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Biomedical subjects

C D Stehouwer

Publications and source records attributed to C D Stehouwer.

At least 19 recordsLinked to original sources

[Diastolic heart failure].

Diastolic heart failure is predominantly a disease of the elderly: at the age of 70 years, almost half of all patients with heart failure have diastolic heart failure. Hypertension and obesity are common underlying disorders in patients with diastolic heart failure. Patients with diastolic heart failure have an equal, or only slightly better, prognosis in terms of mortality compared to patients with systolic heart failure. Echocardiography can distinguish diastolic heart failure from systolic heart failure. Patients with heart failure and a normal ejection fraction almost certainly have a diastolic dysfunction. There is a lack of reliable data about the optimal medicinal treatment strategy for patients with diastolic heart failure. Angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, and (non-dihydropyridine) calcium antagonists have therapeutic potential. Digoxin may be contraindicated.

Adrenergic beta-Antagonists↗

Relation of impaired fasting and postload glucose with incident type 2 diabetes in a Dutch population: The Hoorn Study.

CONTEXT: Persons with impaired glucose tolerance (IGT) are known to have an elevated risk of developing diabetes mellitus. Less is known about diabetes risk among persons with impaired fasting glucose (IFG) or with normal glucose levels. OBJECTIVE: To determine the incidence of diabetes in relation to baseline fasting and postload glucose levels and other risk factors. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study conducted from October 1989 to February 1992 among 1342 nondiabetic white residents of Hoorn, the Netherlands, aged 50 to 75 years at baseline, in whom fasting plasma glucose (FPG) levels and glucose levels 2 hours after a 75-g oral glucose tolerance test were measured at baseline and at follow-up in 1996-1998. MAIN OUTCOME MEASURES: Cumulative incidence of diabetes, defined according to the diagnostic criteria of the World Health Organization (WHO-1985 and WHO-1999) and the American Diabetes Association (ADA-1997), during a mean follow-up of 6.4 years, compared among participants with IFG, IGT, and normal glucose levels at baseline. RESULTS: The cumulative incidence of diabetes was 6.1%, 8.3%, and 9.9% according to the WHO-1985, ADA, and WHO-1999 criteria, respectively. The cumulative incidence of diabetes (WHO-1999 criteria) for participants with both IFG and IGT was 64.5% compared with 4.5% for those with normal glucose levels at baseline. The odds ratios for diabetes (WHO-1999 criteria), adjusted for age, sex, and follow-up duration, were 10.0 (95% confidence interval [CI], 6.1-16.5), 10.9 (95% CI, 6.0-19.9), and 39.5 (95% CI, 17.0-92.1), respectively, for those having isolated IFG, isolated IGT, and both IFG and IGT. In addition to FPG and 2-hour postload glucose levels (P<.001 for both), the waist-hip ratio also was an important risk factor for developing diabetes (P =.002). CONCLUSION: In this study, the cumulative incidence of diabetes was strongly related to both IFG and IGT at baseline and, in particular, to the combined presence of IFG and IGT.

Aged↗

[Hormonal supplements for postmenopausal women: no evidence of protection against cardiovascular disease].

Atherothrombotic cardiovascular disease is a leading cause of death in women, especially in the postmenopause. It is controversial whether postmenopausal hormone replacement therapy is protective with regard to cardiovascular disease. On the one hand, observational studies consistently show that the risk of cardiovascular disease is 35 to 50% lower among users of hormonal replacement than among non-users. In addition, hormonal replacement is associated with an improvement of the lipid profile and several other potentially beneficial effects. On the other hand, two recent placebo-controlled randomised trials did not find evidence in favour of cardiovascular protection by hormonal replacement. This discrepancy may be explained by insufficient adjustment for lifestyle factors in observational studies and insufficient consideration of methodological flaws in experimental studies, both of which lead to an overestimation of the protective effect of hormonal replacement. Hormonal replacement may affect the pathophysiology of atherothrombosis in several ways, both positive and negative. Progress in this field requires the isolation of the positive effects.

Aged↗

Capillary recruitment is impaired in essential hypertension and relates to insulin's metabolic and vascular actions.

