Prevalence and reproducibility of differences between home and ambulatory blood pressure and their relation with hypertensive organ damage.

Home and ambulatory blood pressure (BP) better predict cardiovascular disease than office BP, but are not interchangeable. We hypothesised that home BP may be higher than office BP because of anticipatory reactions to self-measurement and studied prevalence and reproducibility of incremental differences between home and daytime ambulatory BP and their relation with hypertensive organ damage. A total of 176 participants (mean age 57.1±12.8 years, 43.2% female) measured their BP for 2 weeks and received a 24-h ambulatory BP in between. Hypertensive organ damage was assessed by urinary albumin-to-creatinine ratio and electrocardiographic criteria for left ventricular hypertrophy. Thresholds of 10/5 and 20/10 mm Hg were used to define relevant systolic/diastolic differences between home and ambulatory BP. A higher home compared to ambulatory BP was present in 92 (52.3%) and 35 (19.1%) participants, while lower home BP values were present in 36 (20.4%) and 8 (4.5%) subjects for differences ⩾10/5 and ⩾20/10 mm Hg. Participants with higher home than ambulatory BP differences were older, had higher body mass index, higher office BP, more antihypertensive medication and lower glomerular filtration rate (P<0.01). Differences between home and ambulatory BP were highly reproducible (r=0.80 and 0.67 for systolic and diastolic BP, P<0.001). Both home and ambulatory BPs were associated with organ damage, but their difference was not. Many patients have a significantly higher home than ambulatory BP. Differences between home and ambulatory BP are reproducible, but not associated with hypertensive organ damage. Our findings suggest that ambulatory BP remains the standard of reference when positive differences between home and ambulatory BP exist.