BP measurements in diagnosing hypertension and predicting cardiovascular outcomes (cardiovascular death, stroke, and cardiac/coronary events). 10, 11 Importantly, the US Preventative Services Task Force is now recommending ABPM in all patients before the initiation of antihypertensive treatment as a Grade A recommendation. 12 Analyses of ABPM data by sex have generally shown that women have lower day-time and night-time BPs compared with men. Kagan et al13 investigated sex differences in ABPM and their correlation with body mass index in 989 untreated Israelis (49% women) between 2002 and 2006. Both normal weight (body mass index< 25 kg/m2) and obese (body mass index> 30 kg/m2) women were more likely than men to have normal BP (< 135/85 mm Hg during the day and< 120/70 mm Hg during the night). Furthermore, Spanish investigators explored sex differences in hypertension control in 29 148 treated white women and men (48% women) in the Spanish Ambulatory Blood Pressure Registry. 14 In-office BP control (BP< 140/90 mm Hg) was similar in women and men (22% versus 23%), but ABPM showed significantly higher control rates in women than in men (49% versus 39%). Division-Garrote et al15 expanded this assessment by evaluating 70 997 treated individuals (mean age, 62 years, 48% women) in the Spanish ABPM database and confirming a higher rate of BP control among women (44% versus 38%). Importantly, they also noted a significantly higher rate of hypotension (day-time ABPM< 105/65 mm Hg, night-time ABPM< 90/50 mm Hg, and 24-hour ABPM< 100/60 mm Hg) in women compared with men (10% versus 7%). Almost half of the hypotensive individuals were on 3 or more antihypertensive medications. A possible explanation for the apparent overtreatment of BP in these women (mean age 72 years) is that treatment decisions may have been based on in-office BP readings, which are typically higher in older women compared with men. 9 ABPM data also highlight the importance of 24-hour recordings in predicting health outcomes. IDACO (International Database of Ambulatory Blood Pressure in Relation to Cardiovascular Outcome) investigators recorded 24-hour systolic BP (SBP) and diastolic BP (DBP) measurements and health outcomes in 8341 untreated people (mean age 51 years; 47% women) from 12 countries followed for up to 17 years. They found that elevated mean 24-hour DBP predicted total and cardiovascular mortality in individuals younger than 50 years of age, whereas elevated mean 24-hour SBP predicted total and cardiovascular mortality in those over 50 years of age. 16