Exploring the relationship between personality and regional brain volume in healthy aging

Aging is characterized by a reduction in regional brain volumes, particularly in prefrontal and medial temporal regions. Recent evidence suggests that personality may be related to neuroanatomical integrity. The present investigation explored whether the three targeted personality traits of neuroticism, conscientiousness, and extraversion moderated cross-sectional age-related decline in measures of neural integrity. Estimates of the personality traits and volumes of cerebral gray and white matter, prefrontal and medial temporal regions were obtained in a sample of 79 healthy adults aged 44–88. Higher neuroticism was associated with smaller regional volumes and greater decreases in volume with increasing age. Higher conscientiousness was related to larger regional volumes and less decline with advancing age. These results suggest that personality may not only relate to, but may also moderate age-related cross-sectional decline in prefrontal and medial temporal regions.     

The sexual negotiation behavior of HIV-positive gay and bisexual men

This study describes the sexual negotiation practices of 256 HIV-positive gay and bisexual men enrolled in a sexual risk reduction intervention. Negotiation behavior was associated with sexual risk practices. Men who abstained from anal sex and those who had unprotected anal sex had the lowest negotiation scores. Negotiations occurred most often with steady partners and least often with anonymous partners. A logistic regression to predict high versus low frequency negotiators revealed the significance of self-efficacy for condom use and number of months HIV-positive. Findings are discussed in terms of the development of sexual risk reduction interventions for HIV-positive gay and bisexual men.     

A population study of the association between sexual function, sexual satisfaction and depressive symptoms in men

BACKGROUND: Depression and erectile dysfunction (ED) have a complex and bi-directional relationship. We examined the relationships between erectile dysfunction and depressive symptoms or diagnosed depression, sexual activity and sexual satisfaction. METHODS: A population survey of men aged 40-70 years was carried out in Brazil, Italy, Japan and Malaysia in 1997-1998. A questionnaire was used to collect life style, sexual behaviors and medical data. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. ED was classified as moderate or complete if the men reported they were "sometimes" or "never" able to achieve and maintain an erection satisfactory for sexual intercourse. Only men with a sexual partner and not taking psychoactive drugs were considered. RESULTS: Diagnosed depression was reported by 2.0% of the men, depressive symptoms by 21.0%. The prevalence of moderate or complete ED was 17.8%. Sexual satisfaction related to the frequency of sexual intercourse and inversely related to depressive symptoms. Depressive symptoms were positively associated with being single (odds ratio [OR] 1.7), widowed, separated or divorced (OR 2.2), moderate or complete ED (1.8), heart disease (1.6) and smoking (1.6), and negatively associated with age, physical activity and frequency of sexual intercourse. LIMITATIONS: Cross-sectional studies cannot establish a temporal cause-effect relationship. However, the confirmation of known associations reassures about the validity of the original findings. CONCLUSIONS: The findings suggest that depressive symptoms are linked to ED by the mediation of decreased sexual activity and the dissatisfaction generated by the inability to have a healthy sexual life.     

The relationship between specific cognitive functions and falls in aging

The current study examined the relationship between cognitive function and falls in older people who did not meet criteria for dementia or mild cognitive impairment (N = 172). To address limitations of previous research, the authors controlled for the confounding effects of gait measures and other risk factors by means of associations between cognitive function and falls. A neuropsychological test battery was submitted to factor analysis, yielding 3 orthogonal factors (Verbal IQ, Speed/Executive Attention, Memory). Single and recurrent falls within the last 12 months were evaluated. The authors hypothesized that Speed/Executive Attention would be associated with falls. Additionally, the authors assessed whether associations between different cognitive functions and falls varied depending on whether single or recurrent falls were examined. Multivariate logistic regressions showed that lower scores on Speed/Executive Attention were associated with increased risk of single and recurrent falls. Lower scores on Verbal IQ were related only to increased risk of recurrent falls. Memory was not associated with either single or recurrent falls. These findings are relevant to risk assessment and prevention of falls and point to possible shared neural substrates of cognitive and motor function.     

