Table 1.
Baseline characteristics by metabolic syndrome status
| Metabolic Syndrome a | |||
|---|---|---|---|
| Yes | No | p-value | |
| n, % | 1,656 (30.79) | 3,497 (69.21) | |
| Age, years | 63 (11) | 62 (12) | 0.006 |
| Sleep duration (hours), n (%) < 6 | 202 (12.20) | 417 (11.92) | |
| 6- < 7 | 501 (30.25) | 1,040 (29.74) | |
| 7- < 8 | 543 (32.79) | 1,236 (35.24) | |
| 8- < 9 | 323 (19.50) | 679 (19.42) | |
| ≥ 9 | 87 (5.25) | 125 (3.57) | 0.040 |
| Insomnia (IRS ≥ 9), n (%) b | 517 (31.78) | 995 (29.01) | 0.045 |
| Waist circumference > 88 cm | 1,329 (80.40) | 898 (25.79) | < 0.001 |
| Hypertension, n (%) | 1,358 (82.00) | 1,482 (42.38) | < 0.001 |
| Fast glucose ≥ 100 mg/dL | 984 (59.82) | 402 (11.88) | < 0.001 |
| HDL < 50 mg/dL | 1,053 (63.86) | 396 (11.73) | < 0.001 |
| Triglycerides ≥ 150 mg/dL | 1,181 (71.40) | 697 (20.60) | < 0.001 |
| Observational Study, n (%) | 227 (13.71) | 756 (21.62) | < 0.001 |
| Dietary modification trial, n (%) | 888 (53.62) | 1,706 (48.78) | 0.001 |
| Calcium and Vitamin D suppl. trial, n (%) | 728 (43.96) | 1,474 (42.15) | 0.220 |
| HRT study arm, n (%) | 910 (54.95) | 1,546 (44.21) | < 0.001 |
| Use of sleep aids no | 1,274 (76.93) | 2,778(79.44) | |
| < 1t/wk | 127 (7.67) | 312 (8.92) | |
| 1-2t/wk | 84 (5.07) | 161 (4.60) | |
| 3-4t/wk | 46 (2.78) | 84 (2.40) | |
| ≥ 5t/wk | 120 (7.25) | 157 (4.49) | 0.001 |
| Body mass index, kg/m2 | 31.59 (7.27) | 26.20 (6.27) | < 0.001 |
| Education< college | 168 (10.24) | 252 (7.25) | |
| some college | 1,033 (62.99) | 1,891 (54.39) | |
| college graduate | 133 (8.11) | 372 (10.70) | |
| post-college | 306 (18.66) | 962 (27.67) | < 0.001 |
| Ethnicity, n (%) White | 851 (51.39) | 1,918 (54.85) | |
| Black | 392 (23.67) | 752 (21.50) | |
| American Indian/Alaskan Native | 52 (3.1) | 66 (1.9) | |
| Asian or Pacific Islander | 99 (6.0) | 289 (8.3) | |
| Hispanic/Latino | 237 (14.3) | 409 (11.7) | |
| Others | 25 (1.5) | 63 (1.8) | < 0.001 |
| Marital status, n (%) | |||
| Never married | 63 (3.8) | 146 (4.2) | |
| Divorced/ Separated | 300 (18.1) | 610 (17.4) | |
| Widowed | 313 (18.9) | 592 (16.9) | |
| Married/ Marriage-like | 969 (58.5) | 2,130 (60.9) | |
| missed | 11 (0.7) | 19 (0.5) | 0.341 |
| Family income ($), n (%) | |||
| < $35,000 | 831 (50.2) | 1,402 (40.1) | |
| ≥ $35,000-< $50,000 | 318 (19.2) | 687 (19.7) | |
| ≥ $50,000-< $75,000 | 261 (15.8) | 634 (18.1) | |
| ≥ 75,000 | 194 (11.7) | 658 (18.8) | |
| missed | 52 (3.1) | 115 (3.3) | < 0.001 |
| Cancer before enrollment, n (%) | 70 (4.3) | 153 (4.4) | 0.791 |
| Cardiovascular disease before enrollment. n (%) | 242 (16.0) | 469 (14.7) | 0.240 |
| Smoking, n(%) never | 845 (51.03) | 1,856 (53.07) | |
| former | 645 (38.95) | 1,322 (37.80) | |
| current | 144 (8.70) | 278 (7.95) | 0.468 |
| Pack-years of cigarette consumption | 11.64 (20.96) | 11.64 (25.58) | 0.259 |
| Hormone therapy use ever, n (%) | 667 (40.28) | 1,794 (51.30) | < 0.001 |
| Age at menopause, n (%) < 45 | 396 (32.49) | 864 (31.10) | |
| 45–49 | 441 (36.18) | 985 (35.46) | |
| ≥ 50 | 382 (31.34) | 929 (33.44) | 0.410 |
| Alcohol intake, serves /wk | 3 (2) | 4 (3) | < 0.001 |
| Coffee/tea intake cups/day | 1.17 (1.59) | 2.34 (1.59) | 0.003 |
| Physical activity, MET-hrs/wk | 3.75 (10.50) | 6.75 (15.75) | < 0.001 |
| Depression (≥ 5 short CES-D), n (%) | 289 (17.50) | 535 (15.39) | 0.054 |
Data are medians and interquartile ranges, unless otherwise specified. P values from Wilcoxon rank test for continuous variables, and Chi-square test and t-test for categorical ones
Abbreviations: HDL High density lipoprotein, HRT Hormone replacement therapy, MET Metabolic equivalent, CES-D Center for epidemiological studies of depression
a Six women had missing information on MS at baseline
b Ninety six women had missing information on insomnia at baseline