Impaired Insulin Sensitivity, Insulin Secretion, and Glucose Effectiveness Predict Future Development of Impaired Glucose Tolerance and Type 2 Diabetes in Pre-Diabetic African Americans
Implications for primary diabetes prevention
Article Figures & Tables
Tables
- Table 1—
Baseline clinical and metabolic characteristics of high-risk African Americans with NGT
Clinical characteristics n 81 Age (years) 41.5 ± 4.8 Sex ratio (women/men) 54/27 Body weight (kg) 89.9 ± 10.3 Height (m) 1.68 ± 0.1 BMI (kg/m2) 31.3 ± 3.6 Lean body mass (kg) 61.7 ± 7.0 Body fat mass (%) 37.4 ± 4.3 Waist-to-hip ratio 0.90 ± 0.10 Metabolic parameters OGTT Fasting serum glucose (mg/dl) 78.3 ± 8.9 2-h serum glucose (mg/ml) 95 ± 11 Fasting serum insulin (μU/ml) 13.7 ± 1.9 2-h serum insulin (μU/ml) 78 ± 4.9 Fasting serum C-peptide (ng/ml) 2.68 ± 0.35 2-h serum C-peptide (ng/ml) 9.31 ± 1.13 IVGTT AIRpeak at t = 5 min Peak glucose (mg · dl−1 · min−1) 221 ± 32 Peak insulin (μU/ml) 108 ± 88 Peak C-peptide (ng/ml) 6.85 ± 3.20 Acute first phase (AIRFSIGTT) Glucose (mg · dl−1 · min−1) 1,217 ± 245 Insulin (μU · ml−1 · min−1) 354 ± 23 C-peptide (ng · ml−1 · min−1) 17 ± 0.16 Insulin sensitivity indexes Si (×10−4 × min−1 [μU/ml]−1) 2.48 ± 0.33 Sg (×10−2 × min−1) 2.48 ± 0.31 HOMA-IR 2.56 ± 1.4 HOMA-%B 391 ± 54 Data are means ± SD. AIRFSIGTT, acute insulin response to a frequently sampled intravenous glucose tolerance test; IVGTT, intravenous glucose tolerance test.
- Table 2—
Baseline clinical and metabolic characteristics of high-risk African Americans with normal glucose tolerance who were followed for 5–8 years and those who dropped out during the study period
Progressors Nonprogressors Dropouts P value Progressors vs. dropouts Nonprogressors vs. dropouts n 18 19 44 Age (years) 45.5 ± 8.2 42.1 ± 8.2 39.7 ± 8.7 0.029 0.416 Sex ratio (women/men) 14/4 16/3 18/26 BMI (kg/m2) 35.4 ± 5.9 33.5 ± 7.0 33.4 ± 4.4 0.130 0.475 Waist-to-hip ratio 0.91 ± 0.10 0.88 ± 0.06 0.92 ± 0.01 0.722 0.021 Systolic blood pressure (mmHg) 127 ± 14 125.6 ± 20 122.9 ± 7 0.138 0.5557 Diastolic blood pressure (mmHg) 78 ± 12 81.2 ± 14.1 77.7 ± 7.5 0.980 0.01 Metabolic parameters Fasting serum glucose (mg/dl) 95 ± 8 80 ± 14 88 ± 16 0.083 0.064 Fasting serum insulin (μU/ml) 15.1 ± 8.1 11.54 ± 7.85 18.36 ± 8.71 0.185 0.055 Fasting serum C-peptide (ng/ml) 3.04 ± 0.85 2.64 ± 1.17 3.03 ± 0.92 0.990 0.194 Minimal model parameters Si (×10−4 × min−1 [μU/ml]−1) 1.61 ± 1.13 2.67 ± 1.27 2.48 ± 1.34 0.01 0.600 Sg (×10−2 · min−1) 1.48 ± 0.61 2.30 ± 0.97 2.21 ± 0.72 0.01 0.684 Data are means ± SD.
