Table 1.
Baseline characteristics of 2444 black study participants by quintiles of mtDNA-CN, Atherosclerosis Risk in Communities study, 1987–1998
| Mitochondrial DNA copy number quintiles | ||||||
| Overall | Q1 | Q2 | Q3 | Q4 | Q5 | |
| Blacks (N) | 2444 | 489 | 490 | 488 | 488 | 489 |
| mtDNA-CN | 0 (1) | −1.48 (0.76) | −0.39 (0.16) | 0.09 (0.13) | 0.55 (0.14) | 1.25 (0.37) |
| Age, years | 56.7 (6.0) | 56.8 (6.1) | 56.9 (6.1) | 56.7 (5.9) | 56.6 (5.9) | 56.7 (5.9) |
| Female | 64% (1554) | 62% (308) | 63% (310) | 63% (311) | 64% (315) | 63% (310) |
| Center | ||||||
| Forsyth County, North Carolina | 12% (303) | 11% (56) | 14% (71) | 11% (55) | 13% (63) | 12% (58) |
| Jackson, Mississippi | 88% (2163) | 89% (438) | 86% (422) | 89% (438) | 87% (430) | 88% (435) |
| Minneapolis, Minnesota | – | – | – | – | – | – |
| Washington County, Maryland | – | – | – | – | – | – |
| Hypertension | 59% (1460) | 62% (305) | 60% (295) | 56% (277) | 57% (282) | 61% (301 |
| Cardiovascular disease | 11% (258) | 15% (73) | 10% (48) | 10% (49) | 8% (40) | 10% (48) |
| Parental history of diabetes | 22% (531) | 23% (112) | 20% (100) | 21% (103) | 21% (104) | 23% (112) |
| Diabetes | 23% (563) | 23% (115) | 20% (99) | 23% (113) | 24% (119) | 24% (117) |
| BMI, kg/m2 | 30.1 (6.3) | 30.0 (6.4) | 29.5 (5.8) | 30.6 (6.5) | 30.2 (6.6) | 30.1 (6.3) |
| High-risk waist-to-hip ratio | ||||||
| Males (>0.90) | 83% (761) | 82% (153) | 85% (155) | 82% (149) | 84% (149) | 85% (155) |
| Females (>0.85) | 81% (1252) | 82% (253) | 80% (249) | 83% (258) | 78% (245) | 80% (247) |
| HDL-C, mg/dL | ||||||
| Male | 49 (17.5) | 51 (19.0) | 46 (15.4) | 49 (14.8) | 50 (20.0) | 49 (17.5) |
| Female | 56 (16.8) | 55 (15.5) | 57 (17.4) | 56 (16.7) | 56 (18.1) | 55 (16.0) |
| Total cholesterol, mg/dL | 211 (41.8) | 210 (43.5) | 210 (40.9) | 210 (38.9) | 212 (42.8) | 214 (42.8) |
| LDL-C, mg/dL | 134 (39.7) | 133 (40.3) | 134 (38.6) | 133 (36.5) | 134 (41.8) | 137 (41.2) |
| Triglycerides, mg/dL | 119 (76.5) | 122 (99.9) | 117 (73.2) | 117 (72.3) | 118 (67.2) | 119.8 (64.7) |
| Smoking status | ||||||
| Never | 43% (1063) | 39% (194) | 42% (208) | 46% (229) | 45% (224) | 42% (208) |
| Former | 29% (723) | 30% (148) | 28% (137) | 30% (147) | 28% (140) | 31% (151) |
| Current | 27% (658) | 30% (148) | 29% (142) | 23% (115) | 25% (123) | 26% (130) |
| Alcohol drinker | ||||||
| Never | 34% (840) | 32% (160) | 31% (154) | 38% (187) | 32% (158) | 37% (181) |
| Former | 32% (787) | 34% (169) | 33% (162) | 31% (151) | 32% (157) | 30% (148) |
| Current | 33% (817) | 33% (161) | 35% (172) | 31% (153) | 35% (172) | 32% (159) |
| Hemoglobin A1C, % | 6.4 (1.7) | 6.4 (1.7) | 6.3 (1.7) | 6.4 (1.8) | 6.3 (1.6) | 6.4 (1.8) |
| Hemoglobin A1C, mmol/mol | 46 (18.9) | 46 (18.7) | 45 (18.4) | 46 (20.0) | 46 (17.9) | 47 (19.6) |
| Lactate, mmol/L† | 9.5 (3.9) | 9.8 (4.4) | 9.2 (3.5) | 9.4 (3.7) | 9.9 (4.1) | 9.4 (3.8) |
| Fasting glucose, mg/dL* | 130 (66.8) | 132 (70.6) | 128 (68.3) | 129 (67.6) | 131 (66.5) | 129 (61.1) |
| HOMA-IR, U | 0.06 (0.03) | 0.06 (0.14) | 0.08 (0.15) | 0.06 (0.08) | 0.06 (0.08) | 0.04 (0.03) |
| hs-CRP, mg/L† | 6.1 (8.2) | 5.6 (8.2) | 6.4 (8.9) | 6.2 (7.1) | 6.5 (8.3) | 5.9 (8.3) |
Mean (SD) or % (N). Hypertension defined as diastolic blood pressure ≥90 mm Hg or systolic blood pressure ≥140 mm Hg or use of any antihypertensive medication in the past 2 weeks. Cardiovascular disease defined as self-reported history of stroke or coronary heart disease (previous myocardial infarction, coronary heart disease or ECG confirmation of previous myocardial infarction). Diabetes defined as self-report of doctor diagnosis, use of glucose-lowering medication, fasting blood glucose ≥126 mg/dL or non-fasting blood glucose ≥200 mg/dL. To convert lipids from mg/dL to mmol/L, divide by 38.67 for total cholesterol, HDL-C and LDL-C, and by 88.57 for triglycerides.
*Glucose (mg/dL)/405, with insulin measured at visit 1.
†Lactate measured at visit 4, n=259 blacks (224 without diabetes, 32 with diabetes) and n=390 whites (357 without diabetes, 32 with diabetes); CRP measured at visit 2, n=1838 blacks (1431 without diabetes, 392 with diabetes) and n=6914 whites (6356 without diabetes, 554 with diabetes).
BMI, body mass index; HDL-C, high-density lipoprotein cholesterol; HOMA-IR, homeostasis model assessment-estimated insulin resistance (insulin (U/L); hs-CRP, high-sensitivity C reactive protein; LDL-C, low-density lipoprotein cholesterol; mtDNA-CN, mitochondrial DNA copy number.