Describe Sex Differences Research Articles

Abstract P287: Sex Differences in Stroke Incidence: The REGARDS Study

Background: There are strikingly few national data available to describe sex differences in age-specific stroke incidence. Methods: REGARDS is a national, population-based, longitudinal study of black and white participants aged > 45 years old, with oversampling of blacks and residents of the stroke belt. Between 2003 and 2007, 30,239 participants were enrolled and examined; follow-up is every 6 months by telephone for self- or proxy-reported stroke, with retrieval and adjudication of medical records by physicians. This analysis included 27,756 participants with follow up data who had no physician-diagnosed stroke at baseline. Stroke incidence rates were calculated as the number of stroke events divided by the person-years at risk with 95% confidence limits. Proportional hazards models were used to assess the race-specific association of sex with stroke risk by age strata (<65, 65–74, and 75+) after adjustment for socioeconomic factors, and Framingham stroke risk factors. Results: There were 613 incident strokes events over 135,551 person-years of follow-up. Stroke incidence rates increased with age (from 237/100,000 to 1003/100,000), and were higher in men than women in both blacks and whites (left panel of figure). After multivariable adjustment, men had higher risk than women at younger ages (<75) but for the 65–75 age group, the difference is larger for blacks than whites (right panel of figure). Discussion: These national data confirm the patterns in male/female stroke risk observed in the Greater Cincinnati/Northern Kentucky Stroke Study, with smaller sex differences at older ages, and for men, larger excess risk in whites than blacks.

Sex differences in spatial cognition among Hadza foragers

This paper describes sex differences in spatial competencies among the Hadza, a mobile hunter–gatherer population in Tanzania. It addresses the following questions: (a) Is the usual male advantage in Euclidean spatial abilities found in this population, where both women and men are highly mobile? (b) Do Hadza women have better object location memory than men, as the gathering hypothesis predicts? (c) Do women who are nominated by others as being good at finding bushfoods excel at the object location memory task? We tested object location memory with a version of the memory game using cards of local plants and animals. This allowed us to also ask whether women and men would have better spatial memory for the plant and animal cards, respectively. We found that Hadza men were significantly better than women in three tests of spatial ability: the water-level test, targeting, and the ability to point accurately to distant locations (the latter only in the less mobile groups). There was a trend toward a male advantage at the object location memory task, in contrast to results found previously in nonforaging populations, and women's performance at the task deteriorated with age, while that of men did not. The women who were nominated by peers as being good at finding bushfoods were consistently older women. We discuss the probable hormonal causes and functional consequences of age changes in the spatial competencies of female foragers.

Prevalence of Painful Musculoskeletal Conditions in Female and Male Veterans in 7 Years After Return From Deployment in Operation Enduring Freedom/Operation Iraqi Freedom

We sought to describe sex differences in the prevalence of painful musculoskeletal conditions in men and women Veterans after deployment in Operation Enduring Freedom (Afghanistan) and Operation Iraqi Freedom (Iraq) (OEF-OIF). This is an observational study using Veterans Affairs (VA) administrative and clinical databases of OEF-OIF Veterans who had enrolled in and used VA care. The prevalence of back problems, musculoskeletal conditions, and joint disorders was determined at years 1 through 7 after deployment for female and male Veterans using ICD-9 code groupings for these conditions. Female Veterans were younger (mean age 29 vs. 30, P<0.0001), more likely to be African American (26% vs. 13%, P<0.0001), and less likely to be married (34% vs. 47%, P<0.0001). For both female and male Veterans, the prevalence of painful musculoskeletal conditions increased each year after deployment. After adjustment for significant demographic differences, women were more likely than men to have back problems [year 1 odds ratio (OR) 1.06 (1.01, 1.11)], musculoskeletal problems [year 1 OR 1.32 (1.24, 1.40)], and joint problems [year 1 OR 1.36 (1.21, 1.53)] and the odds of having these conditions increased each year for women compared with men in years 1 to 7 after deployment. To provide quality care to female Veterans, the VA must understand the impact of deployment on women's health. Our findings provide an important picture of the increasing prevalence of musculoskeletal conditions in the female Veteran population and highlight the importance of the VA targeting treatment programs that focus on issues of particular importance to women with musculoskeletal pain.

