Telemedicine Home Blood Pressure Measurements and Progression of Albuminuria in Elderly People With Diabetes Walter Palmas, Thomas G. Pickering, Jeanne Teresi, Joseph E. Schwartz, Lesley Field, Ruth S. Weinstock, Steven Shea Abstract—We assessed whether home blood pressure monitoring improved the prediction of progression of albuminuria when added to office measurements and compared it with ambulatory blood pressure monitoring in a multiethnic cohort of older people (n=392) with diabetes mellitus, without macroalbuminuria, participating in the telemedicine arm of the Informatics for Diabetes Education and Telemedicine Study. Albuminuria was assessed by measuring the spot urine albumin:creatinine ratio at baseline and annually for 3 years. The ambulatory sleep:wake systolic blood pressure ratio was categorized as dipping (ratio: 0.9), nondipping (ratio: 0.9 to 1.0), and nocturnal rise (ratio: 1.0). In a repeated-measures mixed linear model, after adjustment that included office pulse pressure, home pulse pressure was independently associated with a higher follow-up albumin:creatinine ratio (P=0.001). That association persisted (P=0.01) after adjusting for 24-hour pulse pressure and nocturnal rise, which were also independent predictors (P=0.02 and P=0.03, respectively). Cox proportional hazards models examined the progression of albuminuria (n=74) as defined by cutoff values used by clinicians. After the adjustment for office pulse pressure, the hazards ratio (95% CI) per 10-mm Hg increment of home pulse pressure was 1.34 (range: 1.1 to 1.7; P=0.01). Home pulse pressure was not an independent predictor in the model including ambulatory monitoring data; a nocturnal rise was the only independent predictor (P=0.035). Cox models built separately for home pulse pressure and ambulatory monitoring exhibited similar calibration and discrimination. In conclusion, nocturnal blood pressure elevation was the strongest predictor of worsening albuminuria. Home blood pressure measurements added to office measurements and may constitute an adequate substitute for ambulatory monitoring. (Hypertension. 2008;51:1282-1288.) Key Words: albuminuria  diabetes mellitus  home blood pressure  ambulatory blood pressure A lbuminuria is independently associated with cardiovas- cular morbidity and mortality in people with and with- out diabetes mellitus. 1–6 An increase in albuminuria is asso- ciated with higher cardiovascular morbidity and mortality, 7 whereas a decrease achieved through drug therapy is associ- ated with better outcomes. 8 Albuminuria is prevalent in older and middle-aged people with type 2 diabetes mellitus, 9 –11 in whom cardiovascular and renal complication rates are the highest. 12–14 Thus, it is of particular importance to identify predictors of worsening albuminuria in older people with diabetes mellitus. Ambulatory blood pressure monitoring (ABPM) predicts progression of albuminuria better than office blood pressure (BP) in people with diabetes, 15–19 and 24-hour pulse pressure (PP) and a nocturnal increase in BP are the most informative variables in elderly diabetic subjects. 18,19 However, ABPM is not yet considered the standard of care for the management of hypertension. On the other hand, a growing number of patients are successfully monitoring their BP at home using oscillometric devices. 20,21 In longitudinal studies, home mon- itoring outperformed office BP measurements in predicting cardiovascular events in hypertensive patients. 22–24 As noted above, progression of albuminuria is independently associ- ated with cardiovascular risk and may help identify patients at need for more aggressive clinical management. Therefore, it is important to determine whether home BP improves the prediction of worsening albuminuria in people with diabetes when added to office BP measurements and how it compares with ABPM in that regard. Although cross-sectional studies have shown that the association of prevalent albuminuria with home BP is stronger than with office BP 25 and comparable to that with ABPM, 26 to the best of our knowledge, there have been no longitudinal studies examining the association with worsening albuminuria. We, therefore, tested the hypothesis Received December 10, 2007; first decision January 4, 2008; revision accepted March 4, 2008. From the Department of Medicine (W.P., L.F., S.S.), Behavioral Cardiovascular Health and Hypertension Program (T.G.P.), Department of Epidemiology, Joseph Mailman School of Public Health (S.S.), and Department of Biomedical Informatics (S.S.), Columbia University, New York; Research Division (J.T.), Hebrew Home for the Aged at Riverdale, Bronx; Columbia University Stroud Center and Faculty of Medicine (J.T.), New York State Psychiatric Institute, New York; Department of Psychiatry and Behavioral Science (J.E.S.), State University of New York at Stony Brook, Stony Brook; Joslin Diabetes Center and Division of Endocrinology (R.S.W.), Diabetes and Metabolism, State University of New York Upstate Medical University, Syracuse; and the Department of Veterans’ Affairs (R.W.S.), Veterans’ Affairs Medical Center, Syracuse, NY. Correspondence to Walter Palmas, Division of General Medicine, 622 W 168th St, PH 9-East, New York, NY 10032. E-mail wp56@columbia.edu © 2008 American Heart Association, Inc. Hypertension is available at http://hyper.ahajournals.org DOI: 10.1161/HYPERTENSIONAHA.107.108589 1282 by guest on February 14, 2016 http://hyper.ahajournals.org/ Downloaded from