Sex differences in the relation of visceral adipose tissue accumulation to total body fatness.
ABSTRACT The associations between the amount of abdominal adipose tissue (AT) measured by computed tomography (CT) or estimated with predictive equations and the amount of total body fat were compared in samples of 89 men and 75 women. After correction for total body fat mass, men had significantly higher values of visceral AT volume (P < 0.0001) and also higher abdominal visceral AT areas, measured by CT or estimated by predictive equations than women (P < 0.0001). In addition, an increase in total fat mass was associated with a significantly greater increase in visceral AT volume in men than in women (P < 0.0001). In conclusion, these results suggest that the greater health hazards associated with excess fatness in men than in women may be explained by the fact that premenopausal women can accumulate more body fat than men of the same age before reaching the amounts of visceral AT found in men.
Full-textDOI: · Available from: Simone Lemieux, Jan 16, 2015
SourceAvailable from: Imtiaz A Samjoo[Show abstract] [Hide abstract]
ABSTRACT: Women have higher adiposity but maintain insulin sensitivity when compared to men. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) inhibits insulin signaling, but it is not known if PTEN regulate insulin resistance in a sex-specific manner. In this cross-sectional study, muscle biopsies from participants in the Molecular Study of Health and Risk in Ethnic Groups (Mol-SHARE) were used to test for sex differences in PTEN expression. Quantitative real-time PCR was performed to determine PTEN gene expression (n = 53), and western blotting detected total and phosphorylated PTEN protein (n = 36). Study participants were comparable in age and body mass index. Women had higher fat mass percentage compared to men (40.25 ± 9.9% in women versus 27.6 ± 8.8% in men; mean difference -0.18, 95%CI (-0.24, -0.11), p-value <0.0001), with similar HOMA-IR (2.46 ± 2.05 in men versus 2.34 ± 3.06 in women; mean difference 0.04; 95% CI (-0.12, 0.21), p-value 0.59). Women had significant downregulation of PTEN gene expression (p-value 0.01) and upregulation of PTEN protein phosphorylation (inactivation) (p-value 0.001) when compared to men after correction for age, ethnicity, HOMA-IR, fat mass and sex. We conclude that the downregulation of muscle PTEN may explain the retention of insulin sensitivity with higher adiposity in women compared to men.
Scientific Reports 03/2015; · 5.08 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: The purpose of this review is to summarize the role of fetuin-A in disease processes prevalent in postmenopausal women and synthesize effective interventions in obtaining healthy fetuin-A levels. A review of databases for articles related to fetuin-A and diseases associated with postmenopausal women was conducted. Articles were limited to full-text access, published in English since 1944. High fetuin-A levels are closely associated with decreased bone mineral density, increased cardiovascular disease risks, impairment of insulin signaling and disruption of adipocyte functioning. Postmenopausal women have increased risk of osteoporosis, cardiovascular disease, insulin-resistance, intra-abdominal fat accumulation and vascular calcification. Low-levels of fetuin-A have been shown to be protective against the latter. The role of fetuin-A is multi-factorial and the mechanisms in which it is involved in each of these processes are vast. The present body of literature is inconsistent in defining high versus low levels of fetuin-A and their association with healthy-matched controls. The diseases associated with high levels of fetuin-A mimic diseases most prevalent in postmenopausal women. In addition, there is no research, to date, exploring fetuin-A levels in postmenopausal women and the associations it may or may not have in related diseases.