The effect of environmental exposure to pyrethroids and DNA damage in human sperm

Figures & data

Table 1. Characteristics of the study population.

Characteristics	N (%)
Education
Primary and vocational	55 (19.23)
Secondary	109 (38.11)
Higher	122 (42.66)
Smoking determined by cotinine level
No	210 (73.43)
Yes	76 (26.57)
BMI (kg/m^2)
<25	91 (31.82)
≥25	195 (68.18)
Mean (SD)	27.2 ± 3.7
Median (min–max)	27.3 (18.3–39.5)
Duration of couple’s infertility (years)
1--2	112 (39.16)
2--3	97 (33.92)
4--5	39 (13.63)
>5	38 (13.29)
Past diseases, which may have impact on semen quality*
No	248 (86.71)
Yes	38 (13.29)
Abstinence [days]
<3	14 (4.90)
3--7	212 (74.13)
>7	17 (5.94)
Missing data	43 (15.03)
Mean (SD)	5.0 ± 2.3
Median (min–max)	5.0 (0.0–20.0)
Age (years)
Mean (SD)	32.22 (4.45)
Median (min–max)	31.70 (22.01–44.26)
Alcohol use
None or <1 drink/week	94 (32.87)
1–3 drinks/week	146 (51.05)
Everyday	46 (16.08)

BMI: body mass index; *Past diseases which may have impact on semen quality - mumps, cryptorchidism, testes surgery, testes trauma

Table 2. Sperm DNA damage and sperm quality among study participants.

	Percentage distribution of sperm characteristics
Sperm quality	25%	50%	75%	95%	Max	Mean	SD
Main semen parameters:
Concentration (mln/ml)	22.5	33.6	85.77	125	360.0	53.6	52.4	286
Motility (%)	46	54.0	66	83	99.0	57.4	19.8	286
Sperm with abnormal morphology [%]	31.22	46.0	69.51	75.25	96.0	47.2	19.7	286
Chromatin:
DFI (%)	8.39	13.3	19.82	35.66	71.2	16.2	11.0	286
M DFI (%)	4.23	6.5	9.56	21.13	60.5	8.5	7.5	286
H DFI (%)	3.46	6.0	10.16	19.73	44.5	7.9	6.6	286
HDS (%)	5.98	8.3	10.90	16.94	30.7	8.8	4.3	286

DFI: DNA fragmentation index; M DFI: medium DNA fragmentation index; H DFI: high DNA fragmentation index; HDS: high DNA stainability index

Table 3. Pyrethroid metabolite levels in urine.

	Percentage distribution of pyrethroid metabolities
Pyrethroid metabolite	25%	50%	75%	95%	Max	Mean ± SD	Geometric mean	N
Unadjusted (µg/l)
CDCCA	0.05	0.12	0.16	0.46	3.27	0.25 ± 0.28	0.12	286
TDCCA	0.05	0.14	0.23	0.60	9.86	0.33 ± 0.15	0.16	286
3PBA	0.05	0.16	0.23	0.51	4.24	0.30 ± 0.16	0.17	286
DBCA	0.05	0.05	0.05	0.26	3.43	0.31 ± 0.51	0.05	286
∑pyrethroids	0.11	0.32	0.88	4.76	22.33	0.22 ± 0.29	0.51	286
CR-adjusted (µg/g creatinine)
CDCCA	0.03	0.11	0.14	0.42	3.18	0.22 ± 0.24	0.11	286
TDCCA	0.03	0.14	0.20	0.56	9.83	0.35 ± 0.11	0.15	286
3PBA	0.05	0.13	0.19	0.46	4.23	0.29 ± 0.11	0.16	286
DBCA	0.03	0.03	0.04	0.24	3.37	0.28 ± 0.49	0.04	286
∑pyrethroids	0.10	0.30	0.85	4.72	22.23	0.20 ± 0.27	0.50	286

SD: standard deviation; n-number of participants; CDCCA: cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid; TDCCA: trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid; 3PBA: 3-phenoxybenzoic acid; DBCA: cis-2,2-dibromovinyl-2,2-dimethylcyclopropane-1- carboxylic acid; ∑pyrethroids: CDCCA + TDCCA + DBCA + 3PBA

Table 4. Pyrethroids metabolites concentration in urine and sperm DNA damage measures.

	CDCCA			TDCCA			3PBA				DBCA			∑pyrethroids
	coef	95%CI	p	coef	95%CI	p	coef	95%CI	p		coef	95%CI	p	coef	95%CI	p
DFI
≤50th	−0.05	−0.14–0.24	0.59	−0.07	−0.12–0.26	0.47	−0.07	−0.27–0.12	0.47	≤LOD	−0.07	−0.13–0.27	0.51	−0.02	−0.05–0.22	0.21
>50th	−0.05	−0.15–0.24	0.63	−0.06	−0.13–0.26	0.53	−0.09	−0.29–0.12	0.41	>LOD	−0.08	−0.13–0.28	0.47	−0.01	−0.05–0.13	0.25
M DFI
≤50th	0.03	−0.15–0.22	0.72	0.14	−0.01–0.35	0.07	0.02	−0.17–0.21	0.84	≤LOD	0.11	−0.09–0.31	0.28	0.06	−0.10–0.18	0.44
>50th	1.10	1.04–1.21	0.04	0.17	−0.01–0.36	0.07	0.13	−0.20–0.20	0.85	>LOD	0.13	−0.07–0.33	0.22	0.13	0.01–1.22	0.13
H DFI
≤50th	0.10	−0.14–0.34	0.40	0.07	−0.31–0.18	0.60	0.09	−0.34–1.16	0.48	≤LOD	0.03	−0.29–0.22	0.81	0.08	−0.08–1.09	0.42
>50th	0.11	−0.14–0.35	0.40	0.08	−0.33–0.17	0.52	1.07	1.04–1.52	0.03	>LOD	0.05	−0.31–0.22	0.73	0.15	0.01–0.32	0.22
HDS
≤50th	0.11	−0.25–0.13	0.13	0.02	−0.12–0.16	0.76	0.04	−0.15–0.15	0.85	≤LOD	0.04	−0.19–0.11	0.62	0.02	−0.09–0.08	0.77
>50th	1.09	1.04–1.55	0.04	0.02	−0.12–0.16	0.77	1.05	−022–1.14	0.22	>LOD	0.05	−0.20–0.10	0.53	0.03	−0.09–0.08	0.76

Statistically significant at the level 0.05; coef: β coefficient; multivariate model adjusted for: sexual abstinence, age, smoking, alcohol consumption, and past diseases; CDCCA: cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid; TDCCA: trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid; 3PBA: 3-phenoxybenzoic acid; DBCA: cis-2,2-dibromovinyl-2,2-dimethylcyclopropane-carboxylic acid; DFI: DNA fragmentation index; M DFI: medium DNA fragmentation index; H DFI: high DNA fragmentation index; HDS: high DNA stainability index; ∑pyrethroids: CDCCA + TDCCA + DBCA + 3PBA

Bold values-statistically significant values