Sex Differences in the Association of Regional Fat Distribution with the Severity of Obstructive Sleep Apnea

To describe sex differences in the associations between severity of obstructive sleep apnea (OSA) and measures of obesity in body regions defined using both dual-energy absorptiometry and traditional anthropometric measures in a sleep-clinic sample. A prospective case-series observational study. The Western Australian Sleep Health Study operating out of the Sir Charles Gairdner Hospital Sleep Clinic, Perth, Western Australia. Newly referred clinic patients (60 men, 36 women) suspected of having OSA. N/A. Obstructive sleep apnea severity was defined by apnea-hypopnoea index from laboratory-based overnight polysomnography. Body mass index, neck, waist and hip circumference, neck-to-waist ratio, and waist-to-hip ratio were measured. Dual energy absorptiometry measurements included percentage fat and lean tissue. Multivariate regression models for each sex were developed. In women, percentage of fat in the neck region and body mass index together explained 33% of the variance in apnea-hypopnea index. In men, percentage of fat in the abdominal region and neck-to-waist ratio together accounted for 37% of the variance in apnea-hypopnea index. Regional obesity is associated with obstructive sleep apnea severity, although differently in men and women. In women, a direct influence of neck fat on the upper airway patency is implicated. In men, abdominal obesity appears to be the predominant influence. The apnea-hypopnea index was best predicted by a combination of Dual Energy Absorptiometry-measured mass and traditional anthropometric measurements.

Sex Differences in the Use of the Internet as a Source of Health Information Among Adolescents

The Internet is a fundamental part of the day-to-day lives of adolescents. Faced with the difficulties of accessing conventional health services, adolescents use the Internet as a confidential and safe means of accessing information about health issues. To describe sex differences in the way in which adolescents search for health information on the Internet. Cross-sectional survey with a questionnaire administered by an interviewer. Sociodemographic and health variables and those related to the conditions of access and use of information and communication technologies were gathered (multivariate analysis). About 823 school-age youths were interviewed (21 questionnaires were discarded due to low quality), among whom 54.1% were girls and 46% were boys. The girls had a lower self-assessed level of health than the boys. About 86.5% of the girls used the Internet, compared with 89.9% of the boys (p = 0.155). About 21.7% and 48.3% of the boys used it daily/weekly and occasionally, respectively, compared with 17.9% and 59.1% of the girls who used it daily/weekly and occasionally, respectively. The multivariate analysis shows that girls (odds ratio [OR], 1.709; 95% confidence interval [CI], 1.277-2.287), those in their last year of secondary school (OR, 1.369; 95% CI, 1.025-1.830) and those who had visited the doctor most often the previous year (OR, 1.061; 95% CI, 1.017-1.107), were statistically significantly more likely to search for health information on the Internet. Adolescent girls tend to seek more information about health than boys and there are differences in the way in which these girls search for health information on the Internet. The Internet provides adolescents, especially adolescent girls, with an opportunity for relaying health recommendations.

Sex differences in the effects of N,N-diethyllysergamide (LSD) on behavioural activity and prepulse inhibition

The aim of this study was to describe sex differences in the behavioural effects of N,N-diethyllysergamide (LSD) (locomotor activity and other behavioural repertoire in the open field) and its effects on sensorimotor gating in rats (prepulse inhibition (PPI) of the acoustic startle reaction). Three groups of animals were analysed: males, oestral and pro-oestral phase females (EP females), and metoestral and dioestral phase females (MD females). LSD (5, 50 and 200 µg/kg subcutaneously) attenuated locomotor activity and normal behavioural repertoire, and induced flat body posture, wet dog shakes and disrupted PPI. The most prominent behavioural findings of LSD were for LSD 200 µg/kg which suppressed almost all behavioural activity. LSD had mainly inhibitory locomotor effects in males and MD females, yet in EP female rats LSD increased locomotion during the second half of testing period. The main sex differences were observed in locomotor and exploratory behaviour. Both EP and MD females were less sensitive to hypolocomotor effects of LSD and had less pronounced thigmotaxis than males. Further EP females had increased rearing after LSD 5 µg/kg. On the contrary although LSD disrupted PPI in males and MD female rats, EP females were protected from this disruptive effect. Thus, EP females seem to have a lower sensitivity to LSD behavioural actions.