OBJECTIVE: In patients with essential hypertension, defects in both the metabolic and vascular actions of insulin have been described. Impaired microvascular function, a well-established abnormality in essential hypertension, may explain part of these defects. In the present study we investigated whether microvascular function is impaired in essential hypertension and relates to insulin's metabolic and vasodilatatory actions. METHODS: We measured 24-h ambulatory blood pressure, capillary recruitment after arterial occlusion, and skin blood flow responses to iontophoresis of acetylcholine and sodium nitroprusside in 18 subjects with untreated essential hypertension and in 18 control subjects. Whole body insulin sensitivity and leg insulin-mediated vasodilatation were assessed with the hyperinsulinaemic clamp technique and plethysmography. RESULTS: Hypertensive, as compared to normotensive, subjects had a decreased insulin sensitivity (0.8+/-0.3 vs. 1.7+/-0. 6 mgkg(-1)min(-1) per pmoll(-1); P<0.001), capillary recruitment after arterial occlusion (21.5+/-5.8 vs. 45.9+/-10.4%; P<0.001), acetylcholine-mediated vasodilatation (331+/-84 vs. 688+/-192%; P<0. 001), and insulin-mediated vasodilatation (median 29.3 vs. 47.2%; P<0.05). Correlation analyses with adjustment for sex, age, body mass index and waist-to-hip ratio showed significant relationships of capillary recruitment after arterial occlusion with blood pressure (r=-0.68; P<0.01), insulin sensitivity (r=+0.55; P<0.01) and insulin-mediated vasodilatation (r=+0.51; P<0.05), which extended from the normotensive to the hypertensive range. CONCLUSION: Skin microvascular function is associated with blood pressure and insulin's metabolic and vasodilatatory actions, both in normotensive and hypertensive subjects. These findings offer a potential mechanistic explanation of the links among insulin resistance, impaired insulin-mediated vasodilatation and hypertension.

Adult↗

Increased alpha3-fucosylation of alpha1-acid glycoprotein in Type I diabetic patients is related to vascular function.

Diabetic mellitus is attended by the development of endothelial dysfunction which is suggested to be accompanied with a chronic low-degree of inflammation. During a chronic hepatic inflammatory response, specific changes in glycosylation of the acute phase protein alpha1-acid glycoprotein (AGP) can be detected. In this report we studied the changes in glycosylation of AGP in more detail and evaluated the relation between a change in glycosylation of AGP and urinary albumin secretion in Type I diabetic patients. The glycosylation of AGP, studied by crossed affinity immunoelectrophoresis (CAIE) and high pH anion exchange chromatography with pulse amperometric detection (HPAEC-PAD), showed an increase in alpha3-fucosylation. Staining with an antibody against sialyl Lewis(x) (sLe(x)) implied that part of the alpha3-fucosylation was present in a sLe(x)-conformation. In the group of Type I diabetic patients with increased urinary albumin excretion, a significant increase in alpha3-fucosylation of AGP (p<0.0005) could be detected. Therefore, the increased alpha3-fucosylation of AGP can be used as an additional marker for the development of vascular complications in Type I diabetic patients.

Adolescent↗

Brachial artery pulse pressure and common carotid artery diameter: mutually independent associations with mortality in subjects with a recent history of impaired glucose tolerance.

BACKGROUND: Decreased large artery function, as reflected by increased brachial artery pulse pressure and increased carotid artery diameter and stiffness, may contribute to the increased mortality risk that is observed in subjects with impaired glucose tolerance. We therefore investigated the association between brachial artery pulse pressure and carotid artery diameter and stiffness, which are estimates of central artery stiffness and arterial remodelling, respectively, and mortality in subjects with a recent history of impaired glucose tolerance. DESIGN: A prospective, population-based cohort study. We measured brachial artery pulse pressure by oscillometric blood pressure measurements, and common carotid artery diameter and distensibility and compliance coefficients by ultrasound in 140 subjects with a recent history of impaired glucose tolerance. During a median 6.6-year follow-up, 16 subjects died. RESULTS: Brachial artery pulse pressure and common carotid artery diameter were positively related to all-cause mortality [hazard ratios per standard deviation, 1.7 (1.2-2.5) and 2.1 (1.3-3.3), respectively]. Results were similar after adjustment for gender, age, waist-to-hip ratio, body mass index, total cholesterol concentration, pre-existent cardiovascular disease, and hypertension, and after additional mutual adjustment. Common carotid artery distensibility and compliance coefficients were not statistically significantly associated with mortality. CONCLUSIONS: Among subjects with a recent history of impaired glucose tolerance, brachial artery pulse pressure and common carotid artery diameter are independently associated with mortality risk. Stiffness of the central arteries may explain the association between pulse pressure and mortality risk. The association between carotid diameter and mortality risk is more likely to reflect arterial remodelling in response to atherosclerosis than that in response to increased local stiffness.

