Conclusions The current evidence does not suggest an association between leptin and PCa outcome .
However , there may be an inverse association between adiponectin and the incidence of advanced PCa that should be investigated by further studies .
Background Obesity has been proposed as a risk factor for prostate cancer ( PCa ) .
In obesity , serum levels of the appetite-regulating hormones — leptin , adiponectin , and ghrelin — become deregulated .
Objective To explore whether serum levels of appetite-regulating hormones associate with the incidence of PCa , the incidence of advanced disease , or PCa-specific mortality .
Circulating ghrelin levels are decreased in human obesity.
Ghrelin is a novel endogenous natural lig and for the growth hormone ( GH ) secretagogue receptor that has recently been isolated from the rat stomach . Ghrelin administration stimulates GH secretion but also causes weight gain by increasing food intake and reducing fat utilization in rodents . To investigate the possible involvement of ghrelin in the pathogenesis of human obesity , we measured body composition ( by dual X-ray absorption ) as well as fasting plasma ghrelin concentrations ( radioimmunoassay ) in 15 Caucasians ( 8 men and 7 women , 31+/-9 years of age , 92+/-24 kg body wt , and 29+/-10 % body fat , mean + /- SD ) and 15 Pima Indians ( 8 men and 7 women , 33+/-5 years of age , 97+/-29 kg body wt , and 30+/-8 % body fat ) .  Fasting plasma ghrelin was negatively correlated with percent body fat ( r = -0.45 ; P = 0.01 ) , fasting insulin ( r = -0.45 ; P = 0.01 ) and leptin ( r = -0.38 ; P = 0.03 ) concentrations . Plasma ghrelin concentration was decreased in obese Caucasians as compared with lean Caucasians ( P < 0.01 ) . Also , fasting plasma ghrelin was lower in Pima Indians , a population with a very high prevalence of obesity , compared with Caucasians ( 87+/-28 vs. 129+/-34 fmol/ml ; P < 0.01 ) . This result did not change after adjustment for fasting plasma insulin concentration . There was no correlation between fasting plasma ghrelin and height . Prospect i ve clinical studies are now needed to establish the role of ghrelin in the pathogenesis of human obesity
Conclusions The current evidence does not suggest an association between leptin and PCa outcome .
However , there may be an inverse association between adiponectin and the incidence of advanced PCa that should be investigated by further studies .
Background Obesity has been proposed as a risk factor for prostate cancer ( PCa ) .
In obesity , serum levels of the appetite-regulating hormones — leptin , adiponectin , and ghrelin — become deregulated .
Objective To explore whether serum levels of appetite-regulating hormones associate with the incidence of PCa , the incidence of advanced disease , or PCa-specific mortality .