The anti-aging factor α-klotho during human pregnancy and its expression in pregnancies complicated by small-for-gestational-age neonates and/or preeclampsia

Figures & data

Table 1. Demographic and clinical characteristics of the study population.

Characteristic	Non-pregnant women (n = 37)	Uncomplicated pregnancy (n = 130)	Preeclampsia without SGA newborns (n = 58)	Preeclampsia with SGA newborns (n = 52)	Pregnancies with SGA newborns (n = 52)	p Value
Age (years)	26 (24–31)	25 (21–29)	24 (19–30)	23 (19–28)	24 (20–29)	0.05
Race						0.52
Black	21 (56.8%)	102 (78.5%)	46 (79.3%)	45 (86.5%)	45 (86.5)
White	11 (29.7%)	15 (11.5%)	6 (10.3%)	6 (11.5%)	4 (7.7%)
Hispanic	1 (2.7%)	7 (5.4%)	4 (6.9%)	1 (1.9%)	1 (1.9%)
Other	4 (11.1%)	6 (4.6%)	2 (3.4%)	0	2 (3.8%)
Nulliparity	22 (59.5%)	35 (26.9%)	38 (65.5%)	29 (55.8%)	26 (50%)	<0.0001
Smoking	3 (10.7%)	22 (17.1%)	7(12.1%)	8 (15.4%)	16 (30.8%)	0.73
GA at venipuncture (weeks)	NA	38 (31.4–39.1)	35.1 (30.1–38.7)	36 (32.4–38.5)	36.9 (32.7–38.4)	0.43
GA at delivery (weeks)	NA	39.3 (38.7–40.3)	35.8 (31.1–38.7)	36 (30.7–38.6)	37.2 (33.6–38.5)	<0.0001
Birth weight (grams)	NA	3352 (3120–3630)	2620 (1740–3180)	1860 (1450–2502)	2060 (1510–2380)	<0.0001

GA, gestational age; SGA, small for gestational age.

Values are expressed as number (percentage) or median (interquartile range). Comparisons among groups were performed using the Kruskal–Wallis test for continuous variables and the Chi-square test for categorical variables. A p value <0.05 was considered statistically significant. Missing data were: Race, n = 1; Smoking, n = 1.

Figure 1. Plasma concentration of α-klotho in non-pregnant women and in women with an uncomplicated pregnancy. Women with an uncomplicated pregnancy had a higher median plasma concentration of α-klotho than non-pregnant women [1206 pg/ml IQR: (894–2012) versus 930 pg/ml IQR: (660–1258); p = 0.004].

Figure 2. Plasma concentration of α-klotho in patients with uncomplicated pregnancy, SGA, and preeclampsia, with and without SGA. Women with PE and SGA [947.6 pg/ml IQR: (762–2013)] and those with SGA without PE [1000.6 pg/ml IQR: (585–1567)] had a lower median plasma concentration of α-klotho than uncomplicated pregnancies [1206 pg/ml IQR: (894–2012)]; p = 0.02 and p = 0.005, respectively). However, there was no significant difference in the median concentration of α-klotho between patients with PE without an SGA neonate [1177.3 pg/ml IQR: (762.4–2013.4)] and women with uncomplicated pregnancies (p = 0.47).

Table 2. Median (IQR) plasma α-klotho concentration (pg/ml) in pregnancies with an SGA neonate, according to the results of uterine and umbilical artery Doppler velocimetry.

		Uterine Artery Doppler Velocimetry				Umbilical Artery Doppler Velocimetry
Category	n	Normal	Abnormal	p value	n	Normal	Abnormal	p value
SGA alone	42	1267 (554–1830)	932 (583–1307)	0.39	43	1256 (815–1939)	730.6 (564–906)	0.008*
Preeclampsia + SGA	37	980 (686–1782)	953 (650–1525)	0.65	39	1065 (680–1685)	974 (621–1088)	0.34
Total	79	1156 (612–1830)	943 (635–1450)	0.31	82	1162 (685–1703)	810 (587–1056)	0.006*

Uterine artery (UT) Doppler velocimetry was defined as abnormal if the mean RI was >95th percentile for gestational age.

Umbilical artery (UA) Doppler velocimetry was defined as abnormal if either the PI > 95th percentile for gestational age or if absent or reversed end-diastolic velocity was present.

*p < 0.05.