Association of polymorphisms in FADS gene with age-related changes in serum phospholipid polyunsaturated fatty acids and oxidative stress markers in middle-aged nonobese men

Figures & data

Table 1 Clinical characteristics, PUFA composition in serum phospholipids, and macronutrition intake at baseline and at 3 years

n = 122	Baseline	3-year follow-up	P
Age (years)	46.7 ± 0.58	49.7 ± 0.60	<0.001
Body mass index (kg/m^2)	24.0 ± 0.20	24.1 ± 0.20	0.501
Systolic blood pressure (mmHg)	120.3 ± 1.10	119.6 ± 1.29	0.483
Diastolic blood pressure (mmHg)	74.5 ± 0.88	74.8 ± 1.05	0.679
Fasting glucose (mg/dL)^§	92.1 ± 0.86	93.5 ± 0.85	0.121
Triglyceride (mg/dL)^§	131.3 ± 6.96	133.4 ± 7.61	0.901
Total cholesterol (mg/dL)^§	191.3 ± 3.10	193.3 ± 3.07	0.367
LDL cholesterol (mg/dL)^§	117.0 ± 3.17	121.7 ± 2.85	0.018
HDL cholesterol (mg/dL)^§	49.6 ± 1.15	46.4 ± 1.08	0.001
hs-CRP (mg/dL)^§	1.64 ± 0.42	1.55 ± 0.29	0.601
Serum TNF-α (pg/mL)^§	11.4 ± 1.01	10.4 ± 0.88	0.856
Serum IL-6 (pg/mL)^§	4.58 ± 0.33	3.63 ± 0.26	0.004
Oxidized LDL (U/L)^§	34.8 ± 1.26	44.7 ± 1.15	<0.001
8-epi-PGF2α (pg/mg creatinine)^§	1318.6 ± 46.6	1363.7 ± 45.2	0.323
PUFA composition (%) in serum PL
Total polyunsaturated	19.1 ± 0.38	19.1 ± 0.46	0.983
ω6 FA
18:2 (ω6)	12.0 ± 0.28	11.8 ± 0.32	0.621
18:3 (ω6)	0.17 ± 0.01	0.20 ± 0.01	0.024
20:2 (ω6)	0.67 ± 0.12	0.43 ± 0.08	0.016
20:3 (ω6)	1.44 ± 0.04	1.43 ± 0.05	0.977
20:4 (ω6)	4.36 ± 0.14	4.78 ± 0.19	0.043
Total polyunsaturated	4.66 ± 0.17	5.03 ± 0.20	0.123
ω3 FA
18:3 (ω3)	0.17 ± 0.02	0.19 ± 0.01	0.425
20:3 (ω3)	0.09 ± 0.01	0.07 ± 0.00	0.054
20:5 (ω3)	1.12 ± 0.05	1.26 ± 0.07	0.115
22:5 (ω3)	0.57 ± 0.03	0.58 ± 0.03	0.727
22:6 (ω3)	2.71 ± 0.12	2.93 ± 0.13	0.171
Estimates of daily nutrient intakes
Total energy intake (kcal)	2440.2 ± 19.1	2425.7 ± 15.8	0.399
Carbohydrate (% of energy)	61.5 ± 0.13	61.5 ± 0.08	0.672
Protein (% of energy)	16.8 ± 0.12	16.5 ± 0.07	0.114
Fat (% of energy)	21.6 ± 0.14	21.7 ± 0.11	0.794
Total energy expenditure (kcal)	2361.5 ± 16.7	2333.0 ± 13.7	0.085

Notes:

§ Tested by logarithmic transformation, P-values derived from paired t-test. Values are means ± standard error.

Abbreviations: PUFA, polyunsaturated fatty acid; LDL, low-density lipoprotein; HDL, high-density lipoprotein; hs-CRP, high sensitivity C-reactive protein; TNF, tumor necrosis factor; IL, interleukin; 8-epi-PGF_2α, urinary 8-epi-prostaglandin F_2α.

