Table 2.
Characteristics of the study cohort by sex, WHO Study on global AGEing and adult health (SAGE) South Africa Wave 2 (2015).
| All n = 457 |
Men n = 109 |
Women n = 348 |
p Value | |
|---|---|---|---|---|
| Age (years) | 52 (24) | 50 (23) | 54 (23) | 0.072 |
| Aged over 50 years, n (%) | 298 (65) | 63 (58) | 235 (68) | 0.066 |
| Ethnicity, n (%) | ||||
| Black African | 315 (73) | 77 (73) | 238 (73) | 0.248 |
| Coloured, mixed race | 70 (16) | 16 (15) | 54 (17) | |
| Indian | 36 (8) | 7 (7) | 29 (9) | |
| White | 10 (2) | 5 (5) | 5 (2) | |
| Rural, n (%) | 131 (29) | 31 (28) | 100 (29) | 0.926 |
| Education (years) | 9 (5) | 10 (4) | 8 (6) | 0.001 |
| Currently employed, n (%) | 83 (31) | 37 (51) | 46 (23) | <0.001 |
| BMI kg/m2 | 29.2 (9.1) | 25.7 (7.3) | 30.3 (9.3) | <0.001 |
| Waist to height ratio, mean ± SD | 0.58 ± 0.13 | 0.53 ± 0.11 | 0.60 ± 0.13 | <0.001 |
| Never used alcohol, n (%) | 287 (81) | 59 (63) | 228 (88) | <0.001 |
| Spot urinary cotinine (ng/mL) | 19.1 (753) | 19 (843) | 19 (725) | 0.867 |
| Median UIC (µg/L) | 130 (129) | 149 (124) | 121 (131) | 0.102 |
| UIC < 100 µg/L, n (%) | 181 (39.5) | 38 (34.9) | 143 (41.0) | 0.255 |
| UIC < 50 µg/L, n (%) | 70 (15.3) | 14 (12.8) | 56 (16.1) | 0.450 |
| Spot urinary iodine per creatinine (µg/g) | 102 (103) | 102 (106) | 102 (99) | 0.305 |
| 24-h urinary volume (mL/day) | 1400 (1390) | 1450 (1350) | 1370 (1430) | 0.929 |
| 24-h urinary iodine (mUIE) (µg/day) | 124 (134) | 137 (190) | 119 (121) | 0.010 |
All data is shown as median (IQR, interquartile range) unless otherwise indicated. Hypertensive categorised as BP ≥ 140/90 mmHg or previous diagnosis; Tobacco use/exposure identified by urinary cotinine analysis; BMI, body mass index; UIC, spot Urinary Iodine Concentration; mUIE, measured 24 h Urinary Iodine Excretion. Continuous median variables compared using Independent Samples Mann-Whitney U test and mean values with independent t-test; categorical variables compared using the Pearson Chi-Square and Fisher’s Exact Test.