Additional evidence for the relationship between Type A behavior and social support in men

This study examined social support as a mediator of susceptibility to coronary disease in Type A individuals. Sixty-four male subjects completed the Jenkins Activity Survey and the Sarason Social Support Questionnaire. The correlations between Type A scores, the speed and impatience and hard-driving competitiveness factors of the Jenkins survey, and Sarason's social support were found to be negative, which was contrary to earlier findings. The authors hypothesize that these differing results may be a function of age and environment. Finally, and pertinent to the mechanism by which social support may be associated with coronary heart disease, systolic blood pressure was negatively correlated to satisfaction with social support.     

The relationship between women's subjective and physiological sexual arousal

Previous literature presents discordant results on the relationship between physiological and subjective sexual arousal in women. In this study, the use of hierarchical linear modeling (HLM) revealed a significant concordance between continuous measures of physiological and subjective sexual arousal as assessed during exposure to erotic stimuli in a laboratory setting. We propose that past studies that have found little or no association between the two measures may have been in part limited by the methodology and statistical analyses employed.     

Assessment of sexual function, interest and activity in depressed men

Sexual function, interest, and activity were assessed in drug-free outpatient depressed men (n = 26) and in age-matched healthy control men (n = 20) by means of the Derogatis Sexual Functioning Inventory (DSFI), a retrospective sexual function questionnaire (SFQ), and a prospective daily sexual function log. Good test-retest reliability over 1 month was demonstrated for the DSFI and the SFQ in depressives and controls. Compared to healthy controls, depressed men reported significantly lower sexual interest and satisfaction, but no less sexual activity, on both retrospective questionnaires and prospective daily logs. Depressed men also showed significantly more negative body image and less 'manly' sexual role function as measured by the DSFI. Significant partial correlations (controlling for the effects of anxiety) were found between severity of depression and sexual interest, satisfaction, and role.     

The relationship between life events and mental health in homosexual men

In a study to determine the extent to which stigmatization influences mental health in homosexual men, 80 homosexual men were administered the General Health Questionnaire and the Gay Affect and Life Events Scale. Data indicated that there were significant associations between life events and mental health; events related to AIDS had the highest correlations. However, general life event scales that included Finances and Work also were associated significantly with mental health, as previously reported in the general population. These data suggest that the impact of life events may be amplified by stigmatization and that degree of life change is associated closely with psychological dysfunction. It is concluded that life events that are related to both stigmatization and life change and related emotional distress are significant predictors of psychology dysfunction.     

The relationship between alexithymia and abnormal illness behavior

The relationship between abnormal illness behavior, measured by the illness Behavior Questionnaire and alexithymia, measured by the Toronto Alexithymia Scale, was studied in four cohorts of subjects. The two measures overlap in that the more alexithymic subjects endorsed more disease conviction, hypochondriacal concern, affective inhibition, affective disturbance, and irritability. Denial was not related to alexithymia, which supports the construct validity of alexithymia. Regression models developed for the four cohorts that consisted of psychiatric outpatients, psychiatric inpatients, medically ill patients and controls differed to suggest that alexithymia state phenomena interact with trait characteristics.     

The relationship between type 2 theta and behavior

Although there is extensive literature on the correlation between Type 1 theta activity in the hippocampus and behavior, little is known about the behavioral correlates of "Type 2" (immobility) theta. In the present study, guinea pigs were exposed to three high "arousal" situations. These situations produced reliable trains of "Type 2" theta. Atropine sulfate abolished "arousal" and Type 2 theta. In the second study, we determined whether the Type 2 theta response was produced by specific stimuli or by a generalized sensitization to incoming sensory stimuli created by the testing situation. In this study, a stimulus which had not previously elicited Type 2 theta was presented a second time after a presentation of a stimulus which did elicit Type 2 theta. The previously neutral stimulus now elicited Type 2 theta. These results were interpreted within an "arousal" theory framework.     

Pulmonary function studies in healthy non-smoking men of Calcutta

Pulmonary function measurements were made in 104 healthy non-smoking men from Calcutta with an age range of 20–59 years. Except for peak expiratory flow rate (PEFR), all the measurements were made with the help of two 9L closed-circuit type expirographs using standard spirometric techniques. PEFR was recorded by two Wright peak flow meters. Prediction formulae were derived on the basis of age and height for all the ventilatory tests except for FEV₁%, FET and PEFR. These were predicted from age only. The prediction equation for VC, FVC, FEV₁, FEV₁%, MVV_F and PEFR were reliable, but those for forced expitatory flows and time were not. The FVC and FEV₁ values of the present subjects, standardized for age and height, were much lower than those of Americans, Caucasians, Europeans and Canadians but similar to those of Pakistani healthy adults. On comparison with the data reported from other parts of our country, it was revealed that the VC and FEV₁ values of the current study, after adjustment of age and height, were much higher than those of southern Indians but comparable with those of north-western Indians.     

