either hypertensive disorder of pregnancy with the other vascular outcomes or with inflammatory markers, lipids, and apolipoproteins. Conclusion Pre-eclampsia and gestational hypertension are associated with higher offspring BP in childhood in the absence of other vascular alterations or metabolic derangements. The findings support the existence of shared mother-offspring risk factors that are specific for higher BP, rather than the additional cardiometabolic abnormalities of hypertensive disorder of pregnancy having long-term consequences for offspring.

Hypertensive Disorders of Pregnancy and Cardiometabolic Health in Adolescent Offspring

An accumulating body of evidence suggests that offspring of mothers with preeclampsia have higher blood pressure during childhood and young adulthood compared with women without preeclampsia. However, the evidence with regard to offspring glucose metabolism and lipids is more scant. We examined whether maternal hypertensive disorders of pregnancy (preeclampsia and gestational hypertension) are associated with a range of cardiometabolic health measures in adolescent offspring. We included data for mother–offspring pairs from a United Kingdom prospective birth cohort (the Avon Longitudinal Study of Parents and Children). Repeat antenatal clinic measures of blood pressure and proteinuria (median 14 and 11, respectively) were used to ascertain maternal preeclampsia (n=53) and gestational hypertension (n=431). Offspring had blood pressure (n=4438), and fasting lipids, insulin, and glucose (n=2888) measured at a mean age of 17 years. There was no strong evidence of differences in fasting insulin, glucose, or lipid concentrations. Systolic and diastolic blood pressures were higher in offspring of mothers with gestational hypertension (mean difference, 2.06 mm Hg; 95% confidence interval, 1.28–2.84 and 1.11 mm Hg; 95% confidence interval, 0.54–1.69, respectively) and preeclampsia (1.12 mm Hg; 95% confidence interval, −0.89–3.12 and 1.71 mm Hg; 95% confidence interval, 0.23–3.17, respectively) compared with offspring of mothers without hypertensive disorders of pregnancy, adjusting for potential confounders (age, sex, maternal age at delivery, household social class, prepregnancy body mass index, parity, and smoking in pregnancy). Results suggest a specific association between maternal hypertensive disorders of pregnancy and offspring blood pressure that may be driven by genetics or familial nongenetic risk factors particular to blood pressure.

Gestational weight gain as a risk factor for hypertensive disorders of pregnancy

Objective Pregnancy interventions to limit gestational weight gain (GWG) have been proposed as a means of preventing hypertensive disorders of pregnancy (HDP); however, it is currently unclear whether GWG has a causal influence on the development of HDP. Thus, we aimed to determine whether GWG in early pregnancy is a risk factor for preeclampsia and gestational hypertension and whether GWG precedes the increases in blood pressure in normotensive women across pregnancy. Study Design We examined repeat antenatal clinic measurements of weight and blood pressure (median of 12 and 14 per woman, respectively) of 12,522 women in the Avon Longitudinal Study of Parents and Children. Results Greater prepregnancy weight was associated with an increased risk of gestational hypertension and preeclampsia per 10 kg of prepregnancy weight: odds ratio (OR), 1.80; 95% confidence interval (CI), 1.70–1.91 and OR, 1.71; 95% CI, 1.49–1.95, respectively, for women weighing 90 kg or less before pregnancy; OR, 1.24; 95% CI, 1.03–1.49 and OR, 1.61; 95% CI, 1.18–2.19 for women weighing more than 90 kg. Fully adjusted odds ratios for gestational hypertension and preeclampsia per 200 g per week GWG up to 18 weeks were OR, 1.26; 95% CI, 1.16–1.38 and OR, 1.31; 95% CI, 1.07–1.62. In normotensive women, GWG in early pregnancy was associated positively with blood pressure change in midpregnancy and negatively with blood pressure change in late pregnancy. In all gestational periods, GWG was positively associated with concurrent blood pressure change. However, there was no evidence that blood pressure changes in any period were associated with subsequent GWG. Conclusion These findings suggest that GWG in early pregnancy may be a potential target for interventions aimed at reducing the risk of HDP.

Association between pre- and perinatal exposures and Tourette syndrome or chronic tic disorder in the ALSPAC cohort

Background Tourette syndrome and chronic tic disorder are heritable but aetiologically complex. Although environment plays a role in their development, existing studies of non-genetic risk factors are inconsistent. Aims To examine the association between pre- and perinatal exposures and Tourette syndrome/chronic tic disorder in the Avon Longitudinal Study of Parents and Children (ALSPAC) prospective longitudinal pre-birth cohort. Method Relationships between exposures and Tourette syndrome/chronic tic disorder were examined in 6090 children using logistic regression. Results Maternal alcohol and cannabis use, inadequate maternal weight gain and parity were associated with Tourette syndrome or Tourette syndrome/chronic tic disorder. Other previously reported exposures, including birth weight and prenatal maternal smoking, were not associated with Tourette syndrome/chronic tic disorder. Conclusions This study supports previously reported relationships between Tourette syndrome/chronic tic disorder and prenatal alcohol exposure, and identifies additional previously unexplored potential prenatal risk factors.

Maternal and offspring adiposity-related genetic variants and gestational weight gain

BACKGROUND Gestational weight gain (GWG) is associated with a range of health outcomes, but little is known about the factors that influence it. OBJECTIVE The objective was to test the hypothesis that maternal and fetal genetic variants that are reliably associated with adiposity are associated with GWG. DESIGN We examined the association of a risk allele score by using 4 adiposity-related single nucleotide polymorphisms (SNPs; rs9939609 in FTO, rs17782313 near MC4R, rs6548238 near TMEM18, and rs10938397 near GNPDA2) with GWG in a pregnancy cohort in which women had detailed repeated assessment of GWG (median number of weight measurements: 10; interquartile range: 8, 11). The numbers included in our analyses varied between 2324 and 7563 for different variant-outcome analyses. A linear spline random-effects model was used to model weight change with gestational age and to relate genetic variants to this. This modeling confirmed 3 distinct periods of GWG: 0-18, 19-28, and ≥29 wk of gestation. RESULTS Maternal risk allele score and SNPs in FTO, MC4R, and TMEM18 were positively associated with prepregnancy weight. Maternal allele score was inversely associated with GWG in the first 18 wk of pregnancy (-14.46 g/wk per allele; 95% CI: -24.75, -4.17 g/wk per allele) but was not associated with other periods of GWG. Offspring allele score and maternal and offspring individual SNPs were not associated with GWG in any period or with birth weight or postnatal weight retention. CONCLUSIONS Our findings suggest that neither maternal nor fetal adiposity-related genetic variants are associated with greater GWG. The inverse association of maternal allele score with GWG in the first 18 wk requires replication.