Aged↗

Homocysteine metabolism in renal failure.

Of the many amino acid abnormalities that are present in chronic renal failure, hyperhomocysteinemia has drawn increasing attention because of its proposed role in the development and/or progression of atherothrombotic disease. Renal function is a major determinant of fasting plasma homocysteine level, and the inverse relationship between the glomerular filtration rate (GFR) and plasma homocysteine level is present throughout the whole range of renal function. Although this suggests an active renal homocysteine metabolism, no important urinary excretion or active homocysteine extraction has been demonstrated in the human kidney. Analysis of plasma concentrations of the various cofactors and substrates of homocysteine metabolism, and the effects of different therapies indicate that an abnormal folate metabolism may be the cause of hyperhomocysteinemia in uremia. This is further supported by the finding that homocysteine remethylation, as assessed by stable isotope techniques, is impaired in dialysis patients. It is unclear whether decreased remethylation is also responsible for other abnormalities of homocysteine metabolism in renal failure such as the exaggerated rise and the impaired decline of plasma homocysteine concentration after methionine or homocysteine loading. More studies are necessary to pinpoint the precise mechanisms that lead to hyperhomocysteinemia in renal failure. This should lead to optimal treatment and, ultimately, to the prevention of cardiovascular complications in this vulnerable patient group.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗

Progression of diabetic nephropathy: role of plasma homocysteine and plasminogen activator inhibitor-1.

Among patients with diabetic nephropathy, the decline in glomerular filtration rate (GFR) varies substantially, ranging from 2 to 20 mL/min per year. Identification of predictors of progression in diabetic nephropathy is important. Plasma total homocysteine (tHcy) rises with urinary albumin excretion rate in diabetes, and plasminogen activator inhibitor-1 (PAI-1) has been correlated with increased matrix accumulation in various glomerulopathies. In this prospective observational cohort study, we evaluated the importance of baseline tHcy and PAI-1 as predictors of the rate of decline in GFR. Baseline tHcy and PAI-1 were measured in 157 type 1 diabetic patients with diabetic nephropathy (92 men; mean age, 41 +/- 10 years; mean diabetes duration, 27 +/- 8 years; median GFR, 80 mL/min/1.73 m(2) [range, 23 to 143 mL/min/1.73 m(2)]). Hereafter, GFR was measured yearly with a plasma clearance technique for at least 3 years (median, 7 years [range, 3.0 to 8.3 years]). The mean rate of decline in GFR was 3.7 +/- 0.3 mL/min per year. A linear regression analysis revealed a borderline significant relationship between rate of decline in GFR and tHcy (P = 0.069) and PAI-1 (P = 0.087). Analysis of the rate of decline in GFR and tertiles of tHcy and PAI-1 revealed that increasing levels of tHcy were correlated with a significantly faster decline in GFR (P = 0.025), whereas increasing levels of PAI-1 were not. After adjustment for other well-established risk factors for progression of nephropathy in a multiple linear regression analysis, however, neither tHcy levels nor PAI-1 levels were independent predictors of rate of decline in GFR.

Adult↗

Prognostic implications of retinopathy and a high plasma von Willebrand factor concentration in type 2 diabetic subjects with microalbuminuria.