Sex differences in the pharmacokinetics and pharmacodynamics of antidepressants: An updated review

An increasing number of studies have reported differences in the pharmacokinetics and/or pharmacodynamics of antidepressants between women and men. This article updates previously published literature describing sex differences in the pharmacokinetics and pharmacodynamics of antidepressants, and examines specific issues that face women with psychiatric illness. An English-language literature search was performed with the PubMed database (March 2003-December 2008) using combinations of the search terms sex, gender, and antidepressants. In addition, each antidepressant was identified in the 63rd edition of the Physicians' Desk Reference. The current data suggest that the pharmacokinetics of antidepressants can be substantially different between women and men. Likewise, the response to antidepressants can be quite variable, including sex differences in adverse effects and time to response. Despite the many sex differences reported, there is still little published work systematically evaluating potential sex differences in antidepressant pharmacokinetics and pharmacodynamics. More research is needed to guide the treatment of depression and other mental illnesses.

Effects of Individual Components, Time, and Sex on Prevalence of Metabolic Syndrome in Adolescents

To examine selected clinical characteristics for cohorts of similar adolescents over 4 survey periods from 1999-2006, to examine changes in rates of adolescents who exceed cutoff points for individual components of metabolic syndrome (MetS), to describe sex differences in individual components of MetS, to describe changes in MetS prevalence from 1999-2006 using 4 common MetS definitions, and to describe sex differences in MetS prevalence from 1999-2006. Cross-sectional, US representational National Health and Nutrition Examination Survey from 1999-2006. Mobile examination centers conducted by the Centers for Disease Control and Prevention. For 1999-2000, 613 adolescents (aged 12-19 years); for 2001-2002, 892 adolescents; for 2003-2004, 857 adolescents; and for 2005-2006, 814 adolescents. Exclusions were pregnancy, taking insulin or diabetic pills, and incomplete measurements. Fasting plasma glucose level, triglyceride level, high-density lipoprotein cholesterol level, waist circumference, and systolic and diastolic blood pressures. Increases in fasting plasma glucose and high-density lipoprotein cholesterol levels and decreases in diastolic blood pressure were observed. Rates of adolescents exceeding cutoff points for fasting plasma glucose levels have increased. Compared with girls, adolescent boys had higher rates exceeding cutoff points for fasting plasma glucose and high-density lipoprotein cholesterol levels. Adolescent girls had higher rates exceeding cutoff points for waist circumference. The prevalence of MetS among adolescents has not changed. No sex differences in MetS prevalence were observed. Some criteria for MetS have remained stable (triglyceride level and systolic blood pressure) and one has improved for boys (high-density lipoprotein cholesterol level), but waist circumference has increased in girls and the rate of an elevated fasting plasma glucose level has nearly doubled for both boys and girls. Adolescent MetS prevalence has remained stable from 1999-2006.

Homogeneity of intrinsic properties of sexually dimorphic vocal motoneurons in male and female zebra finches

