CKD awareness and blood pressure control in the primary care hypertensive population.

BACKGROUND: Chronic kidney disease (CKD) is associated with poor renal and cardiovascular outcomes, and early identification largely depends on general practitioners' (GPs') awareness of it. To date, no study has evaluated CKD prevalence in patients with hypertension in primary care.

STUDY DESIGN: Cross-sectional evaluation of the Italian GPs' database.

SETTING & PARTICIPANTS: 39,525 patients with hypertension representative of the Italian hypertensive population followed up by GPs in 2005.

FACTOR: Estimated glomerular filtration rate (eGFR); eGFR <60 mL/min/1.73 m² was defined as CKD.

OUTCOMES: GPs' awareness of CKD assessed using International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes for CKD, and blood pressure (BP) control.

MEASUREMENTS: Data concerning serum creatinine levels, BPs, and antihypertensive medications were obtained for each patient from the GPs' database; eGFR was calculated according to the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation.

RESULTS: CKD prevalence was 23%, but kidney disease was diagnosed by GPs in only 3.9% of patients. BP control was inadequate in patients with CKD and those with eGFR >60 mL/min/1.73 m², with only 44% of patients reaching a BP target <140/90 mm Hg and 11% achieving <130/80 mm Hg. Patients with eGFR <60 mL/min/1.73 m² whose GPs were aware of CKD were more likely to reach recommended BP target values (OR, 1.35; 95% CI, 1.15-1.59; P < 0.001).

LIMITATIONS: The prevalence of decreased eGFR may be overestimated because of the lack of creatinine calibration. Proteinuria data were not available.

CONCLUSIONS: Awareness of CKD by GPs is critical for achieving the recommended guideline BP targets. However, awareness of CKD by GPs is still far too low, highlighting the need to systematically adopt eGFR for more accurate identification of CKD in high-risk populations.