title: Visit-to-visit variability in blood pressure strongly predicts all-cause mortality in patients with type 2 diabetes: a 5·5-year prospective analysis.
abstract: BACKGROUND
  Elevations in blood pressure and visit-to-visit variability have been found to significantly increase the risk of cardiovascular morbidity and mortality in nondiabetic individuals. This study has assessed the association between all-cause mortality and blood pressure parameters [systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial pressure (MAP) and visit-to-visit variability] in patients with type 2 diabetes.
  
  
  METHODS
  A longitudinal cohort study of 2161 patients with type 2 diabetes and a mean follow-up period of 66·7 ± 7·5 months. Using Cox regression models, blood pressure parameters were related to the risk of all-cause mortality.
  
  
  RESULTS
  Visit-to-visit variability in SBP [HR: 1·048 (95% CI: 1·005-1·092; P = 0·03)], DBP [HR: 1·090 (95% CI: 1·021-1·163; P = 0·01)] and MAP [HR: 1·099 (95% CI: 1·033-1·170; P = 0·003)] significantly predicted all-cause mortality in patients with type 2 diabetes after adjusting for baseline data, mean follow-up blood pressure profiles and HbA1c. Visit-to-visit variability in PP [HR: 1·139 (95% CI: 1·030-1·258; P = 0·01)] significantly predicted cardiovascular mortality. Neither baseline nor follow-up SBP, DBP, PP nor MAP was significantly associated with all-cause and cardiovascular mortality after adjusting for blood pressure variability. The risk of all-cause mortality with a mean follow-up SBP has a U-shaped distribution. Patients with a mean follow-up DBP > 90 mmHg were at higher risk of mortality than those with DBP < 90 mmHg.
  
  
  CONCLUSIONS
  Visit-to-visit variability in blood pressure was significantly associated with all-cause mortality independent of mean BP in patients with type 2 diabetes. The data for blood pressure variability might be regarded as a potentially important therapeutic target in the management of type 2 diabetes.
authors.affiliation: Department of Ophthalmology, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Hsieh
authors.forename: Shih-Te
authors.initials: ST
authors.lastname: Tu
authors.forename: Tzu-Jung
authors.initials: TJ
authors.lastname: Cho
authors.forename: Shun-Jen
authors.initials: SJ
authors.lastname: Chang
authors.forename: Jung-Fu
authors.initials: JF
authors.lastname: Chen
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Hsieh
mesh_terms: D000368:Aged; D044466:Asian People; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000401:mortality* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009819:Office Visits; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors