Impact of non-potassium-sparing diuretics and regular laxative use on cardiovascular mortality of subjects receiving anti-hypertensive treatment
Principal Investigator: Dr Ben Schöttker
Approved Research ID: 21133
Approval date: December 1st 2016
We will address the research question: ?How safe is regular laxative use, in particular in combination with non-potassium-sparing diuretics?? For this purpose, we will compare cardiovascular mortality of subjects regularly using only non-potassium-sparing diuretics, only laxatives, both laxatives and non-potassium-sparing diuretics, or other anti-hypertensives than non-potassium-sparing diuretics. We have performed these analyses also in a German, population-based cohort with 9949 study participants (ESTHER study) but these revealed no significant results because simultaneous, regular diuretic and laxative use is rare. However, we expect significant findings for the meta-analysis of the results from the ESTHER study and the UK Biobank. The importance of adequate potassium levels to prevent life-threatening health outcomes is already well-known. However, data investigating the relationship between potassium level affecting drugs and cardiovascular mortality in the general population is lacking. Furthermore, reliable estimates for the occurrence of adverse events caused by interactions between prescribed non-potassium-sparing diuretics and additionally used laxatives have not yet been assessed in large studies. Up to date, authentic assessments of adverse health outcomes in large population samples can only be generated by prospective cohort studies involving direct contact with both the patients and the physicians, as done in the UK Biobank study. To assess the risk of laxatives in general, cardiovascular mortality of regular laxative users will be compared to a group of non-users with comparable characteristics. In addition, for assessing the risk of interaction between non-potassium-sparing diuretics and laxatives, we will compare the risk of cardiovascular mortality in hypertension-treated subjects within the following four distinct groups: Regular use of non-potassium-sparing diuretics only, regular use of laxatives only, regular use of both non-potassium-sparing diuretics and laxatives, and no use of these drugs. The underlying baseline cardiovascular risk of all four groups will be quite comparable because all groups receive anti-hypertensive drugs. To assess the risk of laxatives in general, cardiovascular mortality of regular laxative users will be compared to a group of non-users with comparable characteristics. To identify subjects with comparable characteristics, the total cohort will be needed. In particular, we need access to the self-reported medication data of about 60,000 participants receiving anti-hypertensive medication and of about 15,000 subjects with self-reported use of laxatives. In addition, we will require the medication data obtained from the verbal interviews during the UK Biobank Assessment Centre of the full study cohort in order to complete and validate the aforementioned data.