Maternal blood pressure trajectories and associations with gestational age at birth: a functional data analytic approach.

BACKGROUND: Research has revealed group-level differences in maternal blood pressure trajectories across pregnancy. These trajectories are typically constructed using clinical blood pressure data and multivariate statistical methods that are prone to bias and ignore the functional, dynamic process underlying a single blood pressure observation. The aim of this study was to use functional data analysis to explore blood pressure variation across pregnancy, and multivariate methods to examine whether trajectories are related to gestational age at birth. METHODS: Clinical blood pressure observations were available from 370 women who participated in a longitudinal pregnancy cohort study conducted in Montreal, Quebec, Canada. Functional data analysis was used to smooth blood pressure data and then to conduct a functional principal component analysis to examine predominant modes of variation. RESULTS: Three eigenfunctions explained greater than 95% of the total variance in blood pressure. The first accounted for approximately 80% of the variance and was characterized by a prolonged-decrease trajectory in blood pressure; the second explained 10% of the variance and captured a late-increase trajectory; and the third accounted for approximately 7% of the variance and captured a mid-decrease trajectory. The prolonged-decrease trajectory of blood pressure was associated with older, and late-increase with younger gestational age at birth. CONCLUSION: Functional data analysis is a useful method to model repeated maternal blood pressure observations and many other time-related cardiovascular processes. Results add to previous research investigating blood pressure trajectories across pregnancy through identification of additional, potentially clinically important modes of variation that are associated with gestational age at birth.

Hypertensive Disorders of Pregnancy and Symptoms of Depression and Anxiety as Related to Gestational Age at Birth: Findings From the All Our Families Study.

OBJECTIVE: The aim of the study was to investigate whether symptoms of depression or state anxiety changed the strength or nature of the association between hypertensive disorders of pregnancy (HDP) and gestational age at birth. METHODS: We conducted a secondary analysis of data from the All Our Families Cohort, a prospective pregnancy cohort study based in Calgary, Alberta, Canada. Self-reported depressive symptoms and state anxiety were assessed between 3 and 5 months of gestation, and obstetrical information, including diagnosis of HDP, parity, type of delivery, and gestational age at birth, was retrieved from the maternal discharge abstract. All models were adjusted for sociodemographic and obstetric confounders. RESULTS: Of 2763 women who had a singleton pregnancy and live birth, 247 (9%) were diagnosed with HDP. Women with HDP had significantly shorter gestational length relative to those without the diagnosis (M = 37.87 versus M = 38.99 weeks of gestation), t(2761) = 9.43, p < .001. Moderation analyses showed significant HDP by depressive symptoms and HDP by state anxiety interactions, such that the strength of the association between HDP and gestational age at birth increased alongside greater depressive symptom and state anxiety severity. CONCLUSIONS: Results suggest that depressive symptoms and state anxiety may add to the increased risk for shortened gestation associated with HDP. Women at high risk of cardiovascular complications during pregnancy may benefit from additional resources to manage symptoms of depression or anxiety.

Insomnia symptoms and heart rate recovery among patients in cardiac rehabilitation.

Insomnia symptoms (i.e., difficulty falling asleep, difficulty staying asleep, and early morning awakenings) are common among people with cardiovascular disease, and have been linked to adverse cardiovascular health outcomes. Reduced parasympathetic tone is one pathway through which risk may be conferred. The purpose of this study was to evaluate whether insomnia symptoms are associated with lower parasympathetic tone in cardiac rehabilitation patients with suspected insomnia. Participants (N = 121) completed a self-report measure of insomnia severity. 1-min heart rate recovery (HRR), an index of parasympathetic tone, was obtained during a maximal exercise test. Difficulty falling asleep, but not difficulty staying asleep or early awakenings, was associated with attenuated 1-min HRR. When analyses were restricted to participants with moderate and severe insomnia severity (n = 51), the strength of this association increased. In a sample of cardiac rehabilitation patients with insomnia, only the symptom of difficulty falling asleep was associated with lower parasympathetic tone, suggesting that individual insomnia symptoms may show specificity in their associations with physiological mechanisms.

The Association Between Insomnia Symptoms and Mood Changes During Exercise Among Patients Enrolled in Cardiac Rehabilitation.

PURPOSE: Insomnia symptoms (ie, difficulty falling asleep, difficulty staying asleep, and early awakenings) are common among patients with cardiovascular disease and may interfere with the beneficial impact of exercise on mood state. This study investigated the association of insomnia symptom severity with mood disturbance and with changes in mood state during exercise in a cardiac rehabilitation (CR) population. METHODS: Insomnia symptom severity was measured using the Insomnia Severity Index upon admission to a 12-week CR program (n = 57). The Physical Activity Affect Scale was administered before and during a single bout of moderate intensity exercise to measure changes in mood state. Indices of mood disturbance included depressive symptoms (Hospital Anxiety and Depression Scale) and pre-exercise mood state (Physical Activity Affect Scale). RESULTS: Greater severity of insomnia symptoms was associated with less pleasant mood overall (r = -0.45, P < .001), including less tranquility (r = -0.37, P = .005), lower positive affect (r = -0.39, P = .003), and worse fatigue (r = 0.36, P = .005); greater insomnia symptom severity also predicted greater improvements during exercise in both overall mood state (b = 0.26, standard error = 0.10, P = .009) and tranquility (b = 0.09, standard error = 0.04, P = .04), following statistical adjustment for demographic variables and pre-exercise mood state. CONCLUSIONS: Although CR patients reporting insomnia symptoms tend to experience daytime mood disturbance, they may benefit from mood-elevating properties of exercise. Future research is needed to help optimize mood during exercise, which may have implications for improving psychological distress and CR adherence.