Leptin secretion from subcutaneous and visceral adipose tissue in women.

Abstract

Upper body obesity is a risk factor for type 2 diabetes. Little is known about the regulation of body fat distribution, but leptin may be involved. This study examined the secretion of leptin in subcutaneous and omental fat tissue in 15 obese and 8 nonobese women. Leptin secretion rates were two to three times higher in subcutaneous than in omental fat tissue in both obese and nonobese women (P < 0.0001 and P < 0.001, respectively). There was a positive correlation between BMI and leptin secretion rates in both subcutaneous (r = 0.87, P < 0.0001) and omental (r = 0.74, P < 0.0001) fat tissue. Furthermore, leptin secretion rates in subcutaneous and omental fat tissue correlated well with serum leptin levels (r = 0.84, P < 0.0001 and r = 0.73, P = 0.001, respectively), although in multivariate analysis, the subcutaneous leptin secretion rate was the major regressor for serum leptin (F = 42). Subcutaneous fat cells were approximately 50% larger than omental fat cells, and there was a positive correlation between fat cell size and leptin secretion rate in both fat depots (r = 0.8, P < 0.01). Leptin (but not gamma-actin) mRNA levels were twofold higher in subcutaneous than in omental fat tissue (P < 0.05). Thus the subcutaneous fat depot is the major source of leptin in women owing to the combination of a mass effect (subcutaneous fat being the major depot) and a higher secretion rate in the subcutaneous than in the visceral region, which in turn could be due to increased cell size and leptin gene expression.

Body fat distribution and cardiovascular risk in normal weight women. Associations with insulin resistance, lipids and plasma leptin

“…Furthermore, it has been shown that omental adipocytes contain less leptin mRNA and also secrete less leptin than subcutaneous adipocytes. 36 Our data thus con®rms the data of other investigators 37 ± 39 that abdominal fat, whether intra-or retro-peritoneal is not a determinant of peripheral plasma leptin.…”

The inflammatory receptor CD40 is expressed on human adipocytes: contribution to crosstalk between lymphocytes and adipocytes

“…In agreement, CD40 mRNA levels in SAT increased with BMI and leptin mRNA level in a population of obese individuals. Like leptin [28,29], the CD40 mRNA level was 45% higher in SAT than in VAT. This could be due to larger fat cells in SAT than VAT [30], in line with the notion that leptin production is correlated with the degree of adipocyte development [31].…”

Gluteofemoral body fat as a determinant of metabolic health

“…6,58,62 Leptin secretion in vitro is higher in subcutaneous adipocytes compared with visceral adipocytes and this secretion rate correlates well with serum leptin levels. 63 There are no studies that have compared regional leptin mRNA expression in subcutaneous adipose tissue; however, there are indirect suggestions that basal expression does not differ between abdominal and gluteofemoral fat. 64,65 Serum leptin increases in parallel with BMI and, interestingly, is higher in women.…”