Leptin: obesity, diabetes and other peripheral effects - a review

Abstract

There is an increasing epidemic of obesity in the Western and developing world that has not spared children and, hence, is of great concern. Obesity presents numerous physiological and psychosocial problems for the child. Childhood obesity not only increases the risk of obesity in adulthood, it is associated with type 2 diabetes mellitus; is the leading cause of pediatric hypertension; increases the risk of coronary heart disease; and increases stress on the weight-bearing joints. Social and psychological problems are also significant consequences of obesity in children, with lowering of self-esteem and its effects on relationships with peers. Obesity is clearly associated with increased levels of the recently discovered hormone, leptin. Leptin, secreted from adipocytes, is involved in the regulation of food intake, energy expenditure, and energy balance in humans. This review focuses on the hormone, leptin, in an effort to document some of its many local and systemic effects on the body and, specifically, its potential role in obesity-induced diabetes.

Defective Adipose Lipolysis and Altered Global Energy Metabolism in Mice with Adipose Overexpression of the Lipolytic Inhibitor G0/G1 Switch Gene 2 (G0S2)

“…Fasting plasma insulin was also decreased in aP2-G0S2 mice, which is further suggestive of a more insulin responsive animal. Furthermore, changes in plasma adipokines including an increase in leptin and an accompanying decrease in adiponectin are consistent with elevated adiposity (32,33). Even with the reduction in plasma adiponectin levels, however, we have found no significant up-regulation of proinflammatory genes (Table 1) or morphological indications of increased inflammation in WAT (data FIGURE 5.…”

Inflammatory markers and metabolic syndrome among adolescents

“…45 Leptin has effects on different systems of the body: central nervous system (inhibition of food intake, reduction of adipose mass and increased thermogenesis), glucose homeostasis, reproductive system (signalling onset of puberty and maintenance of reproductive function), autonomic nervous system, hematopoietic system, skeletal system, oncogenesis and transplantation (contributing to rejection of transplants). 46 Our results show that leptin levels are directly associated with MetS, BMI, blood pressure and inactivity also among adolescents. Previous findings pointed out that girls showed higher levels of leptin than boys independently of the degree of obesity; 47 however, we just found these results among normal weight adolescents.…”

“…Numerous publications in adults suggest leptin as a biomarker for obesity, insulin resistance and MetS. 12,13 PAI-1 is a pro-inflammatory adipokine with pro-thrombotic effects that is also increased in obesity, including children and adolescents when compared with a control group. 14 Some studies have reported an association between PAI-1 and the prevalence of MetS, including adolescents.…”

Biochemical markers of psoriasis as a metabolic disease

“…Therefore, it is supposed that obese patients are resistant to leptin, just as in type 2 diabetes, where insulin resistance is observed [63,76,78]. Furthermore, hyperleptinemia caused by obesity is an important risk factor leading to the development of type 2 diabetes [79].…”