Judith A. Crowell

Circulating Irisin in Relation to Insulin Resistance and the Metabolic Syndrome

CONTEXT Irisin, a recently identified hormone, has been proposed to regulate energy homeostasis and obesity in mice. Whether irisin levels are associated with risk of the metabolic syndrome (MetS), cardiometabolic variables, and cardiovascular disease (CVD) risk in humans remains unknown. OBJECTIVE Our objective was to assess the associations between baseline serum irisin levels and MetS, cardiometabolic variables, and CVD risk. DESIGN, SETTING, AND SUBJECTS We conducted a comparative cross-sectional evaluation of baseline circulating levels of the novel hormone irisin and the established adipokine adiponectin with MetS, cardiometabolic variables, and CVD risk in a sample of 151 subjects. RESULTS Baseline irisin levels were significantly higher in subjects with MetS than in subjects without MetS. Irisin was associated negatively with adiponectin (r = -0.4, P < .001) and positively with body mass index (r = 0.22, P = .008), systolic (r = 0.17, P = .04) and diastolic (r = 0.27, P = .001) blood pressure, fasting glucose (r = 0.25, P = .002), triglycerides (r = 0.25, P = .003), and homeostasis model assessment for insulin resistance (r = 0.33, P < .001). After adjustment for potential confounders, including body mass index, subjects in the highest tertile of irisin levels were more likely to have MetS (odds ratio [OR] = 9.44, 95% confidence interval [CI] = 2.66-33.44), elevated fasting blood glucose (OR = 5.80, 95% CI = 1.72-19.60), high triglycerides (OR = 3.89, 95% CI = 1.16-13.03), and low high-density lipoprotein cholesterol (OR = 3.30, 95% CI = 1.18-9.20). Irisin was independently associated with homeostasis model assessment for insulin resistance and general Framingham risk profile in multiple linear regression analyses after adjustment for confounders. Adiponectin demonstrated the expected associations with outcomes. CONCLUSIONS Irisin is associated with increased risk of MetS, cardiometabolic variables, and CVD in humans, indicating either increased secretion by adipose/muscle tissue and/or a compensatory increase of irisin to overcome an underlying irisin resistance in these subjects.

Stability of attachment representations: The transition to marriage.

This study examined the stability of adult attachment representations across the transition to marriage. One hundred fifty-seven couples were assessed using the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1985), the Current Relationship Interview (J. A. Crowell & G. Owens, 1996), and measures describing relationship functioning and life events 3 months prior to their weddings and 18 months into their marriages. The authors tested the hypotheses that attachment classifications are stable and that change is related to experiences in the relationship and/or life events; 78% of the sample received the same primary AAI classification (secure, preoccupied, and dismissing) at both times. Change was toward increased security and was associated with feelings and cognitions about the relationship. Only 46% of participants initially classified as unresolved retained the classification. Stability of the unresolved classification was associated with stressful life events and relationship aggression.

Assessing secure base behavior in adulthood: development of a measure, links to adult attachment representations, and relations to couples' communication and reports of relationships.

A focus on the secure base phenomenon creates a framework for exploring the function of the attachment system in adulthood. Engaged couples (N = 157) were videotaped in a problem-solving interaction and assessed using the Secure Base Scoring System (SBSS), a system based on Ainsworths analyses of infant-parent secure base use and support. Study 1 showed behavior was significantly related to representations assessed with the Adult Attachment Interview (M. Main & R. Goldwyn, 1994). In Study 2, the interactions were independently scored with the Rapid Marital Interaction Coding System (RMICS; R. E. Heyman & D. Vivian, 1993), a communication-based system. The SBSS predicted relationship variables beyond the RMICS, especially for women. Results indicate that the secure base phenomenon provides a cogent perspective on adult attachment behavior.

