Background
Methods
Study participants and blood collection
Measurement of FlOPs
Assay procedure
Assay stability in blood samples with delayed processing
Assay between- and within- person reproducibility
ED Ascertainment
Statistical analyses
Results
Baseline characteristics according to plasma FlOP levels
Variables | FlOP_360 | FlOP_320 | FlOP_400 | ||||||
---|---|---|---|---|---|---|---|---|---|
Tertile | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 |
Range (FI/ml) | < 184 | ≥ 184; < 233 | ≥ 233 | < 356 | ≥ 356; < 524 | ≥ 524 | < 49.1 | ≥ 49.1; < 62.6 | ≥ 62.6 |
N | 305 | 306 | 306 | 305 | 306 | 306 | 305 | 306 | 306 |
Age (years) |
61.1
|
61.9
|
62.3
|
60.4
|
62.2
|
62.6
|
60.7
|
62.3
|
62.2
|
Body mass index (kg/m2) | 25.8 | 25.8 | 25.7 | 25.5 | 25.9 | 25.9 |
25.4
|
25.9
|
26.0
|
Alcohol intake (g/day)a |
2.9
|
8.2
|
10.0
|
3.5
|
8.8
|
8.6
|
2.4
|
8.2
|
10.4
|
Physical activity (MET-hours/week)a | 26.0 | 33.6 | 29.1 | 27.9 | 34.2 | 26.5 | 28.3 | 29.8 | 28.1 |
Caucasians (%) | 92 | 92 | 95 | 91 | 95 | 93 | 93 | 91 | 95 |
Fasting status (≥ 8 h; %) |
76.4
|
56.2
|
50.3
|
75.7
|
56.5
|
50.7
|
71.2
|
59.5
|
52.3
|
History of BPH with surgery (%) | 1.6 | 3.6 | 3.3 | 1.3 | 3.3 | 3.9 | 2.0 | 3.6 | 2.9 |
History of hypertension (%) |
23.3
|
23.9
|
31.4
| 20.3 | 30.4 | 27.8 | 21.3 | 31.1 | 26.1 |
History of diabetes (%) | 3.6 | 2.6 | 2.9 | 2.6 | 3.3 | 3.3 | 2.3 | 3.9 | 2.9 |
Current smokers (%) |
1.1
|
6.7
|
13.0
|
1.1
|
9.6
|
9.4
|
1.1
|
4.2
|
16.5
|
Past smokers (%) |
37.8
|
49.8
|
60.8
|
38.6
|
55.4
|
54.4
|
35.1
|
50.9
|
62.7
|
Association between plasma FlOPs and ED
Tertile | 1 | 2 | 3 | P for trend |
---|---|---|---|---|
Variables | FlOP_360 | |||
Range (FI/ml) | < 184 | ≥ 184; < 233 | ≥ 233 | --- |
N | 305 | 306 | 306 | --- |
Median (FI/ml) | 160 | 207 | 280 | --- |
Erectile dysfunction incidence (n, %) | 100 (33 %) | 112 (37 %) | 111 (36 %) | --- |
Age adjusted | 1 (ref) | 1.13 (0.79, 1.61) | 1.07 (0.75, 1.52) | 0.84 |
Multivariable adjusteda | 1 (ref) | 1.03 (0.71, 1.51) | 0.90 (0.61, 1.34) | 0.54 |
FlOP_320 | ||||
Range (FI/ml) | < 356 | ≥ 356; < 524 | ≥ 524 | --- |
N | 305 | 306 | 306 | --- |
Median (FI/ml) | 302 | 410 | 1837 | --- |
Erectile dysfunction incidence (n, %) | 102 (33 %) | 114 (37 %) | 107 (35 %) | --- |
Age adjusted | 1 (ref) | 1.00 (0.70, 1.42) | 0.86 (0.60, 1.23) | 0.30 |
Multivariable adjusteda | 1 (ref) | 0.75 (0.51, 1.11) | 0.73 (0.49, 1.07) | 0.27 |
FlOP_400 | ||||
Range (FI/ml) | < 49.1 | ≥ 49.1; < 62.6 | ≥ 62.6 | --- |
N | 305 | 306 | 306 | --- |
Median (FI/ml) | 44.0 | 55.1 | 72.6 | --- |
Erectile dysfunction incidence (n, %) | 100 (33 %) | 99 (32 %) | 124 (41 %) | --- |
Age adjusted | 1 (ref) | 0.82 (0.57, 1.17) | 1.24 (0.87, 1.77) | 0.14 |
Multivariable adjusteda | 1 (ref) | 0.67 (0.45, 0.99) | 0.98 (0.66, 1.45) | 0.72 |
Tertile | 1 | 2 | 3 | P for trend |
---|---|---|---|---|
Variables | FlOP_360 | |||
Range (FI/ml) | < 184 | ≥ 184; < 233 | ≥ 233 | --- |
N | 164 | 144 | 152 | --- |
Median (FI/ml) | 159 | 206 | 279 | --- |
Erectile dysfunction incidence (n, %) | 55 (34 %) | 51 (35 %) | 51 (32 %) | --- |
Age adjusted | 1 (ref) | 1.06 (0.64, 1.75) | 0.90 (0.54, 1.48) | 0.59 |
Multivariable adjusteda | 1 (ref) | 1.02 (0.58, 1.79) | 0.83 (0.47, 1.47) | 0.46 |
FlOP_320 | ||||
Range (FI/ml) | < 356 | ≥ 356; < 524 | ≥ 524 | --- |
N | 160 | 142 | 158 | --- |
Median (FI/ml) | 297 | 411 | 1858 | --- |
Erectile dysfunction incidence (n, %) | 52 (33 %) | 53 (37 %) | 52 (33 %) | --- |
Age adjusted | 1 (ref) | 0.96 (0.57, 1.60) | 0.73 (0.44, 1.22) | 0.17 |
Multivariable adjusteda | 1 (ref) | 0.75 (0.42, 1.35) | 0.55 (0.31, 0.99) | 0.10 |
FlOP_400 | ||||
Range (FI/ml) | < 49.1 | ≥ 49.1; < 62.6 | ≥ 62.6 | --- |
N | 150 | 160 | 150 | --- |
Median (FI/ml) | 43.4 | 54.9 | 73.3 | --- |
Erectile dysfunction incidence (n, %) | 50 (33 %) | 48 (31 %) | 59 (39 %) | --- |
Age adjusted | 1 (ref) | 0.77 (0.46, 1.28) | 1.23 (0.74, 2.03) | 0.29 |
Multivariable adjusteda | 1 (ref) | 0.72 (0.41, 1.28) | 1.07 (0.60, 1.88) | 0.68 |