Sedentary Behavior,Cardiorespiratory Fitness,Physical Activity,and Cardiometabolic Risk in Men: The Cooper Center Longitudinal Study

ObjectiveTo examine the association between sedentary behavior and cardiometabolic risk, while taking into account cardiorespiratory fitness (fitness) and physical activity.Participants and MethodsWe examined the association of sedentary behavior, physical activity, and fitness (exposure variables) to cardiometabolic biomarkers and metabolic syndrome (outcome measures) among a historic cohort (January 2, 1981, through October 16, 2012) of men. First, we estimated the association (cross-sectionally and longitudinally) of sedentary behavior along with physical activity and fitness to lipids and lipoproteins, glucose, blood pressure, and markers of adiposity, including body mass index, waist circumference, and body fat percentage. We then prospectively examined the effects of baseline sedentary time on the incidence of metabolic syndrome, while adjusting for physical activity, fitness, and other covariates in multivariate models.ResultsMultivariate analysis of baseline data revealed that in comparison with the reference group (≤9 h/wk of sedentary time), more sedentary behavior was significantly associated with a higher triglyceride level, a higher triglycerides–high-density lipoprotein cholesterol ratio, and a higher body mass index, waist circumference, and body fat percentage (P<.05 for trend), after adjusting for physical activity and covariates. When adjusting for fitness and covariates, prolonged sedentary time was only associated with a higher triglyceride–high-density lipoprotein cholesterol ratio (P=.02 for trend). Sedentary time was not associated with the incidence of metabolic syndrome in multivariate models. Longitudinal analyses revealed that a 1–metabolic equivalent increase in fitness was significantly (P<.05) associated with almost all biomarkers when adjusting for sedentary behavior, with little moderation observed.ConclusionThe association between prolonged sedentary time and cardiometabolic biomarkers is markedly less pronounced when taking fitness into account. Further exploration of the effects of sedentary behavior on cardiometabolic risk is warranted in cohorts with available fitness data. Furthermore, our findings underscore the need to encourage achieving higher fitness levels through meeting physical activity guidelines to decrease disease risk factors.     

鹿茸提取物复方对骨质疏松症调节作用

目的 探讨鹿茸提取物复方对糖皮质激素性骨质疏松症(GIO)大鼠脂类代谢指标影响及机制。方法将79只Wistar大鼠随机分为对照组、模型组、鹿茸组及骨疏康组,采用后肢肌注地塞米松(2.5 mg/kg,每周2次)造模,造模同时,鹿茸组(0.439 g/kg)及骨疏康组(2.1 g/kg)灌胃处理,连续9周,采用骨密度仪测定大鼠股骨骨密度、自动生化分析仪测定血清高密度脂蛋白胆固醇(HDL-C)含量、实时定量PCR法及Western blot法测定骨组织脂肪细胞型脂肪酸结合蛋白(A-FABP) mRNA和蛋白表达。结果 对照组、模型组、鹿茸组及骨疏康组大鼠股骨骨密度分别为(0.116±0.009)、(0.108±0.006)、(0.115±0.009)、(0.111±0.006) g/cm²,血清HDL-C含量分别为(0.503±0.013)、(0.352±0.017)、(0.496±0.023)、(0.383±0.015) mmol/L;与对照组比较,模型组大鼠股骨骨密度、血清HDL-C含量明显降低(P<0.01),股骨A-FABP mRNA和蛋白表达明显增强(P<0.01);与模型组比较,鹿茸组大鼠股骨骨密度、血清HDL-C含量明显升高(P<0.01),股骨A-FABP mRNA及蛋白表达明显降低(P<0.01)。结论 鹿茸提取物复方对大鼠GIO具有一定干预作用,其机制可能与降低大鼠血清中HDL-C含量、升高骨组织A-FABP表达有关。     

