title: Insulin therapy, hyperglycemia, and hypertension in type 1 diabetes mellitus.
abstract: BACKGROUND
  Diabetes mellitus and hypertension are closely linked, but the long-term blood pressure effects of glucose-lowering therapy and hyperglycemia are not clear.
  
  
  METHODS
  We examined the effects of intensive insulin therapy and hyperglycemia on the development of hypertension in the Diabetes Control and Complications Trial (DCCT) and its observational follow-up, the Epidemiology of Diabetes Intervention and Complications (EDIC) study. Incident hypertension was defined as 2 consecutive study visits with a systolic blood pressure of 140 mm Hg or higher, a diastolic blood pressure of 90 mm Hg or higher, or use of antihypertensive medications to treat high blood pressure.
  
  
  RESULTS
  Participants were enrolled from August 23, 1983, through June 30, 1989. During a 15.8-year median follow-up, 630 of 1441 participants developed hypertension. During the DCCT, the incidence of hypertension was similar comparing participants assigned to intensive vs conventional therapy. However, intensive therapy during the DCCT reduced the risk of incident hypertension by 24% during EDIC study follow-up (hazard ratio, 0.76; 95% confidence interval [CI], 0.64-0.92). A higher hemoglobin A(1c) level, measured at baseline or throughout follow-up, was associated with increased risk for incident hypertension (adjusted hazard ratios, 1.11 [95% CI, 1.06-1.17] and 1.25 [95% CI, 1.14-1.37], respectively, for each 1% higher hemoglobin A(1c) level), and glycemic control appeared to mediate the antihypertensive benefit of intensive therapy. Older age, male sex, family history of hypertension, greater baseline body mass index, weight gain, and greater albumin excretion rate were independently associated with increased risk of hypertension.
  
  
  CONCLUSIONS
  Hyperglycemia is a risk factor for incident hypertension in type 1 diabetes, and intensive insulin therapy reduces the long-term risk of developing hypertension.
authors.affiliation: Division of Nephrology, University of Washington, Box 356521, 1959 NE Pacific St, Seattle, WA 98117, USA. deboer@u.washington.edu
authors.forename: Ian H
authors.initials: IH
authors.lastname: de Boer
authors.forename: Bryan
authors.initials: B
authors.lastname: Kestenbaum
authors.forename: Tessa C
authors.initials: TC
authors.lastname: Rue
authors.forename: Michael W
authors.initials: MW
authors.lastname: Steffes
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cleary
authors.forename: Mark E
authors.initials: ME
authors.lastname: Molitch
authors.forename: John M
authors.initials: JM
authors.lastname: Lachin
authors.forename: Noel S
authors.initials: NS
authors.lastname: Weiss
authors.forename: John D
authors.initials: JD
authors.lastname: Brunzell
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000652:urine; D015992:Body Mass Index; D048909:Diabetes Complications; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D020158:Hyperglycinemia, Nonketotic / Q000150:complications*; D006973:Hypertension / Q000209:etiology* / Q000517:prevention & control; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D012307:Risk Factors; D015430:Weight Gain
chemical_list: D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human