TABLE 3

Association of IRS1 variants with diabetes-related traits in Pima Indians with normal glucose tolerance

Genotype−7120G/A
P−2223C/T
P−446G/A
PAla804 (GCG/GCA)
P
G/GG/A + A/AC/CC/T + T/TG/GG/A + A/AG/GG/AA/A
n1437617552164667013035
Age (years)27 ± 127 ± 127 ± 128 ± 127 ± 127 ± 127 ± 127 ± 126 ± 1
Percent body fat32 ± 135 ± 10.9732 ± 133 ± 10.9633 ± 133 ± 10.7334 ± 133 ± 130 ± 20.80
Fasting plasma glucose (mg/dl)91 ± 192 ± 10.8592 ± 192 ± 10.9892 ± 192 ± 10.8093 ± 191 ± 189 ± 10.09
2-h plasma glucose (mg/dl)125 ± 3130 ± 30.54127 ± 2126 ± 40.74126 ± 3127 ± 30.99133 ± 3127 ± 3109 ± 50.01
Log10 fasting plasma insulin (μU/ml)1.55 ± 0.021.59 ± 0.020.701.55 ± 0.021.58 ± 0.030.761.55 ± 0.021.57 ± 0.030.881.60 ± 0.031.56 ± 0.021.49 ± 0.060.06
Log10 2-h plasma insulin (μU/ml)2.18 ± 0.032.23 ± 0.040.762.20 ± 0.032.21 ± 0.040.892.19 ± 0.032.21 ± 0.040.992.30 ± 0.042.17 ± 0.032.07 ± 0.080.03
Basal glucose turnover (mg · kg EMBS−1 · min−1)1.93 ± 0.021.93 ± 0.030.781.92 ± 0.021.91 ± 0.030.861.92 ± 0.021.92 ± 0.030.791.93 ± 0.031.90 ± 0.021.93 ± 0.040.98
Glucose disposal for low dose insulin clamp (mg · kg EMBS−1 · min−1)2.57 ± 0.082.53 ± 0.110.672.57 ± 0.072.52 ± 0.120.412.56 ± 0.072.58 ± 0.120.502.39 ± 0.092.59 ± 0.092.91 ± 0.200.04
Glucose disposal for high dose insulin clamp (mg · kg EMBS−1 · min−1)8.62 ± 0.188.52 ± 0.220.948.64 ± 0.178.44 ± 0.280.808.57 ± 0.168.69 ± 0.270.558.00 ± 0.218.76 ± 0.199.04 ± 0.400.04
  • Data are given as means ± SE. P values were calculated after adjusting for age, sex, and nuclear family membership for the variable percent body fat; and age, sex, percent body fat, and nuclear family membership for the variables 2-h plasma glucose, 2-h plasma insulin, and log10 glucose disposal for the low- and high-dose insulin clamps. EMBS, estimated metabolic body size; due to the low frequency of the rare alleles for −7120G/A, −2223C/T and −446G/A variants, for statistical analysis the homozygotes for each rare allele were combined with the heterozygotes; therefore, only a dominant effect on risk has been tested for the rare alleles.