胆固醇/高密度脂蛋白-胆固醇比值在脑梗死中的价值研究

目的:探讨胆固醇/高密度脂蛋白-胆固醇比值(TC/HDL-C比值)与脑梗死发病危险性的关系以及这一比值在脑梗死患者合并高血压或糖尿病时的变化。方法:选择197例脑梗死患者分为三组:单纯脑梗死组、合并高血压组、合并糖尿病组。58例健康者作为正常对照组,探讨这一比值的变化。结果:胆固醇(TC)水平及TC/HDL-C比值在脑梗死患者与正常对照组间有显著性差异(P<0.05);脑梗死患者的HDL-C水平较正常对照组降低,但两者差异无显著性(P>0.05);不同病例组间TC、HDL-C水平及TC/HDL-C比值无显著性差异(P>0.05)。结论:TC/HDL-C比值是脑梗死的危险因素,与高血压、糖尿病无关。     

Serum levels of polyunsaturated fatty acids are low in Chinese men with metabolic syndrome,whereas serum levels of saturated fatty acids,zinc, and magnesium are high

The purpose of this study was to examine the hypothesis that serum levels of phospholipid (PL) fatty acids (FA) and minerals are associated with the components of metabolic syndrome (MetS) in the Chinese population and the profiles of changes may differ from patients with MetS from Western countries. The levels of serum PL, FA, and minerals were examined in 201 subjects (52 with MetS and 149 healthy controls without any MetS components) in China. The saturated FA proportion in serum was significantly higher, whereas the proportion of total polyunsaturated FA (PUFA), n-3 and n-6 PUFA (22:6n-3: −16%, P = .006; 20:4n-6: −36%, P < .001), and estimated δ-5 desaturase were significantly lower in the MetS group compared with those that are not MetS. Subjects with MetS had higher levels of serum Zn (P = .037) and Mg (P < .001) than subjects without MetS. The proportion of n-3 PUFA was significantly negatively correlated with body mass index and waist circumference. In conclusion, serum PL FA composition and serum minerals in Chinese men with MetS differed significantly from that of healthy individuals, reflecting a decrease in n-3 and n-6 PUFA, especially 22:6n-3 and 20:4n-6, and an increase in saturated FA, magnesium, and zinc. These changes may reflect improper dietary intake in subjects with MetS, and dietary modification could be useful to prevent MetS and as an adjunctive therapy.     

高密度脂蛋白胆固醇直接测定方法学评价

作者通过一系列实验,从稳定性、特异性、线性和回归分析,干扰物分析及方法学比较等方面对高密度脂蛋白胆固醇的无标本预处理的直接测定法进行了讨论。HDL—C重复测定的最大CV为5.7％,直接法与磷酸钨镁沉淀法有很好的相关性,Y=0.00256±XO.045mmol/1,r=0.970。当TG=2.2时,HDL—C的浓度仅增加2％,Hb对结果有明显的正干扰作用,而胆红素却使HDL—C的结果偏低。实验表明,HDL—C的直接测定法具有操作简单,一定条件下结果稳定,准确,能够应用于全自动分析的特点,该方法对于人群血脂代谢的筛查工作,及时发现和预防心血管疾患的危险致病因素提供了相当便利的条件。     

Modulation of HDL metabolism by the niacin receptor GPR109A in mouse hepatocytes

The niacin receptor GPR109A is a G_i-protein-coupled receptor which mediates the effects of niacin on inhibiting intracellular triglyceride lipolysis in adipocytes. However, the role of GPR109A in mediating the effects of niacin on high density lipoprotein (HDL) metabolism is unclear. We found niacin has no effect on HDL-C in GPR109A knockout mice. Furthermore, niacin lowered intracellular cAMP in primary hepatocytes mediated by GPR109A. We used an adeno-associated viral (AAV) serotype 8 vector encoding GPR109A under the control of the hepatic-specific thyroxine-binding globulin promoter to specifically overexpress GPR109A in mouse liver. Plasma HDL-C, hepatic ABCA1 and the HDL cholesterol production rate were significantly reduced in mice overexpressing GPR109A. Overexpression of GPR109A reduced primary hepatocyte free cholesterol efflux to apoA-I; conversely, GPR109A deficient hepatocytes had increased ABCA1-mediated cholesterol efflux. These data support the concept that the HDL-C lowering effect of niacin in wild-type mice is mediated through stimulation of GPR109A in hepatocytes; such an effect then leads to reduced hepatocyte ABCA1 expression and activity, decreased cholesterol efflux to nascent apoA-I, and reduced HDL-C levels. These results indicate that niacin-mediated activation of GP109A in liver lowers ABCA1 expression leading to reduced hepatic cholesterol efflux to HDL.     

