title: Hostility and urine norepinephrine interact to predict insulin resistance: the VA Normative Aging Study.
abstract: OBJECTIVE
  Previous research has produced mixed results pertaining to the association between hostility and insulin resistance. These inconsistent findings may be the result of a lack of studies examining potential moderators of this relationship and inconsistent measures of insulin resistance and/or hostility. We hypothesized that hostility may interact with circulating norepinephrine (NEPI) levels, indexed by 24-hour urine concentrations, to affect insulin resistance.
  
  
  METHODS
  Six hundred forty-three men (mean age = 63.1 years) free of diabetic medications completed the Minnesota Multiphasic Personality Inventory and participated in a laboratory assessment. The Cook-Medley Hostility (Ho) and 24-hour urine NEPI were used to predict insulin resistance defined by the homeostatic model assessment (HOMA) index, 2-hour postchallenge glucose (PCGL), and insulin levels (PCIL) after controlling for nine common covariates.
  
  
  RESULTS
  Multiple regression showed that the two-way interaction between Ho and NEPI significantly predicted HOMA and PCIL, but not PCGL, after controlling for covariates. Simple regression slopes of Ho on HOMA and PCIL were explored and indicated that, at higher levels of NEPI, higher Ho was associated with higher HOMA (beta = 0.14, p < .05). Ho was not a significant predictor of HOMA at mean and lower levels of NEPI. Similar results were obtained for PCIL, but not PCGL. Cynicism, but not other subscales of Ho, was similarly related to insulin resistance and NEPI.
  
  
  CONCLUSIONS
  Individuals with high stress and high hostility were more likely to have insulin resistance. It is important to study moderators in the relationship between hostility and insulin resistance.
authors.affiliation: Department of Psychology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana, USA. jpzhang2005@gmail.com
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhang
authors.forename: Raymond
authors.initials: R
authors.lastname: Niaura
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Dyer
authors.forename: Biing-Jiun
authors.initials: BJ
authors.lastname: Shen
authors.forename: John F
authors.initials: JF
authors.lastname: Todaro
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: McCaffery
authors.forename: Avron
authors.initials: A
authors.lastname: Spiro
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Ward
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology; D001290:Attitude; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D001900:Boston / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000503:physiopathology; D004032:Diet; D004522:Educational Status; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006791:Hostility; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000503:physiopathology; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008950:MMPI; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology / Q000503:physiopathology; D008875:Middle Aged; D009043:Motor Activity; D009638:Norepinephrine / Q000652:urine*; D019518:Postprandial Period; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013315:Stress, Psychological / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology; D011795:Surveys and Questionnaires; D049629:Waist-Hip Ratio
chemical_list: D001786:Blood Glucose; D007328:Insulin; D009638:Norepinephrine