As of 12 September 2005 with an average 7.7 years of follow-up, 251 incident cases of pancreatic cancer had been identified. Characteristics at baseline of selected variables by quintile of WHR are shown in . Compared with women with lower WHR, those with higher WHR were older, non-white, and less educated. Women with higher WHR were also more likely to be past or current smokers and tended to smoke more cigarettes per day and to have quit more recently, to have higher total energy intake, be less physically active, and have higher prevalence of diabetes and hypertension. WHR was positively associated with weight, BMI, waist and hip circumference.
Table 1 Baseline characteristics of participants in relation to WHR (quintiles) among 138503 postmenopausal womena
Among the tested anthropometric variables, only WHR was significantly associated with the risk of pancreatic cancer. After adjusting for potential confounders, women in the highest quintile of WHR had 70% (95% CI 10–160%) excess risk compared with women in the lowest quintile of WHR. When WHR was analyzed as a continuous variable, risk increased by 27% (95% CI 7–50%) per 0.1 increase. No association was observed between pancreatic cancer risk and other anthropometric variables, including height, BMI, hip circumference, waist circumference, and weight changes during adult life ().
Table 2 Age-adjusted and multivariate-adjusted HR of pancreatic cancer by baseline measures of adiposity among 138503 postmenopausal women
Finally, we repeated all the above analyses with the exclusion of the first 2 years of follow-up; findings remained broadly similar to those from the full analyses with RR=1.6 (95% CI: 1.0–2.6) comparing women in the highest to the lowest of WHR.