Preanalytical conditions that affect coagulation testing, including hormonal status and therapy

Preanalytical conditions, be they due to the individual's physiologic state or to exogenous factors, can affect coagulation factors, in either a transient or a persistent manner, and need to be considered in laboratory testing. These conditions include physical and mental stress, diurnal variation, hormone levels and posture at the time of blood drawing. While testing of these factors has not been exhaustive and some results are conflicting, guidelines for testing conditions can be given.

Pre-eclampsia but not pregnancy-induced hypertension is a risk factor for diabetic nephropathy in type 1 diabetic women

AIMS/HYPOTHESIS

Our aim was to study whether pre-eclampsia and pregnancy-induced hypertension are predictors of diabetic nephropathy in type 1 diabetic women.

MATERIALS AND METHODS

A total of 203 type 1 diabetic women, who were pregnant between 1988 and 1996 and followed at the Department of Obstetrics and Gynaecology in Helsinki, were re-assessed after an average of 11 years within the nationwide, multi-centre Finnish Diabetic Nephropathy Study. Diabetic nephropathy was defined as microalbuminuria, macroalbuminuria or end-stage renal disease.

RESULTS

Patients with prior pre-eclampsia had diabetic nephropathy more often than patients with a normotensive pregnancy (diabetic nephropathy vs normal albumin excretion rate: 41.9% vs 8.9%; p<0.001), whereas patients with a history of pregnancy-induced hypertension did not (10.3% vs 8.9%; p=0.81). CHD was more prevalent in patients with a history of pre-eclampsia than in patients with a normotensive pregnancy (12.2% vs. 2.2%; p=0.03). Pre-eclampsia (odds ratio [OR] 7.7, 95% CI 1.6-36.1; p=0.01) and HbA(1c) (OR 2.0, 95% CI 1.1-3.8; p<0.05) were associated with incident diabetic nephropathy even when adjusted for follow-up time, BMI, smoking, diabetes duration and age.

CONCLUSIONS/INTERPRETATION

These data suggest that a history of pre-eclamptic pregnancy but not pregnancy-induced hypertension is associated with an elevated risk of diabetic nephropathy.

Metabolic syndrome and arterial stiffness: the Health 2000 Survey

Metabolic syndrome and its components have been associated with arterial stiffness and cardiovascular disease. The objective of this study was to examine the independent influences of metabolic syndrome, its components, and other cardiovascular risk factors on arterial stiffness as well as to compare 2 definitions for metabolic syndrome (National Cholesterol Education Program [NCEP] and International Diabetes Federation [IDF]) in their ability to identify subjects with arterial stiffness. The study population consisted of 401 Finnish men and women aged 45 years and older who participated in a substudy of the Finnish population-based Health 2000 Survey. Pulse wave velocity (PWV) measured by whole-body impedance cardiography was used as a marker of elevated arterial stiffness. In multivariate models, systolic blood pressure, age, waist circumference, and fasting blood glucose (P < or = .001 for all) were independent determinants for PWV. In the models including metabolic syndrome instead of its components, the NCEP and IDF definitions were similarly associated with PWV (P < or = .01 for both), the other independent determinants being age, sex (P < .001 for both) and plasma C-reactive protein concentration (P = .016 and P = .005 in models containing the NCEP and IDF definitions, respectively). Systolic blood pressure, age, waist circumference, and fasting blood glucose level were independently associated with increased arterial stiffness. Metabolic syndrome determined increased arterial stiffness independently of other known cardiovascular risk factors. The NCEP and IDF definitions did not differ in their ability to identify subjects with increased arterial stiffness.

