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Biomedical subjects

H Kauma

Publications and source records attributed to H Kauma.

34 records · Page 2Linked to original sources

Heart rate variability and progression of coronary atherosclerosis.

Low heart rate (HR) variability is associated with increased risk of cardiovascular morbidity and mortality, but the causes and mechanisms of this association are not well known. This prospective study was designed to test the hypothesis that reduced HR variability is related to progression of coronary atherosclerosis. Average HR and HR variability were analyzed in 12-hour ambulatory ECG recordings from 265 qualified patients participating in a multicenter study to evaluate the angiographic progression of coronary artery disease in patients with prior coronary artery bypass surgery and low high-density lipoprotein cholesterol concentrations (<1.1 mmol/L). Participants were randomized to receive a placebo or gemfibrozil therapy. The progression of coronary atherosclerosis was estimated by quantitative, computer-assisted analysis of coronary artery stenoses from the baseline angiograms and from repeated angiograms performed an average of 32 months later. The progression of focal coronary atherosclerosis of the patients randomized to placebo therapy was more marked in the tertile with the lowest standard deviation of all normal to normal R-R intervals (SDNN, 74+/-13 ms; mean decrease in the per-patient minimum luminal diameter -0.17 mm; 95% confidence interval [CI], -0.23 to -0.12 mm) than in the middle tertile (SDNN, 107+/-7 ms; mean decrease -0.05 mm; 95% CI, -0.08 to -0.01 mm) or highest tertile (SDNN, 145+/-25 ms; mean change 0.01 mm; 95% CI, -0. 04 to 0.02 mm) (P<0.001 between the tertiles). This association was abolished by gemfibrozil. SDNN was lower (P<0.001) and minimum HR was faster (P<0.01) in the patients with marked progression than in those with regression of focal coronary atherosclerosis. In multiple regression analysis including HR variability, minimum HR, demographic and clinical variables, smoking, blood pressure, glucose, lipid measurements and lipid-modifying therapy, progression of focal coronary atherosclerosis was independently predicted by the SDNN (beta=0.24; P=0.0001). Low HR variability analyzed from ambulatory ECG predicts rapid progression of coronary artery disease. HR variability provided information on progression of focal coronary atherosclerosis beyond that obtained by traditional risk markers of atherosclerosis.

Analysis of Variance↗

Associations between lipoproteins and the progression of coronary and vein-graft atherosclerosis in a controlled trial with gemfibrozil in men with low baseline levels of HDL cholesterol.

BACKGROUND: Lipid-lowering secondary-prevention trials of coronary artery disease (CAD) have implicated triglyceride-rich lipoproteins as the main determinants of angiographic progression after elevated LDL cholesterol levels have been lowered with therapy. The present study focuses on the lipoprotein determinants of angiographic CAD progression in men with low HDL cholesterol concentration as their main baseline lipid abnormality who underwent 32 months of randomized therapy with gemfibrozil or placebo. METHODS AND RESULTS: Men who had undergone coronary bypass surgery (n=372) completed a randomized, placebo-controlled study with gemfibrozil 1200 mg/d. They were selected primarily for HDL cholesterol levels that corresponded to the lowest third for middle-aged men. Average baseline lipid and lipoprotein levels were serum triglyceride, 1.60; serum cholesterol, 5.17; ultracentrifugally separated LDL cholesterol, 3.43; HDL2 cholesterol, 0.41; and HDL3 cholesterol, 0. 61 mmol/L. In the gemfibrozil group, these levels were reduced on average by 40%, 9%, and 6% or increased by 5% and 9%, respectively. On-trial IDL and LDL triglyceride and cholesterol levels significantly predicted global angiographic progression, taking into account changes in native segments and in bypass grafts. HDL3 but not HDL2 cholesterol concentration was associated with protection against progression, especially focal disease in native coronary lesions. VLDL was the lipoprotein most predictive of new lesions in vein grafts; IDL was also significantly related. CONCLUSIONS: This study expands the previous evidence of the triglyceride-rich lipoproteins, especially IDL, as predictors of angiographic progression of CAD but does not negate the significance of mildly elevated LDL levels. Of the HDL subfractions, only HDL3 was protective in this group of men selected for their low initial HDL levels.