- Table 3—
Clinical and metabolic characteristics of 18 high-risk African Americans who progressed to IGT and/or type 2 diabetes and 19 healthy subjects who did not progress at the end of 8 years
Parameters Nonprogressors Progressors GIT P value Baseline After 6 years Baseline After 6 years Nonprogressors: baseline vs. after 6 years Progressors vs. nonprogressors: baseline Progressors vs. nonprogressors: after 6 years n 19 19 18 18 Age (years) 42.1 ± 8.2 49.1 ± 7.9 45.4 8.2 51.6 8.5 0.011 NS NS Sex ratio (female/male) 16/3 16/3 14/14 14/4 Body weight (kg) 84.7 ± 0.7 85.0 ± 3.0 98.7 ± 19 103.6 ± 20.9 NS NS 0.073 Height (m) 1.64 ± 0.7 1.61 ± 0.7 1.66 ± 0.9 1.65 ± 0.1 NS NS NS BMI (kg/m2) 33.5 ± 7.0 32.4 ± 6.7 35.4 ± 5.9 37.7 ± 6.4 NS NS 0.030 Waist-to-hip ratio 0.88 ± 0.06 0.88 ± 0.05 0.91 ± 1.10 0.93 ± 0.37 0.04 NS NS Systolic blood pressure (mmHg) 126.6 ± 20.0 129.1 ± 14.7 127 ± 14 138 ± 20 NS NS NS Diastolic blood pressure (mmHg) 81.2 ± 14.1 82.8 ± 11.7 78 ± 12 82 ± 12 NS NS NS Lipids and lipoproteins (mg/dl) Cholesterol 195 ± 32 191 ± 26 205 ± 31 235 ± 40 NS NS 0.001 Triglycerides 82 ± 30 77 ± 32 128 ± 4 184 ± 60 NS 0.001 0.001 HDL cholesterol 57.9 ± 13.7 51.4 ± 12.3 44.5 ± 10.1 41.7 ± 11.7 NS 0.086 0.001 LDL cholesterol 150 ± 49 124 ± 22 135 ± 3 140 ± 53 NS NS NS Data are means ± SD. Progressors GIT (glucose intolerance) represents patients in both the IGT and diabetes groups who progressed during the 5–8 years of follow-up.
- Table 4—
Metabolic characteristics of 18 high-risk African Americans who progressed to IGT and/or type 2 diabetes and 19 healthy subjects who did not progressed at the end of 8 years
Metabolic parameters Nonprogressors Progressors GIT P value Baseline After 6 years Baseline After 6 years Nonprogressors before vs. after 6 years Progressor vs. nonprogressor baseline GIT vs. progressors before vs. after 6 years Fasting glucose (mg/dl) 80 ± 14 77 ± 10 95 ± 8 158 ± 74 0.035 0.011 0.001 2-h glucose (mg/dl) 100 ± 60 89 ± 53 149 ± 27 258 ± 112 0.541 0.001 0.001 Fasting insulin (μU/mll) 11.54 ± 7.85 13.01 ± 9.32 15.1 ± 8.1 17.4 ± 12 0.474 0.514 0.234 2-h insulin (μU/ml) 77.2 ± 71 72.7 ± 87 117 ± 81 99 ± 60 0.121 0.001 0.344 Fasting C-peptide (ng/ml) 2.64 ± 1.17 3.68 ± 1.44 3.04 ± 0.85 3.84 ± 1.38 0.135 0.149 NS 2 h C-peptide (ng/ml) 9.36 ± 6 0.10 ± 4.12 13.3 ± 5.11 10.17 ± 3.78 0.817 0.065 NS AIRFSIGTT (μU/min) 305 ± 230 — 203 ± 21 — 0.05 — Acute C-peptide (ng · ml−1 · min−1) 17 ± 16 — 8.65 ± 9.80 — 0.05 — Si (×10−4 × min−1 [μU/ml]−1) 2.67 ± 1.25 — 1.61 ± 1.13 — 0.05 — Sg (×10−2 · min−1) 2.30 ± 0.97 — 1.48 ± 0.61 — 0.05 — HOMA-IR 2.36 ± 1.69 2.81 ± 2.06 3.31 ± 1.64 5.44 ± 2.55 0.578 0.459 0.003 HOMA-%B 364 ± 37 261 ± 90 148 ± 60 1 01 ± 48 0.298 0.020 0.001 Data are means ± SD. AIRFSIGTT, acute insulin response to a frequently sampled intravenous glucose tolerance test. Progressors GIT (glucose intolerance) represents patients in both the IGT and diabetes groups who progressed during the 5–8 years of follow-up.
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