Surrogate estimates of insulin sensitivity in subjects with hypertension.
The purpose of the study is to compare surrogate estimates of insulin sensitivity with a directly measured insulin sensitivity index, steady-state plasma glucose (SSPG) from insulin suppression test (IST), in subjects with hypertension. Two hundred and twenty-eight hypertensive patients who received IST for SSPG were included for analysis. Estimates from fasting measurements alone, homeostasis model assessment for insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI)), and indices from fasting and/or 2 h samples (ISI(0,120) and ISI(TX)) were calculated. In addition to Pearson and partial correlations, variance-component models were used to test the relationship between surrogate estimates of insulin sensitivity and SSPG. A large proportion of variance owing to covariates in the variance-component models indicated the goodness of model fit, irrespective of the independence among variables. SSPG was positively correlated with logarithmic transformation (Log) (HOMA-IR) and negatively correlated with QUICKI, Log (ISI(0,120)) and ISI(TX) (all P<0.0001). Log (ISI(0,120)) seemed to have a better correlation with SSPG (r=-0.72) than other measures in partial correlation. The proportion of variance owing to all covariates of Log (ISI(0,120)) and ISI(TX) were larger than those of Log (HOMA-IR) and QUICKI in the variance-component models. After adjustments for demographic and obesity covariates, the proportion of variance explained by Log (ISI(0,120)) were largest among the surrogate measures in the variance-component models. Our results showed that ISI(0,120) and ISI(TX) correlated better with SSPG than those used fasting measures alone (HOMA-IR and QUICKI). Log (ISI(0,120)) currently showing the strongest association with SSPG than other estimates is adaptable for use in large studies of hypertension.
Hwu
C M
CM
Department of Medicine, Section of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. chhwu@vghtpe.gov.tw
Hsiao
C F
CF
Grove
J
J
Hung
Y J
YJ
Chuang
L M
LM
Chen
Y T
YT
Curb
J D
JD
Chen
Y D I
YD
Rodriguez
B
B
Ho
L T
LT
D000328:Adult; D000704:Analysis of Variance; D044466:Asian People; D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D015309:Glucose Clamp Technique / Q000379:methods*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D001786:Blood Glucose; D007328:Insulin