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Dive into the research topics where Risto Kaaja is active.

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Featured researches published by Risto Kaaja.


Metabolism-clinical and Experimental | 1999

Evidence of a state of increased insulin resistance in preeclampsia

Risto Kaaja; Hannele Laivuori; Markku Laakso; Matti J. Tikkanen; Olavi Ylikorkala

Similarities in certain biochemical variables between preeclampsia and the insulin resistance syndrome imply a possible link between insulin resistance and preeclampsia. We measured insulin sensitivity by the minimal model technique between 29 and 39 weeks of gestation in 22 preeclamptic and 16 control women, whose glucose tolerance was first confirmed as normal by an oral glucose tolerance test. In addition, we measured the fasting levels of serum C-peptide, uric acid, lipids, and lipoproteins. Preeclamptic women showed a higher insulin response (P = .001) during the oral glucose tolerance test than the controls. Insulin sensitivity in preeclamptic women (1.11+/-0.15 x 10(-4) x min(-1) x microU/mL) was 37% lower (P = .009) than in control women (1.77+/-0.19 x 10(-4) x min(-1) x microU/mL). The free fatty acid (FFA) concentration in preeclamptic women (0.17+/-0.01 g/L, P = .0004) was 70% higher than in control women (0.10+/-0.01 g/L). Also, baseline serum levels of C-peptide, uric acid, and triglyceride were higher in preeclamptic women. Insulin sensitivity increased fourfold to fivefold within the first 3 postpartum months, but insulin sensitivity in preeclamptic women was still 26% lower (P = .04) than in control women. Preeclampsia is a state of increased insulin resistance, and it persists for at least 3 months after pregnancy. This may be a pathogenetic factor in preeclampsia and may contribute to the excess cardiovascular morbidity among women with prior preeclampsia.


Neurology | 2003

Major malformations in offspring of women with epilepsy

Erja Kaaja; Risto Kaaja; Vilho Hiilesmaa

Background: The offspring of women with epilepsy are at an increased risk of major congenital malformations, but the impact of the various contributing factors remains unresolved. Method: In 1980 through 1998, the authors prospectively followed up 970 pregnancies in women with epilepsy at a single maternity clinic. Of their 979 offspring, 740 were exposed to maternal antiepileptic drugs (AED) during the first trimester of pregnancy and 239 were not exposed. Maternal AED levels and serum folate concentrations were measured at the end of the first trimester. Logistic regression analysis was applied to identify factors associated with the occurrence of major malformations in the fetuses and newborns. Results: Major malformations were detected in 28 fetuses (3.8%) exposed to maternal AED and in 2 (0.8%) not exposed (p = 0.02). After logistic regression analysis, the occurrence of major malformations was independently associated with use of carbamazepine (adjusted OR 2.5; 95% CI 1.0 to 6.0), use of valproate (4.1; 1.6 to 11), use of oxcarbazepine (10.8; 1.1 to 106), low serum folate concentration (5.8; 1.3 to 27), and low maternal level of education (3.0; 1.3 to 6.8). Major malformations were not associated with seizures during the first trimester (0.6; 0.1 to 2.9). Conclusions: Major malformations in the offspring of mothers with epilepsy are associated with use of AED during early pregnancy, and also with low serum folate concentrations and a low level of education.


American Journal of Human Genetics | 2003

Susceptibility Loci for Preeclampsia on Chromosomes 2p25 and 9p13 in Finnish Families

Hannele Laivuori; Päivi Lahermo; Vesa Ollikainen; Elisabeth Widen; Leena Häivä-Mällinen; Helena Sundström; Tarja Laitinen; Risto Kaaja; Olavi Ylikorkala; Juha Kere

