The LRP5 gene is believed to be primarily associated with bone metabolism via Wnt signaling. The latter pathway, however, appears to control various other systems outside the skeleton. To find the relationships of the LRP5 gene to serum follicle stimulating hormone (FSH ) and luteinizing hormone (LH) in the cohort of normal postmenopausal women, we identified the C/T (c.4037:A1330V) polymorphism in the LRP5 gene using a restriction analysis of the PCR product in a cohort of 165 untreated pre- and post-menopausal women. In a subset of 111 post-menopausal women we analyzed the association between the LRP5 genotype and serum levels of sex-hormones including FSH and LH. The distribution of CC, TC and TT genotypes of the C/T polymorphism in the whole group was 73.9 %, 23.6 % and 2.4 %, respectively, which is comparable with other Caucasian populations. As no TT homozygote was found in the group of post-menopausal women, serum sex-hormones were compared between CC and TC genotypes. Women with the CT allele combination had markedly higher serum FSH levels as compared to carriers of the CC genotype (p<0.004). No differences between these genotypes were found in serum LH levels as well as the circulating sex-steroids such as estradiol, testosterone, dehydroepiandrosterone and/or its sulphate, androstenedione and SHBG. To conclude, the LRP5 gene is associated with circulating FSH in normal post-menopausal women in the present study. The mediating role of subtle undetectable variations in estrogen levels is discussed. We did not find any relationship between the LRP-5 genotype and serum LH levels., I. Žofková, M. Hill, K. Zajíčková., and Obsahuje bibliografii a bibliografické odkazy
A predominance of small, dense low-density lipoproteins (LDL) is characteristic of the dyslipidemic state seen in type 2 diabetes. However, no study has investigated the association in gestational diabetes mellitus (GDM), which is pathophysiologically similar to type 2 diabetes. We hypothesized that LDL particle size is reduced in GDM cases compared with controls. Gradient gel electrophoresis was used to characterize LDL subclass phenotypes in non-fasting intrapartum plasma from 105 GDM cases and 96 controls. All participants were free of pre-existing diabetes or hypertension. The authors used logistic regression to estimate odds ratios (OR) and 95 % confidence intervals (CI) adjusted for confounders. Women with this phenotype had a significant 4.9-fold (95 % CI: 1.1-23.2) increased risk of GDM compared with those with the large, buoyant phenotype. The magnitude of this association was attenuated when plasma triglyceride and other confounders were included in the model (OR=4.2, 95 % CI: 0.5-39.5). Mean LDL particle size in GDM cases was smaller compared with controls (270.1 vs. 272.7Å, p=0.003). The OR of GDM risk was 1.8 (95 % CI: 0.9-3.3) for every 10-Å reduction in LDL particle size. Large prospective studies are needed to evaluate the association between smaller LDL particle size in early pregnancy with subsequent GDM risk., C. Qiu, C. Rudra, M. A. Austin, M. A. Williams., and Obsahuje bibliografii a bibliografické odkazy
Insulin resistance is present in patients with Type 2 diabetes mellitus as well as in obese patients without diabetes. The aim of our study was to compare insulin action in diabetic and control persons with or without obesity and to evaluate the influence of serum cholesterol, serum triglyceride and blood pressure on metabolic variables of insulin action. We examined 42 Type 2 diabetic patients and 41 control persons with body mass index (BMI) from 21.1 to 64.5 kg.m-2, and 33 to 71 years old. The isoglycemic hyperinsulinemic clamp technique was performed at an insulin infusion rate of 1 mU.kg-1.min-1 during 120 min. We evaluated the metabolic clearance rate of glucose (MCRG, ml.kg-1.min-1) as the most important indicator of insulin action by isoglycemic clamp. The Pearson's correlation and multiple regression models were used to compare studied factors with the insulin action. We found following predictors of insulin resistance expressed in the relationship with MCRG: BMI (r = -0.68, p<0.001), plasma glucose concentration (r = -0.66, p<0.001), cholesterol (r=-0.55, p<0.001), triglycerides (r = -0.54, p<0.001) and mean blood pressure (r = -0.38, p<0.01). From the multiple regression analysis we conclude that obesity may have even greater influence on the insulin action than diabetes mellitus itself., G. Šindelka, J. Škrha, M. Prázný, T. Haas., and Obsahuje bibliografii
This work describes ocular astigmatism and factors which affect it. Further, total and corneal astigmatism are described and it is analyzed their relationship. An analysis of a diameter of a geometric circle of confusion is performed for the case of defocus and astigmatism. The formulas for modeling fundamental image characteristics of an eye are described. The paper is completed with an example of an experimental analysis of corneal and total astigmatism measured by aberrometry and an analysis of the influence of astigmatism on visual acuity. and V práci je popsána stručně problematika astigmatismu oka a faktorů, které jej ovlivňují. Je charakterizován celkový astigmatismus a tzv. rohovkový astigmatismus. Dále je provedena analýza průměru geometrického rozptylového kroužku na sítnici pro případ defokusace a astigmatismu a jsou popsány vztahy, kterými lze modelovat základní obrazové charakteristiky v důsledku aberací optické soustavy oka. Článek je doplněn příkladem experimentální analýzy astigmatismu při aberometrickém měření a vlivu astigmatismu na zrakovou ostrost.