Table 1.
Characteristics of Participants in the Jackson Heart Study by Quartiles of Morning Serum Cortisol
| All | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | ||
|---|---|---|---|---|---|---|
| Baseline Characteristics ♦ | n=4206 | n=1079 | n=1046 | n=1043 | N=1038 | p-value |
| Age, years | 54.97 (12.76) | 52.02 (11.85) | 54.37 (12.94) | 57.21 (12.16) | 56.38 (13.45) | <0.0001 |
| Female, sex (%) | 63.67 | 81.46 | 67.11 | 57.81 | 47.59 | 0.006 |
| Education | ||||||
| < High School (%) | 18.90 | 13.72 | 17.21 | 19.94 | 24.95 | |
| high school graduate/GED | 18.12 | 17.33 | 17.30 | 18.60 | 19.27 | |
| attended vocational school, trade school or college | 62.98 | 68.95 | 65.49 | 61.46 | 55.78 | 0.000 |
| Occupation, Management/Professional | 36.47 | 40.59 | 38.05 | 35.95 | 31.12 | 0.000 |
| Poor AHA Physical Activity† | 48.48 | 47.36 | 46.94 | 49.28 | 50.39 | 0.365 |
| Current Smoking (%) | 12.72 | 10.94 | 10.90 | 12.27 | 16.86 | 0.000 |
| Alcohol Intake (%) | 46.77 | 44.58 | 46.27 | 44.01 | 52.31 | 0.000 |
| Body-mass Index (kilograms/meter2) | 31.67 (7.20) | 32.93 (7.24) | 32.34 (7.45) | 31.43 (7.21) | 29.93 (6.53) | <0.0001 |
| Waist circumference (cm) | 100.42 (16.10) | 101.45 (16.48) | 101.35 (16.34) | 100.18 (15.40) | 98.64 (16.00) | 0.0001 |
| Systolic blood pressure (mmHg) | 127.16 (16.44) | 124.53 (15.20) | 125.72 (15.53) | 129.10 (17.34) | 129.41 (17.09) | <0.0001 |
| Glucose (mg/dL) | 100.30 (33.21) | 93.75 (23.21) | 98.64 (28.77) | 102.42 (33.54) | 106.64 (43.07) | <0.0001 |
| Hemoglobin A1c (%) | 5.91 (1.21) | 5.74 (0.93) | 5.88 (1.09) | 5.97 (1.27) | 6.05 (1.48) | <0.0001 |
| Cortisol (µg/dL) | 9.2 (6.9, 12) | 5.7 (4.8, 6.4) | 8.1 (7.5, 8.6) | 10.5 (9.9, 11.2) | 14.6 (13.2, 16.6) | 0.0001 |
| Log-Transformed Cortisol | 2.20 (0.43) | 1.66 (0.30) | 2.09 (0.08) | 2.35 (0.75) | 2.72 (0.18) | <0.0001 |
| Cortisol Collection Time (24-hour time) | 10.75 (0.62) | 10.84 (0.58) | 10.77 (0.61) | 10.71 (0.63) | 10.66 (0.64) | <0.0001 |
| Homeostatic model assessment of insulin resistance ‡ | 3.03 (2.19, 4.37) | 3.16 (2.33, 4.38) | 3.13 (2.24, 4.38) | 2.96 (2.09, 4.39) | 2.89 (2.11, 4.29) | 0.0385 |
| Homeostatic model assessment of βcell function (%) ‡ | 191.79 (141.13, 266.63) | 214.80 (161.54, 300.97) | 195.35 (146.51, 276.34) | 177.60 (134.61, 244.18) | 174.05 (124.99, 243.36) | 0.0001 |
| Hormone Replacement Therapy (%) | 15.00 | 13.53 | 14.24 | 15.34 | 16.96 | 0.139 |
| Beta-Blocker Medications (%) | 9.70 | 7.04 | 10.13 | 10.64 | 11.08 | 0.007 |
| Prevalent Diabetes (%) | 18.95 | 13.53 | 18.64 | 19.56 | 24.28 | <0.001 |
GED=General Educational Development (degree equivalent to graduation from high school)
♦
Mean (SD), median (interquartile range) or percentages are listed, p-values calculated using chi-square (categorical variables), ANOVA (parametric continuous variables) and Kruskal-Wallis test (non-parametric continuous variables)
†
AHA = American Heart Association, Ideal physical activity recommendations were defined by AHA “2020” guidelines. Physical Activity was considered poor if participant performed no physical activity.
‡
n = 3,409 participants with HOMA-IR and HOMA-β without diabetes at baseline, (Q1 933, Q2 851, Q3 839, Q4 786)