Table 2. Serum/plasma concentrations of homocysteine, folate, PLP, vitamin B12 and BMI, by quartiles of blood Pb in Pakistani adults.

	Blood Pb
Characteristics*	Q1 (n = 218)	Q2 (n = 218)	Q3 (n = 218)	Q4 (n = 218)	p value**
Homocysteine, µmol/L	13.3 (9.7)/11.1(8.6–14.3)	14.6 (7.5)/12.7 (9.9–16.7)	15.2 (9.1)/12.5 (9.9–17.0)	16.1 (11.2)/13.1 (10.3–17.8)	0.017
Folate, ng/mL	6.9 (4.8)/5.6 (3.3–9.1)	6.8 (4.4)/5.9 (3.7–8.8)	6.3 (4.4)/5.0 (3.2–8.0)	6.4 (4.3)/5.3 (3.3–8.6)	0.3
PLP, nmol/L	34.9 (33)/28.6 (16.4–41.0)	32.2 (30.6)/25.1 (18.0–37.1)	31.9 (29.9)/26.5 (18.0–35.6)	33.4 (36.5)/25.6 (17.4–35.0)	0.7
Vitamin-B12, pg/mL	442 (230)/397 (300–532)	424 (223)/400 (270–540)	434 (232)/385 (280–532)	462 (231)/430 (313–565)	0.3
BMI, kg/m2	25.6 (5.8)/25.3 (21.1–29.1)	24.6 (5.3)/23.9 (20.5–28.1)	24 (5.5)/22.8 (20.0–28.1)	23.4 (5.9)/22.5 (19.1–26.8)	0.001

*Values are expressed as mean (SD)/median (IQR).

**p value is obtained by comparing mean (SD) values in four blood Pb quartiles by using one way ANOVA followed by Bonferroni test.

BMI = body mass index.

PLP = pyridoxal phosphate.