Preeclampsia is a common, pregnancy-specific disorder characterized by reduced placental perfusion, endothelial dysfunction, elevated blood pressure, and proteinuria. The pathogenesis of this heterogeneous disorder is incompletely understood, but it has a familial component, which suggests that one or more common alleles may act as susceptibility genes. We hypothesized that, in a founder population, the genetic background of preeclampsia might also show reduced heterogeneity, and we have performed a genomewide scan in 15 multiplex families recruited predominantly in the Kainuu province in central eastern Finland. We found two loci that exceeded the threshold for significant linkage: chromosome 2p25, near marker D2S168 (nonparametric linkage [NPL] score 3.77; P=.000761) at 21.70 cM, and 9p13, near marker D9S169 (NPL score 3.74; P=.000821) at 38.90 cM. In addition, there was a locus showing suggestive linkage at chromosome 4q32 between D4S413 and D4S3046 (NPL score 3.13; P=.003238) at 163.00 cM. In the present study the susceptibility locus on chromosome 2p25 is clearly different (21.70 cM) from the locus at 2p12 found in an Icelandic study (94.05 cM) and the locus at 2q23 (144.7 cM) found in an Australian/New Zealand study. The locus at 9p13 has been shown to be a candidate region for type 2 diabetes in two recently published genomewide scans from Finland and China. The regions on chromosomes 2p25 and 9p13 may harbor susceptibility genes for preeclampsia.


Journal of Hypertension | 2006

Impaired vascular dilatation in women with a history of pre-eclampsia.

Katja Lampinen; Mats Rönnback; Risto Kaaja; Per-Henrik Groop

Objective The mechanisms underlying increased cardiovascular risk among women with a history of pre-eclampsia remain unclear. Impaired endothelial function has been observed in both pre-eclampsia and atherosclerosis, and provides a plausible link between the two conditions. We studied endothelial function and arterial compliance in non-pregnant, previously pre-eclamptic women. Design A study of 30 women with a history of pre-eclampsia and 21 women with a previous normotensive, uncomplicated pregnancy was carried out. Methods Changes in brachial artery blood flow, induced by intra-arterial infusions of an endothelium-independent (sodium nitroprusside) and an endothelium-dependent (acetylcholine) vasodilator, were measured by venous occlusion plethysmography. Arterial stiffness was assessed by pulse-wave analysis. Results Vasodilatation was impaired in women with previous pre-eclampsia; at low and high concentrations of endothelium-independent (P = 0.004 and P = 0.057, respectively) and endothelium-dependent (P = 0.045 and P = 0.02) vasodilators, respectively. There was no difference in arterial stiffness between the groups (P = 0.45). In multiple regression analyses both endothelium-independent and endothelium-dependent vasodilatations were independently associated with a history of pre-eclampsia and parity. There was no correlation with blood pressure, body mass index (BMI), smoking or age. Conclusions The finding of impaired vascular dilatation several years after a pre-eclamptic pregnancy could contribute to the higher risk of cardiovascular disease in these women.


Thrombosis Research | 1999

Thromboprophylaxis with low molecular weight heparin (dalteparin) in pregnancy.

Ville Pettilä; Risto Kaaja; Pekka Leinonen; Ulla Ekblad; Matti Kataja; Eero Ikkala

Venous thromboembolism remains an important cause of maternal mortality. For women at risk during pregnancy, the recommended venous thromboembolismprophylaxis is unfractionated heparin. Low molecular weight heparins, such as dalteparin, also may be suitable, but randomised trials have not been performed. Pregnant women (105) with confirmed previous or current thromboembolism were randomised to receive either unfractionated heparin twice daily (mean 20569 IU/day) or dalteparin once daily (mean 4631 IU anti-factor Xa units/day) subcutaneously for thromboprophylaxis during pregnancy and postpartum period. Recurrence of venous thromboembolism and safety of treatments were assessed. Dalteparin administered once daily was safe and effective in thromboprophylaxis during pregnancy and postpartum.


Diabetes Care | 2016

Gestational Diabetes Mellitus Can Be Prevented by Lifestyle Intervention: The Finnish Gestational Diabetes Prevention Study (RADIEL): A Randomized Controlled Trial.

Saila B. Koivusalo; Kristiina Rönö; Miira M. Klemetti; Risto P. Roine; Jaana Lindström; Maijaliisa Erkkola; Risto Kaaja; Maritta Pöyhönen-Alho; Aila Tiitinen; Emilia Huvinen; Sture Andersson; Hannele Laivuori; Anita Valkama; Jelena Meinilä; Hannu Kautiainen; Johan G. Eriksson; Beata Stach-Lempinen