Management of cardiovascular risk in the peri-menopausal woman: a consensus statement of European cardiologists and gynaecologists

Cardiovascular risk is poorly managed in women, especially during the menopausal transition when susceptibility to cardiovascular events increases. Clear gender differences exist in the epidemiology, symptoms, diagnosis, progression, prognosis, and management of cardiovascular risk. Key risk factors that need to be controlled in the peri-menopausal woman are hypertension, dyslipidaemia, obesity, and other components of the metabolic syndrome, with the avoidance and careful control of diabetes. Hypertension is a particularly powerful risk factor and lowering of blood pressure is pivotal. Hormone replacement therapy is acknowledged as the gold standard for the alleviation of the distressing vasomotor symptoms of the menopause, but the findings of the Women's Health Initiative (WHI) study generated concern for the detrimental effect on cardiovascular events. Thus, hormone replacement therapy cannot be recommended for the prevention of cardiovascular disease. Whether the findings of WHI in older post-menopausal women can be applied to younger peri-menopausal women is unknown. It is increasingly recognized that hormone therapy is inappropriate for older post-menopausal women no longer displaying menopausal symptoms. Both gynaecologists and cardiovascular physicians have an important role to play in identifying peri-menopausal women at risk of cardiovascular morbidity and mortality and should work as a team to identify and manage risk factors such as hypertension.

Plasma levels of annexins IV and V in relation to antiphospholipid antibody status in women with a history of recurrent miscarriage

INTRODUCTION

The presence of antiphospholipid (aPL) antibodies increases the risk for recurrent miscarriage (RM). Annexins are a family of structurally related proteins which all bind to anionic phospholipids (PLs) preventing clotting on vascular phospholipid surfaces. The aim of our study was to define plasma concentrations of circulating annexins IV and V at the beginning of pregnancy among women with a history of RM, and in connection to their aPL antibody status.

MATERIALS AND METHODS

Sixty-eight women with RM and 25 controls without history of adverse pregnancy outcome were included in the study. Concentrations of annexins IV and V in plasma were determined by using a sandwich ELISA technique.

RESULTS

Hereditary or acquired thrombophilic disorders were found in 53% (36/68) of the patients with RM. Plasma levels of annexin V were significantly higher at the beginning of pregnancy (P=0.03), at the 6th (P=0.01) and 8th week of pregnancy in women with aPL antibodies compared with those without aPL antibodies. A tendency towards higher plasma levels of annexin V was observed in those whose pregnancies ended in miscarriage compared with those with successful pregnancy, although the results did not reach statistical significance (P=0.10). Plasma levels of annexin IV at the first visit in women with aPL antibodies were similar to those at 6 and 8 weeks of gestation. There were no significant differences in plasma annexin IV levels between women with and without aPL antibodies.

CONCLUSIONS

Patients with RM show elevated plasma levels of annexin V in presence of aPL antibodies. These antibodies could displace annexin from anionic phospholipid surfaces of syncytiotrophoblasts (STBs) and hereby promote coagulation activation.

An unfavorable combination of factor V Leiden with age, weight, and blood group causes high risk of pregnancy-associated venous thrombosis—a population-based nested case-control study

INTRODUCTION

Hereditary and acquired risk factors increase the risk for thrombosis among pregnant women. Few risk estimates are, however, well established. The aim of the present study was to assess risk for pregnancy-associated venous thrombosis of factor V Leiden (FVL), FII G20210A, FV A4070G, MTHFR C677T, TFPI C536T, PROC T38853G, FXIII V34L, blood group, age, and body mass index (BMI), and their interactions and public health impact.

MATERIALS AND METHODS

Study design is a population-based nested case-control study of 100,000 consecutive pregnancies in Finland. Cases and controls were identified by combining national registers. Thirty four cases with objectively diagnosed venous thrombosis and 641 controls were studied.

RESULTS

FVL (OR 11.6, 95% CI 3.6-33.6), age >35 vs. <25 (OR 6.3, 95% CI 1.7-23.1), and BMI >30 vs. <25 (OR 5.6, 95% CI 2.3-13.9) were associated with thrombosis. Overall absolute risk of a FVL carrier was 1 in 314. FVL interacted with age, BMI, and blood group. Population attributable risk proportion was 19% for FVL, 23% for age >35, 33% for BMI >25, and 35% for non-O blood group. Unexpectedly, the prevalence of FVL increased with age in controls.

CONCLUSIONS

FVL appeared as a strong risk factor for pregnancy-associated venous thrombosis. Especially in elderly overweight mothers, FVL may cause a substantial thrombosis risk. Further studies are needed to confirm the increased prevalence of FVL in elderly mothers with normal pregnancies.

