Clément Dassa

Stress Pathways to Spontaneous Preterm Birth: The Role of Stressors, Psychological Distress, and Stress Hormones

The authors investigated a large number of stressors and measures of psychological distress in a multicenter, prospective cohort study of spontaneous preterm birth among 5,337 Montreal (Canada)-area women who delivered from October 1999 to April 2004. In addition, a nested case-control analysis (207 cases, 444 controls) was used to explore potential biologic pathways by analyzing maternal plasma corticotrophin-releasing hormone (CRH), placental histopathology, and (in a subset) maternal hair cortisol. Among the large number of stress and distress measures studied, only pregnancy-related anxiety was consistently and independently associated with spontaneous preterm birth (for values above the median, adjusted odds ratio = 1.8 (95% confidence interval: 1.3, 2.4)), with a dose-response relation across quartiles. The maternal plasma CRH concentration was significantly higher in cases than in controls in crude analyses but not after adjustment (for concentrations above the median, adjusted odds ratio = 1.1 (95% confidence interval: 0.8, 1.6)). In the subgroup (n = 117) of participants with a sufficient maternal hair sample, hair cortisol was positively associated with gestational age. Neither maternal plasma CRH, hair cortisol, nor placental histopathologic features of infection/inflammation, infarction, or maternal vasculopathy were significantly associated with pregnancy-related anxiety or any other stress or distress measure. The biologic pathways underlying stress-induced preterm birth remain poorly understood.

THE STRUCTURE OF MENTAL HEALTH: HIGHER-ORDER CONFIRMATORY FACTOR ANALYSES OF PSYCHOLOGICAL DISTRESS AND WELL-BEING MEASURES

This paper addresses the question of whether psychological distress and subjective well-being are the opposite poles of the same axis of mental health or independent constructs that should be measured on two independent axes. The measures used in this study originate from a preliminary ethnosemantic study and the content analysis of narratives of psychological distress and well-being episodes experienced by a random sample of francophone Quebecers (Canada). Two scales were produced: a Psychological Distress Manifestation Scale (PDMS) based on 23 items and four factors (Anxiety/Depression, Irritability, Self-Depreciation, and Social Disengagement), and a Psychological Well-Being Manifestation Scale with 25 items and six factors (Self-Esteem, Social Involvement, Mental Balance, Control of Self and Events, Sociability, and Happiness). Structural equation modeling analyses confirm that these 10 factors can be viewed as components of two correlated dimensions (psychological distress and well-being) (r = −0.65) of a two-dimensional latent construct which reflects a higher-order concept of mental health. We conclude that assessment of mental health in general populations should use concomitant measures of psychological distress and well-being.

Emerging measurement and statistical methods in physical activity research

Although many studies have attempted to identify mediators and moderators of changes in physical activity involvement, the literature is inconclusive regarding which variable(s) relate to physical activity behavior change. The Cooper 2001 Conference series dedicated a session to discussing measurement and statistical methods that could contribute to advancing this research agenda. This article focuses on four such methodologic approaches: qualitative; psychometric; latent-variable, structural equation modeling; and multilevel modeling. The article presents a brief overview of these methods and discusses potential advantages and limitations of using them.

Impact of rhinosinusitis in health care delivery: the Quebec experience.

OBJECTIVE Rhinosinusitis is a common disease affecting 135 per 1,000 population. The cost and the impact on quality of life of this disease are considerable. Health care delivery for a particular disease is evaluated through the health impact of the disease, outcomes of treatments, and their costs. This article reviews our experience with rhinosinusitis and its impact on health, as measured using a generic quality of life instrument, the Medical Outcome Study 36-Item Short-Form Health Survey (SF-36), in a selected patient population. Outcomes of treatments will be introduced, and the economic impact of chronic rhinosinusitis based on a U.S. study will be discussed. MATERIAL AND METHODS One hundred and ten patients (divided into three subgroups: recurrent acute rhinosinusitis, chronic rhinosinusitis, and nasal polyposis) completed the SF-36 survey on the day of the diagnostic visit in the outpatient sinus clinics of two hospitals. RESULTS The scores of the SF-36, in chronic rhinosinusitis, are compared with the normative values of a healthy U.S. population showing statistically significant differences in seven of eight domains. A comparison of the scores of chronic rhinosinusitis with a U.S. study on chronic rhinosinusitis shows statistically significant differences in five of eight domains. A comparison of the scores in the three diagnostic subgroups shows a statistical significance in two domains: bodily pain and vitality are more affected in recurrent acute and chronic rhinosinusitis. CONCLUSIONS Chronic rhinosinusitis affects the quality of life of patients with rhinosinusitis and represents an important health burden. Some differences are noted with the U.S. chronic rhinosinusitis population. Recurrent acute and chronic rhinosinusitis seem to have more impact on vitality and bodily pain than nasal polyposis.

