Table 1. Characteristics of Sample, by Quartiles of Waist Circumference, of 23,042 REGARDS Study Participants Without Coronary Heart Disease or Stroke at Baselinea .
| Characteristic | Total sample (no. of events) | Quartile of waist circumference b
|
P valuec | |||
|---|---|---|---|---|---|---|
| Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | |||
| No. in sample (no. of CHD events from baseline through December 31, 2017) | 23,042 (1,499) | 5,557 (278) | 5,776 (328) | 5,355 (346) | 6,354 (547) | — |
| Individual | ||||||
| Age, mean (SD), y | 64.0 (9.3) | 63.8 (9.8) | 64.6 (9.5) | 64.4 (9.1) | 63.2 (8.7) | <.001 |
| Race–sex group | ||||||
| White male | 6,122 (26.6) | 1,383 (24.9) | 1,561 (27.0) | 1,514 (28.3) | 1,664 (26.2) | <.001 |
| White female | 7,307 (31.7) | 2,384 (42.9) | 1,948 (33.7) | 1,518 (28.3) | 1,457 (22.9) | |
| African American male | 3,432 (14.9) | 932 (16.8) | 829 (14.4) | 711 (13.3) | 960 (15.1) | |
| African American female | 6,181 (26.8) | 858 (15.4) | 1,438 (24.9) | 1,612 (30.1) | 2,273 (35.8) | |
| Region of residenced | ||||||
| Non–Stroke Belt | 10,244 (44.5) | 2,427 (43.7) | 2,585 (44.8) | 2,387 (44.6) | 2,845 (44.8) | .47 |
| Stroke Belt | 7,968 (34.6) | 1,919 (34.5) | 1,965 (34.0) | 1,863 (34.8) | 2,221 (35.0) | |
| Stroke Buckle | 4,830 (21.0) | 1,211 (21.8) | 1,226 (21.2) | 1,105 (20.6) | 1,288 (20.3) | |
| Not married (vs any other marital status) | 9,469 (41.1) | 2,167 (39.0) | 2,269 (39.3) | 2,222 (41.5) | 2,811 (44.2) | <.001 |
| Has a diabetes diagnosis (vs not)e | 4,158 (18.7) | 363 (6.8) | 631 (11.3) | 1,034 (19.9) | 2,130 (34.6) | <.001 |
| Has a hypertension diagnosis (vs not)f | 12,681 (55.1) | 2,077 (37.4) | 2,942 (51.0) | 3,133 (58.6) | 4,529 (71.4) | <.001 |
| Has a lipid disorder diagnosis (vs not)g | 12,150 (54.8) | 2,185 (41.3) | 3,014 (54.0) | 3,109 (60.0) | 3,842 (62.8) | <.001 |
| Smoking status | ||||||
| Never | 10,970 (47.8) | 2,802 (50.6) | 2,785 (48.4) | 2,496 (46.8) | 2,887 (45.6) | <.001 |
| Past | 8,776 (38.2) | 1,776 (32.1) | 2,181 (37.9) | 2,136 (40.1) | 2,683 (42.4) | |
| Current | 3,206 (14.0) | 957 (17.3) | 794 (13.8) | 700 (13.1) | 755 (11.9) | |
| Educational attainment | ||||||
| Less than high school education | 2,524 (11.0) | 433 (7.8) | 569 (9.9) | 611 (11.4) | 911 (14.3) | <.001 |
| High school graduate | 12,052 (52.3) | 2,710 (48.8) | 3,033 (52.5) | 2,842 (53.1) | 3,467 (54.6) | |
| College graduate and above | 8,454 (36.7) | 2,410 (43.4) | 2,172 (37.6) | 1,898 (35.5) | 1,974 (31.1) | |
| Annual household income, $ | ||||||
| ≤35,000 | 9,184 (39.9) | 1,937 (34.9) | 2,213 (38.3) | 2,131 (39.8) | 2,903 (45.7) | <.001 |
| >35,000 | 11,042 (47.9) | 2,880 (51.8) | 2,835 (49.1) | 2,576 (48.1) | 2,751 (43.3) | |
| Refused | 2,816 (12.2) | 740 (13.3) | 728 (12.6) | 648 (12.1) | 700 (11.0) | |
| Has health insurance | 21,370 (92.8) | 5,184 (93.4) | 5,408 (93.7) | 4,972 (92.9) | 5,806 (91.5) | <.001 |
| Does not have a clinic or doctor who provides usual medical care | 4,374 (20.5) | 1,038 (20.0) | 1,078 (20.0) | 1,047 (21.2) | 1,211 (20.7) | .41 |
| Neighborhood | ||||||
| Quintiles of primary care providers per 100,000 population in Primary Care Service Area | ||||||
