about 60% steeper for the mean blood pressure values at 4 years compared to the mean values at baseline. The approximate size of this bias has been confirmed by the results of other studies6 - 16in which repeat measurements of blood pressure were made, and also affects estimates of the association of systolic blood pressure (SBP) with disease risks. These results suggest that the importance of blood pressure - both diastolic and systolic — as a determinant of cardiovascular morbidity and mortality has been grossly underestimated in most previous analyses of prospective observational studies. The associations of usual levels of blood pressure (ie adjusted for regression to the mean) with the incidence of stroke and of CHD have been examined in a collaborative project1 involving 9 prospective observational studies3 -" and a total of 418343 individuals aged 25 years or older who were not known to have had a myocardial infarction, a stroke or treated diabetes prior to the study baseline examination (Table 2). The weighted average follow-up period for disease outcomes in these studies was 10 years. In all the studies, baseline blood pressure was measured at a single visit either from one reading or the average of two readings using a standard mercury sphygmomanometer. Participants in each study were arbitrarily divided into 5 groups according to their baseline DBP (<80, 80-89, 90-99, 100-109, >109 mmHg) and disease risks were calculated for each of these categories relative to the overall risk in the entire study population. For all studies combined, relative risks for each of the categories were calculated by logistic regression analyses with adjustment for study and gender. Average 'usual' (as opposed to 'baseline') blood pressure levels for each of the categories could not be calculated directly for all studies since follow-up at Pennsylvania State University on May 10, 2016 http://bmb.oxfordjournals.org/ Downloaded from BLOOD PRESSURE AND ANTIHYPERTENSIVE DRUG TREATMENT 275 Table 1 Mean DBP (mmHg) at baseline and at examinations after 2 years and 4 years for 5 categories of baseline DBP in 3776 men and women in the Framingham Study Baseline DBP category: mm Hg 1: ABSTRACT Introduction: Atrial fibrillation (AF) is the most common cardiac rhythm disturbance in clinical practice. To prevent adverse outcomes associated with AF, it is necessary to identify and manage the modifiable risk factors. An increased body mass index (BMI) is strongly associated with the incidence of clinically symptomatic AF. However, the association of increased BMI with asymptomatic AF is unknown. Patients and Methods: We prospectively evaluated 449 patients implanted with dual chamber pacemaker. Patients were divided into 3 groups according to their baseline BMI (normal weight: BMI 18-25 kg/m2 , overweight: BMI 25-30 kg/m2 , and obesity: BMI > 30 kg/m2 ). Six months after the device implantation, pacemakers were interrogated to identify atrial high rate episodes (AHREs), which were defined as episodes faster than 220 bpm and longer than 5 minutes. Results: AHRE was detected in 128 (28.5%) patients. Patients in the AHRE (+) group were older (65.51 ± 8.99 years vs. 70.84 ± 8.05 years, p< 0.01) and had greater BMI (26.84 ± 3.41 kg/m2 vs. 28.65 ± 3.75 kg/m2 , p< 0.01) compared to those in the AHRE (-) group. Patients in the AHRE (+) group had significantly higher mean resting heart rate (84.03 ± 7.80 bpm vs. 74.76 ± 6.40 bpm, p< 0.01), greater left atrium antero-posterior (LA-AP) diameter (4.14 ± 0.33 cm vs. 3.90 ± 0.31 cm, p< 0.01), left atrium volume (31.92 ± 3.17 vs. 30.38 ± 3.15, p< 0.01), and CHA2DS2-VASc score (2.29 ± 0.83 vs. 1.81 ± 0.76, p< 0.01). On multivariate analysis, increased BMI, age, mean resting heart rate, LA-AP diameter, and CHA2DS2-VASc score were independently associated with the incidence of AHRE. Conclusion: Increased BMI is not only associated with symptomatic AF but also with asymptomatic AF detected by cardiac implantable electronic devices. Key Words: Silent atrial fibrillation; asymptomatic atrial fibrillation; atrial high rate episodes; obesity; increased body mass index Artmış Vücut Kitle İndeksi Cihaz ile Saptanan Sessiz Atriyal Fibrilasyon Atakları ile İlişkilidir ÖZET Giriş: Atriyal fibrilasyon (AF) klinikte en sık karşılaşılan ritm bozukluğudur. AF ile ilişkili modifiye edilebilen risk faktörlerinin tedavi edilmesi AF’ye bağlı iskemik inme gibi katastrofik sonuçları engelleyebilmektedir. Artmış vücut kitle indeksi (VKİ) semptomatik AF atakları ile ilişkilendirilmiştir. Ancak VKİ ile asemptomatik AF arasındaki ilişki henüz ortaya çıkarılmamıştır. Hastalar ve Yöntem: Daha önce çift odacıklı pacemaker takılmış 449 hasta çalışmaya dahil edilmiştir. Hastalar VKİ değerlerine göre üç gruba ayrılmıştır (normal VKİ: VKİ 18-25 kg/m2 , kilolu: VKİ 25-30 kg/ m2 ve obez: VKİ > 30 kg/m2 ). Cihaz implantasyonundan 6 ay sonra yapılan kontrolde sessiz AF atakları yerine geçen atriyal yüksek hız epizodları (AYHE) tarandı. AYHE 5 dakikadan uzun ve 220/dakika’dan uzun epizodlar olarak tanımlandı. Bulgular: Cihaz kontrolleri sonunda hastaların 128 (28.5%)’inde AYHE saptandı. AYHE (+) hastalar AYHE (-) hastalara göre daha yaşlı (65.51 ± 8.99 vs. 70.84 ± 8.05 p< 0.01) ve daha yüksek VKİ’ye (26.84 ± 3.41 kg/ m2 vs. 28.65 ± 3.75 kg/m2 p< 0.01) sahip bulundu. AYHE (+) hastaların istirahat kalp hızları (84.03 ± 7.80 vs. 74.76 ± 6.40 vs. p< 0.01), sol atriyum