Table 2 Associations of FEN1 rs174537 genotypes with PUFA composition in serum phospholipids in men at baseline and 3-year follow-up

	FEN1 rs174537
	GG (n = 50)	P^a	T allele (n = 72)	P^a	P^b	P^c
PUFA composition (%) in serum PL
18:2 (ω6)
Baseline	11.9 ± 0.42	0.957	12.1 ± 0.38	0.518	0.685
Follow-up	11.9 ± 0.52		11.8 ± 0.41		0.835
Change	0.03 ± 0.52		−0.34 ± 0.53		0.627	0.753
18:3 (ω6)
Baseline	0.18 ± 0.02	0.303	0.16 ± 0.01	0.031	0.413
Follow-up	0.20 ± 0.01		0.20 ± 0.01		0.584
Change	0.02 ± 0.02		0.03 ± 0.01		0.659	0.652
20:2 (ω6)
Baseline	0.61 ± 0.19	0.158	0.72 ± 0.16	0.030	0.665
Follow-up	0.33 ± 0.03		0.51 ± 0.14		0.287
Change	−0.28 ± 0.19		−0.21 ± 0.09		0.733	0.313
20:3 (ω6)
Baseline	1.53 ± 0.07	0.926	1.37 ± 0.06	0.903	0.081
Follow-up	1.53 ± 0.09		1.36 ± 0.06		0.101
Change	0.01 ± 0.10		−0.01 ± 0.08		0.880	0.184
20:4 (ω6)
Baseline	4.79 ± 0.23	0.022	4.04 ± 0.16	0.587	0.007
Follow-up	5.61 ± 0.30		4.17 ± 0.21		<0.001
Change	0.81 ± 0.34		0.14 ± 0.25		0.108	0.001
18:3 (ω3)
Baseline	0.17 ± 0.03	0.742	0.17 ± 0.03	0.463	0.998
Follow-up	0.19 ± 0.01		0.20 ± 0.02		0.589
Change	0.01 ± 0.03		0.02 ± 0.03		0.760	0.591
20:3 (ω3)
Baseline	0.10 ± 0.02	0.037	0.08 ± 0.01	0.613	0.153
Follow-up	0.07 ± 0.00		0.07 ± 0.00		0.392
Change	−0.04 ± 0.02		−0.01 ± 0.01		0.108	0.408
20:5 (ω3)
Baseline	1.19 ± 0.08	0.090	1.07 ± 0.06	0.787	0.231
Follow-up	1.49 ± 0.14		1.09 ± 0.07		0.010
Change	0.30 ± 0.18		0.02 ± 0.08		0.153	0.004
22:5 (ω3)
Baseline	0.54 ± 0.04	0.044	0.59 ± 0.05	0.213	0.441
Follow-up	0.66 ± 0.04		0.53 ± 0.03		0.016
Change	0.12 ± 0.06		−0.06 ± 0.05		0.019	0.011
22:6 (ω3)
Baseline	2.81 ± 0.20	0.134	2.64 ± 0.15	0.649	0.495
Follow-up	3.20 ± 0.20		2.73 ± 0.16		0.071
Change	0.39 ± 0.26		0.09 ± 0.20		0.354	0.088
20:4 (ω6)/20:3 (ω6)
Baseline	3.26 ± 0.15	0.007	3.33 ± 0.35	0.808	0.882
Follow-up	3.96 ± 0.25		3.24 ± 0.19		0.019
Change	0.70 ± 0.25		−0.09 ± 0.36		0.101	0.017
20:4 (ω6)/18:2 (ω6)
Baseline	0.43 ± 0.03	0.202	0.34 ± 0.01	0.237	0.007
Follow-up	0.53 ± 0.06		0.41 ± 0.05		0.146
Change	0.10 ± 0.07		0.06 ± 0.05		0.719	0.185
20:5 (ω3)/18:3 (ω3)
Baseline	9.55 ± 0.88	0.328	9.06 ± 0.87	0.024	0.694
Follow-up	8.42 ± 0.71		6.69 ± 0.53		0.048
Change	−1.13 ± 1.14		−2.37 ± 1.02		0.426	0.048

Notes:

a Values derived from paired t-test;

b values derived from independent t-test;

c values derived after adjusting for baseline values. Values are means ± standard error.

Abbreviations: PUFA, polyunsaturated fatty acid; PL, phospholipid.

Figure 1 Serum phospholipid AA (20:4 ω6), the ratio of 20:4 ω6/20:3 ω6, and urinary levels of 8-epi-PGF_2α according to FEN1 rs174537 G > T in men at baseline (□) and 3-year follow-up (▪).

