Effects of gender, body composition, and menopause on plasma concentrations of leptin.

Abstract

Circulating concentrations of leptin ([leptin]) vary directly with body mass index and percentage body fat, and may thus constitute an afferent limb of a system regulating body fatness. We tested the hypotheses that: 1) Plasma [leptin] vary more directly with absolute fat mass than with fractional body fatness per se: and 2). The relationship between fat mass and [leptin] is significantly affected by gender and by menopausal status. [Leptin] in the post-absorptive state was examined in 67 subjects (26 male, 20 premenopausal female, 21 postmenopausal females; 43 never-obese, 24 obese) at usual body weight. Body composition was determined by hydrodensitometry, and [leptin] was determined by a double antibody ELISA assay. In male and pre-menopausal female subjects, subcutaneous adipose tissue aspirations were performed for determination of adipocyte volume by the osmium fixation method, and a 3 hour oral glucose tolerance tests was performed. At usual body weight, ([leptin]) was better correlated with absolute fat mass than with body mass index (BMI) or percentage body fat. BMI and % body fat did not account for any of the variance in [leptin] beyond that attributable to FM, per se. The regression equations relating FM to [leptin] did not differ significantly between obese and never-obese subjects. [Leptin] and fasting serum insulin concentrations were significantly correlated in males only. [Leptin] was significantly higher in pre- and post-menopausal females compared to males, even when [leptin] was corrected for differences in body composition (pre-menopausal females > post-menopausal females > males). While plasma [leptin], corrected for FM, declines significantly in women post-menopause, this decline is not sufficient to account for the striking sexual dimorphism in the relationship of leptin to fat mass. This sexual dimorphism is apparently also due, in part, to a suppressive effect of circulating androgens on [leptin].

Local Application of Leptin Antagonist Attenuates Angiotensin II–Induced Ascending Aortic Aneurysm and Cardiac Remodeling

“…Immunohistochemistry was performed for α‐SMA, CD68, leptin, and leptin receptor, as described previously 17. For in situ mRNA hybridization, leptin RNA sense and antisense probes were transcribed in vitro and labeled with digoxigenin.…”

“…Leptin is mostly synthesized by adipocytes, and its systemic levels correlate with body fat mass 17. Leptin synthesis is induced to a lesser extent in macrophages and vascular smooth muscle cells (SMCs) by cytokines and AngII, resulting in local cardiovascular pathological conditions 18.…”

Impact of the menstrual cycle on determinants of energy balance: a putative role in weight loss attempts

“…59 Studies of leptin show gender difference with respect to levels of this peptide, also after controlling for body fat. 60,61 However, within-gender difference is also seen as premenopausal women exhibit higher levels than postmenopausal women. 61 This suggests that cyclic changes in estrogen-responsive peptides such as leptin occur.…”

“…60,61 However, within-gender difference is also seen as premenopausal women exhibit higher levels than postmenopausal women. 61 This suggests that cyclic changes in estrogen-responsive peptides such as leptin occur. However, we have been unable to find studies that have investigated whether sex hormones also interact with appetite peptides to control changes in appetite over the course of one menstrual cycle.…”

Reply

“…The authors did not mention the above diseases, and this omission could have influenced the findings of the study. In addition to confounding diseases, it has been suggested that some types of antidepressants, antipsychotics, glucocorticoids, antihypertensive drugs, and statins affect serum leptin levels (5,6). Also, dietary supplements, such as linoleic acid, zinc, vitamin A, vitamin D, vitamin E, and -3 fatty acid, could affect plasma leptin levels (7,8).…”