OBJECTIVE To assess whether gestational diabetes mellitus (GDM) can be prevented by a moderate lifestyle intervention in pregnant women who are at high risk for the disease. RESEARCH DESIGN AND METHODS Two hundred ninety-three women with a history of GDM and/or a prepregnancy BMI of ≥30 kg/m2 were enrolled in the study at <20 weeks of gestation and were randomly allocated to the intervention group (n = 155) or the control group (n = 138). Each subject in the intervention group received individualized counseling on diet, physical activity, and weight control from trained study nurses, and had one group meeting with a dietitian. The control group received standard antenatal care. The diagnosis of GDM was based on a 75-g, 2-h oral glucose tolerance test at 24–28 weeks of gestation. RESULTS A total of 269 women were included in the analyses. The incidence of GDM was 13.9% in the intervention group and 21.6% in the control group ([95% CI 0.40–0.98%]; P = 0.044, after adjustment for age, prepregnancy BMI, previous GDM status, and the number of weeks of gestation). Gestational weight gain was lower in the intervention group (−0.58 kg [95% CI −1.12 to −0.04 kg]; adjusted P = 0.037). Women in the intervention group increased their leisure time physical activity more and improved their dietary quality compared with women in the control group. CONCLUSIONS A moderate individualized lifestyle intervention reduced the incidence of GDM by 39% in high-risk pregnant women. These findings may have major health consequences for both the mother and the child.


Neurology | 2002

Enzyme-inducing antiepileptic drugs in pregnancy and the risk of bleeding in the neonate

Erja Kaaja; Risto Kaaja; Riitta Matila; Vilho Hiilesmaa

BackgroundCase reports suggest that maternal hepatic enzyme-inducing antiepileptic drugs (AED) increase the risk for neonatal bleeding. Antenatal administration of vitamin K1 to mothers using these drugs therefore is widely recommended. There are, however, no studies on the incidence of this complication. ObjectiveTo assess the occurrence of bleeding complications in newborns exposed to maternal enzyme-inducing AED in utero. MethodsThe authors prospectively followed 662 pregnancies in women with epilepsy who used enzyme-inducing AED. Of the 667 neonates, 463 were exposed to carbamazepine, 212 to phenytoin, 44 to phenobarbital, 11 to primidone, and 7 to oxcarbazepine. The control subjects were 1,324 nonepileptic pregnancies (1,334 neonates) matched for maternal age, parity, number of fetuses, and delivery date. None of the mothers received vitamin K1 during pregnancy, but all infants received 1 mg vitamin K1 intramuscularly at birth. ResultsA bleeding complication was observed in five (0.7%) of the offspring exposed to maternal enzyme-inducing AED and in five (0.4%) control subjects (p = 0.3). After logistic regression analysis was performed, bleeding was associated with birth at <32 weeks of gestation (adjusted OR = 13; 95% CI = 2.7 to 64) and alcohol abuse (adjusted OR = 17; 95% CI = 1.8 to 162) but not with exposure to enzyme-inducing AED (adjusted OR = 1.1; 95% CI = 0.3 to 4.6;p = 0.8). ConclusionsThese data do not support the hypothesis that maternal enzyme-inducing AED increase the risk for bleeding in the offspring. Antenatal administration of vitamin K to these mothers may still be needed in selected cases.


Lupus | 1993

Fetal Outcome in Lupus Pregnancy: A Retrospective Case-Control Study of 242 Pregnancies in 112 Patients

Heikki Julkunen; Risto Kaaja; Marjatta Leirisalo-Repo; Eija Stephansson; Timo Palosuop; Kari Teramo; Claes Friman

Fetal outcome in systemic lupus erythematosus (SLE) was retrospectively analysed in 242 pregnancies in 112 unselected patients, and the outcome was compared with that of 417 pregnancies in 192 control women matched for age, parity and socio-economic status. Relative risk for fetal loss after the diagnosis of SLE was 2.5 (95% confidence interval (CI), 1.4-4.5), for prematurity 5.8 (3.2-10.5) and for intra-uterine growth retardation (IUGR) 8.6 (3.0-24.3). Fetal outcome of pregnancy in patients with pre-existing stable lupus nephritis was no worse than in other SLE pregnancies. Relations of three lupus anticoagulant (LA) assays and three anticardiolipin (aCL) enzyme-linked immunosorbent assays to fetal outcome were studied. Patients positive by any LA assay had a previous fetal loss more often than patients negative by all LA assays (odds ratio 3.4; 95% CI, 1.3-9.0; P = 0.01). Of the 41 patients whose antiphospholipid antibody (aPL) tests were all negative, five (12%) had a history of fetal loss (16% in controls). As a group, aCL was more sensitive for fetal loss than LA (64% vs 50%), but LA was more specific (77% vs 52%). Combinations of one aCL assay with one LA assay had a 41-73% sensitivity and a 64-73% specificity for a history of fetal loss. aPL did not correlate to prematurity or fetal growth retardation. In conclusion, fetal loss in SLE is 2.5 times more prevalent than in the normal population. The presence of LA indicates a high risk for fetal loss, and the absence of aPL is an indication of a favorable pregnancy outcome. Prematurity and IUGR are common in SLE, but they are not associated with aPL.