Pulmonary function studies in healthy non-smoking men of Calcutta

Pulmonary function measurements were made in 104 healthy non-smoking men from Calcutta with an age range of 20-59 years. Except for peak expiratory flow rate (PEFR), all the measurements were made with the help of two 9L closed-circuit type expirographs using standard spirometric techniques. PEFR was recorded by two Wright peak flow meters. Prediction formulae were derived on the basis of age and height for all the ventilatory tests except for FEV1%, FET and PEFR. These were predicted from age only. The prediction equation for VC, FVC, FEV1, FEV1%, MVVF and PEFR were reliable, but those for forced expitatory flows and time were not. The FVC and FEV1 values of the present subjects, standardized for age and height, were much lower than those of Americans, Caucasians, Europeans and Canadians but similar to those of Pakistani healthy adults. On comparison with the data reported from other parts of our country, it was revealed that the VC and FEV1 values of the current study, after adjustment of age and height, were much higher than those of southern Indians but comparable with those of north-western Indians.     

The relationship between short-term antibiotic treatments and fatigue in healthy individuals

Summary Antibiotic treatment tends sometimes to result in sensations of fatigue and decreased physical performance. The effects of antibiotics were therefore studied in 50 healthy, male trainees, aged 18–25 years, assigned in a random, double-blind fashion to one of the following treatments: tetracycline, ampicillin, trimethoprim/sulphamethoxazole, placebo I and placebo II. Duration of treatment was five times the half-life of each agent and the placebo was matched accordingly. Muscle enzyme activity (serum glutamine oxaloacetate transaminase, lactate dehydrogenase, creatine phosphokinase), maximal aerobic capacity ( O_2max), muscle strength (MS), and rating of subjective sensation of fatigue were assessed prior to and upon conclusion of treatment. Compared to pretreatment values, plasma enzymes activity was elevated in all five groups (P<0.005). No differences in O_2max or in MS were found among the subjects treated with either one of the antibiotics or those given a placebo. A significant difference in O_2max was found between the groups treated for 1 day (antibiotic and placebo) and the groups treated for 3 days (antibiotic and placebo) (P<0.0001). The rating of subjective sensation was not affected by any of the agents. We concluded that in healthy individuals, a short-term antibiotic treatment had no deleterious effect on aerobic capacity or on muscle strength and was not associated with subjective side effects. The time interval between the two maximal tests could, however, have affected the aerobic capacity. Physiological disturbances associated with a sensation of fatigue following a longer period of antibiotics cannot be excluded.     

Postural differences in hemodynamics and diastolic function in healthy older men

The shift from upright to supine posture increases stroke volume in healthy young adults, primarily through increased end-diastolic volume. Aging is associated with increased ventricular stiffness and impaired diastolic function. The purpose of this study was to determine whether the stroke volume change between the upright and supine posture was blunted in healthy older men and whether the early mitral inflow response to this postural change was reduced by aging. Pulsed Doppler echocardiography and tissue Doppler imaging were used to assess stroke volume and left ventricular function during upright and supine posture in 10 young and 12 older healthy men. Cardiac output was greater in the supine versus upright condition in both groups. In young men supine posture was associated with a large increment in stroke volume (63.1 ± 7.2 upright to 98.6 ± 11.7 ml supine; P < 0.05) and a decrease in heart rate. In older men, the stroke volume increment was smaller (63.9 ± 3.6 upright to 82.0 ± 5.7 ml supine; P < 0.05) and heart rate decreased less than young men when comparing upright to supine posture. Increased stroke volume was associated with higher peak early diastolic filling velocity (E) in young men and higher peak late diastolic filling velocity (A) in older men. These findings indicate that healthy aging attenuates the increase in early filling associated with moving from an upright to a supine posture. Furthermore, healthy older men are more dependent upon atrial diastolic filling to augment end-diastolic and stroke volume, which may be due to age-associated increases in left ventricular filling pressure and impaired compliance.