Serum HDL-C levels, log (TG/HDL-C) values and serum total cholesterol/HDL-C ratios significantly correlate with radiological extent of disease in patients with community-acquired pneumonia

BACKGROUND: In several studies, it was shown that there was a marked decrease in serum levels of HDL-C during infection and inflammation in general. In particular, a decrease in the level of serum HDL-C was also shown in pneumonia. Correlations between inflammatory markers such as acute phase proteins, cytokines and serum HDL-C levels were shown. However, there are no studies indicating a correlation between serum HDL-C levels and the radiological extent of the disease (RED) in community-acquired pneumonia (CAP). AIM: We hypothesized that there could be a relationship between serum HDL-C levels and RED in CAP. MATERIALS AND METHODS: A case-controlled study, including 97 patients with CAP and 45 healthy subjects, was performed. Chest X-rays of CAP patients were scored for RED, and correlations were investigated between RED scores, serum lipid parameters, the erythrocyte sedimentation rate (ESR) and serum albumin levels. RESULTS: The mean serum HDL-C level was lower in CAP patients than in controls. A significant and negative correlation between RED scores (REDS) and serum HDL-C levels was detected (r = -0.64, P = 0.0001). There were also significant correlations between REDS and other lipid parameters. Significant correlations between ESR and serum HDL-C levels and between ESR and other serum lipid parameters were also found. CONCLUSION: It appears that serum HDL-C levels are generally lower in CAP cases than in healthy controls. Serum HDL-C levels and serum albumin levels might decrease and serum total cholesterol/HDL-C ratios and log (TG/HDL-C) values might increase proportionally with RED in CAP patients. These results might have some significance for individuals having long-standing and/or recurrent pneumonia and other cardiovascular risk factors.     

Lipoprotein(a), Cardiovascular Disease,and Contemporary Management

Elevated lipoprotein(a) (Lp[a]) is a causal genetic risk factor for cardiovascular disease. To determine if current evidence supports both screening and treatment for elevated Lp(a) in high-risk patients, an English-language search of PubMed and MEDLINE was conducted. In population studies, there is a continuous association between Lp(a) concentrations and cardiovascular risk, with synergistic effects when low-density lipoprotein (LDL) is also elevated. Candidates for Lp(a) screening include patients with a personal or family history of premature cardiovascular disease, familial hypercholesterolemia, recurrent cardiovascular events, or inadequate LDL cholesterol (LDL-C) responses to statins. Given the comparative strength of clinical evidence, reducing LDL-C to the lowest attainable value with a high-potency statin should be the primary focus of lipid-modifying therapies. If the Lp(a) level is 30 mg/dL or higher in a patient who has the aforementioned characteristics plus residual LDL-C elevations (≥70-100 mg/dL) despite maximum-potency statins or combination statin therapy, the clinician may consider adding niacin (up to 2 g/d). If, after these interventions, the patient has progressive coronary heart disease (CHD) or LDL-C levels of 160-200 mg/dL or higher, LDL apheresis should be contemplated. Although Lp(a) is a major causal risk factor for CHD, no currently available controlled studies have suggested that lowering it through either pharmacotherapy or LDL apheresis specifically and significantly reduces coronary risk. Further research is needed to (1) optimize management in order to reduce CHD risk associated with elevated Lp(a) and (2) determine what other intermediate- or high-risk groups might benefit from Lp(a) screening.     

心房颤动患者血浆高密度脂蛋白胆固醇水平变化的临床研究

目的 探讨血浆高密度脂蛋白胆固醇(HDL-C)水平与心房颤动之间的关系.方法 研究对象为135例房颤患者,按能否自行复律分为阵发性房颤组及非阵发性房颤组,并选择同期健康人群30例作为对照组.非阵发性房颤组又分别按左心房内径(LAD＞35 mm,LAD≤35mm)分成亚组,测量所有房颤及正常对照组患者的血浆HDL-C的水...