Parasympathetic Response Patterns are Associated with Metabolic Syndrome Among Older Women but Not Men

Living arrangements and metabolic syndrome: a national cross-sectional study in the Republic of Korea

BACKGROUND

This study investigated the relationship between living arrangements and metabolic syndrome (MetS) risk in the adult population in the Republic of Korea.

METHODS

The samples were derived from the data collected during the second year of the seventh Korea National Health and Nutrition Examination Survey. The study targeted a total of 6,265 adults who were aged 20 years and above, and multiple logistic regression analysis was conducted. Living arrangements were classified into 4 categories: single-person households, 1-generation households, 2-generation households, and other family types. MetS was identified by the presence of at least 3 out of the 5 National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

For men, the odds ratio (ORs) for MetS in 1- and 2-generation households, compared to single-person households, were 0.92 (95% confidence interval [CI], 0.55-1.54) and 0.97 (95% CI, 0.58-1.62), respectively. The OR for other types of households was 0.96 (95% CI, 0.79-1.17). For women, the OR for MetS in 1- and 2-generation households, compared to single-person households, were 1.52 (95% CI, 1.15-2.01) and 1.29 (95% CI, 1.01-1.67), respectively.

CONCLUSION

Our study suggests that a national strategy involving tailored interventions for women living in high-risk conditions is necessary to reduce the risk of MetS in Korean women.

Mindfulness-Based Stress Reduction in Older Adults at Risk for Coronary Artery Disease: A Pilot Randomized Trial

OBJECTIVES

Stress influences metabolic activity and increases risk for cardiovascular disease (CVD). We sought to a) examine feasibility and acceptability of mindfulness-based stress reduction (MBSR) in older adults at risk for CVD, and b) obtain preliminary data on its metabolic impact.

METHODS

A pilot RCT was conducted using a pre-post, 2-month follow-up design. Eighty-one individuals with metabolic syndrome and non-normative responses to stress in a previous investigation were invited. Participants were randomized (by sex and stress response) to a 9-week MBSR or a wait-list control group. Feasibility and acceptability were assessed and blood assayed. Between-subjects (MBSR vs waitlist control) ANOVAs on metabolic parameter change scores, and one-way repeated measures ANOVAs (pre-, post-, follow-up) were performed.

RESULTS

Thirty-three individuals (41%) responded to invitations, 26 were interested, of whom 19 were randomized (M_age = 67 years, SD = 7.70). Completion rate of MBSR was 72% and overall attendance was 96%. Reported benefits included increased relaxation, greater interpersonal connection, and increased body awareness. MBSR led to a decrease of 15% in LDL cholesterol and 10% in total cholesterol versus 4.5% and 1%, respectively, in the waitlist. Within group analyses showed notable decreases in LDL, triglycerides, and waist circumference post-MBSR and 2 months later.

CONCLUSIONS

A RCT was largely feasible and MBSR acceptable to participants. MBSR may lead to sustained decreases in cholesterol levels, warranting development of large-scale research on this topic.

CLINICAL IMPLICATIONS

Given the role of stress in CVD, addition of stress management interventions may serve as a useful complement to risk management among older individuals.

Physiological Responses to Narrative Anger Recall and Correlates to Anger, Forgiveness, and Rumination

Abstract. Narrative recall, or describing an event from one’s past, is a common method to study anger in the laboratory. However, most research using this method has not included a neutral speaking control, and therefore the physiological response attributable to emotion versus the act of speech is unknown. We evaluated heart rate, blood pressure, skin conductance level, heart rate variability, and salivary alpha-amylase during silent baseline, neutral speaking, anger recall, and recovery periods, and correlated these measures with trait anger, forgiveness, and rumination ( n = 104). Only systolic blood pressure and skin conductance levels were elevated in the anger recall period above the values in the neutral speaking period, showing the need for this important control. Alpha-amylase was inversely correlated to forgiveness, particularly in females. A neutral speaking control is critical for anger recall protocols because the physiological responses are mostly due to speaking, not anger. Salivary alpha-amylase may be a promising autonomic marker in studies of forgiveness and anger.

Clinical Correlates Identify ProBDNF and Thrombo-Inflammatory Markers as Key Predictors of Circulating p75NTR Extracellular Domain Levels in Older Adults

The p75^NTR receptor binds all neurotrophins and is mostly known for its role in neuronal survival and apoptosis. Recently, the extracellular domain (ECD) of p75^NTR has been reported in plasma, its levels being dysregulated in numerous neurological diseases. However, the factors associated with p75^NTR ECD levels remain unknown. We investigated clinical correlates of plasma p75^NTR ECD levels in older adults without clinically manifested neurological disorders. Circulating p75^NTR levels were measured by enzyme-linked immunosorbent assay in plasma obtained from participants in the BEL-AGE cohort (n = 1,280). Determinants of plasma p75^NTR ECD levels were explored using linear and non-linear statistical models. Plasma p75^NTR ECD levels were higher in male participants; were positively correlated with circulating concentrations of pro-brain-derived neurotrophic factor, and inflammatory markers interleukin-6 and CD40 Ligand; and were negatively correlated with the platelet activation marker P-selectin. While most individuals had p75^NTR levels ranging from 43 to 358 pg/ml, high p75^NTR levels reaching up to 9,000 pg/ml were detectable in a subgroup representing 15% of the individuals studied. In this cohort of older adults without clinically manifested neurological disorders, there was no association between plasma p75^NTR ECD levels and cognitive performance, as assessed by the Montreal Cognitive Assessment score. The physiological relevance of high p75^NTR ECD levels in plasma warrants further investigation. Further research assessing the source of circulating p75^NTR is needed for a deeper understanding of the direction of effect, and to investigate whether high p75^NTR ECD levels are predictive biomarkers or consequences of neuropathology.