Reproductive history and carotid intima-media thickness

BACKGROUND

Intima-media thickness (IMT) of the carotid arteries is a valid measure of preclinical atherosclerosis which may predict cardiovascular outcomes. Metabolic and hormonal changes associated with the reproductive history of women may contribute to the development of cardiovascular disease (CVD).

METHODS

In a population-based cross-sectional study comprising 746 Finnish women, aged 45-74 years, associations of reproductive history (assessed by questionnaire) and measures of subclinical atherosclerosis (by ultrasonographic detection) were studied. Statistical methods included linear and logistic regression models.

RESULTS

Mean carotid IMT was positively associated with parity, but after adjustment for age its statistical significance disappeared. Women with a history of stillbirth tended to have higher IMT than other women. History of hysterectomy was an independent determinant of carotid plaque in models with age, blood pressure, fasting blood glucose and cholesterol, body mass index (BMI), education and smoking (odds ratio (OR): 0.32; 95% confidence interval (CI): 0.11-0.96). But when oophorectomy (yes/no) was included in the model, this association lost its statistical significance (adjusted OR: 0.36; 95% CI: 0.11-1.22). A history of stillbirth was associated with an increased age-adjusted risk of plaque (OR=3.43; 95% CI: 1.07-11.05), but in the fully adjusted model it lost its statistical significance (OR=3.61; 95% CI: 0.86-15.23).

CONCLUSION

Stillbirth was associated with increased risk of atherosclerotic plaque. Atherosclerosis is a lifelong process to which stillbirth is related. However, due to the cross-sectional design of this study, the causality of this association remains unclear.

Variations in the thrombomodulin and endothelial protein C receptor genes in couples with recurrent miscarriage

BACKGROUND

Recurrent miscarriage (RM) has been suggested to be caused by mutations in genes coding for various coagulation factors resulting in thrombophilia. Mouse models indicate that genes involved in the protein C anticoagulant pathway are essential for normal embryonic development. Loss of function of two of these genes, thrombomodulin (TM) and endothelial protein C receptor (EPCR), causes embryonic lethality in mice. The aim of this study was to determine whether variations in the human TM or EPCR genes are associated with an increased risk for RM.

METHODS

Forty-six RM patients and 191 controls were screened for mutations in TM and EPCR using denaturing high-performance liquid chromatography (DHPLC). The partners of 40 RM patients were also screened.

RESULTS

One exonic and one intronic variation in TM and two exonic and two intronic sequences in EPCR were detected. Four variants were common in both patients and controls. A previously identified truncating mutation in EPCR, suggested to have a role in pregnancy complications, was identified in two patients and one control. A novel deletion in the 3'UTR region of TM was detected, but its significance remains unsolved.

CONCLUSIONS

These data suggest that mutations in the TM or EPCR genes are not a major cause of RM, although they may exert a modifier effect in combination with other variants.

Peripartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a rare cardiac disorder of unknown cause that occurs in pregnant females, most commonly in the early postpartum period. It shares many clinical characteristics with idiopathic dilated cardiomyopathy but occurs at a younger age and is associated with a better prognosis. The etiology and pathogenic mechanisms have been difficult to study, however current hypotheses include infectious, immunologic, nutritional, and iatrogenic causes. Diagnosis is based upon the clinical presentation of congestive heart failure and objective evidence of left ventricular systolic dysfunction. Mortality rates over the past 10 years in PPCM have decreased, most likely due to advances in medical therapy for heart failure and use of implantable defibrillators. For those patients, who remain refractory to conventional pharmacologic therapy, cardiac transplantation and mechanical circulatory support are viable options. In less than 50% of PPCM patients, left ventricular function normalizes with pharmacologic therapy. However, subsequent pregnancies are often associated with recurrence of left ventricular systolic dysfunction.

