Relationship between serum cystatin C level and pregnancy complications and abnormal glucose tolerance at 6-week postpartum in patients with gestational diabetes mellitus

This study aimed to investigate the relationship between serum cystatin C level and pregnancy complications and abnormal glucose tolerance at 6-week postpartum in patients with gestational diabetes mellitus (GDM).

Clinical data of 298 cases of GDM delivered in Taizhou People’s Hospital from January 2017 to June 2018 were retrospectively analyzed. According to the level of cystatin C before delivery, they were divided into normal group (≤ 1.1 mg/L) and elevated group (> 1.1 mg/L). The general situation, complications of pregnancy, and the incidence of abnormal glucose tolerance at 6 weeks after delivery were compared between the two groups. According to concomitant gestational hypertension in late pregnancy, the patients were divided into group A (GDM with hypertensive disorder complicating pregnancy (HDCP)) and group B (GDM without HDCP). The differences of age, parity, body mass index (BMI) and mean arterial pressure (MAP) in the first trimester of pregnancy, levels of cystatin C, creatinine, urinary microalbumin, and glycosylated hemoglobin in 24-week gestation and before delivering were compared between the two groups.

There was no significant difference in age and parity between the normal group and the elevated group (p > 0.05). The levels of BMI (25.06 ± 3.46 vs 26.34 ± 3.65 kg/m2), creatinine (38.76 ± 16.52 vs 59.75 ± 17.82 mmol/L), and urinary microalbumin (37.11 ± 49.20 vs 61.25 ± 43.52 mg/L) and the incidence of premature delivery (9.35% vs 17.8%), premature rupture of membranes (11.22% vs 20.94%), and abnormal glucose tolerance at 6-week postpartum (18.69% vs 42.93%) in the normal group of cystatin C were significantly lower than that in the elevated group of cystatin C (p < 0.05). There was no significant difference in the incidence of hypertension (8.41% vs 7.85%) and oligohydramnios (33.64% vs 24.61%) between the two groups (p > 0.05). The clinical characteristics of group A (GDM with HDCP) and group B (GDM without HDCP) were compared. The results showed that the levels of age, BMI, and mean arterial pressure (MAP) were significantly different (p < 0.001). The results of binary logistic regression analysis showed that the significance value of MAP was 0.005 after controlling age factors, which indicated that MAP was an independent risk factor of GDM with HDCP, and the OR value of MAP was 1.420 (1.109–1.817).

The increase of cystatin C in patients with GDM does not increase the risk of HDCP, but it does increase the risks of premature delivery, PROM, and abnormal glucose tolerance at 6-week postpartum. Cystatin C is a biological index that may be valuable in predicting the occurrence of these diseases in GDM patients. The independent risk factor of GDM complicating HDCP is MAP.