title: Is HOMA index a predictor of nocturnal nondipping in hypertensives with newly diagnosed type 2 diabetes mellitus?
abstract: OBJECTIVE
  Insulin resistance is involved in glucose intolerance, type 2 diabetes mellitus and hypertension. We aimed to analyze relationship between insulin resistance and nocturnal nondipping.
  
  
  METHODS
  Patients underwent physical and biochemical evaluation, clinic and ambulatory blood pressure measurements. The homeostasis model assessment (HOMA) index was calculated.
  
  
  RESULTS
  Ninety-six essential hypertensive patients, of whom 42 were dippers, with newly diagnosed type 2 diabetes mellitus were included. Nighttime average heart rate and mean arterial pressure of nondippers were higher than dippers (P<0.0001 and 0.001). Nondippers had higher fasting plasma glucose, serum insulin levels and HOMA indices than dipper patients (P=0.006, <0.0001 and <0.0001). Ten dippers and 36 nondippers were insulin resistant (P<0.0001). Clinic (r=+0.22, P=0.031), daytime average (r=+0.27, P=0.007), nighttime average (r=+0.33, P=0.001), 24-h average systolic (r=+0.25, P=0.015) and nighttime average diastolic blood pressures (r=+0.31, P=0.002) were positively correlated with homeostasis model assessment index. Nighttime mean arterial pressure and heart rates (daytime, nighttime, 24-h average) showed positive correlation with homeostasis model assessment index. In multivariate analysis, high homeostasis model assessment index was associated with increased nondipping risk (odds ratio: 1.85, confidence interval: 1.24-2.76, P=0.003). After adjustment of several factors, average nighttime systolic (P<0.0001), diastolic (P<0.0001) and 24-h diastolic blood pressure (P=0.029) and heart rate (P=0.001) measurements of insulin resistant patients were higher than nonresistant patients.
  
  
  CONCLUSIONS
  Insulin resistance is related with diurnal blood pressure variation. The HOMA index may be a predictor of nocturnal nondipping in patients with essential hypertension and newly diagnosed type 2 diabetes mellitus.
authors.affiliation: Department of Nephrology, Baskent University Hospital, Ankara, Turkey. afsarbrs@yahoo.com
authors.forename: Baris
authors.initials: B
authors.lastname: Afsar
authors.forename: Siren
authors.initials: S
authors.lastname: Sezer
authors.forename: Rengin
authors.initials: R
authors.lastname: Elsurer
authors.forename: Fatma Nurhan
authors.initials: FN
authors.lastname: Ozdemir
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006706:Homeostasis; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000150:complications* / Q000503:physiopathology; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests