Impact of the common MTHFR 677C→T polymorphism on blood pressure in adulthood and role of riboflavin in modifying the genetic risk of hypertension: evidence from the JINGO project

Table 1 General participant characteristics by MTHFR genotype

	MTHFR genotype^a
	CC (n = 2677)	CT (n = 2660)	TT (n = 739)	P value^b
MTHFR genotype, n (%)	2677 (44)	2660 (44)	739 (12)
Age, years	68.9 (15.1)	69.0 (15.5)	68.6 (15.6)	0.806
Sex, male	943 (35%)	961 (36%)	256 (35%)	0.678
Waist, cm	94.5 (13.9)	94.5 (14.1)	94.7 (14.7)	0.982
Height, cm	162.6 (10.2)	162.9 (10.1)	162.6 (10.0)	0.619
Weight, kg	73.7 (16.5)	73.7 (16.8)	74.2 (17.3)	0.853
Body mass index, kg/m²	27.8 (5.2)	27.7 (5.4)	27.9 (5.2)	0.458
Current smokers, n (%)	359 (13%)	355 (13%)	89 (12%)	0.530
Alcohol Intake, units/week	8.6 (12.2)	8.8 (12.7)	8.0 (11.3)	0.402
Serum triglycerides, mmol/L	1.51 (0.84)	1.56 (0.88)	1.55 (0.78)	0.087
Serum total cholesterol, mmol/L	4.68 (1.03)	4.68 (1.06)	4.73 (1.05)	0.383
Serum HDL, mmol/L	1.51 (0.49)	1.48 (0.45)	1.49 (0.47)	0.439
Calculated LDL, mmol/L	2.50 (0.88)	2.50 (0.89)	2.54 (0.88)	0.472
Serum creatinine, μmol/L	86.3 (27.4)	86.0 (26.4)	85.9 (27.2)	0.928
B-vitamin biomarkers
Red blood cell folate, nmol/L	1095 (579)^a	1088 (626)^a	971 (563)^b	< 0.001
Serum vitamin B12, pmol/L	295 (155)	295 (238)	296 (238)	0.194
Riboflavin status, EGRac^c	1.35 (0.21)	1.35 (0.21)	1.34 (0.21)	0.769
Plasma homocysteine, μmol/L	14.2 (5.4)^a	14.3 (5.4)^a	15.7 (6.8)^b	< 0.001

Data are expressed as mean (standard deviation) or n (%).
^aCC (wild type), CT (heterozygous), TT (homozygous variant), genotypes for the MTHFR 677C→T polymorphism
^bP value from one-way ANOVA comparing genotype groups, following log-transformation of data for normalisation purposes, as appropriate. Different superscript letters (i.e. a, b) within a row indicate significant differences by Bonferroni post hoc test, whilst the same letter (i.e. a, a) indicates no significant differences. Level of significance (P < 0.003) adjusted for Bonferroni correction (n = 16). Categorical variables are assessed using chi-square analysis
^cBiomarker status of riboflavin determined by the functional assay, erythrocyte glutathione reductase activation coefficient (EGRac); higher EGRac values indicate lower riboflavin status

ISSN: 1741-7015