Gender Medicine: The Journal for the Study of Sex & Gender Differences

Sex Differences in the Association of Adiponectin and Low-Grade Inflammation With Changes in the Body Mass Index From Youth to Middle Age

Tiina Ahonen, Mauno Vanhala, Hannu Kautiainen, Esko Kumpusalo, Juha Saltevo — 2012-02-01

Abstract: Background: There are sex differences in low-grade inflammation markers in obesity-related disorders. Little is known, however, about a possible sex-specific association of relative weight change from youth to adulthood with actual low-grade inflammation. Objective: The aim of this study was to identify possible sex differences in adiponectin, interleukin-1β (IL-1β), interleukin-1Ra (IL-1Ra), and high-sensitivity C-reactive protein (hs-CRP) levels with respect to the relative change in body mass index (BMI) from youth to middle age. Methods: The study population consisted of 403 men and 500 women from 1 Finnish town. Weight, height, and adiponectin, IL-1β, IL-1Ra, and hs-CRP levels were measured in 2003 at a mean age of 46 years. Self-reported weight at the age of 20 years was recorded. Results: In women, even after adjustment for BMI in adulthood, a statistically significantly negative linear association was observed between the quartiles of relative change in BMI and adiponectin levels (P < 0.001 for linearity). Significantly positive linear associations were also observed between the change in BMI and IL-1Ra (P = 0.032 for linearity) and hs-CRP (P = 0.029 for linearity) levels. In men, there was no statistically significant association among the quartiles of relative change in BMI and measured inflammatory markers after adjustment for BMI in adulthood. Conclusions: A relative increase in weight may be more harmful in women than in men with respect to adiponectin and inflammatory markers.

Vanished Gender Differences of Cardiometabolic Risk Factors After Matching the Apnea Hypopnea Index at Postmenopausal Age

2012-01-27

Abstract: Background: Sleep-disordered breathing (SDB) and cardiometabolic risk factors are male prevalent. Objective: This study investigated whether gender differences remained prominent after matching for the apnea hypopnea index (AHI) and postmenopause. Methods: In a retrospective analysis of 350 eligible SDB patients, female patients were matched with male patients of the same age and body mass index (BMI) (age-BMI-matched [nAHImt]; n = 102 pairs) or were matched with male patients of the same age, BMI, and AHI (age-BMI-AHI-matched [AHImt]; n = 66 pairs). The nAHImt or AHImt patients were further separated into junior and senior subgroups. Results: In the nAHImt/junior group, women had shorter neck circumferences, better sleep architecture, and lower AHI, Epworth Sleepiness Scale (ESS) score, blood pressure (BP), total cholesterol (TC), triglyceride (TG), and uric acid (UA) than nAHImt/junior men. In the AHImt/junior group, women had shorter neck circumferences, lower waist/hip ratios, ESS, BP, TG, and UA than AHImt junior men. In the nAHImt/senior group, women had lower AHI, neck circumferences, waist/hip ratios, diastolic BP, and UA than men. In contrast, in the AHImt/senior group, most cardiometabolic parameters were similar between women and men. After further matching for the AHI, many elements of gender differences disappeared. Conclusions: Compared with AHImt men, women had lower UA, TG, BP, and daytime sleepiness before menopause, but gender differences became indistinguishable postmenopause. We suggested that matching sleep quality or adjusting AHI would be noteworthy and required for studying gender differences.

Postnatal Ontogeny of Angiotensin Receptors and ACE2 in Male and Female Rats

Amanda K. Sampson, Karen M. Moritz, Kate M. Denton — 2012-01-24

Abstract: Background: Sex differences in the expression of the angiotensin (Ang) II receptors and angiotensin-converting enzyme 2 (ACE2) have been hypothesized to be a potential mechanism contributing to sex-specific differences in arterial pressure. Currently, sex differences in the expression of the angiotensin receptors and ACE2 remain undefined. Objectives: The aim of this study was to define the postnatal ontogeny of mRNA expression, from birth to adulthood, of the Ang II and Ang-(1-7) receptors and ACE2 in male and female rats. Methods: Kidney and heart tissue was collected from male and female Sprague Dawley rats and snap-frozen at postnatal days (PNDs) 1, 30, 42, 70, and 110 (adult), and real-time polymerase chain reaction was performed to determine relative expression of the Ang II and Ang-(1-7) receptors (AT1aR, AT1bR, AT2R, and MasR) and ACE2. Results: All these components of the renin-angiotensin system (RAS) were detected in the kidney and left ventricle, although expression levels differed significantly between the sexes and across organs. Gene expression of most components of the RAS was high at birth and decreased with age in both sexes, except for ACE2 expression, which increased in the left ventricle with age (PAge < 0.001). Low levels of AT2R were observed in the ventricles in both sexes as adults. Most notably, AT2R expression was greatest in female kidneys and lowest in male kidneys compared with the left ventricle (PAge*Sex < 0.05). Interestingly, MasR expression in the female kidney was similar to the level of AT2R expression. Left ventricular MasR expression was greater than AT2R expression in both sexes but was not different between the sexes. The highest level of ACE2 expression was observed in adult female kidneys (PAS < 0.05). Conclusions: The enhanced mRNA expression of the vasodilatory arm of the renal RAS (ACE2, AT2R) in females observed in the present study may contribute to sex differences in the regulation of arterial pressure and the incidence of cardiovascular disease in women.