Inherited thrombophilia and preeclampsia within a multicenter cohort: the Montreal Preeclampsia Study.

OBJECTIVE We sought to evaluate the association between inherited thrombophilia and preeclampsia. STUDY DESIGN From a multicenter cohort of 5337 pregnant women, we prospectively identified 113 women who developed preeclampsia and selected 443 control subjects who did not have preeclampsia or nonproteinuric gestational hypertension. Blood samples were tested for DNA polymorphisms affecting thrombophilia (factor V Leiden mutation, prothrombin G20210A mutation, methylenetetrahydrofolate reductase C677T polymorphism), homocysteine, and folate levels, and placentae underwent pathological evaluation. RESULTS Thrombophilia was present in 14% of patients and 21% of control subjects (adjusted logistic regression odds ratio, 0.6; 95% confidence interval, 0.3-1.3). Placental underperfusion was present in 63% of patients vs 46% of control subjects (P < .001) and was more frequent in women with folate levels in the lowest quartile (P = .04), but was not associated with thrombophilia. CONCLUSION We did not find evidence to support an association between inherited thrombophilia and increased risk of preeclampsia. Placental underperfusion is associated with preeclampsia, but this does not appear to be consequent to thrombophilia.

Vasculopathic and thrombophilic risk factors for spontaneous preterm birth

BACKGROUND Mothers who give birth to preterm infants are at increased risk of mortality from coronary heart disease and stroke, but the biological pathways underlying these associations have not been explored. METHODS We carried out a case-control study nested in a large (n = 5337) prospective, multicentre cohort. All cohort women had an interview, examination and venipuncture at 24-26 weeks. Frozen plasma samples in spontaneous preterm births (n = 207) and 444 term controls were analysed for plasma homocysteine, folate, cholesterol (total, low-density lipoprotein and high-density lipoprotein) and thrombin-antithrombin (TAT) complexes. DNA was extracted and analysed for seven gene polymorphisms involved in thrombophilia or folate or homocysteine metabolism. Fresh placentas were fixed, stained and blindly assessed for histologic evidence of infarction and decidual vasculopathy. RESULTS High (above the median) plasma homocysteine and HDL cholesterol were significantly and independently associated with the risk of spontaneous preterm birth [adjusted odds ratios (OR)s = 1.9 (95% 1.1-3.3) and 0.5 (0.3-0.9), respectively]. A higher proportion of women with high homocysteine concentrations had decidual vasculopathy [(13.0 vs 6.8%; OR = 1.9 (1.1-3.5)], although the positive association between decidual vasculopathy and preterm birth did not achieve statistical significance [OR = 1.5 (0.9-2.7)]. No significant associations were observed with the DNA polymorphisms or with plasma TAT or folate levels. CONCLUSIONS Similar vasculopathic risk factors may underlie preterm birth and adult coronary heart disease and stroke.

The criterion-related validity of the IADL Profile with measures of executive functions, indices of trauma severity and sociodemographic characteristics

Primary objective: To examine relationships between classical measures of executive functions (EF) and indices of traumatic brain injury (TBI) severity with the IADL Profile, a new performance-based measure of independence in instrumental activities of daily living (IADL) based on EF. This study hypothesized the presence of correlations between classical tests of EF and the IADL Profile, as the latter aims to establish whether the subjects main difficulties pertain to goal formulation, planning, carrying out the task and/or attaining the initial task goal; all important components of EF. Methods and procedures: One hundred subjects with a moderate/severe TBI aged 16–65 years (convenience sample) were recruited. Subjects were tested with the IADL Profile and three measures of EF within their home environment. Data was analysed using Pearson correlations, t-tests and multiple stepwise regressions. Results: Post-traumatic amnesia and working memory emerged as the major determinants of IADL Profile scores. Together, indices of injury severity, measures of EF, education, age and environmental factors accounted for 12–28% of the variance in IADL Profile scores. Conclusions: This study has shown that the IADL Profiles non-structured approach permits the observation of a broad range of behaviours related to EF deficits and thus provides a closer approximation of the persons independence in IADL. Further study is required to demonstrate the IADL Profiles ability to inform more targeted treatment interventions.

