摘要:

Increased intima–media thickness (IMT) is a non-invasive marker of early arterial wall alteration, which is easily assessed in the carotid artery by B-mode ultrasound, and more and more widely used in clinical research. Methods of IMT measurement can be categorized by two approaches: (i) measurement at multiple extracranial carotid sites in near and far walls and (ii) computerized measurement restricted to the far wall of the distal common carotid artery. Because IMT reflects global cardiovascular risk, its normal value might be better defined in terms of increased risk rather than in terms of statistical distribution within a healthy population. The available epidemiological data indicate that increased IMT (at or above 1 mm) represents a risk of myocardial infarction and/or cerebrovascular disease. Close relationships have been shown between: (i) most traditional cardiovascular risk factors; (ii) certain emerging risk factors such as lipoproteins, psychosocial status, plasma viscosity, or hyperhomocysteinemia; and (iii) various cardiovascular or organ damages such as white matter lesion of the brain, left ventricular hypertrophy, microalbuminuria or decreased ankle to brachial systolic pressure index. Thus, IMT gives a comprehensive picture of the alterations caused by multiple risk factors over time on arterial walls. Prospective primary and secondary prevention studies have also shown that increased IMT is a powerful predictor of coronary and cerebrovascular complications (risk ratio from 2 to 6) with a higher predictive value when IMT is measured at multiple extracranial carotid sites than solely in the distal common carotid artery. Therapeutic double-blind trials have shown that lipid-lowering drugs, such as resin and overall statines, and to a lesser extent antihypertensive drugs, such as calcium antagonists, may have a beneficial effect on IMT progression in asymptomatic or in coronary patients. However, methodological standardization of IMT measurement still needs to be implemented before routine measurement of IMT can be proposed in clinical practice as a diagnostic tool for stratifying cardiovascular risk in primary prevention and for aggressive treatment decision. It can be anticipated however, that the presence of increased carotid IMT in one individual with intermediate cardiovascular risk would lead to his classification into the high-risk category and thus influence the aggressiveness of risk factor modifications.

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesTo assess the risk of hypertension associated with smoking status.DesignA population-based cross-sectional study in 12 417 men screened for a routine medical and biological check-up provided by their medical insurance at the ‘Institut inter-Régional pour la Santé’ (IRSA, Regional Institute for Health), a group of 10 medical centres in Western and Central France.Main outcome measuresThe prevalence and the relative risk of hypertension associated with smoking status.ResultsOverall, the prevalence of hypertension was higher in former smokers than in never smokers (13.5 versus 8.8%,P<0.001). The risk of hypertension was higher [odds ratio (OR) 1.31 (1.13–1.52),P<0.001] in former smokers than in never smokers, independently of age and alcohol intake. Both current and former smokers were at risk for systolic hypertension, especially those subjects aged 60 years and above. The risk of hypertension was associated with the number of cigarettes smoked [OR per 10 cigarettes smoked daily: 1.13 (1.05–1.21),P<0.001] and the duration of smoking cessation [OR 0.99 (0.98–1.00),P= 0.01]. When body mass index was entered into the model, the risk of hypertension in former smokers was no longer significant; however, current smokers remained at risk for systolic hypertension.ConclusionsFormer smokers are at risk for hypertension, probably because of the higher prevalence of overweight and obese subjects in this group. Current smokers are also at risk for systolic hypertension, especially in those subjects aged 60 years or older. However, this risk is independent of body mass index.

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesTo investigate the tracking of systolic arterial blood pressure (SBP) during childhood.Design and settingAll children born during 1981–82 in a rural community of eastern Finland were followed at the ages of 6 months, 7 and 15 years (SBP-6m, SBP-7y, SBP-15y). One hundred and thirty-eight out of 205 children completed the full follow-up period, of which 100 (45 girls) were included in the analysis with complete data.Main outcome measuresSBP (mmHg).ResultsSBP-6m was associated with SBP-7y (r= 0.715;P<0.001) and with SBP-15y (r= 0.238;P= 0.017) and SBP-7y was associated with SBP-15y (r= 0.348;P<0.001). Adjustment for confounders did not change these results. Children at the highest tertile of SBP-6m had a higher probability of being at the highest tertile of SBP-7y [relative risk (RR) = 4.3; 95% confidence interval (CI), (2.4–7.6)] and SBP-15y [RR = 1.9; 95% CI, (1.1–3.3)]. Children at the highest tertile of SBP-7y had a higher probability of being at the highest tertile of SBP-15y [RR = 2.6 (1.5–4.6)]. The regression analysis showed a significant main effect on SBP-15y for birth weight (negative association), male gender, current body mass index (BMI), change of BMI between the ages of 7 years and 15 years, SBP–6m, SBP-7y and the mean SBP between the ages of 6 months and 7 years (all with positive association). Children with family history of hypertension appear to have a higher SBP during childhood; however, this association did not reach a significant level.ConclusionsThe study confirmed the tracking of SBP during childhood. Birth weight was inversely associated with SBP-15y. Family history of hypertension was not significantly associated with SBP during childhood.

