Low Diastolic Blood Pressure and Risk of Ischemic Colitis in the Women’s Health Initiative Cohort

Objectives: – To identify risk and protective factors in older women for incidence of ischemic colitis (IC) and 30-day mortality.Methods: – We conducted a prospective study of 100, 825 women in the Women’s Health Initiative, with average of 13.1 years follow-up and extensive phenotypic and outcomes data in diverse race and ethnic groups. Lasso Cox regression selected variables related to incidence of ischemic colitis from multiple domains (demographic, comorbidities, risk factors, biomarkers, psychosocial factors, dietary factors). Cox regressions modelled the selected variables to obtain adjusted hazard ratios and 95% confidence limits.Results: – Incidence rate of IC was twice as high among those with history of cardiovascular disease (55.7 per 10, 000 person-years (py)) compared to those with no such history (27.3 per 10, 000 py). After adjustment for multiple covariates, higher risk was associated with diastolic blood pressure below 90mmHg, using two or more types of antihypertensive medication compared to none (aHR =1.62, 95%CI: 1.47, 1.78), having gastrointestinal symptoms (aHR = 1.31, 95%CI: 1.20, 1.42 highest versus lowest quartile). Higher fiber intake was associated with lower risk, (aHR per increase of 10 grams per day = 0.93, 95%CI: 0.89, 0.97) Black women had lower adjusted risk of IC than White women (aHR = 0.73, 95%CI: 0.63, 0.83). Post IC 30-day all-cause mortality was 10.6% sepsis was an important cause of death.Conclusions: – Incidence rate of IC in older women was twice as high in those with a history of cardiovascular disease and was associated with low diastolic blood pressure and multi-class antihypertensive treatment. Dietary fiber intake was associated with lower risk. Black women had lower risk of IC compared to White women.