Leptin Concentrations in Relation to Body Mass Index and the Tumor Necrosis Factor-α System in Humans¹

Abstract

The expression of leptin, an adipocyte-derived protein whose circulating levels reflect energy stores, can be induced by tumor necrosis factor (TNF)␣ in rodents, but an association between the TNF␣ system and leptin levels has not been reported in humans. To evaluate the potential association between serum leptin and the TNF␣ system, we measured the levels of soluble TNF␣-receptor (sTNF␣-R55), which has been validated as a sensitive indicator of activation of the TNF␣ system. We studied two groups: 1) 82 young healthy normal controls and 2) 48 patients with noninsulin dependent diabetes mellitus (NIDDM) and 24 appropriately matched controls. By simple regression analysis in controls, there was a strong positive association between leptin and 3 parameters: body mass index, sTNF␣-R55, and insulin levels. In a multiple regression analysis model, leptin remained significantly and strongly associated with body mass index, and the association of leptin with both insulin and sTNF␣-R55, although weakened, remained significant. Patients with NIDDM had leptin concentrations similar to controls of similar weight. Importantly, serum levels of sTNF␣-R55 were also positively and independently associated with leptin in this group of diabetic subjects and matched controls. These data are consistent with the hypothesis that the TNF␣ system plays a role in regulating leptin levels in humans. Further elucidation of a possible role of the TNF␣ system in leptin expression and circulating levels may have important implications for our understanding of obesity and cachexia in humans. (J Clin Endocrinol Metab 82: 3408 -3413, 1997)

Regulatory effects of resveratrol on glucose metabolism and T-lymphocyte subsets in the development of high-fat diet-induced obesity in C57BL/6 mice

“…Leptin can increase sympathetic activity and energy expenditure as well as exert a potent anti-obesity effect. 28 Indeed, plasma leptin levels are elevated in obese rodents 29 and humans, 30,31 which is associated with leptin resistance. 30 Being consistent with previous studies, 26,32 plasma leptin in HF mice was signicantly increased compared with that in control mice aer 6 weeks of high-fat feeding, which suggests increased leptin resistance in HF mice.…”

The Potential of Visceral Adipose Tissue in Distinguishing Clear Cell Renal Cell Carcinoma from Renal Angiomyolipoma with Minimal Fat

“…Body adipose tissue has the biological functions of altering lipid metabolism, regulating fat factors and causing chronic inflammation. An increase in visceral adipose tissue (VAT) leads to an increase in proinflammatory cytokines, 13 a decrease in circulating adiponectin level, 14 and increases in leptin level 15 and the severity of insulin resistance. 16 The role of visceral fat in the development of RCC is more significant than that of subcutaneous fat.…”

Inflammatory Markers in Response to Different Intensity of Aerobic Exercise in Obese Male Wistar Rats

“…However, it is inconsistent with the findings of Arslan et al (29). TNF-α is one of the most important proinflammatory cytokines, which has a strong association with leptin levels and energy metabolism in the body (30). In this regard, there is a complex relationship between energy metabolism and TNF-α; thus, increased levels of TNFα in the blood may increase resting metabolism and energy expenditure, and weight loss (31).…”