Racial Differences in and Prognostic Value of Biomarkers of Hyperglycemia
Article Figures & Tables
Figures
- Figure 1
Adjusted associations of hyperglycemia with incident CVD, incident ESRD, and prevalent retinopathy by race. Hazard ratios (HRs) for CVD and ESRD were obtained using separate Cox proportional hazards regression models for white and black participants. Odds ratios for prevalent retinopathy were obtained using separate logistic regression models for white and black participants. In models that included both white and black participants, P values for interactions were calculated by conducting a likelihood ratio test to compare models with and without terms for the interaction between race and hyperglycemia. Models included adjustment for age; sex (male, female); BMI; BMI2; LDL-c; HDL-c; triglycerides; cholesterol-lowering medication use (yes, no); systolic blood pressure; antihypertensive medication use (yes, no); eGFR; family history of diabetes (yes, no); education level (less than high school, high school or some college, college or more); alcohol consumption (current, former, never); cigarette smoking status (current, former, never); and physical activity level. Categories of diabetes—no diabetes; no diabetes, intermediate levels; no diabetes, elevated levels; diabetes; and diabetes, elevated levels—were defined using the following levels of each biomarker, respectively: fasting glucose: <100, 100–125, ≥126, <149, ≥149 mg/dL; HbA1c: <5.7, 5.7–6.4, ≥6.5, <7.0, ≥7.0%; fructosamine: <239.8, 239.8–268.6, ≥268.7, <275.7, ≥275.7 mg/dL; glycated albumin: <13.52, 13.52–15.55, ≥15.56, <16.46, ≥16.46%; 1,5-AG: ≥15.0, 7.9–14.9, <7.9, >9.2, ≤9.2 μg/mL. Gray symbols indicate results for white participants. Black symbols indicate results for black participants. DM, diabetes.
Tables
- Table 1
Characteristics of the study population by diabetes status and race, ARIC visit 2 (1990–1992)
No diagnosed diabetes Diagnosed diabetes White (n = 8,096) Black (n = 2,277) P value* White (n = 425) Black (n = 302) P value* Age, years 57.3 (5.6) 56.2 (5.7) <0.001 58.7 (5.7) 57.6 (5.7) 0.013 Male sex 43.9% 35.8% <0.001 48.0% 29.5% <0.001 Less than HS education 13.9% 35.0% <0.001 24.2% 44.0% <0.001 Obese (BMI ≥ 30 kg/m2) 21.7% 41.5% <0.001 47.5% 55.0% 0.048 Current smoking 20.5% 24.5% <0.001 17.9% 21.2% 0.265 Current drinking 66.2% 36.8% <0.001 48.5% 21.5% <0.001 Family history of diabetes 21.9% 25.0% 0.002 41.9% 41.1% 0.824 Hypertension† 29.4% 51.4% <0.001 51.3% 64.9% <0.001 Antihypertensive medication use 21.7% 40.3% <0.001 42.6% 57.0% <0.001 Systolic BP, mmHg 118.8 (17.4) 125.5 (19.9) <0.001 125.2 (17.2) 127.9 (20.1) 0.052 Systolic BP ≥140 mmHg 11.7% 21.0% <0.001 19.8% 22.2% 0.428 Diastolic BP, mmHg 71.2 (9.7) 75.7 (10.8) <0.001 70.8 (9.7) 73.0 (9.7) 0.003 Diastolic BP ≥90 mmHg 3.8% 10.1% <0.001 3.3% 4.3% 0.478 HDL-c, mg/dL 50.1 (16.6) 54.5 (17.0) <0.001 42.1 (12.8) 49.1 (13.6) <0.001 Total cholesterol, mg/dL 209.0 (37.4) 208.9 (40.0) 0.921 208.7 (39.2) 217.5 (45.6) 0.005 LDL-c, mg/dL 132.8 (35.6) 133.7 (38.3) 0.281 132.6 (35.2) 141.4 (42.7) 0.003 Triglycerides, mg/dL 130.7 (64.5) 103.5 (50.0) <0.001 169.5 (75.3) 134.8 (68.3) <0.001 Cholesterol-lowering medication use 5.5% 2.8% <0.001 12.9% 5.0% <0.001 Glucose-lowering medications‡ — — — 61.5% 76.5% <0.001 eGFR <60 mL/min/1.73 m2 1.2% 1.1% 0.670 2.4% 4.6% 0.090 Prevalent retinopathy§ 1.6% 3.3% <0.001 19.6% 30.7% 0.005 Baecke sport index‖ 2.5 (0.8) 2.2 (0.7) <0.001 2.4 (0.8) 2.1 (0.6) <0.001 Data are mean (SD) or percentages.
BP, blood pressure; HS, high school; IQR, interquartile range.
↵*Two-sided P values calculated using the Student t test for continuous variables and the χ2 test for categorical variables.
↵†Hypertension defined as diastolic BP ≥90 mmHg or systolic BP ≥140 mmHg or antihypertensive medication use.