When "New" Meets "Old": Configurations of Adult Attachment Representations and Their Implications for Marital Functioning

Two studies addressed the implications of concordance versus discrepancy of attachment representations in individuals at 2 stages in their marital relationships. Engaged (n = 157) and dating (n = 101) couples participated in a multimethod 6-year longitudinal study of adult attachment. Individuals completed the Adult Attachment Interview (AAI), the Current Relationship Interview (CRI), and various questionnaires and were observed in interactions with partners. On the basis of AAI and CRI classifications, participants were placed in one of four groups: Secure-sub(AAI)/Secure-sub(CRI), Secure-sub(AAI)/Insecure-sub(CRI), Insecure-sub(AAI)/Secure-sub(CRI), or Insecure-sub(AAI)/Insecure-sub(CRI). Each of the configurations showed a particular pattern of behavior, feelings about relationships and the self, and likelihood of relationship breakup. The findings of the studies address important points about the protective effects of attachment security and have interesting implications for the extension of attachment theory into adulthood.

Bowlby's secure base theory and the social/personality psychology of attachment styles: Work(s) in progress

John Bowlbys goal in developing modern attachment theory was to preserve what he considered some of Freuds most valuable insights about human development and close relationships. First among these were insights into the importance of early experience and the notion that infant-mother and adult-adult relationships are similar in kind. Focussing on prospective and observational methods, Bowlby replaced Freuds drive reduction model of relationship motivation with one that emphasized the role relationships play in support of exploration and competence. He also introduced concepts from control systems theory to highlight and account for the complex monitoring of internal states, relationship experience, and context that shapes proximity seeking, communication across a distance, and exploration away from attachment figures. And where Freud had explained the effects of early experience in terms of psychodynamic structures, Bowlby introduced the concept of mental models. These cognitive constructs are thought to reflect ordinary experience as well as trauma, to tend toward stability, and to remain open to new information.

Mothers' conceptualizations of parent-child relationships: Relation to mother-child interaction and child behavior problems

Knowledge of parental state of mind with respect to parent-child attachment relationships may provide insight into etiology or maintenance of problematic parent-child interactions and development of child psychopathology. Forty-nine mothers and their behaviorally disturbed children, aged 5 to 11 years, were assessed in a child psychiatry clinic. Mothers and children were observed in a semistructured interaction consisting of free play, three tasks, separation, and reunion. Mothers were scored on supportiveness, helpfulness, organization, and so forth. Children were rated on relationship behaviors with mother, task behaviors, activity level, and so forth. Parents and teachers completed rating scales of child aggression and oppositionality, inattention and hyperactivity, and competence. Children rated themselves on feelings of depression and anxiety. Mothers were given the Adult Attachment Interview (George, Kaplan, & Main, 1985) and were classified as secure, dismissing, or preoccupied in state of mind with respect to attachment. Mothers classified as secure were supportive and well organized with their children. Mothers classified as insecure were unsupportive and cool. The secure classification was associated with the children reporting low levels of anxiety and depression, being described as competent and relatively low in symptomatology. The dismissing classification was associated with oppositional and aggressive symptoms in the children, greater symptomatology overall, and child self-reports of distress. Maternal attachment classification appears to contribute to understanding of the development of psychopathology in children and its type and severity.

Prospective Associations From Family-of-Origin Interactions to Adult Marital Interactions and Relationship Adjustment

To test the social learning-based hypothesis that marital conflict resolution patterns are learned in the family of origin, longitudinal, observational data were used to assess prospective associations between family conflict interaction patterns during adolescence and offsprings later marital conflict interaction patterns. At age 14 years, 47 participants completed an observed family conflict resolution task with their parents. In a subsequent assessment 17 years later, the participants completed measures of marital adjustment and an observed marital conflict interaction task with their spouse. As predicted, levels of hostility and positive engagement expressed by parents and adolescents during family interactions were prospectively linked with levels of hostility and positive engagement expressed by offspring and their spouses during marital interactions. Family-of-origin hostility was a particularly robust predictor of marital interaction behaviors; it predicted later marital hostility and negatively predicted positive engagement, controlling for psychopathology and family-of-origin positive engagement. For men, family-of-origin hostility also predicted poorer marital adjustment, an effect that was mediated through hostility in marital interactions. These findings suggest a long-lasting influence of family communication patterns, particularly hostility, on offsprings intimate communication and relationship functioning.

