Vascular associated gene variants in patients with preeclampsia: results from the Danish National Birth Cohort

Haplotype Analysis of Candidate Genes Involved in Inflammation and Oxidative Stress and the Susceptibility to Preeclampsia

Unbalanced inflammatory reactions and oxidative stress are inseparably interconnected, and both may play crucial roles in the pathophysiological mechanisms of preeclampsia (PE). In the published previous studies, we have genotyped for SNPs that related to inflammation (rs2227485, rs153109, rs17855750, rs2027432, rs2275913, rs763780, rs4819554, and rs13015714) and oxidative stress (rs1695, rs4680, rs1800566, rs4807542, rs713041, rs7579, rs230813, rs1004467, rs3824755, and rs9932581) to investigate whether these polymorphisms were associated with susceptibility to PE in a Chinese Han population. In this present study, we collected these data of experimental and clinical from above studies for haplotype analysis of inflammation-related SNPs in 631 PE patients and 720 normal pregnancy and oxidative stress-related SNPs in 342 PE patients and 457 normal pregnancies for susceptibility to PE. The data of genotype distribution and allele frequency comparisons after correction for multiple comparisons (P/8 or P/10) showed 2 among the 8 candidate inflammation-related SNPs have significant differences (rs2027432 genotype χ² = 407.377, p < 0.001, p < 0.00625). Moreover, the minor alleles of rs2027432 T (minor allele χ² = 450.923, p < 0.001, p < 0.00625; OR = 21.439, 95%CI = 15.181‐30.278) and rs4819554 G (minor allele χ² = 163.465, p < 0.001, p < 0.00625; OR = 5.814, 95%CI = 4.380‐7.719) were confirmed as risk allele of PE, respectively. Our analysis revealed rs2027432 (TT) of NLRP3 and rs4819554 (GG) of IL-17RA are risk factors for PE. However, no significant difference was found at the oxidative stress-related SNPs. In the candidate loci for oxidative stress, we also identified 3 SNP matches (rs4807542 and rs713041, rs230813 and rs75799, rs1004467 and rs3824755) that had high linkage disequilibrium (LD) with each other and were selected as a block (r² = 0.98, r² = 0.97, r² = 0.97, r² > 0.9), and the GT and GC haplotypes of rs4807542 and rs713041 in GPX4 showed significant differences between the PE and control groups (χ² = 5.143, p = 0.0233, p < 0.05; χ² = 6.373, p = 0.0116, p < 0.05). So, we inferred that polymorphisms of NLRP3 rs2027432 and IL-17RA rs4819554, which are related to inflammation, and the rs713041 variant of GPX4, which is related to oxidative stress, were associated with susceptibility to PE. The GT and GC haplotypes of rs4807542 and rs713041 in GPX4 may increase the risk of PE in the Chinese Han population.

Ancient DNA reveals selection acting on genes associated with hypoxia response in pre-Columbian Peruvian Highlanders in the last 8500 years

Archaeological evidence shows that humans began living in the high altitude Andes approximately 12,000 years ago. Andean highlanders are known to have developed the most complex societies of pre-Columbian South America despite challenges to their health and reproductive success resulting from chronic exposure to hypoxia. While the physiological adaptations to this environmental stressor are well studied in contemporary Andean highlanders, the molecular evolutionary processes associated with such adaptations remain unclear. We aim to better understand how humans managed to demographically establish in this harsh environment by addressing a central question: did exposure to hypoxia drive adaptation via natural selection within Andean populations or did an existing phenotype –characterized by reduced susceptibility to hypoxic stress–enable human settlement of the Andes? We genotyped three variable loci within the NOS3 and EGLN1 genes previously associated with adaptation to high altitude in 150 ancient human DNA samples from Peruvian high altitude and coastal low altitude sites in a time frame between ~8500–560 BP. We compare the data of 109 successful samples to forward simulations of genetic drift with natural selection and find that selection, rather than drift, explains the gradual frequency changes observed in the highland populations for two of the three SNPs.

Associations between nitric oxide synthase 3 gene polymorphisms and preeclampsia risk: a meta-analysis

Previous studies have examined the role of three NOS3 gene polymorphisms [G894T, T-786C, and the variable number of tandem repeats 4b/a (VNTR 4b/a)] in the susceptibility to preeclampsia with inconclusive findings. We therefore conducted an updated meta-analysis by including more studies. The most appropriate genetic model was chosen for each polymorphism by using a well-established method. Pooled results indicated that, compared with the GT + GG genotype, the TT genotype of G894T was associated with an increased risk of preeclampsia (odds ratio (OR) = 1.46; 95% confidence interval (CI) = 1.21–1.77, P < 0.001; I² = 40.2%). The CC genotype of T-786C was also associated with a higher risk of preeclampsia (OR = 1.30; 95% CI = 1.07–1.58, P = 0.034; I² = 46.9%) than the CT + TT genotype. No association was found for VNTR 4b/a. Stratified analysis indicated that the increased risk was evident for high-quality studies both for G894T and T-786C, and for studies conducted among Caucasians and Africans for T-786C. However, the increased risk for T-786C among Africans needs further confirmation due to the high probability of false-positive reports. Our results suggested that G894T and T-786C polymorphisms, but not VNTR 4b/a, were associated with an increased risk of preeclampsia.

Incidence of incisional hernia after cesarean delivery: a register-based cohort study

OBJECTIVE

To estimate the incidence of incisional hernias requiring surgical repair after cesarean delivery over a 10-year period.

METHODS

This population- and register-based cohort study identified all women in Denmark with no history of previous abdominal surgery who had a cesarean delivery between 1991 and 2000. The cohort was followed from their first until 10 years after their last cesarean delivery within the inclusion period or until the first of the following events: hernia repair, death, emigration, abdominal surgery, or cesarean delivery after the inclusion period. For women who had a hernia repair, hospital records regarding the surgery and previous cesarean deliveries were tracked and manually analyzed to validate the relationship between hernia repair and cesarean delivery. Data were analyzed with a competing risk analysis that included each cesarean delivery.

RESULTS

We identified 57,564 women who had had 68,271 cesarean deliveries during the inclusion period. During follow-up, 134 of these women had a hernia requiring repair. Of these 68 (51% [95% CI 42-60%]) were in a midline incision although the transverse incision was the primary approach at cesarean delivery during the inclusion period. The cumulated incidence of a hernia repair within 10 years after a cesarean delivery was 0.197% (95% CI 0.164-0.234%). The risk of a hernia repair was higher during the first 3 years after a cesarean delivery, with an incidence after 3 years of 0.157% (95% CI 0.127-0.187%).

CONCLUSIONS

The overall risk of an incisional hernia requiring surgical repair within 10 years after a cesarean delivery was 2 per 1000 deliveries in a population in which the transverse incision was the primary approach at cesarean delivery.