Notes:^†P < 0.05; ^††P < 0.01 for baseline vs 3 years, tested by paired t-test; ^‡P < 0.05; ^‡‡P < 0.01; and ^‡‡‡P < 0.001 for GG vs T-allele group, tested by independent t-test; *after adjusting for baseline values. Changes are differences between baseline and 3 years; values are means ± standard error.
Abbreviation: 8-epi-PGF_2α, urinary 8-epi-prostaglandin F_2α.

Table 3 Associations of FEN1 rs174537 genotypes with LDL-cholesterol, hs-CRP, cytokines, and oxidative stress markers in men at baseline and 3-year follow-up

	FEN1rs174537
	GG (n = 50)	P^a	T allele (n = 72)	P^a	P^b	P^c
LDL cholesterol (mg/dL)
Baseline^§	117.8 ± 4.61	0.043	116.5 ± 4.31	0.145	0.830
Follow-up^§	123.3 ± 3.92		120.7 ± 3.99		0.498
Change	5.50 ± 3.11		4.21 ± 3.25		0.785	0.677
hs-CRP (mg/dL)
Baseline^§	1.38 ± 0.35	0.828	1.82 ± 0.67	0.424	0.751
Follow-up^§	1.46 ± 0.35		1.62 ± 0.43		0.603
Change	0.08 ± 0.18		−0.20 ± 0.79		0.769	0.623
Serum IL-6 (pg/mL)
Baseline^§	3.83 ± 0.42	0.557	5.07 ± 0.47	0.001	0.038
Follow-up^§	3.90 ± 0.46		3.44 ± 0.30		0.702
Change	0.07 ± 0.49		−1.63 ± 0.54		0.030	0.307
Serum TNF-α (pg/mL)
Baseline^§	11.7 ± 1.42	0.943	11.2 ± 1.40	0.863	0.467
Follow-up^§	12.0 ± 2.02		9.26 ± 0.55		0.376
Change	0.33 ± 2.27		−1.95 ± 1.40		0.369	0.089
8-epi-PGF2α (pg/mg creatinine)
Baseline^§	1342.7 ± 60.4	0.156	1301.0 ± 67.9	0.995	0.349
Follow-up^§	1531.8 ± 86.7		1240.1 ± 40.1		0.011
Change	189.2 ± 104.5		−60.9 ± 78.2		0.053	<0.001
Oxidized LDL (U/L)
Baseline^§	33.1 ± 1.77	<0.001	36.1 ± 1.76	<0.001	0.292
Follow-up^§	45.2 ± 1.53		44.3 ± 1.64		0.373
Change	12.2 ± 1.83		8.19 ± 1.70		0.119	0.241

Notes:

§ Tested by logarithmic transformation;

a values derived from paired t-test;

b values derived from independent t-test;

c values derived after adjusting for baseline value. Values are means ± standard error.

Abbreviations: PUFA, polyunsaturated fatty acid; LDL, low-density lipoprotein; hs-CRP, high-sensitivity C-reactive protein; TNF, tumor necrosis factor; IL, interleukin; 8-epi-PGF_2α, urinary 8-epi-prostaglandin F_2α.

Table 4 Correlations between 8-epi-PGF_2α and cytokine

	8-epi-PGF2α		IL-6
	r	P	r	P
IL-6	0.242	0.015	–	–
TNF-α	0.246	0.013	0.464	<0.001
hs-CRP	0.085	0.364	0.507	<0.001

Abbreviations: 8-epi-PGF_2α, urinary 8-epi-prostaglandin F_2α ; IL, interleukin; TNF, tumor necrosis factor; hsCRP, high-sensitivity C-reactive protein C-reactive protein.

Figure 2 Relation of changes in serum phospholipid arachidonic acid with changes in oxidized LDL, urinary 8-epi-PGF_2α and serum IL-6 in all male subjects.

Note: Changes are differences between baseline and 3 years.
Abbreviations: 8-epi-PGF_2α, urinary 8-epi-prostaglandin F_2α; LDL, low-density lipoprotein; IL, interleukin.

