Zhou Guoli, Holzman Claudia, Luo Zhehui, Margerison Claire
Biomedical Research Informatics Core, Clinical & Translational Sciences Institute, Michigan State University, East Lansing, MI, USA.
Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, 909 Fee Road, Room B601, East Lansing, MI 48824, USA.
Eur J Obstet Gynecol Reprod Biol. 2018 Mar;222:64-69. doi: 10.1016/j.ejogrb.2018.01.008. Epub 2018 Jan 9.
Studies find both very low and high serum uric acid (UA) levels are related to oxidative stress and to conditions such as cardiovascular diseases and chronic kidney disease in the general population. Pregnancy studies have focused only on high maternal UA. In present study, we tested whether unusually high and low levels of maternal serum UA are associated with increases in blood pressure (BP) during pregnancy.
The Pregnancy Outcomes and Community Health Study enrolled 3019 pregnant women between their 16th-27th week of pregnancy from 52 clinics in 5 Michigan communities (1998-2004). UA levels were measured in maternal blood collected at enrollment from a sub-cohort of 1223 participants. BP was abstracted from prenatal medical records; these analyses used highest recorded diastolic BP (DBP) and its companion systolic BP (SBP). Mean arterial pressure (MAP) was calculated using the formula of (2 × DBP + SBP)/3. Covariates, including maternal race/ethnicity, age at enrollment, education level, medical insurance status, body mass index before pregnancy, parity, smoking during pregnancy, alcohol use during pregnancy, and gestational week at blood collection, were considered as potential confounding variables. Associations between UA levels and BP were evaluated with linear spline or multiple linear regression models. Models' robustness was examined with bootstrap estimation of variance, sensitivity analysis, and 10-fold cross-validation.
Both DBP and MAP had a J-shaped relationship with maternal UA; the breakpoints (nadirs) were 0.153 and 0.161 mmol/L UA, respectively. For DBP versus UA, adjusted regression coefficient (β) = -95.67 (standard error (SE) = 37.67 and p = 0.01) for the left and adjusted β = 48.95 (SE = 9.56 and p < 0.01) for the right; for MAP versus UA, adjusted β = -58.48 (SE = 31.42 and p = 0.06) for the left and adjusted β = 52.23 (SE = 11.39 and p < 0.01) for the right. Maternal SBP followed a positive linear trend with UA levels (adjusted β = 37.75, SE = 12.93, and p < 0.01). All results were robust.
Extreme high and low maternal serum UA levels may be informative in studying maternal blood pressure during pregnancy.
研究发现，在普通人群中，血清尿酸（UA）水平极低和极高均与氧化应激以及心血管疾病和慢性肾病等病症相关。妊娠研究仅关注孕妇的高尿酸水平。在本研究中，我们测试了孕妇血清尿酸水平异常高和低是否与孕期血压升高有关。
妊娠结局与社区健康研究招募了1998年至2004年期间密歇根州5个社区52家诊所的3019名怀孕16至27周的孕妇。对1223名参与者亚组入组时采集的母血进行尿酸水平测量。从产前病历中提取血压数据；这些分析使用记录的最高舒张压（DBP）及其对应的收缩压（SBP）。平均动脉压（MAP）使用公式（2×DBP + SBP）/3计算。协变量包括孕妇种族/民族、入组年龄、教育水平、医疗保险状况、孕前体重指数、产次、孕期吸烟、孕期饮酒以及采血时的孕周，被视为潜在的混杂变量。使用线性样条或多元线性回归模型评估尿酸水平与血压之间的关联。通过方差的自助估计、敏感性分析和10折交叉验证来检验模型的稳健性。
舒张压和平均动脉压与孕妇尿酸均呈J形关系；转折点（最低点）的尿酸水平分别为0.153和0.161 mmol/L。对于舒张压与尿酸，左侧调整后的回归系数（β）= -95.67（标准误（SE）= 37.67，p = 0.01），右侧调整后的β = 48.95（SE = 9.56，p < 0.01）；对于平均动脉压与尿酸，左侧调整后的β = -58.48（SE = 31.42，p = 0.06），右侧调整后的β = 52.23（SE = 11.39，p < 0.01）。孕妇收缩压随尿酸水平呈正线性趋势（调整后的β = 37.75，SE = 12.93，p < 0.01）。所有结果均具有稳健性。
孕妇血清尿酸水平极高和极低可能对研究孕期孕妇血压具有参考价值。
