Blood pressure management in hypertensive people with non-dialysis chronic kidney disease in Queensland, Australia

Background: High blood pressure is the most significant risk factor for the development and progression of chronic kidney disease (CKD). Lowering blood pressure is a goal to prevent CKD progression. This study of adults with CKD who have hypertension aimed to determine blood pressure control rates and the treatment patterns of hypertension and to explore factors associated with control of hypertension.

Methods: This cross-sectional study included all non-dialysis people with CKD stages 3A to 5 under nephrology care in three public renal clinics in Queensland, who joined the CKD.QLD registry from May 2011 to Dec 2015 and had a history of hypertension. Demographic information, other health conditions, laboratory markers and anti-hypertensive medications in use at consent were extracted from the registry.

Results: Among 1814 CKD people in these three sites in the registry who were age ≥ 18 years and had CKD stage 3A to 5, 1750 or 96% had a history of hypertension. Of these, the proportion with BP control to < 140/90 mmHg was 61.7% and to < 130/80 mmHg was 36.3%. With target BP < 140/90 mmHg or < 130/80 mmHg, participants aged ≥65 years were 1.23 (95% CI 1.06-1.42) or 1.12 (1.03-1.22) times more likely to have uncontrolled BP compared to those < 65 years old. Participants with severe albuminuria or proteinuria were 1.58 (1.32-1.87) or 1.28 (1.16-1.42, p < 0.001) more likely to have uncontrolled BP compared to those without significant albuminuria or proteinuria. Participants who had cardiovascular disease (CVD) were less likely to have uncontrolled BP compared to those without CVD (0.78, 0.69-0.89 or 0.86, 0.80-0.92). Factors associated with use of more classes of antihypertensive medicines among participants with uncontrolled BP (> 140/90 mmHg) were older age, diabetes, CVD, obesity and severe albuminuria/proteinuria (p < 0.05). Renin Angiotensin Aldosterone System inhibitors were the most frequently used medicines, regardless of the number of medicine classes an individual was prescribed.

Conclusions: Blood pressure control rates in these hypertensive people with CKD was still far from optimal. People with CKD and hypertension aged 65 or older or with severe albuminuria or proteinuria, a group at risk of progression of kidney disease, have higher rates of uncontrolled BP.