Metabolism-clinical and Experimental | 2000

Leptin during and after preeclamptic or normal pregnancy: its relation to serum insulin and insulin sensitivity.

Hannele Laivuori; Risto Kaaja; Heikki A. Koistinen; Sirkka-Liisa Karonen; Sture Andersson; Veikko A. Koivisto; Olavi Ylikorkala

Hyperleptinemia may be part of the insulin resistance syndrome. We studied serum leptin in preeclampsia, which is an insulin-resistant state, and sought associations between leptin and insulin or insulin sensitivity during and after pregnancy. Twenty-two proteinuric preeclamptic women and 16 normotensive controls were studied during the third trimester. Leptin was higher in preeclampsia (mean +/- SE, 34.6 +/- 3.9 v 20.0 +/- 3.3 microg/L, P = .002) and correlated directly with the level of proteinuria (r = .47, P = .03) and normal pregnancy (r = .52, P = .04), whereas insulin sensitivity as assessed by an intravenous glucose tolerance test showed no relationship to leptin. Leptin was 19.0 +/- 3.6 microg/L in 14 preeclamptic women and 10.1 +/- 2.0 microg/L (P = .11) in 11 controls 3 months after delivery. Leptin correlated directly with insulin both in preeclamptic puerperal women (r = .63, P = .02) and in controls (r = .81, P = .003). Leptin and insulin sensitivity correlated only in preeclamptic puerperal women (r = -.59, P = .02). In conclusion, (1) serum leptin is elevated in preeclampsia, (2) insulin is an important determinant of serum leptin in preeclamptic and normotensive women both during pregnancy and in the puerperium, and (3) hyperleptinemia may be part of the insulin resistance syndrome also in women with prior preeclampsia.


Hypertension in Pregnancy | 2005

Pulse Wave Reflection in Currently and Previously Preeclamptic Women

Mats Rönnback; Katja Lampinen; Per-Henrik Groop; Risto Kaaja

Objective. Disturbed maternal endothelial function is believed to be central in the pathogenesis of preeclampsia and has been observed to persist for several years following the preeclamptic pregnancy. Endothelial dysfunction has been reported to cause increased pulse wave reflection, a measure of systemic arterial stiffness. This study tested the hypothesis that preeclampsia and a history of preeclampsia are associated with increased pulse wave reflection. Design and Methods. We carried out a cross-sectional case-control study of 26 pregnant women with preeclampsia, 26 pregnant controls, 22 normotensive nonpregnant previously preeclamptic women, and 22 nonpregnant controls. Pulse wave reflection was assessed by applanation tonometry on the radial artery. Results. Pregnant preeclamptic women had a significantly higher heart rate–adjusted augmentation index than did pregnant controls (23 ± 1 vs. 8 ± 1%, P < 0.001). The augmentation index of women with a history of preeclampsia was similar to that of the nonpregnant controls (9 ± 2 vs. 9 ± 2%, P = 0.78). In a multiple linear regression analysis (R2 = 0.76) the augmentation index of pregnant women was independently associated with a diagnosis of preeclampsia (P < 0.001) and heart rate (P < 0.001), but not with mean arterial blood pressure (P = 0.59). Conclusions. This study demonstrates that pulse wave reflection and, thus, systemic arterial stiffness are increased in pregnant women with preeclampsia, but not in normotensive nonpregnant women with a history of preeclampsia. The results support the concept of generalized vascular dysfunction in preeclampsia.

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Vilho Hiilesmaa

Helsinki University Central Hospital

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Kari Teramo

University of Helsinki

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Olavi Ylikorkala

Helsinki University Central Hospital

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Sirpa Loukovaara

Helsinki University Central Hospital

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