| <45 | 4,486 (19.5) | 1,027 (18.5) | 1,110 (19.2) | 1,036 (19.4) | 1,313 (20.7) | .03 |
| 45–62 | 4,789 (20.8) | 1,152 (20.7) | 1,250 (21.7) | 1,075 (20.1) | 1,312 (20.7) | |
| 63–79 | 4,431 (19.2) | 1,100 (19.8) | 1,124 (19.5) | 1,048 (19.6) | 1,159 (18.2) | |
| 80–107 | 4,683 (20.3) | 1,115 (20.1) | 1,129 (19.6) | 1,143 (21.4) | 1,296 (20.4) | |
| ≥108 | 4,636 (20.1) | 1,160 (20.9) | 1,156 (20.0) | 1,048 (19.6) | 1,272 (20.0) | |
| Quintiles of percentage of population in zip code living below 200% of the federal poverty level | ||||||
| <20.4 | 4,610 (20.0) | 1,380 (24.8) | 1,252 (21.7) | 1,006 (18.8) | 972 (15.3) | <.001 |
| 20.4–31.3 | 4,652 (20.2) | 1,163 (20.9) | 1,190 (20.6) | 1,114 (20.8) | 1,185 (18.7) | |
| 31.4–39.5 | 4,521 (19.6) | 1,028 (18.5) | 1,130 (19.6) | 1,080 (20.2) | 1,283 (20.2) | |
| 39.6–49.1 | 4,633 (20.1) | 1,014 (18.3) | 1,146 (19.9) | 1,085 (20.3) | 1,388 (21.9) | |
| ≥49.2 | 4,604 (20.0) | 969 (17.4) | 1,048 (18.2) | 1,064 (19.9) | 1,523 (24.0) | |
| Zip code–level segregation, mean (SD)h | 61.0 (13.3) | 60.3 (13.0) | 61.2 (13.4) | 61.2 (13.4) | 61.3 (13.2) | <.001 |
| Urban vs rural residencei | ||||||
| Urban | 20,613 (89.6) | 5,012 (90.3) | 5,173 (89.8) | 4,785 (89.5) | 5,643 (88.9) | .07 |
| Rural | 2,393 (10.4) | 536 (9.7) | 589 (10.2) | 562 (10.5) | 706 (11.1) | |
Abbreviation: —, does not apply; CHD, coronary heart disease; REGARDS, REasons for Geographic and Racial Differences in Stroke.
Participants were recruited and baseline data were collected from January 2003 through October 2007. All values are number (percentage) unless otherwise indicated.
Quartile 1: women, <32.0 in; men, <36.0 in. Quartile 2: women, ≥32.0 to <36.0 in; men, ≥36.0 to <38.5 in. Quartile 3: women, ≥36.0 to <40.0 in; men, ≥38.5 to <42.0 in. Quartile 4: women, ≥40.0 in; men, ≥42.0 in.
χ2 test used to assess significance for categorical variables; analysis of variance or Kruskal–Wallis used for continuous variables.
Categorized as Stroke Belt (Alabama, Arkansas, Louisiana, Mississippi, and Tennessee; and non–coastal plain of Georgia, North Carolina, and South Carolina); Stroke Buckle (coastal plain of Georgia, North Carolina, and South Carolina); non–Stroke Belt (all other states).
Diabetes if fasting glucose ≥126 mg/dL, nonfasting glucose ≥200 mg/dL, or taking oral medication or insulin.
Hypertension if systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or self-reported current medication use to control blood pressure.
Dyslipidemia defined as total cholesterol ≥240 mg/dL, low-density lipid cholesterol ≤40 mg/dL, or taking medication.
An index of dissimilarity for African American and White populations in the zip code was used to indicate the proportion of the population that would have to move into the zip code to have uniform distribution of the population by race across the zip code (37).
Rural–Urban Commuting Areas (RUCA) categorization (35): RUCA 1.0,1.1, 2.0, 2.1, 3.0, 4.1, 5.1, 7.1, 8.1, and 10.1 categorized as urban; RUCA 4.0, 4.2, 5.0, 5.2, 6.0, 6.1, 7.0, 7.2, 7.3, 7.4, 8.0, 8.2, 8.3, 8.4, 9.0, 9.1, 9.2, 10.0, 10.2, 10.3, 10.4, 10.5, and 10.6 categorized as rural.