Oral health in women with pregnancy and delivery complications

Oral health was retrospectively studied in 207 women (mean age 30 years) in the Helsinki Womens' Hospital with the hypothesis that women with pregnancy complications and/or delivery complications would present poorer dental status than women without complications. Computerized dental records of the City of Helsinki Health Department were used with decayed, missing, filled index (DMF) and community periodontal index (CPI) scoring systems and a summary dental health index (DHI) was constructed for statistics. In 72%, the delivery was uncomplicated, while 18% had Caesarean section. Of the women, 8% had gestational diabetes, 7.1% had gestational hypertension, and 1.8% had preeclampsia. Fifteen (6.6%) preterm babies were born; eight (3.5%) babies weighed <2.500 g, seven (3.2%) received a 1-min Apgar point <7 indicating less than satisfactory state of the newborn. DMF was 12.9+/-6.6 in women without complications compared to 15.3+/-6.7 in women with complications (n.s.). CPI values did not differ between the groups. The mean DHI values were 2.07 in women with normal pregnancy complications and no delivery complications, 2.23 in those with pregnancy complications, and 2.13 in those with delivery complications, respectively. In logistic regression analysis, no oral health parameters associated with any complications. Thus, this study failed to show an association between poor dental health and pregnancy or delivery complications.

Variations of the Amnionless gene in recurrent spontaneous abortions

Recurrent spontaneous abortions (RSA) are estimated to affect 0.5-1% of couples trying to have a child. The causes of RSA are unknown in the majority of cases. This study aimed to determine whether homozygous mutations in the AMN gene in a fetus cause spontaneous abortions in humans, as they are known to cause spontaneous abortions in mice. The study was conducted by screening 40 couples and 5 women with three or more unexplained spontaneous abortions for heterozygous mutations in the AMN gene using denaturing high-performance liquid chromatography. Altogether, 3 exonic and 11 intronic sequence variations were found. There were no significant differences in the frequencies of the variations between the patients and a control group. One of the exonic variations was non-synonymous, and three of the variations may affect gene splicing. None of the putative phenotype-affecting variations were found in both partners in any couple. These results indicate that RSA in the couples studied cannot be explained by homozygous AMN mutations in the fetus. However, two couples had different, potentially deleterious variations in both partners. If these variations have a phenotypic effect, the RSA experienced by these couples may be caused by mutations in the AMN gene. In addition, birthplaces of the patients' ancestors revealed some clustering, suggesting that some patients may carry a founder mutation in another gene which may contribute to RSA.

Coronary heart disease: from a disease of middle-aged men in the late 1970s to a disease of elderly women in the 2000s

AIMS

To analyse secular changes in the prevalence of coronary heart disease (CHD) and to assess changes in the burden of CHD at population level.

METHODS AND RESULTS

Data were used from two large cross-sectional health examination surveys representing the entire Finnish adult population in 1980 and 2000. In the 1978-80 survey, the sample covered 5101 individuals aged > or =45, of whom 88% participated. The 2000-2001 survey comprised 5310 individuals in the same age range. Participation rate in the health examination was 87%. Prevalence of CHD decreased in men and women under the age of 65 and increased among those aged > or =75. Prevalence of large Q-waves indicating previous myocardial infarction decreased in all male age groups and in women aged 65-74. The total estimated number of persons with CHD increased by 18% (95% CI=6-30) during the past 20 years in Finland. In 1980, the most dominant CHD group was men aged 45-64, whereas in 2000, women aged > or =75 comprised the largest CHD group.

CONCLUSION

Although the prevalence of CHD has decreased among middle-aged persons, the number of CHD cases has increased during the past 20 years in Finland.

Congenital anomaly rate in offspring of mothers with diabetes treated with insulin lispro during pregnancy

AIM

To determine the rate of major congenital anomalies in offspring of a large group of women with diabetes mellitus treated with insulin lispro (Humalog).

METHODS

This multinational, multicentre, retrospective study included mothers with diabetes mellitus (diagnosed prior to conception) who were treated with insulin lispro for at least 1 month before conception and during at least the first trimester of pregnancy. Anomalies were assessed by two independent dysmorphologists not affiliated with the sponsor.

