| 1. |
- Boman, J, et al.
(författare)
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High prevalence of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells in patients with cardiovascular disease and in middle-aged blood donors.
- 1998
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Ingår i: Journal of Infectious Diseases. - 0022-1899 .- 1537-6613. ; 178:1
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Tidskriftsartikel (refereegranskat)abstract
- Nested polymerase chain reaction (nPCR) demonstrated the presence of Chlamydia pneumoniae-specific DNA in peripheral blood mononuclear cells (PBMC). PBMC samples were obtained from 103 consecutive patients (62 male, 41 female) aged 22-85 years (mean, 64) admitted for coronary angiography because of suspected coronary heart disease and from 52 blood donors (43 male, 9 female) aged 40-64 years (mean, 49). Of the 101 evaluable patients, 60 (59%) were identified by nPCR assay as C. pneumoniae DNA carriers; C. pneumoniae-specific microimmunofluorescence (MIF) serology confirmed exposure to the bacterium in 57 (95%) of the 60 nPCR-positive patients. Among the 52 blood donors, the nPCR assay identified 24 (46%) C. pneumoniae DNA carriers, all of whom were positive by C. pneumoniae-specific serology. Thirty-two patients (32%) and 23 blood donors (44%) were MIF antibody-positive but repeatedly nPCR-negative; Bartonella henselae- or Bartonella quintana-specific antibodies were not detected among any of these subjects. In this study, C. pneumoniae DNA was common in PBMC of patients with coronary heart disease and in middle-aged blood donors.
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| 2. |
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| 3. |
- Söderberg, Stefan, 1957-
(författare)
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Leptin : a risk marker for cardiovascular disease
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A major cause of morbidity and early death in the Western societies is cardiovascular disease (CVD) secondary to atherosclerotic disease. Metabolic aberrations have been linked to CVD. Particular combinations of these so-called risk markers are common and (central) obesity, Type 2 diabetes, impaired glucose tolerance, hypertension, dyslipidemia, dysfibrinolysis and hyperinsulinemia are often associated. This has been entitled the Insulin Resistance Syndrome (1RS), due to underlying insulin resistance. Moreover, aberrations in circulating levels of androgens and IGF-binding proteins are associated with 1RS.The main hypothesis in this thesis was that increased levels of leptin, the recently discovered adipocyte derived hormone in combination with obesity may be an important factor in the link between 1RS and the development of CVD.The association between leptin levels and variables associated with the Insulin Resistance Syndrome was studied in a healthy sample (n=163) of middle-aged men and women from the northern Sweden MONICA health survey. Central obesity was associated with high levels of leptin and insulin in men and women. In contrast, central obesity was linked to low testosterone levels in men, whereas in women, central obesity was associated with high testosterone but low SHBG levels. Furthermore, in males and postmenopausal women central obesity was a major determinant for circulating leptin. Leptin levels were associated with biochemical androgenicity in non-obese men and women. The direction of this association was dependent on gender and body fat distribution. Specifically, testosterone was inversely associated to leptin in non-obese men and in normal weight women whereas testosterone was positively associated to leptin in non-obese women. In contrast, adiposity and insulin levels, but not testosterone, were associated to leptin in obese men and women. Similarly, leptin was associated to IGFBP-1 and proinsulin in non-obese men and premenopausal women. Hyperleptinemia was significantly associated to high PAI-1 levels in men and in centrally obese women. In a multivariate model, high leptin levels predicted PAI-1 levels in men but not in women. Finally, leptin levels were related to blood pressure in obese men.The impact of hyperleptinemia on future risk for development of CVD was tested in a nested case-referent study based on the MONICA and the Västerbotten Intervention Program surveys. It was found that hyperleptinemia and high total cholesterol levels were associated with increased risk for development of myocardial infarction whereas high levels of apolipoprotein A-l were protective. Hyperleptinemia together with hypertension remained as significant risk markers for hemorrhagic stroke whereas hypertension alone predicted ischemic stroke. The combinations of hyperleptinemia on one hand and low apolipoprotein A- 1 and high blood pressure on the other were associated with a pronounced increased risk for myocardial infarction and hemorrhagic stroke, respectively.In conclusion, hyperleptinemia is independently associated with several risk markers for CVD included in the insulin resistance syndrome. Furthermore, high leptin levels predict the development of CVD.
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| 4. |
- Söderberg, Stefan, et al.
(författare)
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Leptin is a risk marker for first-ever hemorrhagic stroke in a population-based cohort.
