Mouse models of obesity (ob/ob) and diabetes (db/db) in which the leptin (Lep) and leptin receptor (Lepr) genes have been mutated, respectively, have contributed to a better understanding of human obesity and type 2 diabetes and to the prevention, diagnosis, and treatment of these metabolic diseases.
On the other hand, the decrease in leptin and leptin:adiponectin ratio assessments could reflect an amelioration of the cardiovascular risk profile linked to hyperleptinaemia in ageing men with T2D.
Functional polymorphisms of the leptin and leptin receptor genes are associated with longevity and with the risk of myocardial infarction and of type 2 diabetes mellitus.
In subjects with and without type 2 diabetes, rs2016520 was associated with body mass index, high-density lipoprotein cholesterol, leptin, and TNFalpha and was dependent on gender.
A significant association between the variation of G-2548A allele with body mass index (BMI), serum leptin levels and FPG was observed in T2DM patients.
Carriers of the PPARγ variant allele had statistically significantly lower rates of type 2 diabetes (P = 0.04), lower BMI (P = 0.01), and HOMA scores [P = 0.004; non-Hispanic White (NHWs) only]; carriers of the TNF-α variant A allele had higher serum glucose (P = 0.004, NHW only); and the IRS-1 variant was associated with higher leptin levels (P = 0.003, Hispanics only).
In conclusion, we observed that several polymorphisms in LEPR that had previous reports of association with BMI were significantly replicated in our samples and newly found that some variations of LEP were associated with T2DM and metabolic traits.
This study was designed to assess the role of soluble leptin and LepRb in NAFLD and to investigate whether leptin receptor gene (LepR) single nucleotide polymorphism (SNP; ID rs6700896) influences NAFLD complicated with or without type 2 diabetes mellitus (T2DM).
The purpose of this clinical trial study was to evaluate the effects of CoQ10 supplementation on serum values of adiponectin (A), leptin (L), 8-isoprostane, malondialdehyde (MDA), the A/L ratio in women with T2DM.
A population of 1,974 White European individuals at increased risk for type 2 diabetes was characterized by an oral glucose tolerance test with glucose and insulin measurements (1,409 leptin measurements) and genotyped for five tagging SNPs covering 100% of common genetic variation (minor allele frequency ≥ 0.05) in the SERPINF1 locus.
We therefore examined the prevalence of the CAC(His) --> CAT(His) mutation in non-diabetic first degree relatives of subjects with type 2 diabetes to determine a possible association of this mutation to leptin levels and insulin sensitivity.
To investigate the association of serum levels and the -2518 A-->G promoter polymorphism of the gene for chemokine monocyte chemoattractant protein-1 (MCP-1), a major chemoattractant of monocytes and activated lymphocytes, with metabolic parameters as well as insulin, leptin and the cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in 534 Caucasian patients with type 2 diabetes mellitus.
Pro12Ala substitution in the peroxisome proliferator-activated receptor-gamma is associated with increased leptin levels in women with type-2 diabetes mellitus.
Association of rs9939609 variant with higher FBG, plasma insulin, and leptin levels indicates that this polymorphism may disturb the metabolism in adult females and predispose them to obesity and type 2 diabetes.
I propose that: (1) metabolic thrift, the capacity for efficient acquisition, storage and use of energy, is an ancient, complex trait, (2) the environmentally responsive gene network encoding this trait is subject to genetic canalization and thereby has become robust against mutational perturbations, (3) DNA sequence polymorphisms play a minor role in the aetiology of obesity and type 2 diabetes-instead, disease susceptibility is predominantly determined by epigenetic variations, (4) corresponding epigenotypes have the potential to be inherited across generations, and (5) Leptin is a candidate gene for the acquisition of a thrifty epigenotype.
Heterozygosity for the Trp64Arg polymorphism of the beta 3-adrenergic receptor gene is not accompanied by obesity, impaired glucose tolerance and type 2 diabetes mellitus in the general elderly Dutch population, and is also not associated with changes in circulating leptin levels.
Low levels of adiponectin, IGF-binding protein 1 (IGFBP1) and IGFBP2 and high levels of leptin correlate with several indices of insulin resistance and risk of type 2 diabetes.
In the present study, we examined whether common single nucleotide polymorphisms (SNPs) in the leptin (LEP; 19G>A) gene and its receptor (LEPR; Q223R and K109R) are associated with birth weight and adult metabolic risk factors for type 2 diabetes in twins.
To illustrate these concepts, we focus on epigenetic programming of insulin resistance, obesity and type 2 diabetes, with emphasis on the potential role of the adipocyte and three of its products, fatty acids, leptin and tumour necrosis factor alpha.
BCAA were measured by nuclear magnetic resonance, whereas leptin and adiponectin were measured by immunoassay, in subjects with normal fasting glucose (n = 30), impaired fasting glucose (n = 25), and T2DM (n = 15).
These results suggest that the increase in DF male leptin could be a compensatory mechanism for reduced insulin sensitivity in a pre-clinical alteration of glucose metabolism.
It has recently been proposed that a defect in the beta3-AR in humans may contribute to a resistance to the sympathetically mediated effects of leptin on thermogenesis and lipolysis, thus leading to obesity and type 2 diabetes mellitus.