The role of blood pressure variability in the development of nephropathy in type 1 diabetes.
OBJECTIVE
Increases in blood pressure and visit-to-visit variability have both been found to independently increase the likelihood of cardiovascular events in nondiabetic individuals. This study has investigated whether each may also influence the development of microvascular complications in type 1 diabetes by examining data from the Diabetes Control and Complications Trial (DCCT).


METHODS
Using binary longitudinal multiple logistic regression, mean systolic (SBP) and diastolic (DBP) blood pressure as well as annual visit-to-visit variability (SD.SBP and SD.DBP, respectively) was related to the risk of the development/progression of nephropathy and retinopathy in initially normotensive subjects who did not become pregnant during the DCCT.


RESULTS
Mean SBP and SD.SBP were independently predictive of albuminuria (odds ratio 1.005 [95% CI 1.002-1.008], P<0.001 and 1.093 [1.069-1.117], P<0.001, respectively, for 1 mmHg change), although SBP variability did not add to mean SBP in predicting retinopathy (0.999 [0.985-1.013], P=0.93). DBP variability was also independently predictive of nephropathy (1.102 [1.068-1.137], P<0.001) and not of retinopathy (0.991 [0.971-1.010], P=0.37). Mean SBP was poorly related to SD.SBP (r2<0.01) as was mean DBP with SD. DBP (r2<0.01).


CONCLUSIONS
Visit-to-visit variability in blood pressure consistently independently added to mean blood pressure in predicting the risk of nephropathy, but not retinopathy, in the DCCT. This observation could have implications for the management and treatment of blood pressure in patients with type 1 diabetes.
Kilpatrick
Eric S
ES
Department of Clinical Biochemistry, Hull Royal Infirmary, Hull, UK. eric.kilpatrick@hey.nhs.uk
Rigby
Alan S
AS
Atkin
Stephen L
SL
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult
Diabetes Care. 2007 Oct;30(10):2523-8
17630266
Diabetologia. 1998 Jul;41(7):784-90
9686919
Lancet Neurol. 2010 May;9(5):469-80
20227347
N Engl J Med. 2009 Jul 2;361(1):40-51
19571282
Diabetes Care. 2008 Nov;31(11):2198-202
18650371
Arch Intern Med. 2008 Sep 22;168(17):1867-73
18809813
Diabetes Care. 2010 Jan;33 Suppl 1:S11-61
20042772
N Engl J Med. 1993 Sep 30;329(14):977-86
8366922
BMJ. 2008 Aug 26;337:a918
18728082
Lancet. 2010 Mar 13;375(9718):895-905
20226988
Lancet. 2010 Mar 13;375(9718):906-15
20226989
Diabet Med. 1990 Dec;7(10):887-97
2149686
Diabetes. 2008 Apr;57(4):995-1001
18223010
N Engl J Med. 2002 Sep 12;347(11):797-805
12226150
J Am Soc Nephrol. 2001 Feb;12(2):333-340
11158223
N Engl J Med. 1993 Nov 11;329(20):1456-62
8413456
BMJ. 2000 Aug 12;321(7258):412-9
10938049
Lancet. 2010 Mar 13;375(9718):938-48
20226991
Disabil Rehabil. 1999 Apr;21(4):145-51
10390080