Apolipoproteins↗

Association of variation in hepatic lipase activity with promoter variation in the hepatic lipase gene. The LOCAT Study Invsestigators.

The associations between six genetic polymorphisms in the hepatic lipase (HL) gene (LIPC) and variation in postheparin HL activity and fasting serum lipoproteins were evaluated in 395 male Finnish coronary heart disease patients with HDL cholesterol concentrations </= 1.1 mmol/liter. The LIPC promoter polymorphism at position -514 was highly significantly associated with variation in HL activity (P = 0.0000008), with mean activities of 20.4, 17.5, and 13.2 mumol free fatty acid/ml per hour in subjects having C/C, C/T, and T/T genotypes, respectively. Furthermore, the triglyceride content of low density lipoprotein, intermediate density lipoprotein and HDL, and the cholesterol content of intermediate density lipoprotein were found to be associated with variation at LIPC position -514. However, there was no association of this polymorphism with coronary heart disease. These data suggest that the LIPC promoter variation is likely to be the basis for variation in HL activity, which underlies the variation in serum lipoprotein phenotypes in this sample.

Cholesterol↗

Heart rate variability and baroreflex sensitivity in hypertensive subjects with and without metabolic features of insulin resistance syndrome.

Both abnormal autonomic control of heart rate, assessed by heart rate variability (HRV) and baroreflex sensitivity (BRS), and insulin resistance syndrome are common in hypertensive patients. It is not known, however, whether abnormalities in HRV and BRS in hypertension are related to the insulin-resistance syndrome. Therefore, we compared HRV and BRS in hypertensive subjects with and without metabolic features of the insulin-resistance syndrome. HRV was analyzed using the autoregressive method from a 45-min electrocardiographic recording (15 min lying, sitting, and standing) and BRS using the Valsalva maneuver. The groups were matched for age, sex, and antihypertensive medication, and age- and sex-matched normotensive subjects served as a control group (n = 69 in each group). The insulin-resistance syndrome was defined using the criteria of 1) hypertension (blood pressure >160/90 mm Hg), 2) hypertriglyceridemia (fasting serum triglycerides > or =2.0 mmol/L), and 3) hyperinsulinemia (fasting serum insulin > or =12 mU/L). Standard deviation of RR intervals, total, very-low-, and low-frequency power of HRV were significantly lower in hypertensive subjects with insulin-resistance syndrome compared to hypertensive subjects without the syndrome and to normotensive controls (P < .001 for all), but the hypertensive group without the syndrome did not differ from the normotensive group. High-frequency power of HRV (P < .01) and BRS (P < .05) were reduced in both hypertensive groups compared to the normotensive group. In multiple regression analysis, systolic blood pressure (P < .01) and serum triglyceride level (P < .001) were independent predictors of reduced total power of HRV, but BRS was related only to systolic blood pressure (P < .01). Thus, most of the abnormalities in overall HRV seem to be confined to the subgroup of hypertensive subjects with insulin-resistance syndrome, but baroreflex and respiratory modulation of heart rate are impaired also in hypertensive subjects without metabolic features of insulin-resistance syndrome.

Adult↗

Apolipoprotein E phenotype determines the effect of alcohol on blood pressure in middle-aged men.

Apolipoprotein E (apoE) has an essential role in lipoprotein metabolism, but recent studies have also revealed other functions associated with it, eg, neurologic and malignant diseases. We studied the association between apoE phenotypes E2/3, E3/3, and E4/3 and blood pressure after adjustment for covariates, as well as the association between phenotypes and adjusted plasma glucose and insulin levels in the standard oral glucose tolerance test in a random middle-aged population-based cohort of 259 men and 267 women. Systolic blood pressure was associated with apoE phenotype in the men with moderate or heavy alcohol consumption (>115 g/week), the mean systolic blood pressure value being 16 mm Hg higher in the E2/3 and 11 mm Hg higher in the E3/3 phenotypes than in the E4/3 phenotype, P = .04. No association was seen in occasional drinkers or teetotalers (lowest tertile <24 g/week), whereas in the middle tertile the association was intermediate. The same association was seen with diastolic blood pressure. In men, there was a significant correlation between systolic blood pressure and alcohol consumption in the E2/3 phenotype (rs = 0.71, P < .01) and in the E3/3 phenotype (rs = 0.25, P < .01), but not in the E4/3 phenotype (rs = 0.03, NS). No association between apoE phenotypes and insulin resistance was observed. In conclusion, in middle-aged men, apoE phenotype significantly influences the blood-pressure-increasing effect of alcohol consumption. This gene environment interaction may have marked implications for the prevention and treatment of hypertension.