Sex differences in behavioral repertoires are often reflected in the underlying electrophysiological and morphological properties of motor neurons. Male zebra finches produce long, spectrally complex, learned songs and short calls, whereas female finches only produce short, innate, and spectrally simple calls. In both sexes, vocalizations are produced by using syringeal muscles controlled by motoneurons within the tracheosyringeal part of the hypoglossal motor nucleus (XIIts). We asked whether the sexually dimorphic vocal repertoire of adult zebra finches is paralleled by structural and functional differences in syringeal motoneurons. By using immunohistochemical and intracellular staining methods, we describe sex differences in the morphology of XIIts and its surrounding neuropil (suprahypoglossal region; SH). Although the overall number of XIIts neurons and the proportions of somata/neuropil were not sexually dimorphic, the volumes of both XIIts and SH were larger in males, in part because male XIIts neurons had larger somata. In contrast, female XIIts motoneurons had a more complex dendritic structure than did male neurons, suggesting that the larger volume of the male XIIts is due in part to increased numbers of afferents. Intracellular recordings in brain slices revealed that the intrinsic electrophysiological properties of female XIIts neurons were similar to published values for male XIIts motoneurons. We also show that female neurons received glycinergic inputs from the brainstem respiratory premotor column, similar to those described in males. These findings indicate that male and female zebra finches produce their disparate vocal repertoires using physiologically similar motoneurons. Thus, sites upstream of the motoneuron pool may be the major determinants of sexually dimorphic vocal behaviors in this species.

Sex and age cohort differences in patterns of socioemotional functioning in older adults and their links to physical resilience

Although the aging process brings with it some common challenges to older men and women, there has been little attention to gender differences in patterns of socioemotional functioning or their links to adaptive outcome. In this paper we examine patterns of socioemotional functioning among 687 “younger” (65–73 years) and 426 “older” (74–86 years) men and women, describe sex differences in these patterns, and examine whether the same patterns are linked to physical resilience in the same ways across groups. Cluster analysis was applied to 11 measures of socioemotional functioning with ten qualitatively different patterns emerging. As expected, men and women from our two age groups were not equally distributed across the patterns. As expected, older men more frequently manifested patterns of adaptation characterized by inhibited emotion but, together with younger men, were less likely to be represented in patterns characterized by stress-buffering friend support networks. The patterns also showed predictable links to a measure of physical resiliency, which was predicted by participant sex, and both sex and age interacted with cluster membership in predicting resiliency. Taken together, these data underscore the complexity of adaptation to later life among men and women and highlight the possibility that the existence of particular patterns of later life adaptation may have differing late life consequences for older men and women. Implications for the continued study of sex differences in adaptation to later life and directions for future research are given.

SEX DIFFERENCES IN BODY SIZE AND BODY CONDITION OF CALIFORNIA SEA LION (ZALOPHUS CALIFORNIANUS) PUPS FROM THE GULF OF CALIFORNIA

AbstractThe Gulf of California harbors about 15% of the total California sea lion (Zalophus californianus californianus) population. We studied pup morphometrics from eight Gulf of California rookeries during the 1996 and 1997 reproductive seasons to describe sex differences in body size and body condition indices. Newborn pup body size was not different from previous reports. Male pups were heavier and larger than female pups in terms of all linear dimensions. Morphometric relationships, however, showed that males were 3%‐4% denser, and that after removing the effects of length, they were about 2% heavier than females. Sculp depth adjusted for length was 12% larger in female than in male pups. Our data provide further evidence that male otariid pups may allocate a larger fraction of milk energy to muscular and skeletal growth compared to female pups.

Sex differences in cocaine- and nicotine-induced antinociception in the rat

Several recent reports describe sex differences in opioid antinociception. The present study examined sex differences in stimulant-induced antinociception. On the 50°C hotplate test, cocaine (0.1–1.0 μg i.c.v.) produced dose- and time-dependent increases in response latency in male but not female Sprague–Dawley rats. In contrast, nicotine (3–30 μg i.c.v.) produced increases in hotplate latency in both sexes, but produced greater effects in females; nicotine also decreased spontaneous locomotor activity significantly more in females than in males. These sex differences probably are not due to differential pharmacokinetics, and underscore the importance of including female subjects in experimental drug research.