- 1999
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Ingår i: Stroke. - 0039-2499 .- 1524-4628. ; 30:2, s. 328-337
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Leptin, important for body weight regulation, may be involved in the pathogenesis of the insulin resistance syndrome, associated with cardiovascular disease. We tested to determine whether leptin is a risk marker for first-ever stroke in a nested case-referent study.METHODS: We identified 113 patients with first-ever stroke (94 with ischemic and 19 with hemorrhagic stroke) who, before the stroke, had participated in population-based health surveys in northern Sweden. Referents were matched for sex, age, date and type of health survey, and geographic region. Blood pressure (BP), body mass index (BMI), and presence of smoking, diabetes, and hypertension were recorded. Total cholesterol, insulin, and leptin were analyzed in stored samples. Risk markers for first-ever stroke were analyzed by conditional logistic regression analysis.RESULTS: Patients with hemorrhagic stroke had higher levels of BMI and systolic and diastolic BPs. Leptin levels were 72% and 59% higher in males and females, respectively, with hemorrhagic stroke versus referents. Patients with ischemic stroke more often had hypertension, diabetes mellitus, and higher fasting glucose and insulin levels. A diagnosis of hypertension and elevated systolic and diastolic BPs were significant risk markers for first-ever hemorrhagic stroke in univariate analysis. High leptin (OR=20.55; 95% CI, 1.12 to 376.7) levels together with hypertension (OR=16.28; 95% CI, 1.49 to 177.3) remained as significant risk markers in a multivariate model. The combination of high leptin and high systolic or diastolic BP were associated with a profoundly increased risk for hemorrhagic stroke (OR=22.11; 95% CI, 1.57 to 310.9). Diabetes, hypertension, and obesity (BMI >/=27), together with high levels of insulin, glucose, systolic and diastolic BP, were significant risk markers for first-ever ischemic stroke in univariate analysis. Hypertension (OR=2.10; 95% CI, 1.14 to 3.86) remained as an independent risk marker in a multivariate model.CONCLUSIONS: Plasma leptin is strongly associated with an increased risk for first-ever hemorrhagic stroke, independent of other risk markers for cardiovascular disease. Leptin may be an important link in the development of cardiovascular disease in obesity.
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| 5. |
- Söderberg, Stefan, et al.
(författare)
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Leptin is associated with increased risk of myocardial infarction.
- 1999
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Ingår i: Journal of Internal Medicine. - 0954-6820 .- 1365-2796. ; 246:4, s. 409-418
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES AND DESIGN: Leptin is involved in the regulation of bodyweight and metabolism in man and might also be involved in the pathophysiology of the insulin resistance syndrome, which is associated with the development of cardiovascular diseases. We tested whether leptin is a risk factor for acute myocardial infarction (AMI) in a nested case-referent study.SUBJECTS AND METHODS: Sixty-two men with first-ever AMI were identified who, prior to AMI, had participated in population-based health surveys in Northern Sweden. Referents were matched for sex, age, date and type of health survey, and geographical region. Blood pressure, body mass index (BMI) and the presence of smoking, diabetes and hypertension were recorded. Total cholesterol, apolipoprotein A-1 (apo A-1), apolipoprotein B (apo B), plasminogen activator inhibitor (PAI-1), insulin, and leptin were analysed in stored samples. Their influences on first-ever AMI were analysed by conditional logistic regression analysis.RESULTS: Men with first-ever AMI had higher BMI, plasma insulin and leptin, and diastolic blood pressure than the referents. Furthermore, they had lower plasma apo A-1 and were more often smokers. Smoking, high leptin, PAI-1 and cholesterol, and low apo A-1 levels were significant risk factors for first-ever AMI in univariate analysis. High leptin (OR 8.97; 95% CI: 1.73-46.5) and cholesterol (OR 5.18; 95% CI: 1.34-20.0) levels remained significant risk factors for AMI in a multivariate model. High apo A-1 was protective (OR = 0.13; 95% CI: 0.03-0.55). The combination of high leptin and low apo A-1 was associated with a particularly pronounced increased risk for AMI.CONCLUSION: Plasma leptin strongly predicts first-ever AMI. Our data support the hypothesis that leptin is an important link in the development of cardiovascular disease in obesity.
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| 6. |
- Söderberg, Stefan, et al.
(författare)
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Plasma leptin levels are associated with abnormal fibrinolysis in men and postmenopausal women.
- 1999
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Ingår i: Journal of Internal Medicine. - 0954-6820 .- 1365-2796. ; 245:5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Leptin is a crucial mediator of satiety signals and energy balance, and its circulating levels are increased in obesity. It has recently been shown that plasma leptin levels in humans correlate with circulating insulin and to insulin secretion. This indicates that leptin may be an important link in metabolic consequences of the insulin resistance syndrome. Whether this includes abnormalities in fibrinolysis has not been studied.METHODS AND RESULTS: Healthy subjects (n = 165; 85 men and 80 women) from the Northern Sweden MONICA population were investigated. Anthropometric measurements, oral glucose tolerance tests and sampling for plasma leptin, lipids, fibrinogen and fibrinolytic variables were made. Leptin levels were 342% higher in women than in men and were in both sexes strongly correlated to body mass index (BMI). After adjustments for age and BMI, leptin levels correlated significantly to pre/post glucoseload insulin levels in both sexes. After further adjustment for baseline insulin levels, leptin levels were in males significantly associated with increased waist circumference (P<0.001), low HDL cholesterol (P<0.05), low tPA activity (P<0.01) and high PAI-1 activity (P<0.001). In postmenopausal females, a significant association between leptin and low tPA activity/high PAI-1 activity was seen after adjustment for age and BMI (P<0.05). Conclusions. Circulating levels of leptin are associated with components of the insulin resistance syndrome, including defective fibrinolysis, in men and postmenopausal women. This suggests that leptin may be involved in the mediation of consequences of insulin resistance.
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