Childhood maltreatment and health in the UK Biobank: triangulation of outcome-wide and polygenic risk score analyses.

BACKGROUND: Childhood maltreatment is common globally and impacts morbidity, mortality, and well-being. Our understanding of its impact is constrained by key substantive and methodological limitations of extant research, including understudied physical health outcomes and bias due to unmeasured confounding. We address these limitations through a large-scale outcome-wide triangulation study. METHODS: We performed two outcome-wide analyses (OWAs) in the UK Biobank. First, we examined the relationship between self-reported maltreatment exposure (number of maltreatment types, via Childhood Trauma Screener) and 414 outcomes in a sub-sample of 157,316 individuals using generalized linear models ("observational OWA"). Outcomes covered a broad range of health themes including health behaviors, cardiovascular disease, digestive health, socioeconomic status, and pain. Second, we examined the relationship between a polygenic risk score for maltreatment and 298 outcomes in a non-overlapping sample of 243,006 individuals ("genetic OWA"). We triangulated results across OWAs based on differing sources of bias. RESULTS: Overall, 23.8% of the analytic sample for the observational OWA reported at least one maltreatment type. Of 298 outcomes examined in both OWAs, 25% were significant in both OWAs and concordant in the direction of association. Most of these were considered robust in the observational OWA according to sensitivity analyses and included outcomes such as marital separation (OR from observational OWA, ORo = 1.25 (95% CI: 1.21, 1.29); OR from genetic OWA, ORg = 1.06 (1.03, 1.08)), major diet changes due to illness (ORo = 1.27 (1.24, 1.29); ORg = 1.01 (1.00, 1.03)), certain intestinal diseases (ORo = 1.14 (1.10, 1.18); ORg = 1.03 (1.01, 1.06)), hearing difficulty with background noise (ORo = 1.11 (1.11, 1.12); ORg = 1.01 (1.00, 1.01)), knee arthrosis (ORo = 1.13 (1.09, 1.18); ORg = 1.03 (1.01, 1.05)), frequent sleeplessness (ORo = 1.21 (1.20, 1.23); ORg = 1.02 (1.01, 1.03)), and low household income (ORo = 1.28 (1.26, 1.31); ORg = 1.02 (1.01, 1.03)). Approximately 62% of results were significant in the observational OWA but not the genetic OWA, including numerous cardiovascular outcomes. Only 6 outcomes were significant in the genetic OWA and null in the observational OWA; these included diastolic blood pressure and glaucoma. No outcomes were statistically significant in opposite directions in the two analyses, and 11% were not significant in either OWA. CONCLUSIONS: Our findings underscore the far-reaching negative effects of childhood maltreatment in later life and the utility of an outcome-wide triangulation design with sensitivity analyses for improving causal inference.

Assessing causal links between age at menarche and adolescent mental health: a Mendelian randomisation study.

BACKGROUND: The timing of puberty may have an important impact on adolescent mental health. In particular, earlier age at menarche has been associated with elevated rates of depression in adolescents. Previous research suggests that this relationship may be causal, but replication and an investigation of whether this effect extends to other mental health domains is warranted. METHODS: In this Registered Report, we triangulated evidence from different causal inference methods using a new wave of data (N = 13,398) from the Norwegian Mother, Father, and Child Cohort Study. We combined multiple regression, one- and two-sample Mendelian randomisation (MR), and negative control analyses (using pre-pubertal symptoms as outcomes) to assess the causal links between age at menarche and different domains of adolescent mental health. RESULTS: Our results supported the hypothesis that earlier age at menarche is associated with elevated depressive symptoms in early adolescence based on multiple regression (ß = - 0.11, 95% CI [- 0.12, - 0.09], pone-tailed < 0.01). One-sample MR analyses suggested that this relationship may be causal (ß = - 0.07, 95% CI [- 0.13, 0.00], pone-tailed = 0.03), but the effect was small, corresponding to just a 0.06 standard deviation increase in depressive symptoms with each earlier year of menarche. There was also some evidence of a causal relationship with depression diagnoses during adolescence based on one-sample MR (OR = 0.74, 95% CI [0.54, 1.01], pone-tailed = 0.03), corresponding to a 29% increase in the odds of receiving a depression diagnosis with each earlier year of menarche. Negative control and two-sample MR sensitivity analyses were broadly consistent with this pattern of results. Multivariable MR analyses accounting for the genetic overlap between age at menarche and childhood body size provided some evidence of confounding. Meanwhile, we found little consistent evidence of effects on other domains of mental health after accounting for co-occurring depression and other confounding. CONCLUSIONS: We found evidence that age at menarche affected diagnoses of adolescent depression, but not other domains of mental health. Our findings suggest that earlier age at menarche is linked to problems in specific domains rather than adolescent mental health in general.

Lifetime History of Low Birth Weight Delivery and Cognitive Function in Middle-Aged Parous Women.

BACKGROUND AND OBJECTIVES: Pregnancy outcomes such as low birth weight (LBW) delivery may reflect vascular or metabolic dysfunction in mothers and presage future cognitive impairment and dementia. However, the evidence is currently limited. Our objective was to examine the extent to which a lifetime history of LBW delivery was associated with cognitive function in parous middle-aged women. METHODS: We studied participants from the Nurses' Health Study II, an ongoing longitudinal cohort of female nurses enrolled in 1989. In 2009, participants completed a reproductive history questionnaire. Participants who completed at least one of 2 post-traumatic stress disorder questionnaires were invited to participate in a cognition substudy with 2 waves of baseline data collection (2014 or 2018). We restricted the analysis to participants with one valid cognitive assessment who reported ≥1 birth at 18 years and older. We defined LBW delivery history as having delivered offspring with a birth weight <2,500 g (<5.5 lbs) in any pregnancy. The outcome was a single assessment of cognitive function evaluated with the self-administered Cogstate Brief Battery. The battery comprises 4 tasks, which we used to create 2 composite z-scores measuring psychomotor speed/attention and learning/working memory (higher z-scores = better cognitive function). We used multivariable linear regression models. RESULTS: The analysis included 15,323 participants with a mean age of 62 (standard deviation: 4.9 years) at cognitive assessment. Among them, 1,224 (8%) had a history of LBW delivery. After adjusting for age at cognitive assessment, race, and ethnicity, participants' education, wave of baseline cognitive assessment, socioeconomic status, and prepregnancy characteristics, women with a history of LBW delivery had lower z-scores in the psychomotor speed/attention (ß, -0.06; 95% CI -0.12 to -0.01) and learning/working memory (ß, -0.05; 95% CI -0.09 to -0.01) composites than parous women without a history of LBW delivery. We observed a gradient of lower z-scores with an increasing number of LBW deliveries. DISCUSSION: History of LBW delivery may be marker of future poorer cognition. If confirmed, our findings support future investigations into the value of early preventive efforts targeting women with a history of LBW delivery to reduce the burden of cognitive impairment in women.