Height, body mass index, physical activity, and risk of colorectal cancer in relation to expression of insulin receptor: The Japan Public Health Center-based Prospective Study
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View abstract on PubMed
Summary
This summary is machine-generated.Obesity increases colorectal cancer (CRC) risk, particularly for CRC expressing insulin receptors (IRs). Increased physical activity lowers this risk, while height shows no association. These factors do not impact IR-negative CRC.
Area Of Science
- Oncology
- Endocrinology
- Epidemiology
Background
- Insulin receptors (IRs) play a role in cell growth and metabolism.
- Dysregulation of IR signaling is implicated in various cancers, including colorectal cancer (CRC).
- Understanding lifestyle factors associated with IR-mediated CRC is crucial for prevention strategies.
Purpose Of The Study
- To investigate the association between height, body mass index (BMI), and physical activity with CRC risk.
- To examine these associations in relation to CRC subtypes defined by insulin receptor beta-subunit (IRβ) expression.
- To clarify the role of IRs in colorectal carcinogenesis influenced by lifestyle factors.
Main Methods
- A large-scale, population-based prospective cohort study of 18,158 middle-aged and elderly Japanese individuals.
- Utilized Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
- Classified CRC into IRβ-positive and IRβ-negative subtypes using immunohistochemistry.
Main Results
- Obesity (BMI ≥30.0 kg/m²) was associated with a significantly increased risk of IRβ-positive CRC (HR=1.77).
- Increased physical activity was significantly associated with a decreased risk of IRβ-positive CRC (HR per 5 METs-hour/day=0.93).
- No significant associations were found between height, BMI, physical activity, and IRβ-negative CRC.
Conclusions
- Obesity appears to promote the development of IRβ-positive CRC.
- Physical activity demonstrates a protective effect against IRβ-positive CRC.
- Lifestyle modifications related to BMI and physical activity may be important for preventing CRC subtypes associated with insulin receptor expression.
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