RESULTS

The charts of 496 women were reviewed for 533 pregnancies resulting in 542 offspring (500 live births, 31 spontaneous and seven elective abortions, and four stillbirths). Mothers' characteristics: mean (+/- SD) age was 29.9 (+/- 5.2) years, 85.6% were Caucasian and 97.2% had Type 1 diabetes mellitus. Insulin lispro continued to be the main mealtime insulin for more than 96% of the women during the second and third trimester. The dysmorphologists determined that 27 (5.4%) offspring had major congenital anomalies and 2 (0.4%) offspring had minor congenital anomalies.

CONCLUSIONS

The rate of major congenital anomalies was 5.4% [95% CI (3.45%, 7.44%)] for offspring of mothers with diabetes mellitus treated with insulin lispro before and during pregnancy. The current published rates of major anomalies in infants born to mothers with diabetes treated with insulin are between 2.1 and 10.9%. This suggests that the anomaly rate with insulin lispro treatment does not differ from the published major congenital anomaly rates for other insulin treatments.

Retinal Artery and Vein Diameters during Pregnancy in Diabetic Women

PURPOSE

To study systemic and retinal circulatory variables and vasoactive hormones during pregnancy in women with and without diabetes.

METHODS

Prospective study of 45 women with type 1 diabetes and 6 healthy pregnant women, from the first trimester of pregnancy to half a year after delivery, by using a fundus photographic method of determining retinal vessel diameters.

RESULTS

In diabetic women, the mean arterial blood pressure increased from 90.7 +/- 10.9 mm Hg (mean +/- SD) in the first trimester to 102.4 +/- 16.4 mm Hg in the third trimester, accompanied by retinal arteriolar constriction, from a mean diameter of 95.5 +/- 11.3 to 92.2 +/- 12.9 microm (P = 0.007), arteriolar constriction being prominent in nonsmokers, from 96.6 +/- 11.1 to 92.3 +/- 13.0 microm (P < 0.001; n = 38), but absent in smokers, from 89.2 +/- 11.5 to 92.0 +/- 13.6 microm (P = 0.28). Healthy nonsmoking women demonstrated an increase in blood pressure during pregnancy comparable to that in diabetic women, but the change in mean retinal arteriolar diameter, from 88.5 +/- 10.9 microm in the first to 91.6 +/- 10.2 microm in the third trimester, did not reach statistical significance (P = 0.38). Diabetic retinopathy levels increased during pregnancy, but the change in arteriolar diameter from the first to the third trimester did not correlate with retinopathy, arterial blood pressure, HbA(1c), or atrial natriuretic peptide. Plasma angiotensin II correlated positively with the change in arteriolar diameter in women who did not smoke (P < 0.05). After delivery, retinal vessel diameters returned to the first trimester range in all subgroups.

CONCLUSIONS

From the first to the third trimester of pregnancy, blood pressure increased and retinal arteriolar diameter decreased in diabetic women, but the arteriolar constriction associated with pregnancy and systemic arterial blood pressure increase was remarkably absent in diabetic women who smoked tobacco before and during pregnancy. It is unknown whether smoking inhibits this vasoconstrictive response by deactivating mechanisms of physiological adaptation or by activating these mechanisms before the first trimester of pregnancy.

Pregnancy in essential thrombocythaemia: experience with 40 pregnancies

In this study, the course of 40 pregnancies in 16 women with essential thrombocythaemia (ET) was analysed retrospectively. Of the pregnancies, 45% were complicated, 55% uncomplicated, and 62% resulted in live birth. The most common complication was spontaneous abortion during the first trimester seen in 33% of all pregnancies and comprising 72% of all complications. Two intrauterine foetal deaths occurred at weeks 22 and 28. Three pregnancies were complicated by eclampsia or pre-eclampsia. Nine of 16 women with 29 pregnancies had at least one complicated pregnancy. In seven of 16 women, all 11 pregnancies were uneventful. The non-pregnancy-related symptoms of ET or the platelet count before conception or during pregnancy did not correlate with the risk of pregnancy complications. Treatment with low-dose acetylsalicylic acid (ASA) alone during pregnancy or platelet-lowering drugs before or during pregnancy reduced the risk of complications.

