Body mass index and risk of pancreatic cancer in a Chinese population

10.1371/journal.pone.0085149PLoS ONE91-POLN

Body mass index and risk of pancreatic cancer in a Chinese population.

Few studies have examined the association between body mass index (BMI: kg/m(2)) and pancreatic cancer risk in Asian populations. We examined this relationship in 51,251 Chinese men and women aged 45-74 who enrolled between 1993 and 1998 in the population based, prospective Singapore Chinese Health Study. Data were collected through in-person interviews. By December 31, 2011, 194 cohort participants had developed pancreatic cancer. A Cox proportional hazards model was used to estimate hazard ratios (HR) and their 95% confidence intervals (95% CI). We hypothesized the association between BMI and pancreatic cancer risk may vary by smoking status (ever v. never) and there was evidence for this as the interaction between BMI and smoking status was significant (p = 0.018). Among ever smokers, being classified as underweight (BMI <18.5 kg/m(2)), was associated with a significantly elevated risk of pancreatic cancer relative to smokers with a BMI of 21.5-24.4 kg/m(2) (HR = 1.99, 95% CI  =  1.03-3.84). This association was strengthened after exclusion of the first three years of follow-up time. Among never smokers, there was no association between BMI and pancreatic cancer risk. However, after excluding pancreatic cancer cases and person-years in the first three years of follow-up, never smokers with a BMI ≥ 27.5 kg/m(2) showed a suggestive increased risk of pancreatic cancer relative to never smokers with a BMI of 21.5-24.4 kg/m(2) (HR  =  1.75, 95% CI  =  0.93-3.3). In conclusion, Singaporean Chinese who were underweight with a history of smoking had an increased risk of developing pancreatic cancer, whereas there was no significant association between BMI and pancreatic cancer in never smokers

Standardized Pancreatic Cancer rate and Hazard Ratios According to Body Mass Index (BMI), The Singapore Chinese Health Study.

<p>SCHS =  Singapore Chinese Health Study.</p><p>Standardized rate = Age and sex standardized cancer rate per 100,000 person years using person year time, age & sex distributions of SCHS.</p><p>HR (95% CI)  =  Hazard Ratio; 95% confidence interval: Model adjusted for age, sex, year of enrollment, dialect, education, diabetes status,</p><p>smoking (in whole population analysis), age of initiation of smoking habits, number of cigarettes per day, years of smoking, alcohol intake, dietary pattern score,</p><p>physical activity, sleep and energy intake.</p><p>BMI categories combined for ever-smokers into ≥ 24.5 kg/m²_.</p

Participant Characteristics According to Body Mass Index (kg/m²) at Baseline, The Singapore Chinese Health Study.

<p>Dietary pattern (top 20%)  =  Dietary pattern score of greatest conformity in the population to a diet rich in vegetables, fruit and soy foods.</p><p>Data for age represent mean (SD).</p

Standardized Pancreatic cancer rates and Hazard Ratios According to Body Mass Index (BMI), Excluding the First Three Years of Follow-Up, The Singapore Chinese Health Study.

<p>SCHS =  Singapore Chinese Health Study.</p><p>Standardized rate = Age and sex standardized cancer rate per 100,000 person years using person year time, age & sex distributions of SCHS.</p><p>HR (95% CI)  =  Hazard Ratio; 95% confidence interval: Model adjusted for age, sex, year of enrollment, dialect, education, diabetes status,</p><p>smoking (in whole population analysis), age of initiation of smoking habits, number of cigarettes per day, years of smoking, alcohol intake, dietary pattern score,</p><p>physical activity, sleep and energy intake.</p><p>BMI categories combined for ever-smokers into ≥ 24.5 kg/m²_.</p