SummaryPostmortem examination offive institutionalised patients with Down's syndrome (DS) aged 40-66 years showed a complete absence of atheroma, while a similar number of mental defectives without DS were found to have mild or severe atheroma. Previous investigation of risk factors for atheroma in 70 patients with DS and 70 ageand sex-matched mental defectives living in the same institution showed significantly lower systolic and diastolic blood pressures in the DS group, with the exception of systolic pressure in men under 40. Fasting serum cholesterol and triglyceride concentrations were similar in the two groups, but triglyceride concentrations were significantly lower than in normal people without a history of vascular disease. These unexplained observations may be relevant in further studies of the pathogenesis of atheroma.

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. Supplementary informationThe online version of this article (https://