Increased Plasma Leptin Levels Are Associated With Fat Accumulation in Japanese Americans

Abstract

Although the hormone leptin seems to play a role in ensuring the maintenance of adequate energy stores and thereby protects against starvation, its role in the regulation of body weight and adiposity under normal circumstances is unclear. Overweight individuals have markedly elevated circulating leptin levels, suggesting that leptin's effect on food intake and thermogenesis is diminished or absent in obesity. Recent evidence, though, indicates that weight gain in Pima Indians is associated with relatively decreased levels of the hormone. Because it is important to understand whether a deficiency in circulating leptin contributes to the development of obesity, we sought to determine whether there is a relationship between leptin levels and subsequent changes in adiposity in a more typical population. We compared baseline plasma leptin concentrations to changes over 5 years in body weight, BMI, and computed tomography-determined total fat in 492 second- and third-generation Japanese Americans. Subjects were of 100% Japanese ancestry; male subjects had a mean BMI at baseline of 25.4 kg/m2 and a mean age of 54 years; female subjects had a mean BMI of 23.1 kg/m2 and a mean age of 53 years. Changes in weight (men: r = 0.17, P < 0.05; women: r = 0.20, P < 0.05), BMI (men: r = 0.17, P < 0.05; women: r = 0.18, P < 0.05), and total fat (men: r = 0.19, P < 0.05; women: r = 0.20, P < 0.01) were positively correlated with baseline leptin levels adjusted for baseline adiposity, fasting insulin, and age. In Japanese Americans, then, relatively increased leptin levels are associated with greater subsequent gains in weight and adiposity. We concluded that in this population, fat accumulation is associated not with leptin deficiency but possibly with leptin resistance and is preceded by increased leptin levels.

Adipokine levels during the first or early second trimester of pregnancy and subsequent risk of gestational diabetes mellitus: A systematic review

“…Leptin is an adipose tissue-derived hormone that plays a key role in the regulation of energy intake and energy expenditure. Circulating leptin levels are elevated with increasing adiposity [45], reflecting a state of leptin resistance [46]. Several studies have positively associated leptin levels with insulin resistance independent of body mass index (BMI), whereas other studies suggest that the relationship between leptin levels and insulin resistance is mainly accounted for by obesity [47, 48].…”

CSF and Brain Indices of Insulin Resistance, Oxidative Stress and Neuro-Inflammation in Early versus Late Alzheimer’s Disease

“…Increased levels of leptin [78] and reduced levels of PYY [79] are features of obesity with peripheral insulin resistance [80]. The presence of similar abnormalities in AD brains suggests that leptin and PYY levels could also serve as indices of brain insulin resistance.…”

Hyperleptinemia, Adiposity, and Risk of Metabolic Syndrome in Older Adults

“…Previous studies on the role of adiposity on the association of serum leptin and metabolic disorders have shown inconsistent results. The inverse association between serum leptin and increased risk of diabetes was independent of obesity in the Atherosclerosis Risk in Communities (ARIC) [32], whereas it was mediated by adiposity and insulin insensitivity in a study among Japanese men and women [24]. Similarly, association between serum leptin, insulin resistance, and metabolic syndrome was mediated through central obesity in a cross-sectional study on Iranian population [33].…”