Association of FADS2 polymorphism rs174538 with fatty acid metabolism and disease severity in Japanese patients with Crohn’s disease

Table 1 Clinical data for study subjects, n (%)

Variable	Value
Age, years, median (min-max)	33.4 ± 13.2 (18-73)
Female	15 (28.8)
BMI, median (min-max)	21.0 (14.9-31.6)
Disease location
Ileum-colon type	36 (69.2)
Ileum type	9 (17.3)
Colon type	7 (13.5)
Disease duration, year
< 1	13 (25.0)
1-3	11 (21.2)
> 3	28 (53.8)
Medications, n
TNF-α inhibitor	30 (IFX: 17, ADA: 13)
Azathioprine	17
Aminosalicylate	51
Corticosteroids	1
CDAI, median ± SD	114.9 ± 90.6
Surgery	15 (28.8)
Endoscopic activity
Remission	10 (19.2)
Mild	13 (25.0)
Moderate	18 (34.6)
Severe	3 (5.8)
ND	8 (15.4)

BMI: Body mass index; TNF: Tumor necrosis factor; IFX: Infliximab; ADA: Adalimumab; CDAI: Crohn’s disease activity index; ND: No data.

Table 2 Serum and erythrocyte membrane fatty acid composition in Crohn’s disease patients, n = 52

Plasma	median ± SD	RBC	median ± SD
SFA (%)		SFA (%)
C16:0 PA	24.4 ± 2.05	C16:0 PA	23.1 ± 1.94
C18:0 SA	6.97 ± 0.83	C18:0 SA	17.3 ± 0.86
C20:0 AdA	0.27 ± 0.05	C20:0 AdA	0.42 ± 0.05
C24:0 LgA	0.52 ± 0.14	C24:0 LgA	5.89 ± 0.53
n-9 (%)		n-9 (%)
C16:1 PtA	2.82 ± 1.61	C16:1 PtA	0.32 ± 0.17
C18:1 OA	23.3 ± 4.05	C18:1 OA	12.4 ± 1.07
C20:1 EA	0.15 ± 0.05	C20:1 EA	0.21 ± 0.04
C22:1 EcA	0.02 ± 0.03	C22:1 EcA	0.09 ± 0.02
C24:1 NA	1.33 ± 0.40	C24:1 NA	6.25 ± 0.57
n-3 (%)		n-3 (%)
C18:3 ALA	0.79 ± 0.82	C18:3 ALA	0.09 ± 0.06
C20:5 EPA	1.71 ± 1.69	C20:5 EPA	1.08 ± 0.97
C22:5 DPA	0.60 ± 0.29	C22:5 DPA	1.82 ± 0.56
C22:6 DHA	3.74 ± 1.53	C22:6 DHA	6.31 ± 2.02
n-6 (%)		n-6 (%)
C18:2 LA	22.9 ± 6.81	C18:2 LA	6.86 ± 1.54
C20:2 EDA	0.20 ± 0.04	C20:2 EDA	0.22 ± 0.04
C18:3 GLA	0.46 ± 0.43	C18:3 GLA	0.55 ± 0.03
C20:3 DGLA	1.33 ± 0.43	C20:3 DGLA	1.39 ± 0.29
C20:4 AA	6.54 ± 1.75	C20:4 AA	12.0 ± 1.67
C22:4 DTA	0.21 ± 0.09	C22:4 DTA	2.05 ± 0.61
d5di: AA/DGLA	5.26 ± 1.78	d5di: AA/DGLA	8.95 ± 1.88
rd.d6di: GLA/LA	0.03 ± 0.05	rd.d6di: GLA/LA	0.01 ± 0.01

%: Percentage weight of each fatty acid. AA: Arachidonic acid; AdA: Arachidic acid; ALA: Α-linolenic acid; rd.d6di: Redefined δ6 desaturase index; d5di: Δ5 desaturase index; DGLA: Dihomo-γ-linolenic acid; DHA: Docosahexaenoic acid; DPA: Docosapentaenoic acid; DTA: Docosatetraenoic acid; EcA: Erucic acid; EDA: Eicosadienoic acid; EPA: Eicosapentaenoic acid; GLA: γ-linolenic acid; LA: Linoleic acid; LgA: Lignoceric acid; MA: Myristic acid; NA: Nervonic acid; OA: Oleic acid; PA: Palmitic acid; PtA: Palmitoleic acid; SA: Stearic acid; SFA: Saturated fatty acid.

Table 3 Serological data for Crohn’s disease patients with wild-type or mutant allele

rs174538 in FADS2 gene	Wild-type (GG)	With mutant allele (GA or AA)	P value	Mean difference (95%CI)
Hemoglobin, g/dL	13.1	13.4	0.535	-1.3002 to 0.6833
Leukocytes, count/μL	5547	6203	0.206	-1684.2 to 372.83
CRP, g/dL	0.51	0.84	0.231	-0.8884 to 0.2202
ESR	20.1	22.1	0.707	-12.693 to 8.669
CDAI	115.2	114.6	0.983	-52.381 to 53.511

CDAI: Crohn’s disease activity index; CRP: C-reactive protein; ESR: Equivalent series resistance.