Table 1.
Distribution of potential confounders among men with and without vasectomy.
| Total (N = 2425) |
With vasectomy (N = 485) | Without vasectomy (N = 1940) | P value | |
|---|---|---|---|---|
| Age and anthropometric measures | ||||
| Age (years) | 58.3 ± 8.5 | 58.4 ± 8.5 | 58.3 ± 8.4 | 0.85 |
| Height (cm) | 164.2 ± 6.7 | 162.9 ± 6.7 | 164.6 ± 6.7 | <0.001 |
| Weight (kg) | 64.7 ± 11.3 | 63.9 ± 11.6 | 64.9 ± 10.9 | 0.07 |
| BMI (kg/m2) | 23.9 ± 3.4 | 23.97 ± 3.63 | 23.9 ± 3.6 | 0.77 |
| AC (cm) | 85.4 ± 11.4 | 85.1 ± 11.4 | 85.4 ± 11.4 | 0.51 |
| Smoking status - no./total (total no. (%)) | 0.72 | |||
| Never smoked | 795 (32.8) | 147 (30.6) | 648 (33.4) | |
| Former smoker | 301 (12.4) | 56 (11.5) | 245 (12.6) | |
| Current smoker | 1329 (54.8) | 281 (57.9) | 1048 (54.0) | |
| Alcohol intake (total no. (%)) | 0.72 | |||
| None | 717 (29.6) | 132 (27.2) | 585 (30.2) | |
| 1–4 days/wk | 1348 (55.6) | 267 (55.1) | 1081 (55.7) | |
| ≥5 days/wk | 360 (14.8) | 86 (17.7) | 274 (14.1) | |
| Education (total no. (%)) | 0.92 | |||
| 0–9 years | 1006 (41.4) | 214 (44.1) | 792 (40.8) | |
| >10 years | 1419 (58.6) | 271 (55.9) | 1148 (59.2) | |
| Residence no./total (total no. (%)) | <0.001 | |||
| township | 754 (31.1) | 101 (20.8) | 653 (33.7) | |
| village | 1671 (68.9) | 384 (79.1) | 1287 (66.3) | |
| Married | 2239 (92.3) | 455 (93.8) | 1784 (91.9) | 0.17 |
| Health status | ||||
| AMS | 30.62 ± 9.74 | 31.27 ± 10.16 | 30.45 ± 9.63 | 0.58 |
| SF-36 score | 539.96 ± 132.00 | 524.17 ± 133.02 | 543.90 ± 131.48 | 0.45 |
| IPSS | 6.50 ± 7.68 | 6.92 ± 7.46 | 6.40 ± 7.73 | 0.79 |
| Score on Beck Depression Inventory | 3.51 ± 4.83 | 3.93 ± 5.39 | 3.41 ± 4.67 | 0.01 |
| Hormone levels | ||||
| TT (nmol/l) | 16.16 ± 5.59 | 16.36 ± 6.01 | 16.11 ± 5.36 | 0.02 |
| LH (U/l) | 6.46 ± 4.76 | 6.78 ± 5.31 | 6.38 ± 4.57 | 0.07 |
| SHBG (nmol/l) | 49.86 ± 24.36 | 50.27 ± 24.99 | 49.74 ± 24.2 | 0.31 |
| cFT (nmol/l) | 0.26 ± 0.09 | 0.27 ± 0.12 | 0.26 ± 0.08 | 0.67 |
| FTI | 0.37 ± 0.15 | 0.37 ± 0.15 | 0.37 ± 0.15 | 0.56 |
| TSI | 3.30 ± 1.94 | 3.27 ± 1.95 | 3.3 ± 1.93 | 0.47 |
| fPSA (mmol/l) | 0.29 ± 0.52 | 0.38 ± 1.09 | 0.27 ± 0.25 | <0.01 |
| Glucose (mmol/l) | 5.22 ± 1.47 | 4.98 ± 1.36 | 5.27 ± 1.49 | 0.49 |
| Cholesterol (mmol/l) | 5.38 ± 1.15 | 5.28 ± 1.14 | 5.37 ± 1.19 | 0.09 |
| Triglyceride (mmol/l) | 1.70 ± 1.75 | 1.89 ± 2.05 | 1.82 ± 1.8 | 0.01 |
| HDL (mmol/l) | 1.56 ± 0.53 | 1.64 ± 0.5 | 1.66 ± 0.52 | 0.80 |
| Total protein (mmol/l) | 80.94 ± 7.49 | 79.32 ± 6.3 | 81.24 ± 7.66 | <0.01 |
BMI = body mass index; AC: abdomen circumference; AMS: aging males’ symptoms; TT = total testosterone; LH = luteinizing hormone; SHBG = sex hormone-binding globulin; cfT = calculated free testosterone; FTI = free testosterone index; TSI = testosterone secreting index; fPSA: free prostate specific antigen; HDL = high-density lipoprotein cholesterol; Statistical significance is set at p < 0.05.