Men had a Higher Risk of Recurrent Venous Thromboembolism than Women: A Large Population Study

2012-02-01

Abstract: Background: Most reports of sex differences in the risk of recurrent venous thromboembolism (VTE) are based on small or moderate sized cohorts of selected patients with VTE. Methods: We aimed to determine the effect of sex on recurrent VTE in a large non-selected, real-world population of men and women with incident VTE. Using the linked administrative health care databases of the province of Québec, Canada, we constructed a cohort of patients with a first-time diagnosis of VTE between January 1, 1996 and December 31, 2004. Patients were followed forward in time for the occurrence of recurrent VTE until the earliest of either death, termination of health coverage, or end of study period (December 31, 2005). The cohort comprised 55,314 patients (43% men and 57% women) with incident VTE and the mean age was 61.9 years. Results: During a mean follow-up of 3.9 years, 5243 (9.5%) of patients developed recurrent VTE. Men had a significantly higher rate of recurrence than women (adjusted hazard ratio = 1.13; 95% CI, 1.07–1.19), and this difference persisted when women with hormonally mediated VTE were excluded from the analysis (adjusted hazard ratio = 1.15; 95% CI, 1.08–1.21). At 5 years, the cumulative probability of recurrent VTE was 12.4% among men versus 10.9% among women (P = 0.0001). Conclusions: Our study is the largest to date to report an effect of sex on risk of VTE recurrence, with men having about a 13% higher risk of recurrence than women. This provides further evidence that sex is a significant predictor of VTE recurrence.

Sex Differences in Parietal Lobe Structure and Development

2012-02-01

Abstract: Structural magnetic resonance imaging studies provide evidence for sex differences in the human brain. Differences in surface area and the proportion of gray to white matter volume are observed, in particular in the parietal lobe. To our knowledge, no studies have examined sex differences in parietal lobe structure in younger populations or in the context of development. The present study evaluated sex differences in the structure of the parietal lobe in children aged 7 to 17 years. In addition, by adding a cohort of previously studied adults aged 18 to 50 years, sex differences in parietal lobe structure were examined across the age span of 7 to 50 years. Compared with the adult sample, the younger sample showed that the ratio of parietal lobe cortex to white matter was greater in female brains, but no sex differences in surface area. When examining the effects of age, surface area exhibited a significant sex-age interaction. In male brains, there was essentially no decrease in surfaces area over time, whereas in female brains, there was a significant decrease in surface area over time. These findings support the notion of structural sex differences in the parietal lobe, not only in the context of cross-sectional assessment but also in terms of differences in developmental trajectories.

Hypogonadism Due to Hyperprolactinemia and Subsequent First Episode of Psychosis

2012-02-01

Abstract: Background: Hyperprolactinemia causes hypogonadotrophic hypogonadism. Hyperprolactinemia can be pre-existing in some patients with schizophrenia. Dopamine is the most important prolactin-inhibiting factor, and dopaminergic hyperactivity has been implicated in the pathophysiology of psychosis. Objective: Since dopamine is a prolactin-inhibiting factor and dopamine imbalanced has been implicated in the pathophysiology of psychotic disorders, we investigated the probable relationship between hyperprolactinemia and the development of psychotic symptoms, in a patient with hypogonadism due to hyperprolactnemia and subsequent first episode of psychosis. Since dopamine is a prolactin-inhibiting factor and dopamine imbalance has been implicated in the pathophysiology of psychotic disorders, we investigated the probable relationship between hyperprolactinemia and the development of psychotic symptoms. Methods: We present the case of a patient with hypogonadism secondary to chronic, untreated hyperprolactinemia who developed acute psychotic symptoms. Results: Psychotic symptoms resolved soon after treatment with aripiprazole in conjunction with cabergoline, with a concomitant decrease in serum prolactin level. Conclusion: This is an interesting case illustrating a complicated relationship among hypogonadism secondary to a prolactinoma and dopamine and psychosis.

Editorial Board

2012-02-01