Adult↗

Variants of renin-angiotensin system genes and echocardiographic left ventricular mass.

AIMS: Variants of renin-angiotensin system genes are shown to be associated with cardiovascular pathology. The association between renin-angiotensin system genes and left ventricular mass was investigated in a population-based case-control study. METHODS AND RESULTS: The association between echocardiographic left ventricular mass and both insertion/deletion polymorphism of the angiotensin-converting enzyme gene and the methionine-threonine variant at position 235 of the angiotensinogen gene was studied in a random cohort of 430 hypertensive and 426 control subjects. No differences in the adjusted left ventricular mass values between the different genotypes were seen among either the hypertensive or the control subjects, whether men or women, or in the subgroups of normotensive or physically active subjects. Gene variation had no statistically significant synergistic effect on left ventricular mass values. In control women, the deletion allele of the angiotensin-converting enzyme gene was associated with an increased risk of left ventricular hypertrophy. However, this finding was based on a small number of women with left ventricular hypertrophy and should be interpreted with caution. CONCLUSION: Variations in renin-angiotensin system genes had no major effect on left ventricular mass in this middle-aged population-based cohort of hypertensives and control subjects.

Adult↗

Hyperinsulinemia and carotid atherosclerosis in hypertensive and control subjects.

OBJECTIVE: To analyze the relationships between carotid atherosclerosis measured as intima-media thickness (IMT) and different measures of insulin in a population-based case-control study of men and women. RESEARCH DESIGN AND METHODS: Carotid ultrasonographic measurements and 2-h oral glucose tolerance tests were performed in a random sample of 513 hypertensive subjects, aged 40-59 years, and in 518 age- and sex-matched control subjects. The associations between IMT and the different measures of insulin were analyzed through multiple regression and by insulin quintiles. The independent effect of insulin was estimated after concurrent adjustment for age, obesity, LDL cholesterol, and systolic blood pressure. RESULTS: The most powerful correlates with IMT were LDL cholesterol, age, systolic blood pressure, pack-years of smoking, and of the different insulin parameters, 2-h post-load insulin. In stepwise regression analysis, the independent predictors of the mean IMT were LDL cholesterol, systolic blood pressure, pack-years of smoking, and age (P < 0.0001) after adjustment for the independent predictors. In analysis of variance, no positive association of insulin parameters with IMT was found between the 2-h insulin quintiles after adjustment for the independent variables. The exclusion of diabetic subjects did not change the results. CONCLUSIONS: The present study of a population-based sample of men and women found inconsistent associations between different insulin measures and IMT after adjustment for the independent variables.

Adult↗

Effect of hypertension, diabetes and other cardiovascular risk factors on kidney size in middle-aged adults.

The aim of the study was to investigate in a population-based series (1031 subjects, age range 40-60 years) whether the renal size of hypertensive subjects differs from that of control subjects and whether the difference might be due to hypertension itself or risk factors associated with hypertension. The renal measurements were performed by abdominal ultrasound. The genders were analyzed separately. Hypertensive men had slightly larger kidneys than controls (70.1+/-8.9 cm2 vs. 67.9+/-8.7 cm2, p <0.008). The difference was, however, mediated mainly through the body mass index (BMI), whereas hypertension, blood pressure or hypertensive medication did not affect renal size. High serum concentrations of uric acid and creatinine were associated with smaller kidney size (p <0.001 and p <0.05, respectively). Alcohol users had slightly larger kidneys than abstainers, but the difference was not significant. Renal size increased with pack years of smoking. Diabetics had 4.8% larger kidneys (p <0.039), but no difference was observed between the subjects with impaired glucose tolerance and those with normal test results. In multivariate analysis, the most significant factors associated with enlarged kidney size were the fasting blood glucose concentration (p < or = 0.0001), smoking (p < or = 0.0001) and atherosclerotic lesions in carotid arteries (p <0.002). The kidneys were also slightly larger in hypertensive women than in control subjects, but the difference was only of borderline significance (p <0.08). Women on hormone replacement therapy had smaller kidneys than other women (p <0.05), but there was no difference in renal measures between premenopausal and postmenopausal women. In multivariate analysis, the most significant factors contributing to large kidney size were blood glucose concentration (p <0.0001) and smoking (p <0.05), while age and serum creatinine concentration were associated with smaller kidney size (p <0.0001 and p <0.0001). We conclude that renal size is related to sex and the subject's height and weight. Smoking, abnormal glucose tolerance, blood uric acid, creatinine, carotid atherosclerosis and hormone replacement therapy in women were also significant factors for renal size. Hypertensive subjects had larger kidneys than controls, mainly because of their more frequent obesity and abnormal glucose test.