Is attachment theory ready to contribute to our understanding of disruptive behavior problems

Attachment theory and research have traditionally been subspecialties in infant social development. Recent work has extended the relevance of attachment theory and assessments well into childhood and has established firm ties to work with adults. Many of the same variables associated with the development of disruptive behavior problems also influence the development of attachment. In addition, recent data point to consistent relations between attachment status and disruptive behavior problems. This paper reviews attachment theory, summarizes mechanisms through which attachment might be related to disruptive behavior problems, and discusses the relevance of attachment theory to prevention and therapy. We emphasize the diversity of possible relations between attachment and disruptive behavior problems and the fact that incorporating attachment theory into research on disruptive behavior problems does not mean interpreting every disruptive behavior as attachment related or every attachment-related disruption as serving the same function.

Diet quality is associated with circulating C-reactive protein but not irisin levels in humans

OBJECTIVE Adherence to a healthy diet has been shown to decrease the incidence of obesity and associated comorbidities. C-reactive protein (CRP) is an established inflammatory marker and irisin was recently identified as a molecule which may play a role in energy regulation and obesity but whether diet alters irisin levels remains unknown. We aimed to investigate the association between circulating irisin, leptin, and CRP levels and dietary quantity and quality using the Alternate Healthy Eating Index (AHEI) and the Alternate Mediterranean Diet Score (aMED). MATERIALS/METHODS The study evaluated dietary data and biomarker levels of 151 participants between 2009 and 2011 (71 male vs. 80 female, over 35 years old, obese 43.7%). AHEI and aMED scores were calculated based on data derived from self-administered 110-item food-frequency questionnaires estimating usual nutrient intake over the past year. Cross-sectional associations between dietary quantity, quality, body composition by bioelectric impedance, and biomarker levels including irisin, leptin, and CRP after fasting were assessed. RESULTS CRP, but not irisin, was negatively correlated with AHEI (r=-0.34) and aMED (r=-0.31). Irisin was positively correlated with BMI (r=0.22), fat mass (r=0.21), waist circumference (r=0.24), waist-hip ratio (r=0.20), leptin (r=0.32), and CRP (r=0.25). Participants with the highest AHEI scores tended to have 11.6% lower concentrations of irisin (P for trend =0.09), but they were not significant after adjustment for potential confounders. Better diet quality was associated with lower CRP concentrations (P for trend=0.02) in multivariate model. Percentage of energy from carbohydrate was inversely associated with CRP. CONCLUSIONS Unlike CRP, irisin is not associated with dietary quality or quantity.

Early Life Adversity Is Associated With Elevated Levels of Circulating Leptin, Irisin, and Decreased Levels of Adiponectin in Midlife Adults

CONTEXT Early-life adversity, defined as physical, emotional, or sexual abuse and neglect before 18 years of age, is associated with metabolic syndrome, obesity, and type 2 diabetes mellitus in adult life. However, the underlying mechanism is not fully understood, and whether adipomyokines are associated with early-life adversity independent of other factors such as body mass index, psychosocial risks, and health behaviors is not known. OBJECTIVES The objective of the study was to evaluate the association between early-life adversity and circulating the levels of the adipomyokines such as leptin, adiponectin, and irisin and the inflammatory marker, C-reactive protein (CRP). DESIGN/SUBJECTS/SETTING: This study was a cross-sectional study of 95 adults at a university-based research center. We collected venous blood from participants and analyzed serum for leptin, adiponectin, irisin, and CRP. RESULTS Circulating leptin, irisin, and CRP levels were significantly higher in the highest adversity tertile group compared with low and middle tertile groups (P < .001 for leptin, P = .01 for irisin, and P = .02 for CRP). Adiponectin levels were lower in the highest tertile group compared with the low and middle tertile groups (P = .03). After adjusting for demographic variables, physical activity, diet, current mental health, and body mass index, the associations between early-life adversity leptin, irisin, and did not change. However, adiponectin and CRP levels were no longer significantly related to early life adversity. CONCLUSION Early-life adversity is directly associated with elevated circulating leptin and irisin, and indirectly associated with elevated CRP and decreased adiponectin. These findings suggest that these adipomyokines may play a role in the pathogenesis of metabolic abnormality in a population with significant early life adversity.