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundIn a previous study, we found that increased sodium concentrations in the drinking water led to an increase in mean arterial pressure (MAP) and systolic blood pressure (SBP) in fourth- and fifth-grade school children. Milk powder formulae have a low content of sodium, almost identical to that of breast milk. However, the final sodium concentration in the milk formula depends upon the concentration of sodium in the diluting water, which varies remarkably.ObjectiveTo evaluate changes in blood pressure during the first 2 months of life in neonates receiving low-sodium mineral water (LSMW), high-sodium tap water (HSTW), or breast milk.DesignA randomized, prospective study in a teaching hospital.MethodsFifty-eight Jewish term infants maintained on milk formula were randomly assigned to two groups. Group 1 consisted of 25 infants whose formula was diluted with LSMW (Eden Spring Mineral Water) having a sodium concentration of 32 mg/l (1.4 mmol/l). Group 2 contained 33 infants whose formula was diluted with HSTW having a sodium concentration of 196 mg/l (8.5 mmol/l). Fifteen breastfed babies served as the control group (group 3). Weekly weight, height, head circumference, heart rate, and systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were recorded for each infant for 8 consecutive weeks after birth. After 8 weeks, group 1 reverted to a diet similar to that of group 2. At 6 months of age (week 24), a follow-up blood pressure measurement was performed in 11, 20 and seven infants in groups 1, 2 and 3, respectively. Blood pressure was measured during sleep. Urinary sodium : creatinine ratio was determined monthly during the initial 2 months.ResultsIncreases in weight and height were equal in all groups. Heart rate did not differ between groups during the entire study period. From the age of 6 weeks until week 8, MAP, SBP and DBP were found to be significantly greater in the group 2 (HSTW). In parallel, the urinary sodium : creatinine ratio was significantly greater in this group. At week 24, blood pressure values in group 1 increased towards those of group 2.ConclusionsDiluting milk formula with tap water containing a high concentration of sodium will result in the infant being fed a high-salt diet. To equilibrate with breast milk, formula should be diluted with low-salt water. Blood pressure in the neonate is increased by a high sodium intake via drinking water.

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo determine to what extent urinary excretion of blood pressure-modulating electrolytes is genetically determined, and to identify their chromosomal localization.Design and methodsTwenty-six rat recombinant inbred strains (RIS) originating from reciprocal crosses of normotensive Brown Norway (BN.Lx) and spontaneously hypertensive rats (SHR) were used. A pilot experiment on a subset of strains determined that fasting decreases the impact of environmental noise and increases that of heritability. Twenty-four-hour urinary collections were obtained from fasting rats aged 6–12 weeks (3–8 rats per strain). Sodium (Na), potassium (K) and calcium (Ca) excretions were measured, and the Na/K ratio calculated. These phenotypes served as quantitative traits for the search of quantitative trait loci (QTLs) by scanning the RIS genome that was mapped with 475 polymorphic markers.ResultsConstant Na intake resulted in a low heritability for Na excretion, reflecting the environmental impact (intake = excretion), whereas fasting revealed a gradient among RIS indicative of the genetic component of the traits. In the fasting state, a locus on chromosome 14 was found to be significantly associated with K excretion (Alb,P= 0.00002,r= −0.69, logarithm of the odds score (LOD) 3.9), whereas another locus on chromosome 10 (D10Cebrp97s5,P= 0.0003,r= −0.69, LOD 3.0) and one on chromosome 6 (D6Cebrp97s14,P= 0.0007,r= −0.65, LOD 1.9) were more significantly associated with Na excretion and the Na/K ratio respectively. The observed correlations were all negative for Na, K and Na/K, indicating a higher excretion of Na and K and a greater Na/K ratio in rats bearing BN.Lx alleles at these loci, i.e. salt retention in fasting SHR. These three loci accounted for 47–55% of variance of their associated trait, suggesting that they are the main genetic determinants for these phenotypes in basal fasting conditions. Rats bearing the Y chromosome of SHR origin had significantly higher K excretion that, in turn, led to a significantly lower Na/K ratio. Finally, a locus on chromosome 7 was linked to Ca excretion, explaining 46% of the trait variance (D7Mit10, LOD score 3.0).ConclusionRIS enabled us to determine QTLs for environmentally modulated traits such as Na, K and Ca excretions. We demonstrated that whereas urinary electrolytes are determined mainly by intake (environment) in a steady state, their excretion in an adaptive state (fasting) is predominantly genetically determined by distinct QTL on autosomes as well as the Y chromosome. Furthermore, the loci responsible for Na and K excretions act independently of the locus governing the relative excretion of Na/K. Thus, the salt-retaining aspects of some hypertensives may be, in large part, determined by genes responsible for renal excretion, the impact of which is predominant over the environment under acute challenge.

ISSN:0263-6352    

出版商:OVID    

年代:2002

数据来源: OVID