Antihypertensive Treatment and Resistant Hypertension in Patients With Type 1 Diabetes by Stages of Diabetic Nephropathy

OBJECTIVE: To assess blood pressure (BP) control, antihypertensive treatment, and prevalence of resistant hypertension (RH) in patients with type 1 diabetes stratified by stage of diabetic nephropathy. RESEARCH DESIGN AND METHODS: This cross-sectional study included a nationally representative cohort of patients with type 1 diabetes (N = 3,678) from the Finnish Diabetic Nephropathy Study (FinnDiane). The data were linked to the Drug Prescription Register to obtain purchases of antihypertensive drugs 6 months prior to the baseline visit. The treatment targets were based on the American Diabetes Association guidelines. RH was defined as failure to reach BP target despite the use of three or more antihypertensive drugs of different classes (one of which was a diuretic). RESULTS: In patients with normal albumin excretion rate, 14.1% were on antihypertensive treatment and 74.6% of them had uncontrolled BP despite treatment. The corresponding figures were 60.5 and 71.2% for the microalbuminuric patients, 90.3 and 80.0% for the macroalbuminuric patients, 88.6 and 88.1% for dialysis, and 91.2 and 90.4% for kidney-transplanted patients. The prevalence of RH was 1.2% in the normoalbuminuric, 4.7% in the microalbuminuric, 28.1% in the macroalbuminuric, 36.6% in the dialysis, and 26.3% in the kidney transplant groups. Age (odds ratio 1.04 [95% CI 1.02-1.05]), estimated glomerular filtration rate (0.97 [0.96-0.97]), waist-to-hip ratio (1.44 [1.15-1.80]), triglycerides (1.19 [1.01-1.40]), microalbuminuria (2.58 [1.43-4.67]), and macroalbuminuria (5.61 [3.20-9.84]) were independently associated with RH. CONCLUSIONS: The prevalence of uncontrolled hypertension and RH increases with advanced diabetic nephropathy. These data suggest that there is an urgent need for improvement of antihypertensive treatment.