Table 1.
Mean values and population-specific high-risk cut points for allostatic load parameters in the MIDUS Biomarker Substudy
| System and representative biomarkers |
Number | Mean | SD | Min | Max | High-risk cut point by population-specific quartile |
|---|---|---|---|---|---|---|
| Cardiovascular | ||||||
| Resting SBP (mmHg) | 1254 | 131.5 | 18.3 | 83.0 | 222.0 | ≥144.0 (n = 309) |
| Resting heart rate (bpm) | 1253 | 71.1 | 11.2 | 36.0 | 111.0 | ≥79.0 (n = 314) |
| Resting pulse pressure (mmHg) | 1254 | 55.8 | 14.7 | 24.0 | 114.0 | ≥65.0 (n = 312) |
| Metabolic lipids | ||||||
| BMI (kg/m2) | 1254 | 29.8 | 6.63 | 15.0 | 65.1 | ≥33.1 (n = 313) |
| WHR | 1253 | 0.89 | 0.10 | 0.62 | 1.72 | ≥0.97 (n = 316) |
| Triglycerides (mg/dL) | 1244 | 132.5 | 131.8 | 25.0 | 3299.0 | ≥156.0 (n = 312) |
| HDL cholesterol (mg/dL) | 1242 | 55.4 | 18.0 | 19.0 | 121.0 | ≤42.0 (n = 310) |
| LDL cholesterol (mg/dL) | 1242 | 105.5 | 35.4 | 6.00 | 283.0 | ≥128.0 (n = 310) |
| Metabolic glucose metabolism | ||||||
| Glycosylated hemoglobin (%) | 1235 | 6.10 | 1.16 | 3.58 | 19.7 | ≥6.24 (n = 314) |
| Fasting glucose (mg/dL) | 1236 | 102.1 | 28.4 | 5.00 | 418.0 | ≥105.0 (n = 314) |
| Insulin resistance (HOMA-IR) | 1236 | 3.58 | 3.98 | 0.04 | 53.7 | ≥4.36 (n = 310) |
| Inflammation | ||||||
| CRP (mg/L) | 1235 | 3.02 | 4.78 | 0.14 | 61.7 | ≥3.66 (n = 309) |
| IL6 (pg/mL) | 1243 | 3.04 | 3.04 | 0.16 | 23.0 | ≥3.48 (n = 310) |
| Fibrinogen (mg/dL) | 1235 | 348.9 | 87.8 | 45.0 | 857.0 | ≥399.0 (n = 313) |
| sE-selectin (ng/MI) | 1242 | 43.4 | 22.7 | 0.09 | 178.1 | ≥51.9 (n = 310) |
| sICAM-1 (ng/MI) | 1242 | 288.5 | 115.6 | 44.0 | 1076.6 | ≥335.8 (n = 310) |
| Sympathetic nervous system | ||||||
| Urine epinephrine (μg/g creatine) | 1233 | 1.96 | 1.28 | 0.09 | 10.6 | ≥2.47 (n = 308) |
| Urine norepinephrine (μg/g creatine) | 1243 | 27.4 | 13.9 | 3.50 | 187.1 | ≥33.0 (n = 311) |
| Hypothalamic pituitary adrenal axis | ||||||
| Urine cortisol (μg/g creatine) | 1252 | 15.8 | 24.6 | 0.40 | 725.0 | ≥20.0 (n = 308) |
| Blood DHEA-S (μg/dL) | 1239 | 105.1 | 77.0 | 0.90 | 685.0 | ≤51.0 (n = 313) |
| Parasympathetic nervous system | ||||||
| SDRR (msec) | 1148 | 35.6 | 17.2 | 5.56 | 138.8 | ≤23.7 (n = 287) |
| RMSSD | 1148 | 22.9 | 17.7 | 2.64 | 209.7 | ≤12.1 (n = 287) |
| Low frequency spectral power | 1148 | 424.3 | 607.5 | 1.60 | 10,943.6 | ≤114.6 (n = 287) |
| High frequency spectral power | 1148 | 316.5 | 729.4 | 2.45 | 15,731.7 | ≤58.8 (n = 287) |
| Allostatic load | 1233 | 1.72 | 1.03 | 0 | 5.03 | |
| Allostatic load (with medication data) | 1233 | 1.94 | 1.10 | 0 | 5.37 |
Allostatic Load was defined in accordance with previous studies conducted within this population using a score that captured dysregulation across seven systems, including multiple markers of cardiovascular pathways, sympathetic nervous system, parasympathetic nervous system, HPA axis, inflammation, lipid and general metabolic activity, and glucose metabolism, and could range from 0 to 7
BMI body mass index, CRP C-reactive protein, DHEA-S dehydroepiandrosterone sulfate, PNS parasympathetic nervous system, HPA hypothalamic pituitary axis, IL-6 interleukin-6, RMSSD root mean square of successive differences, SBP systolic blood pressure, SDRR the standard deviation of R-R (heartbeat to heartbeat) intervals, sE-selectin soluble adhesion molecule E-selectin, sICAM soluble intracellular adhesion molecule-1, SNS sympathetic nervous system