Adult↗

Prevention of the angiographic progression of coronary and vein-graft atherosclerosis by gemfibrozil after coronary bypass surgery in men with low levels of HDL cholesterol. Lopid Coronary Angiography Trial (LOCAT) Study Group.

BACKGROUND: Studies have shown that treatment of hyperlipidemia, especially lowering of plasma LDL levels, retards the progression of coronary atherosclerosis and prevents clinical cardiovascular events. No such studies have focused on subjects with low levels of HDL cholesterol. METHODS AND RESULTS: We randomly assigned 395 post-coronary bypass men, who had an HDL cholesterol concentration < or = 1.1 mmol/L and LDL cholesterol < or = 4.5 mmol/L, to receive gemfibrozil 1200 mg/d or placebo. Coronary angiography was performed at baseline and after, on average, 32 months of therapy. Changes in coronary dimensions were assessed by computer-assisted analysis. Average on-trial serum triglyceride concentrations were 1.69+/-0.68 and 1.02+/-0.37, total cholesterol 5.48+/-0.68 and 4.83+/-0.63, LDL cholesterol 3.84+/-0.59 and 3.39+/-0.56, and HDL cholesterol 0.88+/-0.15 and 0.98+/-0.17 mmol/L in the placebo and gemfibrozil groups, respectively (mean+/-SD, each P<.001). The change in per-patient means of average diameters of native coronary segments was -0.04+/-0.11 mm in the placebo group and -0.01+/-0.10 mm in the gemfibrozil group (P=.009). The equivalent changes in minimum luminal diameters of stenoses were -0.09+/-0.18 and -0.04+/-0.15 mm, respectively (P=.002). A similar, albeit nonsignificant, trend toward treatment benefit was found in the predefined primary study end point, segments unaffected by grafts and those distal to graft insertions. In aortocoronary bypass grafts, 23 subjects (14%) assigned to placebo had new lesions in the follow-up angiogram, compared with 4 subjects (2%) assigned to gemfibrozil (P<.001). CONCLUSIONS: Gemfibrozil therapy retarded the progression of coronary atherosclerosis and the formation of bypass-graft lesions after coronary bypass surgery in men with low HDL cholesterol as their main lipid abnormality.

Aged↗

Sex-related differences in autonomic modulation of heart rate in middle-aged subjects.

BACKGROUND: Women have worse outcomes when they experience acute myocardial infarction (MI), but the reasons for this sex-related difference are not well understood. Because cardiovascular neural regulation plays an important role in cardiac mortality, we studied possible sex-related differences in the autonomic modulation of heart rate (HR) in middle-aged subjects without known heart disease. METHODS AND RESULTS: Baroreflex sensitivity (BRS) and HR variability were studied in randomly selected, age-matched populations of middle-aged women (n = 186; mean age, 50 +/- 6 years) and men (n = 188; mean age, 50 +/- 6 years) without hypertension, diabetes, or clinical or echocardiographic evidence of heart disease. BRS measured from the overshoot phase of the Valsalva maneuver was significantly lower in women (8.0 +/- 4.6 ms/mm Hg, n = 152) than in men (10.5 +/- 4.6 ms/mm Hg, n = 151) (P < .001), and the low-frequency component of HR variability measured from ECG recordings also was lower in women (P < .001), whereas the high-frequency component was higher in women than in men (P < .001). The ratio between the low-and high-frequency oscillations also was lower in the women (P < .001). The increase of HR and decrease of high-frequency component of HR variability in response to an upright posture were smaller in magnitude in women than in men (P < .01 for both). After adjustment for differences in the baseline-variables, such as blood pressure, HR, smoking, alcohol consumption, and psychosocial score, the sex-related differences in BRS and HR variability still remained significant (P < .001 for all). Women with estrogen replacement therapy (n = 46) had significantly higher BRS and total HR variance than the age-matched women without hormone treatment (P < .01 for both), and the BRS and HR variability of the women with estrogen therapy did not differ from those of the age-matched men. CONCLUSIONS: Baroreflex responsiveness is attenuated in middle-aged women compared with men, but the tonic vagal modulation of HR is augmented. Hormone replacement therapy appears to have favorable effects on the cardiovascular autonomic regulation in postmenopausal women.

