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 .
Prostate cancer risk and serum levels of insulin and leptin: a population-based study.
BACKGROUND In a previous study of Chinese men , we found that men with a higher waist-to-hip ratio ( WHR ) have a higher prostate cancer risk . Because leptin and insulin are related to body fat distribution , we examined whether leptin and insulin were associated with prostate cancer risk . METHODS Blood sample s were collected from 128 case patients with incident prostate cancer and from 306 healthy control subjects r and omly selected from residents of Shanghai , CHINA : Epidemiologic information and anthropometric measurements were collected in personal interviews . Serum leptin , insulin , and sex hormone levels were measured by radioimmunoassay , and  insulin-like growth factor-I ( IGF-I )  was measured by enzyme-linked immunosorbent assay . Multiple logistic regression analyses were used to estimate odds ratios for prostate cancer in relation to serum insulin and leptin levels . All statistical tests were two-sided . RESULTS After adjustment for body mass index , WHR , IGF-I , and sex hormone levels , higher serum insulin levels were associated with a statistically significantly elevated risk of prostate cancer ( P<.001 ) . Men in the highest tertile of insulin levels had a 2.56-fold ( 95 % confidence interval [ CI ] = 1.38 to 4.75 ) risk of prostate cancer compared with men in the lowest tertile . Regardless of the tertile level of WHR , higher serum insulin levels were associated with an increased risk of prostate cancer : Men in the highest tertiles of WHR ( > 0.900 ) and insulin ( > 8.83 microU/mL ) had 8.55 times ( 95 % CI = 2.80 to 26.10 ) the prostate cancer risk of men in the lowest tertiles of both , and those in the lowest tertile of WHR ( < 0.873 ) and highest tertile of insulin had 4.30 times ( 95 % CI = 1.17 to 15.70 ) the risk . By contrast , the association between leptin levels and prostate cancer risk was not statistically significant . CONCLUSION Our results suggest that serum insulin levels may influence the risk of prostate cancer in Chinese men . Further research , especially prospect i ve studies , is needed to confirm these findings in high-risk population s and to clarify the underlying mechanisms involved
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 .