Sex differences in symptom presentation associated with acute myocardial infarction: A population-based perspective

Objectives To describe sex differences in symptom presentation after acute myocardial infarction (AMI) while controlling for differences in age and other potentially confounding factors.Background Although several studies have examined sex differences in diagnosis, management, and survival after AMI, limited data exist about possible sex differences in symptom presentation in the setting of AMI.Methods Community-based study of patients hospitalized with confirmed AMI in all 16 metropolitan Worcester, Mass., hospitals (1990 census population = 437,000). Men (n = 810) and women (n = 550) hospitalized with validated AMI in 1986 and 1988 comprised the study sample.Results After simultaneously controlling for age, medical history, and AMI characteristics through regression modeling, men were significantly less likely to complain of neck pain (adjusted odds ratio (OR) = 0.52; 95% CI: 0.35, 0.78), back pain (OR = 0.38; 95% CI: 0.26, 0.56), jaw pain (OR = 0.50; 95% CI: 0.31, 0.81), and nausea (O.R. = 0.58; 95% CI: 0.45, 0.75) than women. Conversely, men were significantly more likely to report diaphoresis (OR = 1.27; 95% CI: 1.00, 1.61) than women. There were no statistically significant sex differences in complaints of chest pain though men were more likely to complain of this symptom.Conclusions The results of this population-based observational study suggest differences in symptom presentation in men and women hospitalized with AMI. These findings have implications for public and health care provider education concerning recognition of sex differences in AMI-related symptoms and health care seeking behaviors. (Am Heart J 1998;136:189-95.)

Agency, communion, and cardiovascular reactivity during marital interaction.

The concepts of agency and communion have been used to describe sex differences in vulnerability to specific stressor domains. This study examined blood pressure and heart rate responses of 60 married couples to experimental manipulations of disagreement (i.e., communion stressor) and achievement challenge (i.e., agency stressor). Consistent with predictions, disagreement elicited heightened cardiovascular reactivity among wives, but not husbands. In contrast, the achievement challenge elicited heightened cardiovascular reactivity among husbands, but not wives. Participants' responses to a circumplex measure of interpersonal appraisal were consistent with the interpretation of differential responses to agency and communion stressors. Results are congruent with a situational approach to sex differences in cardiovascular reactivity and illustrate the utility of interpersonal methods in the explication of psychosocial risk for cardiovascular disease.

Sex Differences in Measures of Body Fat and Body Fat Distribution in the Elderly

This study describes sex differences in obesity and body fat distribution using commonly used assessment methods in 140 men and 245 women age 65-96 years from Rancho Bernardo, California. Significant correlations were shown among all obesity measures. The waist/hip ratio was more strongly correlated with the truncal fat/leg fat ratio in women than in men. The waist/hip ratio correlated significantly with the subscapular/ triceps skinfold ration in women only. In both sexes, waist circumference was more strongly correlated with body mass index and the percentage of body fat by bioelectric impedance analysis and dual-energy X-ray absorptiometry than with the waist/hip ratio. In those aged over 80 years, age stratification showed that the waist/hip ration was not correlated with any other measurement of obesity or fat distribution in men and correlated only with subscapular skinfolds in women. Waist circumference, however, correlated significantly with almost all other measures of central obesity in older and younger men and women. Estimates of upper body (central) fat distribution appear to be age specific. After age 80, the waist/hip ratio is a poor method of assessing central or visceral adiposity, and waist circumference is a better measure of body fat distribution.

Sex differences in patient recovery patterns after coronary artery bypass surgery

To describe sex differences in physical, psychologic, and social recovery patterns after coronary artery bypass surgery (CABS). Repeated measures between groups (men versus women) design. Data were collected before discharge from the hospital and at 1, 3, and 6 weeks after discharge. Five teaching hospitals: one urban, three suburban, and one midstate hospital that serves rural and urban clients The initial sample consisted of 187 men and 70 women; 132 men and 47 women completed the study. Physical recovery was assessed by three subscales of the Sickness Impact Profile--ambulation, sleep-rest, body care and movement; a Symptom Inventory, and a Cantril Ladder Scale. Psychologic recovery was measured by the Beck Depression Inventory, the Rosenberg Self-Esteem Scale, and a Cantril Ladder Scale. Social recovery was measured by three subscales of the Sickness Impact Profile--home management, social interaction, and recreation and pastimes. All measures indicated significant improvement over time with the exception of self-esteem and perception of mental health, which remained stable. There were significant differences between men and women on five recovery variables: ambulation dysfunction, physical symptoms, perceptions of physical health, symptoms of depression, and home management dysfunction. Though it is encouraging that both sex groups experienced significant improvement in recovery over time, men and women show some differences in recovery experiences that need to be considered when planning their care.