Autonomic Nervous System↗

Sex difference in the regulation of plasma high density lipoprotein cholesterol by genetic and environmental factors.

Association between high density lipoprotein (HDL) cholesterol concentration and restriction fragment length polymorphisms at the cholesteryl ester transfer protein (CETP) gene locus was studied in a random population-based cohort of 526 Caucasian subjects (259 men, mean age 50.9 years, and 267 women, mean age 51.8 years). HDL cholesterol concentration was adjusted for age, body mass index, alcohol consumption, smoking and plasma triglyceride and low density lipoprotein cholesterol levels. In females, the HDL cholesterol levels were associated with TaqIB polymorphism (1.46 mmol/l in the B1B1 genotype, 1.56 mmol/l in B1B2 and 1.72 mmol/l in B2B2, P = 0.0001 for the trend). In contrast, this was not observed in men (1.24, 1.20, 1.27 mmol/l, NS). The association was seen even in women who were current smokers (1.41, 1.56, 1.75 mmol/l, n = 72, P = 0.007), but not in male smokers (1.26, 1.19, 1.14 mmol/l, n = 102, NS). In male non-smokers the association was weak (1.22, 1.20, 1.32 mmol/l, n = 157, P = 0.05). In postmenopausal women not receiving hormone replacement therapy (n = 108), the association continued to be present, although weaker (1.50, 1.58, 1.70 mmol/l, P = 0.06). CETP activity (n = 101) tended to be lower in subjects with the B2B2 genotype. In conclusion, a clear-cut sex difference was observed in the genotype effect on plasma HDL cholesterol levels. The slight attenuation of the gene dosage effect after menopause suggests that the gender difference may be, at least in part, due to sex hormones. A genetic subgroup (men with the B2B2 genotype) particularly susceptible to the HDL cholesterol decreasing effect of smoking could be demonstrated.

Adult↗

Association between angiotensin converting enzyme gene polymorphism and carotid atherosclerosis.

OBJECTIVE: Variations in the angiotensin converting enzyme (ACE) gene have been implicated in cardiovascular pathology. Therefore, the association between the intima-media thickness (IMT) of the carotid artery and the insertion/ deletion (I/D) polymorphism of the ACE gene was investigated. SUBJECTS: Three hundred men and 300 women were selected randomly from the middle-aged population living in the town Oulu, Finland, of whom 515 subjects (85.8%) participated. METHODS: The IMT of the carotid arteries was determined by bilateral B-mode ultrasonography. IMT values were adjusted for gender, age, height, plasma low-density lipoprotein cholesterol level, smoking and systolic blood pressure. The I/D polymorphism of the ACE gene was determined by polymerase chain reaction. RESULTS: Among non-smokers, the subjects with the DD genotype had significantly higher carotid IMT than did those with II or ID. The association was found also in combined IMT plaque values. In the total population the association was weaker and it was absent in current smokers. Genotype could explain 1.3-2.7% of the variance of carotid IMT in non-smokers. No association between the amount or size of carotid plaques and genotype was observed. CONCLUSIONS: Variations at the ACE gene locus contribute to the degree of the early changes in carotid atherosclerosis in the population. The gene effect is, however, masked by stronger effects of environmental factors such as smoking. The lack of association between atherosclerotic plaques and genotypes may reflect different mechanisms being involved in plaque development and early arterial wall thickening.

Adult↗

Prevalence of carotid atherosclerosis in middle-aged hypertensive and control subjects. A cross-sectional systematic study with duplex ultrasound.

