Metabolic Syndrome and Prostate Cancer Risk in a Population-Based Case–Control Study in Montreal, Canada

Audrey Blanc-Lapierre; Andrea Spence; Pierre I. Karakiewicz; Armen Aprikian; Fred Saad; Marie-Élise Parent

Disclosures

BMC Public Health. 2015;15(913) 

In This Article

Background

Prostate cancer (PCa) is the most frequent non-skin cancer diagnosed in men in the western world.[1] The only established risk factors (age, family history of PCa and ancestry) are not modifiable.[2] Evidence from migration studies provide support for a role of environmental factors in PCa etiology.[3] Parallel increases in rates of PCa and metabolic disorders in North America suggest that factors associated with westernization, such as diet and physical activity, may be involved in PCa carcinogenicity.[4,5]

Metabolic syndrome (MetS), defined as a cluster of metabolic disorders associated with insulin resistance and visceral adiposity, was first used to identify subjects at increased risk of type 2 diabetes (T2D) and cardiovascular diseases. Different definitions of MetS have been proposed since 1998, varying from a glucocentric definition to an obesity-centric one, but all including glucose intolerance (high fasting glucose blood level), dyslipidemia (high triglycerides [TG] or low high-density lipoprotein cholesterol [HDL-C] blood levels), hypertension and abdominal obesity.[6,7] MetS represents a growing public health concern given its high prevalence worldwide,[8] especially in the United States where one third of the adult population is currently affected.[4,9]

MetS is suspected to influence the regulation of PCa growth and progression through various pathways, including the IGF-1 pathway stimulated by hyperinsulinemia, the sex steroid pathway (increased estradiol, decreased sex hormone-binding globulin and lower testosterone levels) and inflammation mediated by cytokines and hormones produced by adipocytes.[10–13] Although inter-related, MetS components affect PCa risk differently when considered separately. For instance, obesity assessed using the body mass index (BMI) is associated with an increased risk of high-grade PCa, but data remain insufficient regarding the specific role of abdominal fat.[14–18] Long-standing diabetes is associated with decreased incidence of PCa.[19,20] Thus, metabolic disorders have to be considered together when evaluating their relation with PCa in order to provide useful guidelines for the management of PCa risk by physicians.[21]

Recent investigations integrating multiple MetS components into a single condition have shown positive, negative or no relationship with PCa risk.[10,22,23] Studies have usually relied on MetS status at study baseline, precluding the evaluation of MetS timing in relation to PCa, which may be of importance for a disease with a long natural history such as PCa. We provide here new evidence for the association between MetS and PCa, using data from a large Canadian population-based case–control study.

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