Reproductive Factors in Hodgkin's Disease in Women: A Review

Understanding of Hodgkin's disease causes continues to be elusive. The prime etiologic candidate, Epstein-Barr virus, has been detected in only a proportion of cases, and there are few other active leads. Epidemiologic data reviewed here describe sex differences in Hodgkin's disease consistent with an involvement of reproductive and thus hormonal factors in its pathogenesis in women. This hypothesis has received very little research attention. Yet, the male predominance in incidence shows variation with age, particularly around the childbearing years, that is unusual for a malignancy. Indirect evidence relating Hodgkin's disease incidence to marital status, religion, and population parity trends demonstrates lower rates in women of presumed higher parity. Two studies that examined parity found strong but opposing associations with risk of Hodgkin's disease. The role of parity is difficult to interpret because of study design differences and the likelihood of confounding by social class. However, the incidence, clinical, and experimental findings, which should not be due to social class differences between men and women, are also compatible with a protective influence of reproductive experience in Hodgkin's disease in women. Prior infection with any ubiquitous virus seems unlikely to explain the sex differences in descriptive statistics. On the whole, the evidence suggests a role of hormonal factors in the pathogenesis of Hodgkin's disease, possibly operating through an effect on the immune system, and this hypothesis may prove fruitful to explore.

Patterns of Social Grooming in Adult White-tailed Deer

-This study describes sex differences and seasonal variation in social grooming among captive adult white-tailed deer (Odocoileus virginianus) and relates these differences to dominance relationships. Two distinct patterns of grooming were observed. One was characterized by random distribution of initial licks of a grooming bout over four body areas of target animals and a high probability of reciprocation by the targets. This pattern was used by does during both the breeding and nonbreeding seasons and by bucks only during the nonbreeding season. The second pattern, observed only in bucks during the breeding season, was characterized by a clear tendency to groom other bucks on the head more than any other body area and a low probability of reciprocation by targets. Grooming initiated by both bucks and does was related in complex ways to dominance rank. The first pattern suggests a means of maintaining social relationships among members of relatively closed groups. Expression of the other pattern coincided with the appearance of two forms of scentmarking by bucks during the breeding season and suggests that bucks can monitor the marking activity of other bucks by matching the scent of individuals identified during bouts of grooming with the scent left at rubs and scrapes.

Sex differences in child psychiatric outpatients: cognitive, personality, and behavioral characteristics.

This paper describes sex differences in a clinically referred sample on direct measures of child competence and ratings of psychopathology. The sample comprised 117 6-12 year-old boys and 63 girls referred to a psychiatric outpatient service. The results indicated that although boys and girls did not differ in overall problems or on externalizing problems, girls had significantly more internalizing problems and were more impaired as measured by both individual and composite measures of competence.

Nonverbal and Paraverbal Control in Dyads and Triads: Sex or Power Differences?

The somewhat misleading term genderlects has been used to describe sex differences in nonverbal communication. This research sought evidence for the existence of powerlects rather than genderlects in same-sex groups. Specifically examined were sex differences in three methods of control: initial eye gaze dominance, initial speaking order, and time consumed while speaking in status undifferentiated dyads and triads. The findings indicate that females are as consistent as males in using these forms of control with members of the same sex, which suggests that power rather than sex is the important factor in these nonverbal and paraverbal modes of communication. There were several differences in usage but no consistent pattern of dissimilarity. One interesting result was a tendency for females to avert initial gaze as they simultaneously spoke first, which would be predictedfrom past research. Males, however, were more likely to maintain the initial gaze as they spoke first. The data also suggest caution in generalizing about nonverbal and paraverbal behavior in twoto three-person social units.