title: Prevalence of insulin resistance in essential hypertension.
abstract: OBJECTIVE
  To establish the prevalence of insulin resistance in hypertensive subjects.
  
  
  METHODS
  The euglycaemic hyperinsulinaemic clamp was performed in 420 hypertensive patients taking no antihypertensive medication and in 51 age- and sex-matched healthy controls. No subjects with known diabetes mellitus or fasting hyperglycaemia were included in the study.
  
  
  RESULTS
  The mean value for insulin-mediated glucose uptake (M-value at clamp) in the healthy control group (8.2 mg/kg per min) -2 SD was chosen as the cutoff limit for insulin resistance (4.4 mg/kg per min). At this cutoff limit, 27% of the hypertensive subjects were insulin resistant (mean value 3.1 mg/kg per min in this group, range 0.7-4.3). A similar prevalence of insulin resistance in hypertensive patients was found (31%) if the 95th percentile of the non-normally distributed insulin sensitivity index (M/I at clamp) was used to define the cutoff limit for insulin resistance: (4.4 mg/kg per min)/(mU/l x 100). In the insulin-resistant group, 50% showed elevated levels of serum triglycerides (> 2.0 mmol/l), 50% had abdominal obesity (waist:hip ratio > 0.95), 20% had elevated levels of serum uric acid (> 400 mumol/l) and 48% had low high-density lipid (HDL)-cholesterol levels (< 1.0 mmol/l). Half of the insulin-resistant hypertensives but only 20% of the non-insulin resistant group had two or more of these other four metabolic impairments (P < 0.001). Insulin resistance in hypertension was also associated with an increased heart rate (+3 beats/min faster than in non-insulin resistant hypertensive patients, P < 0.01), but no significant differences in blood pressure were found between insulin resistant and non-insulin resistant hypertensive patients.
  
  
  CONCLUSIONS
  When insulin resistance was defined as an M-value at clamp of < 4.4 mg/kg per min, based on calculations from a healthy control sample, about 25% of a sample of hypertensive subjects, taking no antihypertensive treatment and with no history of diabetes mellitus or hyperglycaemia, was found to be insulin resistant. This group of insulin-resistant hypertensives also displayed a high degree of clustering of other metabolic impairments.
authors.affiliation: Department of Internal Medicine, University Hospital, Uppsala, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Lind
authors.forename: C
authors.initials: C
authors.lastname: Berne
authors.forename: H
authors.initials: H
authors.lastname: Lithell
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001824:Body Constitution; D008076:Cholesterol, HDL / Q000097:blood; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D015995:Prevalence
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D007328:Insulin