Table S1 Information for the prescreening of eight single-nucleotide polymorphisms (SNPs) and selection of four SNPs

	FEN1 10154G >T		FADS2 rs174575		FADS3 rs1000778		FADS2 rs2727270		FADS2 rs174576		FADS2 rs174570		FADS2 rs174583		FADS3 rs174456
	D′	r^2	D′	r^2	D′	r^2	D′	r^2	D′	r^2	D′	r^2	D′	r^2	D′	r^2
FEN1 −10154G > T	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
FADS2 rs174575	0.96	0.16	–	–	–	–	–	–	–	–	–	–	–	–	–	–
FADS3 rs1000778	0.21	0.04	0.46	0.04	–	–	–	–	–	–	–	–	–	–	–	–
FADS2 rs2727270	0.98	0.71	1.00	0.03	0.13	0.01	–	–	–	–	–	–	–	–	–	–
FADS2 rs174576	1.00	0.98	1.00	0.17	0.22	0.04	1.00	0.72	–	–	–	–	–	–	–	–
FADS2 rs174570	1.00	0.98	1.00	0.17	0.21	0.04	0.99	0.71	1.00	0.99	–	–	–	–	–	–
FADS2 rs174583	0.99	0.95	0.96	0.16	0.22	0.04	1.00	0.71	0.99	0.98	0.99	0.97	–	–	–	–
FADS3 rs174456	0.21	0.04	0.46	0.04	1.00	1.00	0.01	0.01	0.22	0.04	0.21	0.04	0.22	0.04	–	–

Table S2 Associations of FADS2 rs 2727270 genotypes with polyunsaturated fatty acid (PUFA) composition in serum phospholipids in men at baseline and 3-year follow-up

	FADS2 rs 2727270C>T
	CC (n = 59)	P^a	T allele (n = 63)	P^a	P^b	P^c
PUFA composition (%) in serum PL
18:2 (ω6)
Baseline	12.1 ± 0.38	0.971	12.0 ± 0.42	0.511	0.880
Follow-up	12.1 ± 0.47		11.6 ± 0.45		0.455
Change	0.02 ± 0.48		−0.38 ± 0.58		0.594	0.466
18:3 (ω6)
Baseline	0.18 ± 0.02	0.215	0.16 ± 0.01	0.051	0.452
Follow-up	0.20 ± 0.01		0.20 ± 0.01		0.693
Change	0.02 ± 0.02		0.03 ± 0.02		0.666	0.756
20:2 (ω6)
Baseline	0.59 ± 0.17	0.172	0.75 ± 0.18	0.024	0.508
Follow-up	0.36 ± 0.03		0.51 ± 0.16		0.357
Change	−0.23 ± 0.17		−0.24 ± 0.11		0.946	0.516
20:3 (ω6)
Baseline	1.51 ± 0.06	0.974	1.36 ± 0.06	0.943	0.083
Follow-up	1.52 ± 0.08		1.36 ± 0.07		0.123
Change	0.00 ± 0.09		−0.01 ± 0.09		0.941	0.219
20:4 (ω6)
Baseline	4.73 ± 0.20	0.027	3.99 ± 0.18	0.559	0.008
Follow-up	5.42 ± 0.27		4.16 ± 0.23		0.001
Change	0.69 ± 0.30		0.16 ± 0.28		0.206	0.003
18:3 (ω3)
Baseline	0.17 ± 0.02	0.319	0.18 ± 0.03	0.945	0.912
Follow-up	0.21 ± 0.02		0.18 ± 0.01		0.267
Change	0.04 ± 0.03		0.00 ± 0.03		0.474	0.268
20:3 (ω3)
Baseline	0.10 ± 0.02	0.029	0.08 ± 0.01	0.702	0.276
Follow-up	0.06 ± 0.00		0.07 ± 0.00		0.123
Change	−0.04 ± 0.02		−0.01 ± 0.01		0.138	0.128
20:5 (ω3)
Baseline	1.18 ± 0.07	0.134	1.06 ± 0.07	0.585	0.240
Follow-up	1.41 ± 0.12		1.11 ± 0.07		0.033
Change	0.24 ± 0.16		0.05 ± 0.09		0.293	0.027
22:5 (ω3)
Baseline	0.54 ± 0.03	0.088	0.60 ± 0.05	0.250	0.333
Follow-up	0.63 ± 0.04		0.54 ± 0.04		0.085
Change	0.09 ± 0.05		−0.06 ± 0.05		0.043	0.058
22:6 (ω3)
Baseline	2.74 ± 0.18	0.130	2.69 ± 0.16	0.694	0.819
Follow-up	3.10 ± 0.18		2.77 ± 0.18		0.205
Change	0.36 ± 0.23		0.09 ± 0.22		0.399	0.215
20:4(ω6)/20:3(ω6)
Baseline	3.24 ± 0.13	0.008	3.36 ± 0.39	0.798	0.785
Follow-up	3.84 ± 0.22		3.25 ± 0.21		0.052
Change	0.60 ± 0.22		−0.11 ± 0.41		0.134	0.043
20:4(ω6)/18:2(ω6)
Baseline	0.42 ± 0.03	0.206	0.34 ± 0.02	0.232	0.024
Follow-up	0.50 ± 0.06		0.42 ± 0.06		0.314
Change	0.08 ± 0.06		0.07 ± 0.06		0.921	0.377
20:5(ω3)/18:3(ω3)
Baseline	9.36 ± 0.79	0.148	9.18 ± 0.96	0.060	0.883
Follow-up	7.88 ± 0.64		6.99 ± 0.58		0.306
Change	−1.49 ± 1.01		−2.19 ± 1.14		0.646	0.307