The factorial validity and internal consistency of the Instrumental Activities of Daily Living Profile in individuals with a traumatic brain injury

The objective of the study was to investigate the factorial validity and internal consistency of the Instrumental Activities of Daily Living (IADL) Profile. A group of 96 patients aged 16 to 65 years, with moderate to severe traumatic brain injuries, was recruited from 12 rehabilitation hospitals in Quebec. The IADL Profile was administered by an occupational therapist in each subjects home and community environment. Principal axis factoring and confirmatory factor analysis provide preliminary support for six correlated factors (F): (F1) going to grocery store/shopping for groceries, (F2) having a meal with guests/cleaning up, (F3) putting on outdoor clothing, (F4) obtaining information, (F5) making a budget, (F6) preparing a hot meal for guests. Total explained variance was 73.6%. Cronbachs alpha analysis revealed high to very high internal consistency for all scales ranging from .81 to .98; internal consistency of the total scale was very high (0.95). The findings suggest that the IADL Profile is a promising means of documenting both IADL independence and the repercussions of executive function deficits on everyday tasks in real-world environments.

Antioxidant vitamins, long-chain fatty acids, and spontaneous preterm birth.

Background: Neither macro- nor micronutrient supplements have been clearly demonstrated to reduce the risk of preterm birth. However, there has been little attention to carotenoids, tocopherols, and long-chain fatty acids other than n-3 polyunsaturates. Methods: We conducted a case–control study nested in a large (n = 5337) prospective, multicenter cohort. All cohort women had an interview, examination, and venipuncture at 24–26 weeks’ gestation. Frozen plasma samples in spontaneous preterm births (n = 207) and approximately 2-term controls per case (n = 443) were analyzed for carotenoids, retinol, tocopherols, and long-chain fatty acids. Fresh placentas were fixed, stained, and assessed (without knowledge of pregnancy outcome) for histologic evidence of infection or inflammation, decidual vasculopathy, and infarction. Results: High (above the median) plasma concentrations of &agr;- and &bgr;-carotene, &agr;- and &bgr;-cryptoxanthin, and lycopene were all associated with reductions in risk of spontaneous preterm birth, with evidence of dose-response effects across quartiles. Modest increases in risk were observed with elevated total monounsaturated, total polyunsaturated, and total n-6 polyunsaturated long-chain fatty acids concentrations. Paradoxically, a high &ggr;-tocopherol concentration was associated with increased preterm birth risk (adjusted odds ratio = 1.8 [95% confidence interval = 1.2–2.6]). Only one of the studied micronutrients (lutein) was independently associated with a reduced risk of decidual vasculopathy (0.5 [0.3–0.9]). Conclusions: Carotenoids and long-chain fatty acids warrant further investigation in in vitro, animal, and human studies of preterm birth.

Sexual behaviour condom use and HIV risk situations in the general population of Quebec.

We conducted 3501 telephone interviews to determine the sexual and protective behaviours of the general population in Quebec. Among the 858 respondents who had had at least one occasional partner during the last 5 years, 25.4% had had at least one occasional partner who refused to use a condom. More women had had an occasional partner who had refused than men (29.8% vs 21.1%, P < 0.001) and fewer women than men succeeded in negotiating condom use, but more of these women decided not to have sexual relations. The frequency of condom use during the last sexual relation changes if the partner is a regular cohabiting partner (12.5%), a regular non-co-habiting partner (42.2%) or an occasional partner (70.8%). Our study provides important information for the development of prevention programmes for the heterosexual population and demonstrates the importance of the type of relationship maintained by the partners on the sexual behaviours.