Usefulness of ambulatory blood pressure measurement for hypertension management in India: the India ABPM study

The present paper reports differences between office blood pressure (BP) measurement (OBPM) and ambulatory blood pressure measurement (ABPM) in a large multi-centre Indian all comers' population visiting primary care physicians. ABPM and OBPM data from 27,472 subjects (aged 51 +/- 14 years, males 68.2%, treated 45.5%) were analysed and compared. Patients were classified based on the following hypertension thresholds: systolic BP (SBP) >= 140 and/or diastolic BP (DBP) >= 90 mmHg for OBPM, and SBP >= 130 and/or DBP >= 80 mmHg for 24-h ABPM, and SBP >= 120 and/or DBP >= 70 mmHg for night-time ABPM and SBP >= 135 and/or DBP >= 85 mmHg for daytime ABPM, all together. White coat hypertension (WCH) was seen in 12.0% (n = 3304), masked hypertension (MH) in 19.3% (n = 5293) and 55.5% (n = 15,246) had sustained hypertension. Isolated night-time hypertension (INH) was diagnosed in 11.9% (n = 3256). Untreated subjects had MH relatively more often than treated subjects (23.0% vs. 14.8%,p < 0.0001; respectively). Females had higher relative risk (RR) of having WCH than males (RR 1.16 [CI 95, 1.07-1.25],p < 0.0001). Whereas, males had higher RR of MH than females (RR 1.09 [CI 95, 1.02-1.17]p < 0.01). INH subjects had lower average systolic and diastolic dipping percentages (0.7 +/- 6.6/ 2.2 +/- 7.9 vs. 9.0 +/- 7.3/11.9 +/- 8.5,p < 0.001) than those without INH. In conclusion, for diagnosis of hypertension there was a contradiction between OBPM and ABPM in approximately one-third of all patients, and a substantial number of patients had INH. Using ABPM in routine hypertension management can lead to a reduction in burden and associated costs for Indian healthcare.