Department of Medicine, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
RIKEN Center for Life Science Technologies, Molecular Network Control Genomics Unit, Yokohama, Kanaga-wa, Japan.
Int J Obes (Lond). 2017 Oct;41(10):1564-1569. doi: 10.1038/ijo.2017.148. Epub 2017 Jun 20.
BACKGROUND/OBJECTIVE: Differences in subcutaneous abdominal adipose tissue (SAT) fat cell size and number (cellularity) are linked to insulin resistance. Men are generally more insulin resistant than women but it is unknown whether there is a gender dimorphism in SAT cellularity. The objective was to determine SAT cellularity and its relationship to insulin sensitivity in men and women.
In a cohort study performed at an outpatient academic clinic in Sweden, 798 women and 306 men were included. Estimated SAT mass (ESAT) was derived from measures of dual-energy X-ray absorptiometry and a formula. SAT biopsies were obtained to measure mean fat cell size; SAT adipocyte number was obtained by dividing ESAT with mean fat cell weight. Fat cell size was also compared with level of insulin sensitivity in vivo.
Over the entire range of body mass index (BMI) both fat cell size and number correlated positively with ESAT in either sex. On average, fat cell size was larger in men than in women, which was driven by significantly larger fat cells in non-obese men compared with non-obese women; no gender effect on fat cell size was seen in obese subjects. For all subjects fat cell number was larger in women than men, which was driven by a gender effect among non-obese individuals (P<0.0001). The relationship between fat cell size and insulin resistance was significant in both genders (P<0.0001) but steeper in men than in women (F=19, P<0.0001).
Although both fat cell size and number determine SAT mass, adipocyte number contributes more and size less in women than in men and this is most evident in non-obese subjects. Over the entire BMI range, fat cell size contributes stronger to insulin resistance in men.
背景/目的：皮下腹部脂肪组织（SAT）脂肪细胞大小和数量（细胞密度）的差异与胰岛素抵抗有关。男性通常比女性更具胰岛素抵抗性，但尚不清楚 SAT 细胞密度是否存在性别二态性。本研究旨在确定男性和女性的 SAT 细胞密度及其与胰岛素敏感性的关系。
在瑞典一家门诊学术诊所进行的队列研究中，纳入了 798 名女性和 306 名男性。估计的 SAT 质量（ESAT）来自双能 X 射线吸收法测量和公式计算。通过 SAT 活检测量平均脂肪细胞大小；通过将 ESAT 除以平均脂肪细胞重量获得 SAT 脂肪细胞数量。还比较了脂肪细胞大小与体内胰岛素敏感性水平的关系。
在整个 BMI 范围内，无论男女，脂肪细胞大小和数量均与 ESAT 呈正相关。平均而言，男性的脂肪细胞大小大于女性，这是由于非肥胖男性的脂肪细胞明显大于非肥胖女性；在肥胖人群中未观察到性别对脂肪细胞大小的影响。对于所有受试者，女性的脂肪细胞数量大于男性，这是由于非肥胖个体的性别差异所致（P<0.0001）。脂肪细胞大小与胰岛素抵抗之间的关系在两性中均具有统计学意义（P<0.0001），但在男性中更为陡峭（F=19，P<0.0001）。
尽管脂肪细胞大小和数量都决定了 SAT 质量，但在女性中，脂肪细胞数量比男性的影响更大，而脂肪细胞大小的影响更小，这种差异在非肥胖人群中最为明显。在整个 BMI 范围内，脂肪细胞大小对男性的胰岛素抵抗的贡献更强。