BACKGROUND: Microalbuminuria in subjects with type 2 diabetes may be heterogeneous with respect to clinical features, renal histology, and prognosis. There may be at least two types of microalbuminuria in diabetes, namely with and without generalized endothelial dysfunction. We investigated whether, among microalbuminuric subjects with type 2 diabetes, the presence of generalized endothelial dysfunction, as indicated by the presence of retinopathy or a high plasma von Willebrand factor (vWf) level, has prognostic implications. METHODS: In 173 type 2 diabetic subjects of a population-based cohort, we assessed the urinary albumin-to-creatinine ratio, the plasma vWf level, and the presence of retinopathy. The main outcome was cardiovascular mortality. RESULTS: The absolute difference in 7 years' cardiovascular mortality between microalbuminuric (albumin-to-creatinine ratio 2.0-30.0 mg/mmol) and normoalbuminuric subjects was higher in the presence as compared to the absence of retinopathy (55.6 vs 11.1%). The age- and sex-adjusted relative risk (95% confidence interval) of cardiovascular mortality, as compared to normoalbuminuric subjects without retinopathy, was 1.1 (0.1-9.2) for normoalbuminuric subjects with retinopathy, 1.8 (0.5-6.7) for microalbuminuric subjects without retinopathy, and 9.8 (3.1-30.9) for microalbuminuric subjects with retinopathy. The absolute difference in risk of 7 years' cardiovascular mortality between microalbuminuric and normoalbuminuric subjects was higher in the presence as compared to the absence of a high (>1.89 IU/ml) vWf level (49.8 vs 16.4%). The age- and sex-adjusted relative risk of cardiovascular mortality, as compared to normoalbuminuric subjects without a high vWf level, was 1.5 (0.4-5.5) for normoalbuminuric subjects with a high vWf level, 2.6 (0.7-9.6) for microalbuminuric subjects without a high vWf level, and 12.0 (2.9-49.5) for microalbuminuric subjects with a high vWf level. These differences in risk of cardiovascular mortality did not change materially after further adjustment for known duration of diabetes, hypertension, creatinine clearance, level of glycated haemoglobin and high-density lipoprotein cholesterol, and presence of cardiovascular disease. Analysis of all-cause instead of cardiovascular mortality showed a similar difference in risk of mortality between microalbuminuric subjects with or without retinopathy or a high vWf level. CONCLUSIONS: Among type 2 diabetic subjects with microalbuminuria, the presence of retinopathy or a high plasma vWf level affects the risk of cardiovascular death. Although larger studies are necessary, these findings support the concept that microalbuminuria in type 2 diabetes can occur in the absence or the presence of generalized endothelial dysfunction, and that the latter is a much more 'malignant' condition than the former.

Aged↗

Serum homocysteine levels are associated with the development of (micro)albuminuria: the Hoorn study.

Microalbuminuria is a strong indicator of the risk of future cardiovascular disease and renal dysfunction. Slightly increased levels of homocysteine, an independent risk factor for atherothrombotic disease, have recently been found to be associated with the presence of (micro)albuminuria. However, it is unknown whether increased homocysteine levels precede the occurrence of (micro)albuminuria. Normoalbuminuric subjects (n=316, 66 with non-insulin-dependent diabetes mellitus [NIDDM]) of an age-stratified, sex-stratified, and glucose tolerance-stratified sample of a population-based cohort study were investigated at baseline and after a mean follow-up duration of 6.1 years. Development of (micro)albuminuria was defined as a mean albumin-to-creatinine ratio >2.0 mg/mmol at the follow-up examination. The cumulative incidence of (micro)albuminuria was 14. 0% (9.7 % to 18.3%) among nondiabetic subjects and 22.7% (12.9% to 32.5%) among NIDDM patients. Age-adjusted, sex-adjusted, and glucose tolerance status-adjusted logistic regression analyses showed development of (micro)albuminuria to be significantly associated with baseline homocysteine levels >19.0 micromol/L compared with homocysteine levels <9.1 micromol/L (odds ratio [OR] 5.1, 95% CI 1.1 to 23.0). For homocysteine levels of 9.1 to 14.0 micromol/L and 14.1 to 19.0 micromol/L, the values were OR 1.2 (95% CI 0.5 to 3.0) and OR 1.8 (95% CI 0.6 to 5.3), respectively. Additional adjustment for baseline insulin resistance, blood pressure, body mass index, presence of cardiovascular disease and retinopathy, current smoking, or estimates of glomerular filtration rate did not materially affect the results. Substituting homocysteine levels as a continuous variable for categories of homocysteine levels showed that a 5-micromol/L increase of the homocysteine level was associated with an increased risk of developing (micro)albuminuria (OR 1.38, 95% CI 0.97 to 1.95). Analyses performed in nondiabetic and diabetic subjects separately gave similar results among nondiabetic subjects. Among diabetic subjects, the association between homocysteine level and (micro)albuminuria could not be estimated, because there was an insufficient number of diabetic subjects with high homocysteine levels. Hyperhomocysteinemia is an independent determinant of the development of (micro)albuminuria among nondiabetic subjects, even after adjustment for estimates of glomerular filtration rate. We could neither confirm nor reject an association between homocysteine levels and the development of (micro)albuminuria among NIDDM subjects. These data suggest that homocysteine may play a pathophysiological role in the development of (micro)albuminuria.

