Abstract
BACKGROUND: Allostatic load (AL) reflects the cumulative physiological burden of chronic stress across cardiovascular, metabolic, immune, and renal systems. While AL has been implicated in cancer development, evidence in Asian populations remains limited. We examined sociodemographic and lifestyle factors of AL and its association with colorectal cancer (CRC) risk in a multiethnic Asian cohort. METHODS: Data were drawn from 30,443 Chinese, Malay, and Indian adults (≥ 18 years) between 2004 and 2016. Participants were followed from baseline assessment until CRC diagnosis, death, or end of follow-up, whichever occurred first (median follow-up: 7.2 years). AL was derived from nine biomarkers, with high-risk cutoffs set at the 75th percentile (≤ p25 for HDL). High AL was defined as a score ≥ 3. CRC incidence was ascertained through linkage with the Singapore Cancer Registry. Modified Poisson regression was used to identify factors associated with high AL, and Cox proportional hazards models assessed associations with incident CRC. CRC incidence was ascertained through linkage with the Singapore Cancer Registry. RESULTS: During follow-up, 162 CRC cases were observed; 60.3% of participants had high AL. Older age, male sex, Malay and Indian ethnicity, lower education, unemployment, diabetes, low physical activity, and prolonged sitting were significantly associated with higher AL scores. High AL was associated with increased CRC risk after adjustment for age, sex, ethnicity, and cohort (aHR = 1.53; 95% CI = 1.10, 2.14). The association remained similar in models additionally adjusting for SES, smoking, history of diabetes, or physical activity and sitting time. DISCUSSION: These findings are consistent with prior research in Western populations and highlight AL as a potential biomarker for identifying individuals at increased CRC risk. Incorporating AL into population health strategies may support earlier detection and targeted prevention in Asian settings.