Table 1. Characteristics of the study population.
| Variable | Total | Birth season | |||
|---|---|---|---|---|---|
| Spring | Summer | Autumn | Winter | ||
| Number of patients | 858 | 257 | 189 | 208 | 204 |
| Age (y) | 61.6±10.6 | 61.6±10.4 | 60.5±10.0 | 62.2±11.0 | 62.2±11.1 |
| Digit ratio | 0.947±0.039 | 0.950±0.038a | 0.951±0.040c | 0.947±0.038 | 0.941±0.040a,c |
| PV (mL) | 36.2±19.2 | 36.1±19.6 | 33.4±14.9b,c | 36.9±20.4b | 38.2±20.7c |
| PSA (ng/mL) | 4.24±11.69 | 4.53±12.53 | 4.59±15.54 | 3.87±8.01 | 3.94±9.44 |
| PSAD (ng/mL/mL) | 0.107±0.305 | 0.110±0.283 | 0.129±0.473 | 0.093±0.172 | 0.096±0.234 |
| Biopsy (%) | 20.6 (177/858) | 21.0 (54/257) | 17.5 (33/189) | 19.7 (41/208) | 24.0 (49/204) |
| Cancer (%) | 7.8 (67/858) | 6.2 (16/257) | 5.3c (10/189) | 8.7 (18/208) | 11.3c (23/204) |
| Detection (%) | 37.9 (67/177) | 29.6 (16/54) | 30.3 (10/33) | 43.9 (18/41) | 46.9 (23/49) |
Values are presented as number only or mean±standard deviation.
PV, prostate volume; PSA, prostate-specific antigen; PSAD, PSA density.
a:p-value <0.05 for spring vs. winter. b:p-value <0.05 for summer vs. autumn. c:p-value <0.05 for summer vs. winter.
According to the definition of the solar season, the birth seasons were set as follows. Spring: February, March, and April; summer: May, June, and July; autumn: August, September, and October; and winter: November, December, and January.
Student’s t-test was used.