Age Factors↗

Decreased smooth muscle cell/extracellular matrix ratio of media of femoral artery in patients with atherosclerosis and hyperhomocysteinemia.

The aim of this study was to determine whether the morphology of the muscular femoral artery in patients with atherosclerosis and hyperhomocysteinemia differs from that of atherosclerotic vessels from patients with normal homocysteine levels. Whole-vessel biopsies of the superficial femoral artery were taken from patients with symptomatic atherosclerotic disease with and without hyperhomocysteinemia and from patients without atherosclerosis from traumatic amputations. The morphology of these specimens was studied qualitatively by light and electron microscopy and quantitatively by light microscopy in combination with a video overlay system. Atherosclerotic lesions in patients with hyperhomocysteinemia were morphologically similar to those in patients with normal homocysteine levels, except for a significantly decreased smooth muscle cell/extracellular matrix ratio of the media in hyperhomocysteinemic patients (P=0.02 versus normohomocysteinemic atherosclerotic group and P=0.001 versus group without a history of cardiovascular disease). Hyperhomocysteinemia is associated with a significant decrease of the smooth muscle cell/extracellular matrix ratio of the media of muscular femoral arteries without significant changes in medial thickness. Further investigations should concentrate on the cause of this newly discovered phenomenon and its impact on vascular compliance.

Adult↗

Impaired skin capillary recruitment in essential hypertension is caused by both functional and structural capillary rarefaction.

Capillary rarefaction occurs in many tissues in patients with essential hypertension and may contribute to an increased vascular resistance and impaired muscle metabolism. Rarefaction may be caused by a structural (anatomic) absence of capillaries, functional nonperfusion, or both. The aim of this study was to assess the extent of structural versus functional capillary rarefaction in the skin of subjects with essential hypertension. We examined skin capillary density with video microscopy before and during maximization of the number of perfused capillaries by venous congestion (structural capillary number) and before and during postocclusive reactive hyperemia (capillary recruitment, which may have a structural and/or functional basis). The study group was composed of 26 patients with never-treated essential hypertension and 26 normotensive control subjects. In both groups, intermittently perfused capillaries in the resting state were an important functional reserve for recruitment during postocclusive hyperemia. Recruitment of perfused capillaries during postocclusive reactive hyperemia was decreased in the hypertensive subjects compared with normotensive control subjects (47.9+/-6.8 versus 55.3+/-8.2 capillaries/mm(2), respectively; P<0.01). During venous occlusion, maximal capillary density was significantly lower in the hypertensive subjects than in the control subjects (52.5+/-6.6 versus 57.2+/-8.6 capillaries/mm(2), respectively; P<0.05), suggesting structural rarefaction. However, in the hypertensive subjects compared with the normotensive subjects, a smaller proportion of the maximal number of capillaries was perfused during postocclusive hyperemia (91.6+/-7.5% versus 97.2+/-2.7%, respectively; P<0.05), suggesting an additional functional impairment of capillary recruitment. If the difference in capillary numbers during venous congestion ( approximately 4.6 capillaries/mm(2)) truly reflects the structural difference between the normotensive and hypertensive subjects, then, at most, 62% (4.6/7.4x100%) of the difference in capillary numbers during postocclusive hyperemia ( approximately 7.4 capillaries/mm(2)) can be explained by structural defects, and at least 38% can be explained by functional defects. In conclusion, in patients with essential hypertension, recruitment of perfused capillaries is impaired, which can be explained by both functional and structural rarefaction.

Capillaries↗

Long-term homocysteine-lowering treatment with folic acid plus pyridoxine is associated with decreased blood pressure but not with improved brachial artery endothelium-dependent vasodilation or carotid artery stiffness: a 2-year, randomized, placebo-controlled trial.

