Abstract Body: Introduction: 3 million Canadians and 23 million Americans have concurrent hypertension and diabetes. Blood pressure (BP) control reduces the risk of heart attacks, strokes, retinopathy, and kidney disease. We investigated hypertension control rates in patients with diabetes, responses to uncontrolled BP measurements, and use of antihypertensive drug classes.
Methods: We performed an observational study of adults with diabetes and hypertension drawing from the IQIVA primary care database (contains data on 1.2 million Canadians). Our first outcome was mean BP at 3, 6, 12, and 24 months after inclusion. Our second outcome was the number of uncontrolled BP measurements (≥130/80) followed by a physician BP check, medication dose/frequency increase, or new medication in the subsequent 6 weeks. Our third outcome (for a subset of individuals with medication data available) was the number of individuals prescribed renin-angiotensin-aldosterone-system inhibitors (RAASi), dihydropyridine calcium channel blockers (DHP-CCBs), or thiazide/thiazide-like diuretics.
Results: We identified 10,814 individuals identified with both diabetes and hypertension. Mean BP (in mmHg) remained largely unchanged over 24 months: 136.7/78.6 at 3 months, 135.5/82.2 at 6 months, 137.2/82.8 at 12 months, and 136.6/82.3 at 24 months. Over the two years of follow-up there were 55,381 uncontrolled BP events, and in the subsequent 6 weeks only 27,877 (50.3%) were followed by ≥1 physician BP checks. Among individuals with medication data, there were 16,364 uncontrolled BP events, 33.4% followed by a new antihypertensive medication and 18.2% followed by an antihypertensive dose/frequency change. Of the 6,919 individuals for whom we had medication data, 6,216 (89.8%) were prescribed a RAASi, 2,371 (34.3%) were prescribed a DHP-CCB, and 1,672 (24.2%) were prescribed thiazide/thiazide like diuretic.
Conclusion: Over two-thirds (68.8%) of people with diabetes and hypertension had uncontrolled blood pressure that persisted over 2 years during which half of uncontrolled BPs were followed by a physician BP check in 6 weeks, and one-fifth by a antihypertensive dose/frequency change. While almost 90% were treated with RAASi, over a third were on a DHP-CCB and less than one quarter were treated with a thiazide/thiazide like diuretic. Therapeutic inertia and under-prescribing of dual and triple therapy contribute to persistently high BP thus represent opportunities for improvement.