Endothelial Function In Elders With Metabolic Syndrome

BackgroundEpidemiological studies showed that elders belong to the high-risk group for metabolic syndrome(MS) and that MS , related to age significantly, has been common in elders. From Framingham off-spring study, Tofler et al confirmed that advancing age is associated with elevated levels of hemostatic factors indicative of a prothrombotic state and suggested that the age-related increase in cardiovascular risk may be a result of a prothrombotic imbalance. Aging and thrombosis has been an important clinical problem ,and the MS also leads to thrombatic imbalance, which result in the increase of the possibility of the thrombotic events. For elders, MS is a strong predictive factor for myocardial infarction and cerebral stroke. However, the pathophysiologic mechanisms of MS haven't been clearly elucidated. In recent years, the relationship between endothelial functions and MS has been more and more interesting and been a new important approach to understanding MS. ObjectiveTo study the endothelial functions of the elders with MS, discuss the relationship between the risk factors and the endothelial dysfunction and provide evidence for the early diagnosis and intervention for endothelial dysfunction. Methods1. Division People were divided into healthy elders (HE) group (19 men and 9 women, mean age 72.00±4.01 years), the elders with metabolic syndrome (EMS) group (21 men and 12 women, mean age 71.83±5.93 years), and adults with metabolic syndrome (AMS) group (23 men and 7 women, mean age 49.42±6.37 years)and 2. Detection Waist circumstance (WC), high desity lipoprotein-cholesterol (HDL-C), triglyceride (TG), systolic blood pressure (SBP), diastolic blood pressure (DBP) and fast blood glucose (FBG) were detected following the formal criteria. Endothelin-1 (ET-1), nitric oxide (NO) and the prothrombotic markers, such as tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), fibrinogen (FIB) and D-dimer (DD), were detected with the agents supplied by the proper companies. High resolution ultrasound was used to measure the diameters of the brachial arteries including basal diameter (D₀), diameter in response to reactive hyperemia(D₁), and diameter after the administration of Nitroglycerin (D2). Obviously, the index of the flow-mediated dilation or EDD, replaced by â–³D₁%, could be calculated as â–³D₁% = (D₁-D₀)/D₀×100%; and the index of the non-flow- mediated dilation or endothelial-independent dilation (EID), replaced by â–³D₂, could be calculated asâ–³D₂% = ( D₂-D₀)/D₀×100%.3. Statistical Analysis Statisticses were analysised by SPSS10.0. Single linear regression analysis and multivariate regression analysis were adopted.Results1. Compared with HE, for EMS: WC, HDL-C, TG, SBP, DBP and FBG increased significantly (P<0.05);2. Compared with AMS, for EMS: in EMS, age, SBP and FBG increased significantly (P<0.05), and DBP decreased significantly (P<0.05);3. Compared with HE, for EMS: NO (ug/l), t-PA (ng/ml), â–³D₁%, â–³D₂ decreased significantly (85.38±14.10 vs 43.20±10.09; 27.31±10.27 vs 18.80±6.56; 11.46±4.44 vs 4.05±3.34; 15.67±6.41 vs 9.78±5.79, P<0.05); ET-1 (pg/ml), PAI-1 (ng/ml), FIB(g/l), DD(ug/l) increased significantly (46.87±8.47 vs 86.04±16.37; 49.09±8.57 vs 106.07±21.98; 2.82±0.75 vs 3.93±1.04; 422.30±94.95 vs 631.37±156.87, P<0.05);4. Compared with AMS, for EMS: NO (ug/l), â–³D₂% decreased significantly (53.20±14.17 vs 43.20±10.09; 15.17±4.88 vs 9.78±5.79, P<0.05), ET-1 (pg/ml), PAI-1 (ng/ml), FIB(g/l) increased significantly (64.52±21.29 vs 86.04±16.37; 83.33±16.75 vs 106.07±21.98; 3.08±0.83 vs 3.93±1.04, P<0.05); no significance existed among t- PA, DD, â–³D₁%(P>0.05);5. Single linear regression analysis showed that EDD had a negative correlation with WC, TG, HDL-C, FBG, SBP, DBP, PAI-1, FIB, DD; whereas had a positive correlation with NO, t-PA;6. Multivariate regression analysis showed that EDD had a negative correlation with SBP, PAI-1, FIB, DD; whereas had a positive correlation with NO, t-PA; Conclusions1. Endothlial dysfunction and prothrombolic state are present in the patients with MS;2. Elders with MS are in a more severe prothrombolic state than the adults with MS, which suggests that the aging is a very important risk factor of the endothlial dysfunction and prothrombolic state;3. In the elders with MS, there exists a negative correlationship among the EDD and obesity, hypertension, dyslipidemia and hyperglycemia, and the elevated level of SBP is a very important independent risk factor for the endothlial dysfunction and prothrombolic state;4. In the elders with MS, there exists a negative correlationship among the EDD and indices of the prothrombolic state, and the elevated levels of the PAI-1, DD and the reduced levels of the NO, t-PA are very important independent risk factors for the endothlial dysfunction and prothrombolic state;5. In the elders with MS, the EID also blunts, which means that the smooth muscles blunt as well;6. As for the elders with MS, the combination of the control of the SBP plus anti-thrombosis may represent an effective approach to the improvenment of the EDD.