Homocysteine is associated with atherothrombotic disease, which may be mediated through associations of homocysteine levels with blood pressure, endothelial function, or arterial stiffness. In a placebo-controlled, randomized clinical trial, we measured blood pressure, brachial artery endothelium-dependent vasodilation, and common carotid artery stiffness in 158 clinically healthy siblings of patients with premature atherothrombotic disease at baseline and after 1 and 2 years of homocysteine-lowering treatment with folic acid (5 mg) plus pyridoxine (250 mg). Intention-to-treat analyses limited to participants (n=130) who underwent at least 1 measurement after the baseline visit showed that compared with placebo, treatment with folic acid plus pyridoxine was associated with a 3.7-mm Hg (95% CI -6.8 to -0.6 mm Hg) lower systolic and a 1.9-mm Hg (95% CI -3.7 to -0.02 mm Hg) lower diastolic blood pressure over the 2-year trial period. Together with the decreased occurrence of abnormal exercise electrocardiography tests reported previously, our results support the hypothesis that homocysteine-lowering treatment with folic acid plus pyridoxine has beneficial vascular effects. Because no effects could be demonstrated on brachial artery endothelium-dependent vasodilation or on common carotid artery stiffness, the present study does not support the hypothesis that the cardiovascular effects of homocysteine are mediated through these factors, at least in clinically healthy individuals.

Adult↗

Evidence for genetic factors explaining the association between birth weight and low-density lipoprotein cholesterol and possible intrauterine factors influencing the association between birth weight and high-density lipoprotein cholesterol: analysis in twins.

Recent studies have demonstrated an association between low weight at birth and an atherogenic lipid profile in later life. To examine the influences of intrauterine and genetic factors, we investigated 53 dizygotic and 61 monozygotic adolescent twin pairs. Regression analysis demonstrated that low birth weight was associated with high levels of total cholesterol, low-density lipoprotein (LDL) cholesterol and apolipoprotein B (-0.17 mmol/liter per kg, P = 0.07; -0.18 mmol/liter per kg, P = 0.04; and -0.07 g/liter per kg, P = 0.02, respectively) and with low levels of high-density lipoprotein (HDL) cholesterol (+0.04 mmol/liter per kg, P = 0.1), after adjustment for age, sex, and body mass index. Intrapair differences in birth weight were significantly associated with differences in total cholesterol, LDL cholesterol, and apolipoprotein B in dizygotic twins after adjustment for differences in current body mass index (-0.49 mmol/liter per kg, P = 0.02; -0.51 mmol/liter per kg, P = 0.01; and -0.10 g/liter per kg, P = 0.04, respectively), demonstrating that the larger the difference in birth weight, the higher these risk factors in the twin with the lower birth weight, compared with the cotwin with the higher birth weight. In monozygotic twins, however, the associations between intrapair differences in birth weight and differences in total cholesterol, LDL cholesterol, and apolipoprotein B were in the opposite direction (+0.32 mmol/liter per kg, P = 0.03; +0.23 mmol/liter per kg, P = 0.08; and +0.06 g/liter per kg, P = 0.04, respectively). The association between intrapair differences in birth weight and differences in HDL cholesterol was not significant in dizygotic twins (+0.04 mmol/liter per kg, P = 0.6) and of borderline significance in monozygotic twins (+0.11 mmol/liter per kg, P = 0.05). These data suggest that genetic factors account for the association of low birth weight with high levels of total cholesterol, LDL cholesterol, and apolipoprotein B, whereas intrauterine factors possibly play a role in the association between birth weight and HDL cholesterol.

Adult↗

Markers of inflammation and cellular adhesion molecules in relation to insulin resistance in nondiabetic elderly: the Rotterdam study.

