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 .
Association of C-peptide and leptin with prostate cancer incidence in the Health Professionals Follow-up Study
Abstract Purpose Hyperinsulinemia is hypothesized to influence prostate cancer risk . Thus , we evaluated the association of circulating C-peptide , which is a marker of insulin secretion , and leptin , which is secreted in response to insulin and influences insulin sensitivity , with prostate cancer risk . Methods We identified prostate cancer cases ( n = 1,314 ) diagnosed a mean of 5.4 years after blood draw and matched controls ( n = 1,314 ) in the Health Professionals Follow-up Study .  Plasma C-peptide and leptin concentrations were measured by ELISA .  Odds ratios ( ORs ) and 95 % confidence intervals ( CI ) were estimated taking into account the matching factors age and history of a PSA test before blood draw and further adjusting for body mass index , diabetes , and other factors . Results Neither C-peptide ( quartile [Q]4 vs. Q1 : OR 1.05 , 95 % CI 0.82–1.34 , p-trend = 0.95 ) nor leptin ( Q4 vs. Q1 : OR 0.85 , 95 % CI 0.65–1.12 , p-trend = 0.14 ) was associated with prostate cancer risk . Further , neither was associated with risk of advanced or lethal disease ( n = 156 cases ; C-peptide : Q4 vs. Q1 , OR 1.18 , 95 % CI 0.69–2.03 , p-trend = 0.78 ; leptin : Q4 vs. Q1 , OR 0.74 , 95 % CI 0.41–1.36 , p-trend = 0.34 ) . Conclusions In this large prospect i ve study , circulating C-peptide and leptin concentrations were not clearly associated with risk of prostate cancer overall or aggressive disease . Well into the PSA era , our findings do not appear to be supportive of the hypothesis that hyperinsulinemia influences risk of total or aggressive prostate cancer
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 .