Notes:

a Values derived from paired t-test;

b values derived from independent t-test;

c values derived after adjusting for baseline values. Values are means ± standard error.

Abbreviations: PUFA, polyunsaturated fatty acid; PL, phospholipids

Table S3 Associations of FADS2 rs2727270 genotypes with LDL cholesterol, hs-CRP, cytokines, and oxidative stress markers in men at baseline and 3-year follow-up

	FADS2rs2727270C>T
	CC (n = 59)	P^a	T allele (n ==63)	P^a	P^b	P^c
LDL cholesterol (mg/dL)
Baseline^§	119.3 ± 4.14	0.035	114.9 ± 4.76	0.184	0.447
Follow-up^§	124.5 ± 3.46		119.2 ± 4.47		0.210
Change	5.22 ± 2.98		4.26 ± 3.51		0.837	0.533
hs-CRP (mg/dL)
Baseline^§	1.34 ± 0.30	0.972	1.92 ± 0.77	0.534	0.606
Follow-up^§	1.45 ± 0.30		1.65 ± 0.49		0.947
Change	0.11 ± 0.15		−0.27 ± 0.90		0.691	0.477
Serum IL-6 (pg/mL)
Baseline^§	4.27 ± 0.40	0.199	4.87 ± 0.52	0.006	0.407
Follow-up^§	3.87 ± 0.39		3.39 ± 0.34		0.474
Change	−0.41 ± 0.46		−1.48 ± 0.61		0.168	0.268
Serum TNF-α (pg/mL)
Baseline^§	13.4 ± 1.73	0.765	9.53 ± 1.02	0.603	0.067
Follow-up^§	11.9 ± 1.68		8.87 ± 0.57		0.122
Change	−1.42 ± 2.24		−0.66 ± 1.16		0.761	0.303
8-epi-PGF2α (pg/mg creatinine)
Baseline^§	1313.0 ± 55.5	0.123	1324.3 ± 75.4	0.809	0.736
Follow-up^§	1484.1 ± 76.2		1243.3 ± 43.9		0.022
Change	171.1 ± 93.2		−80.9 ± 85.1		0.048	0.003
Oxidized LDL (U/L)
Baseline^§	34.0 ± 1.61	<0.001	35.7 ± 1.96	<0.001	0.663
Follow-up^§	45.9 ± 1.49		43.4 ± 1.74		0.147
Change	11.9 ± 1.65		7.76 ± 1.87		0.097	0.092

Notes:

§ Tested by logarithmic transformation;

a values derived from paired t-test;

b values derived from independent t-test;

c values derived after adjusting for baseline values. Values are means ± standard error.

Abbreviations: LDL, low-density lipoprotein; hs-CRP, high-sensitivity C-reactive protein; TNF, tumor necrosis factor; IL, interleukin; 8-epi-PGF_2α, urinary 8-epi-prostaglandin F_2α.