Risk of miscarriage in women with chronic diseases in Norway: A registry linkage study

BackgroundIncreased risk of miscarriage has been reported for women with specific chronic health conditions. A broader investigation of chronic diseases and miscarriage risk may uncover patterns across categories of illness. The objective of this study was to study the risk of miscarriage according to various preexisting chronic diseases.Methods and findingsWe conducted a registry-based study. Registered pregnancies (n = 593,009) in Norway between 2010 and 2016 were identified through 3 national health registries (birth register, general practitioner data, and patient registries). Six broad categories of illness were identified, comprising 25 chronic diseases defined by diagnostic codes used in general practitioner and patient registries. We required that the diseases were diagnosed before the pregnancy of interest. Miscarriage risk according to underlying chronic diseases was estimated as odds ratios (ORs) using generalized estimating equations adjusting for woman’s age. The mean age of women at the start of pregnancy was 29.7 years (SD 5.6 years). We observed an increased risk of miscarriage among women with cardiometabolic diseases (OR 1.25, 95% CI 1.20 to 1.31; p-value <0.001). Within this category, risks were elevated for all conditions: atherosclerosis (2.22; 1.42 to 3.49; p-value <0.001), hypertensive disorders (1.19; 1.13 to 1.26; p-value <0.001), and type 2 diabetes (1.38; 1.26 to 1.51; p-value <0.001). Among other categories of disease, risks were elevated for hypoparathyroidism (2.58; 1.35 to 4.92; p-value 0.004), Cushing syndrome (1.97; 1.06 to 3.65; p-value 0.03), Crohn’s disease (OR 1.31; 95% CI: 1.18 to 1.45; p-value 0.001), and endometriosis (1.22; 1.15 to 1.29; p-value <0.001). Findings were largely unchanged after mutual adjustment. Limitations of this study include our inability to adjust for measures of socioeconomic position or lifestyle characteristics, in addition to the rareness of some of the conditions providing limited power.ConclusionsIn this registry study, we found that, although risk of miscarriage was largely unaffected by maternal chronic diseases, risk of miscarriage was associated with conditions related to cardiometabolic health. This finding is consistent with emerging evidence linking cardiovascular risk factors to pregnancy complications.

In this registry data study, Maria Magnus and colleagues study associations between miscarriage risk and chronic conditions.     

Some aspects of the mechanism of complexation of red kidney bean alpha-amylase inhibitor and alpha-amylase

Bovine pancreatic alpha-amylase binds 1 mol of acarbose (a carbohydrate alpha-amylase inhibitor) per mol at the active site and also binds acarbose nonspecifically. The red kidney bean alpha-amylase inhibitor-bovine pancreatic alpha-amylase complex retained nonspecific binding for acarbose only. Binding of p-nitrophenyl alpha-D-maltoside to the final complex of red kidney bean alpha-amylase inhibitor and bovine pancreatic alpha-amylase has a beta Ks (Ks') value that is 3.4-fold greater than the Ks (16 mM) of alpha-amylase for p-nitrophenyl alpha-D-maltoside alone. The initial complex of alpha-amylase and inhibitor apparently hydrolyzes this substrate as rapidly as alpha-amylase alone. The complex retains affinity for substrates and competitive inhibitors, which, when present in high concentrations, cause dissociation of the complex. Maltose (0.5 M), a competitive inhibitor of alpha-amylase, caused dissociation of the red kidney bean alpha-amylase inhibitor--alpha-amylase complex. Interaction between red kidney bean (Phaseolus vulgaris) alpha-amylase inhibitor and porcine pancreatic alpha-amylase proceeds through two steps. The first step has a Keq of 3.1 X 10(-5) M. The second step (unimolecular; first order) has a forward rate constant of 3.05 min-1 at pH 6.9 and 30 degrees C. alpha-Amylase inhibitor combines with alpha-amylase, in the presence of p-nitrophenyl alpha-D-maltoside, noncompetitively. On the basis of the data presented, it is likely that alpha-amylase is inactivated by the alpha-amylase inhibitor through a conformational change. A kinetic model, in the presence and absence of substrate, is described for noncompetitive, slow, tight-binding inhibitors that proceed through two steps.     

A rapid high-yield purification procedure for the cyclic adenosine 3′,5′-monophosphate receptor protein from Escherichia coli

A new method for the purification of the cyclic adenosine 3′,5′-monophosphate receptor protein from Escherichia coli has been developed. The method is rapid and simple, and a very high yield of the purified protein is obtained which is not contaminated with either DNAase or RNAase activity.     

Some Results on the Tukey-Mclaughlin and Yuen Methods for Trimmed Means when Distributions are Skewed

In applied work, distributions are often highly skewed with heavy tails, and this can have disastrous consequences in terms of power when comparing groups based on means. One solution to this problem in the one-sample case is to use the TUKEY and MCLAUGHLIN (1963) method for trimmed means, while in the two-group case YUEN's (1974) method can be used. Published simulations indicate that they yield accurate confidence intervals when distributions are symmetric. Using a Cornish-Fisher expansion, this paper extends these results by describing general circumstances under which methods based on trimmed means can be expected to give more accurate confidence intervals than those based on means. The results cover both symmetric and asymmetric distributions. Simulations are also used to illustrate the accuracy of confidence intervals using trimmed means versus means.     

Genetic differences in alteration of albumin in the house mouse,Mus musculus

Two strains of mice were shown to differ in relative proportion of two major protein bands of liver under acid conditions of electrophoresis. Genetic control was autosomal and by a pair of dominant and recessive genes. The difference was observed only if liver homogenates were extracted by treating with dilute acid and alkali. The two protein bands were identified as albumin on the basis of electrophoretic migration, molecular weight, and immunological response. No differences were found between strains in relative amounts of comparable bands of plasma. However, in studies with extraction of mixtures, liver homogenates of one strain but not another were capable of converting a large proportion of albumin from several sources to a faster-migrating form. It was concluded that the strains differ in a factor in liver capable of causing a secondary modification of the albumin molecule.