BACKGROUND: Arterial hypertension has been found to increase atherosclerotic lesions, although contradictory results have suggested that hypertension has little or no effect. These discrepancies are probably caused by differences in populations. OBJECTIVE: To examine the effect of hypertension on carotid atherosclerosis in a population-based series of patients with an established diagnosis of arterial hypertension and controls. METHODS: Carotid intima-media thickness (IMT) and plaques were evaluated with duplex ultrasound in 1031 middle-aged (aged 40-60 years) men (n = 511) and women (n = 520), 513 with arterial hypertension and 518 controls. IMT was measured in the internal carotid artery, bifurcation and proximal, middle and distal common carotid artery, determining mean and maximal values for each patient. RESULT: Male sex, age, smoking and cholesterol were the most significant risk factors for combined plaque and intima-media thickness (CPIMT); hypertension and and abnormal glucose test result were further significant risk factors. There was a significant difference in CPIMT between the hypertensive and control subjects, but this was caused by the differences in the men; there were no statistically significant differences among the women. Plaques were found more frequently in the hypertensive men than they were in their controls (62.8 versus 49.8%), the corresponding percentages for the hypertensive and control women being 38.0 and 32.1%. There was a larger proportion of male subjects with a long duration of hypertension (> or = 7 years) who had plaques and greater CPIMT than there was of those with a short duration of hypertension. CONCLUSION: Hypertension had a significant effect on CPIMT and on the prevalence of plaques in men, but its effect in women was not significant. A long duration of hypertension resulted in greater CPIMT values and a higher prevalence of plaques, particularly in men.

Adult↗

Variation at the angiotensin-converting enzyme gene and angiotensinogen gene loci in relation to blood pressure.

To investigate whether the polymorphisms in the angiotensin-converting enzyme and angiotensinogen genes are associated with hypertension, we carried out a case-control study of 508 hypertensive and 523 control subjects randomly selected from the Social Insurance Institution register. The cohorts were well characterized and matched for age and sex. The insertion/ deletion polymorphism of the angiotensin-converting enzyme gene and the methionine-->threonine variant at position 235 of the angiotensinogen gene were determined by the polymerase chain reaction technique. The allele frequencies and genotype distributions of both polymorphisms were similar in hypertensive and control subjects. Systolic and diastolic pressures adjusted for age, body mass index, and alcohol consumption did not differ significantly between the different genotypes of the angiotensin-converting enzyme and angiotensinogen genes. The variation at the angiotensinogen and angiotensin-converting enzyme genes did not have any statistically significant synergistic effect on blood pressure levels. In conclusion, the polymorphisms in the reninangiotensin cascade genes do not confer a significantly increased risk for the development of hypertension in this middle-aged, population-based cohort.

Adult↗

Therapeutic effect of heme arginate in myelodysplastic syndromes.

In order to investigate, whether heme would induce a response in myelodysplastic syndromes (MDS), 14 symptomatic patients (4 RA, 3 RARS and 7 RAEB) were treated with infusions of heme arginate 3 mg/kg body weight on 4 consecutive days, mostly for six cycles at 2-week intervals. Three of 14 patients (21%) showed an improvement in anemia (97-152, 79-120 and 92-114 g/l) within a few weeks, and 1 showed a milder increase in hemoglobin level (102-118 g/l). Of the 2 responders with marked thrombocytopenia, 1 showed an improvement in the platelet count (7-37 x 10(9)/l) and her regular need for red cell and platelet transfusions ceased. Some regression in bone marrow (BM) cytology was seen in all 3 responders. One of the responders is still in remission 41 months after cessation of the treatment, while in the other 2 the response lasted for 26 and 5 months. Four patients progressed during the treatment: 1 RA to RAEB, 1 RAEB to RAEBt and 2 RAEB, both with very complex chromosomal abnormalities at the beginning of the therapy, to acute erythroleukemia (AML-M6). Pretreatment delta-aminolevulinic acid synthase and heme synthase activities were generally low. Five patients had mild thrombophlebitis, but not after the infusion procedure was changed. No other side-effects common to growth factors occurred. In conclusion, it is likely that heme arginate has a therapeutic effect on some MDS patients, obviously by stimulating erythropoiesis. The response may be long-lasting.

Adult↗