Sex differences in human adipose tissues – the biology of pear shape

Abstract

Women have more body fat than men, but in contrast to the deleterious metabolic consequences of the central obesity typical of men, the pear-shaped body fat distribution of many women is associated with lower cardiometabolic risk. To understand the mechanisms regulating adiposity and adipose tissue distribution in men and women, significant research attention has focused on comparing adipocyte morphological and metabolic properties, as well as the capacity of preadipocytes derived from different depots for proliferation and differentiation. Available evidence points to possible intrinsic, cell autonomous differences in preadipocytes and adipocytes, as well as modulatory roles for sex steroids, the microenvironment within each adipose tissue, and developmental factors. Gluteal-femoral adipose tissues of women may simply provide a safe lipid reservoir for excess energy, or they may directly regulate systemic metabolism via release of metabolic products or adipokines. We provide a brief overview of the relationship of fat distribution to metabolic health in men and women, and then focus on mechanisms underlying sex differences in adipose tissue biology.

Adipose morphology and metabolic disease

“…Arner et al (2010) found that hyperplastic and hypertrophic morphologies were present at equal frequencies in both males and females, and in obese and non-obese people . Strikingly, at comparable BMI, women typically present with ∼10% higher body fat, which is characterized by greater SAT in the abdomen and gluteofemoral regions (Camhi et al, 2011;Jackson et al, 2002;Karastergiou et al, 2012;Womersley, 1977). Body fat distribution is linked to health in both males and females, but the protective peripheral distribution is mainly seen in females (Krotkiewski et al, 1983 .…”

Hypothalamic-pituitary-adrenal axis dysregulation and cortisol activity in obesity: A systematic review

“…For example, males have less gluteofemoral fat than females and tend to exhibit a normal or high waist-to-hip ratio, but are rarely "pear shaped" (Arner, 1997). This relationship may be driven by sex hormones as both subcutaneous and gluteofemoral fat, for instance, are shaped in part by estrogens (Karastergiou et al, 2012). Additionally, some research suggests that certain sex hormones might regulate the synthesis of corticosteroid binding globulin, which may affect cortisol reactivity when examining free cortisol measures (Misao et al, 1999), as is most commonly done in the studies reviewed on CAR, diurnal, and cortisol reactivity.…”

Differences in Hematopoietic Stem Cells Contribute to Sexually Dimorphic Inflammatory Responses to High Fat Diet-induced Obesity

“…Estrogen receptor signaling probably contributes to many of these effects, but because estrogen replacement therapy alone is not sufficient to improve health, other mechanisms are likely involved (2). Sex differences in adipose tissue depot development, cell intrinsic differences in preadipocyte proliferation and differentiation, and modulatory effects of sex steroids on adipocytes have been proposed to contribute to the sexually dimorphic differences in obesity-associated metabolic disease (3).…”