Table 1.
Baseline Characteristics of Participants and according to first and second generation.
| Variable* | Participants at both examinations | First Generation | Second Generation | P value | |||
|---|---|---|---|---|---|---|---|
| (n = 2105) | (n = 793)† | (n = 1312)†† | |||||
| Mean or n | SD or % | Mean or n (%) | SD or % | Mean or n (%) | SD or % | ||
| Age (years) | 56.20 | 9.07 | 59.54 | 10.22 | 54.18 | 7.62 | <0.001 |
| Sex, Male | 1047 | 49.74 | 400 | 50.44 | 647 | 49.31 | 0.93 |
| Hypertension, yes | 1177 | 55.99 | 486 | 61.29 | 691 | 52.79 | 0.34 |
| Systolic Blood Pressure, (mmHg) | 134.11 | 19.30 | 135.97 | 19.56 | 132.99 | 19.06 | 0.29 |
| Diastolic Blood Pressure, (mmHg) | 77.75 | 10.11 | 77.11 | 9.77 | 78.14 | 10.30 | 0.38 |
| Diabetes | 570 | 27.17 | 235 | 29.67 | 335 | 25.65 | 0.18 |
| Hba1c, % | 6.36 | 1.32 | 6.33 | 1.22 | 6.38 | 1.37 | 0.04 |
| Chronic Kidney Disease | 105 | 5.16 | 49 | 6.36 | 56 | 4.43 | 0.08 |
| Blood Creatinine (mmol/l) | 0.85 | 0.25 | 0.86 | 0.24 | 0.85 | 0.26 | 0.32 |
| History of Myocardial Infarction | 162 | 7.70 | 72 | 9.09 | 90 | 6.86 | 0.13 |
| History of Stroke | 43 | 2.04 | 19 | 2.40 | 24 | 1.83 | 0.87 |
| Body Mass Index (kg/m2) | 26.20 | 4.48 | 25.82 | 3.98 | 26.44 | 4.74 | 0.01 |
| Total Cholesterol (mg/dl) | 5.21 | 1.07 | 5.07 | 1.04 | 5.29 | 1.08 | <0.001 |
| HDL Cholesterol (mg/dl) | 1.06 | 0.31 | 1.05 | 0.31 | 1.07 | 0.30 | 0.01 |
| LDL Cholesterol (mg/dl) | 3.35 | 0.93 | 3.25 | 0.92 | 3.41 | 0.92 | 0.10 |
| Triglycerides (mg/dl) | 1.96 | 1.17 | 1.94 | 1.15 | 1.98 | 1.19 | 0.60 |
| C-reactive Protein (mg/l), mgL | 4.08 | 5.75 | 3.65 | 5.61 | 4.34 | 5.81 | 0.02 |
| Formal Education, yes | 1787 | 84.97 | 621 | 78.41 | 1166 | 88.94 | 0.58 |
| Low income, <$2000 | 1440 | 70.24 | 545 | 70.96 | 895 | 69.81 | 0.28 |
| Low Economic Status*, yes | 967 | 47.19 | 366 | 47.72 | 601 | 46.88 | 0.02 |
| Cigarette Smoking status | 0.13 | ||||||
| Never smoked | 1570 | 74.58 | 624 | 78.69 | 946 | 72.10 | |
| Current smoker | 285 | 13.54 | 71 | 8.95 | 214 | 16.31 | |
| Past Smoker | 246 | 11.69 | 98 | 12.36 | 148 | 11.28 | |
| Alcohol Intake, yes | 273 | 12.98 | 93 | 11.74 | 180 | 13.73 | 0.21 |
| Moderate drinking (1 to 3 days of drinking a week) | 231 | 10.98 | 76 | 9.60 | 155 | 11.82 | 0.30 |
| Heavy drinking (4 to 7 days of drinking a week) | 42 | 2.00 | 17 | 2.15 | 25 | 1.91 | |
| Refractive Error | |||||||
| Myopia | 522 | 24.80 | 186 | 23.46 | 336 | 25.61 | 0.90 |
| Emmetropia | 803 | 38.15 | 287 | 36.19 | 516 | 39.33 | |
| Hyperopia | 741 | 35.20 | 303 | 38.21 | 438 | 33.38 | |
| Cataract Surgery | 238 | 11.33 | 139 | 17.57 | 99 | 7.56 | 0.70 |
| Axial length (mm)¶ | 22.76 | 3.99 | 22.44 | 4.47 | 22.95 | 3.66 | 0.02 |
| Spherical equivalent¶ | −0.07 | 2.06 | 0.11 | 1.76 | −0.18 | 2.21 | 0.51 |
| CFH rs10801555 | |||||||
| Non-carrier | 700 | 33.25 | 300 | 37.83 | 400 | 30.49 | 0.25 |
| Heterozygote | 694 | 32.97 | 281 | 35.44 | 413 | 31.48 | |
| Homozygote | 176 | 8.36 | 65 | 8.20 | 111 | 8.46 | |
| ARMS2 rs3750847 | |||||||
| Non-carrier | 671 | 31.88 | 265 | 33.42 | 406 | 30.95 | 0.38 |
| Heterozygote | 717 | 34.06 | 294 | 37.07 | 423 | 32.24 | |
| Homozygote | 182 | 8.65 | 87 | 10.97 | 95 | 7.24 | |
SD = standard deviation;
†First generation participants are those who are born outside of Singapore (m = 793).
††Second generation participants are those who are born in Singapore, and whose parents are of Indian origins (n = 1312).
*Low economic status defined as participants with primary or lower education only and individual monthly income <$2,000 Singapore dollars. ±P-values is between first and second-generation immigrants. For continuous variables, adjusted t-tests for age were done; while for discrete variables, Logistic/Poisson Regression controlling for age were performed to check whether the two samples were having the same distribution.
¶Ocular values of affected eye. If not affected with AMD, then the right eye is taken. If both eyes are affected, then right eye is taken.