Insulin resistance, which is highly prevalent in the elderly, is suggested to be accompanied by an increased acute phase response. Until now, it is unclear whether cellular adhesion molecules are involved in the clustering of insulin resistance. In the present study, we examined the relationship of insulin resistance (measured by postload insulin) with levels of markers of inflammation and cellular adhesion molecules in a random sample of 574 nondiabetic elderly men and women participating in the Rotterdam Study. Associations were assessed by regression analysis, with ln-insulin as the dependent variable [regression coefficient (95% confidence interval)]. In our population, insulin was strongly and significantly (P < 0.001) associated with the markers of inflammation C-reactive protein [1.52 (0.96-2.08)], alpha-1-antichymotrypsin [1.25 (0.82-1.69)], and IL-6 [2.60 (1.69-3.52)], adjusted for age and gender. Associations weakened, to some extent, after additional adjustment for measures of obesity, smoking, and cardiovascular disease. Insulin was associated with the soluble intercellular adhesion molecule 1 [2.22 (1.29-3.16; P < 0.001)], whereas no association with the soluble vascular cell adhesion molecule 1 was found. The strength of the associations of insulin with C-reactive protein, alpha-1-antichymotrypsin, IL-6, and soluble intercellular adhesion molecule 1, as assessed by standardized regression coefficients, was comparable with the strength of the associations of insulin with high-density lipoprotein cholesterol, body mass index, and waist-to-hip ratio. The results of this population-based study indicate that low-grade inflammation and the cellular adhesion molecule soluble intercellular adhesion molecule 1 are an integral part of insulin resistance in nondiabetic elderly. These factors may contribute to the well-known relationship between insulin resistance and cardiovascular disease risk and might potentially become therapeutic targets in insulin resistant subjects.

Aged↗

Intra-uterine and genetic influences on the relationship between size at birth and height in later life: analysis in twins.

Epidemiological studies have consistently shown a positive association between size at birth (i.e. birth weight or birth length) and height in children, adolescents and adults. To examine whether this association is explained by genetic or nongenetic (intra-uterine) factors, we investigated birth weight, birth length and height in 60 dizygotic and 68 monozygotic adolescent twin pairs still living with their parents. Birth weight of the twins was obtained from their mothers. Height was measured in a standardised way. The mean age was 17+/-1.7 years for the dizygotic twins and 16+/-1.8 years for the monozygotic twins. Both dizygotic and monozygotic twins with the lowest birth weight from each pair had a height that was lower compared to their co-twins with the highest birth weight (dizygotic twins: 172.2+/-7.9 vs. 173.8+/-9.4 cm [p = 0.05]; monozygotic twins: 171.1+/-9.4 vs. 171.8+/-9.5 cm [p = 0.01]). Similarly, both dizygotic and monozygotic twins with the shortest birth length from each pair had a height that was lower compared to their co-twins with the longest birth length (dizygotic twins: 172.3+/-7.9 vs. 174.9plus minus9.7 cm [p < 0.05]; monozygotic twins: 168.9+/-10.6 vs. 169.9+/-10.2 cm [p < 0.01]). In addition, intra-pair differences in birth weight and birth length were significantly associated with differences in height in both dizygotic twins (regression coefficient: 4.3 cm/kg [95% confidence interval: 1.0 to 7.5] and 0.96 cm/cm [0.17 to 1.74], respectively) and monozygotic twins (2.8 cm/kg [1.4 to 4.1] and 0.73 cm/cm [0.40 to 1.06], respectively). These associations were stronger in dizygotic than in monozygotic twins, but this difference was not statistically significant (for birth weight p = 0.4; and for birth length p = 0.6). However, genetic model fitting indicated that models incorporating a genetic source of the covariance gave a better description of the observed association of birth weight and length with height in later life than models not incorporating this genetic source. The results were similar for data on adult height after 12 years of follow-up in a subgroup of these twin pairs. These data suggest that the association between size at birth and height in later life is influenced by non-genetic intra-uterine and by genetic factors.

Adolescent↗

Heterogeneity of the association between plasma homocysteine and atherothrombotic disease: insights from studies of vascular structure and function.

Among individuals with severe hyperhomocysteinaemia, there is a striking heterogeneity in the severity of the clinical features. This observation demonstrates that factors must exist that modulate the relationship between hyperhomocysteinaemia and clinical disease. Investigations of the association between mild-to-moderate hyperhomocysteinaemia and atherothrombotic disease also suggest heterogeneity in the association between plasma homocysteine levels and 1) clinical disease; 2) angiographic and echographic estimates of the extent of atherosclerosis; 3) arterial stiffness; 4) endothelial function; and 5) procoagulant status. The commonly held view that homocysteine is a vasculotoxic substance that promotes atherogenesis by causing endothelial damage is incomplete, because it cannot explain this heterogeneity. I suggest that homocysteine may have both prothrombotic and proatherogenic properties, but that there are strong, as yet unidentified enhancing and protective factors, the prevalence of which may differ among populations. This concept could account for some of the observed heterogeneity. Identifying these factors would be of major clinical importance and would provide crucial mechanistic insights.

Arteries↗