Brain-Derived Neurotrophic Factor Mitigates the Association Between Platelet Dysfunction and Cognitive Impairment

Background: Platelet hyperactivity is deleterious in coronary artery disease (CAD), requiring lifelong antiplatelet therapy, and is associated with worse cognitive outcomes. Upon activation, platelets release Brain-Derived Neurotrophic Factor (BDNF), a neurotrophin protective against cognitive decline. Given these apparently opposing effects of platelet activation on cognitive health, we investigated whether BDNF levels intercede in the relationship between platelet activation and cognitive function; and whether this relationship is moderated by the presence of CAD.

Methods: In this cross-sectional study, 1,280 participants with (n = 673) and without CAD (n = 607) completed the Montreal Cognitive Assessment (MoCA). Plasma BDNF and soluble P-selectin (a marker of platelet activity) levels were assessed using multiplex flow cytometry.

Results: In a mediation model, platelet activity was correlated with higher plasma BDNF concentrations (b = 0.53, p < 0.0001). The relationship between sP-selectin and BDNF concentrations was stronger for individuals without CAD (b = 0.71, p < 0.0001) than for CAD participants (b = 0.43, p < 0.0001; p_interaction <0.0001). Higher BDNF concentrations were associated with higher MoCA scores (b = 0.26, p = 0.03). The overall effect of platelet activity on cognitive performance was non-significant (total effect: b = −0.12, p = 0.13), and became significant when accounting for BDNF as a mediating factor (direct effect: b = −0.26, p = 0.01). This resulted in a positive indirect effect of platelet activity (via BDNF) on MoCA scores (b = 0.14, CI 95% 0.02–0.30), that was smaller in CAD participants than in non-CAD participants [Δ −0.07 (95% CI −0.14 to −0.01)].

Conclusions: BDNF released from activated platelets could be a mitigating factor in a negative association between platelet activity and cognitive function.

Integrated and diurnal indices of maternal pregnancy cortisol in relation to sex-specific parasympathetic responsivity to stress in infants

Maternal hypothalamic-pituitary-adrenal axis activity may prenatally program sex-specific stress-response pathways. We investigated associations between maternal cortisol during pregnancy and infant parasympathetic responsivity to stress among 204 mother-infant pairs. Cortisol indices included 3rd trimester hair cortisol, as well as diurnal slope and area under the curve, derived from saliva samples collected during pregnancy. Mother-infant dyads participated in the Repeated Still-Face Paradigm (SFP-R) at age 6 months. We calculated respiration-adjusted respiratory sinus arrhythmia (RSA_c ), an indicator of parasympathetic activation, from infant respiration and cardiac activity measured during the SFP-R. We used multivariable linear mixed models to examine each cortisol index in relation to infant RSA_c and investigated sex differences using cross-product terms. Diurnal cortisol indices were not associated with RSA_c . There was no association between hair cortisol and baseline RSA_c . However, hair cortisol was associated with sex-specific changes in RSA_c over the SFP-R such that, among girls, parasympathetic withdrawal was reduced with increasing prenatal exposure to cortisol. Consistently higher levels of prenatal cortisol exposure may lead to dampened parasympathetic responsivity to stress during infancy, particularly among girls. Maternal hair cortisol may be particularly valuable for studying the effects of prenatal cortisol exposure on infant autonomic reactivity.

The associations of hostility and defensiveness with telomere length are influenced by sex and health status

Background

Shorter telomere length (TL) may indicate premature cellular aging and increased risk for disease. While there is substantial evidence for shorter TL in individuals suffering from psychiatric disorders, data is scarce on maladaptive personality traits related to coronary artery disease (CAD). The purpose of this study was to evaluate the association of TL with hostility and defensiveness in individuals with CAD or other non-cardiovascular illnesses and whether associations were moderated by CAD status and sex.

Methods

One thousand thirty-six individuals (M_age = 65.40 ± 6.73 years) with and without CAD completed the Marlowe-Crowne Social Desirability Scale and the Cook–Medley Hostility Scale. Relative TL was measured via quantitative polymerase chain reaction of total genomic DNA samples. Analyses involved hierarchical regressions on TL, performed separately for hostility and defensiveness, controlling for pertinent sociodemographic, behavioural, and medical risk factors. Separate analyses were performed on 25 healthy participants.

Results

A hostility by sex interaction emerged (β = − .08, p = .006) in the patient groups, where greater hostility was associated with shorter TL in women only (p < .01). A Defensiveness by CAD status interaction (β = − .06, p = .049) revealed longer TL in more defensive CAD patients only (p = .06). In healthy men, shorter TL was observed in those with greater defensiveness (β = .52, p = .006) but lower hostility (β = − .43, p = .049).

Conclusion

Hostility and defensiveness are differentially associated with TL as a function of sex and health status. The implication of these results for health remains to be determined, but propose an additional pathway through which the effect of maladaptive personality traits may contribute to CV and other disease.