Regional differences in the prevalence of pre-eclampsia in relation to the risk factors for coronary artery disease in women in Finland

AIMS

The aim of this study was to examine the prevalence of pre-eclampsia in Southern, Eastern, and Northern Finland, and the relationship between history of pre-eclampsia and maternal coronary artery disease (CAD) risk factors.

METHODS AND RESULTS

Women aged 25-64 years, who participated in a cross-sectional population survey and had been pregnant (n=3650), were studied. The proportion of women who had ever had pre-eclampsia was lower in Southern (7.9%) compared with Northern Finland (13.9%) (P=0.001), but did not differ from Eastern Finland (11.1%). In the logistic regression model, the age-adjusted prevalence of pre-eclampsia was 1.92-fold in Northern (95% CI: 1.46-2.53, P<0.001) and 1.47-fold in Eastern Finland (95% CI: 1.11-1.96, P=0.008) compared with Southern Finland. The odds ratios (ORs) were 1.70 (95% CI: 1.21-2.38, P=0.002) and 1.16 (95% CI: 0.82-1.64, P=0.40), respectively, when adjusted for age at first birth, current age, parity, body mass index (BMI), increased blood cholesterol, hypertension, diabetes/impaired glucose tolerance, CAD, and mother's myocardial infarction. History of pre-eclampsia was associated with increased blood cholesterol, higher current BMI and blood pressure, and higher current prevalence of hypertension, diabetes/impaired glucose tolerance.

CONCLUSIONS

Pre-eclampsia is most prevalent in the Northern part of Finland and could only be partly explained by higher prevalence of CAD risk factors.

Is there any link between insulin resistance and inflammation in established preeclampsia?

Both insulin resistance and inflammation may contribute to the onset of preeclampsia. They also could be interrelated. We studied the relationship between inflammatory cytokines and markers of insulin resistance. During their third trimester, 22 proteinuric preeclamptic women and 16 normotensive controls underwent intravenous glucose tolerance test (minimal model). Preeclamptic women were more insulin-resistant (P = .009), and they had higher levels of serum soluble tumor necrosis alpha receptor II (TNFalpha RII) (P = .002), triglycerides (P = .006), uric acid (P = .001), and leptin (P = .002) than did the controls. However, the study groups did not differ in serum TNFalpha, C-reactive protein (CRP), interleukin-6 (IL-6), sex hormone-binding globulin (SHBG), and high-density lipoprotein-2 (HDL(2))-cholesterol. In multiple regression analysis only SHBG (P = .01) and triglycerides (P = .0036) were associated with insulin sensitivity independently of body mass index (BMI), weight gain, HDL(2)-cholesterol, CRP, TNFalpha, and TNFalpha RII, IL-6, and leptin. We conclude that insulin resistance and the inflammatory markers studied were not associated in established preeclampsia.

Diurnal blood glucose profiles in women with gestational diabetes with or without hypertension

AIM

The aim of the study was to establish whether diurnal blood glucose profiles differed in women with gestational diabetes (GDM) with different forms of hypertensive complications.

METHODS

The subjects were patients diagnosed at 26-32 gestational weeks as having GDM (n = 178). They were classified as being normotensive, having chronic hypertension (with or without superimposed pre-eclampsia on chronic hypertension) or pregnancy-induced hypertension (with or without proteinuria). We compared diurnal blood glucose profiles (blood glucose taken every 4 h over 24 h) in these three groups.

RESULTS

Hypertension complicated 43% of the women with GDM. The glucose profiles were similar between the three groups, except that in early morning hours (from 04:00 to 08:00 h) blood glucose concentrations increased in mothers with chronic hypertension, whereas they decreased in the normotensive women. In univariate regression analysis, both obesity (BMI > or = 28 kg/m(2)) and chronic hypertension showed significant association with blood glucose rise from 04:00 to 08:00 h, but in a multiple regression model neither showed significant independent effect.

CONCLUSIONS

The rise in blood glucose levels during the early morning hours in women with GDM and chronic hypertension could reflect greater insulin resistance and sympathetic overactivity.