↵‡Among persons with diabetes, 13 black and 22 white participants are missing a response to self-reported use of glucose-lowering medication.
↵§Retinopathy was assessed at visit 3 (1993–1995) and therefore was available for only a subset of the main study population (176 blacks and 317 whites among participants with diagnosed diabetes; 1,516 blacks and 6,561 whites among participants without diagnosed diabetes).
↵‖The Baecke sport index is a score of sport index during leisure time, with values ranging from 1 to 5, based on intensity (light, moderate, heavy); time (hours per week); and proportion (months per year) of activity. Higher values indicate higher levels of physical activity.
- Table 2
Baseline levels of biomarkers of hyperglycemia by diabetes status and race
Median (25th, 75th percentile) Median (25th, 75th percentile) P value* Among people without diagnosed diabetes White (n = 8,096) Black (n = 2,277) FG, mg/dL 101 (95, 108) 104 (97, 113) <0.001 FG <100 mg/dL 94 (90, 97) 94 (90, 97) 0.189 FG 100–125 mg/dL 106 (102, 111) 108 (103, 114) <0.001 FG ≥126 mg/dL 136 (129, 151) 138 (131, 154) 0.150 HbA1c, % 5.4 (5.1, 5.6) 5.7 (5.4, 6.0) <0.001 FG <100 mg/dL 5.3 (5.1, 5.4) 5.5 (5.2, 5.7) <0.001 FG 100–125 mg/dL 5.4 (5.2, 5.7) 5.7 (5.4, 6.0) <0.001 FG ≥126 mg/dL 6.2 (5.8, 6.8) 6.6 (6.2, 7.2) <0.001 Fructosamine, μmol/L 225 (214, 237) 234 (220, 250) <0.001 FG <100 mg/dL 224 (212, 234) 230 (217, 242) <0.001 FG 100–125 mg/dL 226 (214, 237) 234 (220, 249) <0.001 FG ≥126 mg/dL 247 (229, 268) 260 (236, 285) <0.001 Glycated albumin, % 12.5 (11.7, 13.3) 13.3 (12.4, 14.3) <0.001 FG <100 mg/dL 12.4 (11.7, 13.2) 13.1 (12.3, 13.9) <0.001 FG 100–125 mg/dL 12.4 (11.7, 13.2) 13.3 (12.4, 14.3) <0.001 FG ≥126 mg/dL 14.1 (12.8, 15.8) 15.2 (13.6, 17.3) <0.001 1,5-AG, μg/mL 18.9 (15.3, 22.5) 17.3 (13.9, 21.0) <0.001 FG <100 mg/dL 18.6 (15.2, 22.1) 17.3 (14.2, 21.1) <0.001 FG 100–125 mg/dL 19.4 (15.8, 22.9) 17.8 (14.3, 21.2) <0.001 FG ≥126 mg/dL 15.5 (10.0, 20.4) 14.6 (8.2, 18.7) 0.055 Among people with diagnosed diabetes White (n = 425) Black (n = 302) FG, mg/dL 158 (122, 216) 194 (136, 271) <0.001 FG <149 mg/dL 117 (103, 133) 120 (103, 135) 0.517 FG ≥149 mg/dL 209 (176, 256) 245 (191, 296) <0.001 HbA1c, % 7.1 (5.9, 8.6) 8.4 (6.7, 10.6) <0.001 FG <149 mg/dL 5.8 (5.4, 6.5) 6.4 (5.9, 7.1) <0.001 FG ≥149 mg/dL 8.4 (7.4, 9.8) 9.7 (8.0, 11.4) <0.001 Fructosamine, μmol/L 280 (241, 358) 331 (267, 423) <0.001 FG <149 mg/dL 240 (221, 260) 254 (237, 281) <0.001 FG ≥149 mg/dL 341 (290, 404) 378 (316, 465) <0.001 Glycated albumin, % 16.6 (13.3, 22.4) 21.7 (16.0, 29.0) <0.001 FG <149 mg/dL 13.1 (12.1, 14.9) 15.0 (13.4, 16.4) <0.001 FG ≥149 mg/dL 21.1 (17.4, 27.1) 25.0 (21.1, 32.7) <0.001 1,5-AG, μg/mL 7.7 (2.4, 15.4) 4.0 (1.5, 12.1) <0.001 FG <149 mg/dL 15.1 (10.2, 20.1) 13.3 (9.5, 17.3) 0.040 FG ≥149 mg/dL 2.8 (1.4, 7.1) 2.1 (1.2, 5.3) 0.065 Among people without diagnosed diabetes, there were 3,573 whites and 772 blacks with FG <100 mg/dL; 4,133 whites and 1,266 blacks with FG 100–125 mg/dL; and 390 whites and 239 blacks with FG ≥126 mg/dL. Among people with diagnosed diabetes, there were 193 whites and 95 blacks with FG <149 mg/dL and 232 whites and 207 blacks with FG ≥149 mg/dL. FG, fasting glucose.
↵*P values were calculated using the Wilcoxon rank sum (Mann-Whitney U) test.
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