RESUMO
BACKGROUND: Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Recently, triglyceride rich lipoproteins are proposed to contribute to CAD risk; its concentrations would be partly determined by lipoprotein lipase (LPL) and endothelial lipase (EL). Epicardial adipose tissue (EAT), a visceral AT surrounding myocardium and coronary arteries, emerged as an important actor in CAD; the increase in its volume could be a consequence of LPL and EL. Circulating enzymes levels would be conditioned by local tissue factors. Our aim was to evaluate LPL, EL and their regulators levels in serum and EAT from CAD patients, searching for possible parallelisms and their role in the lipoprotein profile. METHODS: In serum, EAT and subcutaneous AT (SAT) from patients undergoing coronary artery bypass graft (CABG, n = 25) or valve replacement (No CABG, n = 25), LPL, EL and glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein-1 (GPIHBP1) expression were evaluated. Besides, Apoprotein (Apo)CII, CIII and AV were determined in serum, along with lipoprotein profile. RESULTS: Insulin-resistance markers were higher in CABG (p < 0.05). Serum LPL levels were decreased (p = 0.045), while EL levels increased (p < 0.001) in CABG, without differences in EAT or SAT. Circulating GPIHBP1 concentrations were decreased in CABG (p = 0.047), while EAT GPIHBP1 expression was increased (p < 0.001). ApoCII and ApoAV concentrations were higher in CABG (p = 0.016 and p = 0.047, respectively), without differences in ApoCIII concentrations between groups. CONCLUSIONS: In EAT, LPL and EL protein levels were not changed in CAD, although GPIHBP1 protein levels were higher. EAT would be a minor contributor to the circulating levels of the enzymes.
Assuntos
Doença da Artéria Coronariana , Receptores de Lipoproteínas , Tecido Adiposo , Humanos , Lipase LipoproteicaRESUMO
BACKGROUND: Qualitative lipoprotein changes, such as an increase in fasting remnants, are reported in subclinical hypothyroidism (SCH). It was hypothesized that such changes are due to reduced hepatic lipase (HL) activity in SCH: HL is an enzyme regulated by thyroid hormones, and is involved in the degradation of triglyceride (TG)-rich remnants. This study aimed to quantify remnant-like lipoproteins (RLP), small dense LDL (sdLDL), and HL activity in women with SCH, and to assess these parameters after levothyroxine replacement therapy. METHODS: This was an observational cross-sectional study with a subsequent longitudinal follow-up. Findings in women with thyrotropin levels >4.5 mIU/L (SH group) were compared with age- and body mass index (BMI)-matched euthyroid women (control group). In addition, a subgroup analysis was undertaken in SCH women who chose to receive levothyroxine treatment (0.9 µg/kg/day) for 6 months. RLP was quantified by measuring cholesterol (RLP-C) and triglycerides (RLP-TG) after immunoaffinity chromatography, and sdLDL by automated standardized methods; HL activity was measured in post-heparin plasma. RESULTS: The SCH group included 37 women; 29 women were included in the control group. In addition, 22 women with SCH were included in the subgroup analysis (levothyroxine treatment). Significantly higher RLP values were observed in the SCH group than in the control group: RLP-C (median [range], mg/dL): 20.3 (5.8-66.8) versus 10.2 (2.7-36.3), p = 0.005; RLP-TG (mg/dL): 26.3 (3.2-123.3) versus 12.1 (2.5-61.6), p = 0.033. HL activity (mean ± standard deviation [SD], µmol free fatty acid/mL post-heparin plasma.h)-9.83 ± 4.25 versus 9.92 ± 5.20, p = 0.707-and sdLDL levels (mg/dL)-23.1 ± 10.7 versus 22.6 ± 8.4, p = 0.83-were similar. After levothyroxine, RLP-C decreased-21.5 (5.8-66.8) versus 17.2 (4.1-45.6), p = 0.023-and HL increased-9.75 ± 4.04 versus 11.86 ± 4.58, p = 0.012-in the subgroup of SCH women. No changes in sdLDL were observed. CONCLUSIONS: Women with SCH have higher RLP levels than matched controls do, but their RLP-C levels decrease significantly following levothyroxine therapy. Furthermore, HL activity also increases after levothyroxine therapy and can be interpreted as a possible explanation for the decrease in RLP-C.
Assuntos
Terapia de Reposição Hormonal , Hipotireoidismo/tratamento farmacológico , Lipase/metabolismo , Lipoproteínas LDL/sangue , Fígado/efeitos dos fármacos , Tiroxina/uso terapêutico , Adulto , Idoso , Doenças Assintomáticas , Biomarcadores/sangue , Estudos de Casos e Controles , Colesterol/sangue , Estudos Transversais , Feminino , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/diagnóstico , Hipotireoidismo/enzimologia , Lipoproteínas/sangue , Fígado/enzimologia , Estudos Longitudinais , Pessoa de Meia-Idade , Resultado do Tratamento , Triglicerídeos/sangueRESUMO
BACKGROUND: Type 2 diabetes (T2DM) and chronic renal disease constitute important risk factors of atherosclerotic cardiovascular disease, associated with lipid abnormalities, and proinflammatory states. Advances in renal replacement therapy such as hemodialysis (HD) have not reduced morbi-mortality. It has not been elucidated if the concomitant presence of T2DM or metabolic syndrome with end-stage renal disease further impairs the atherogenic profiles. METHODS: We studied 122 HD patients, among which 44 presented with T2DM (HD-T2DM) and 30 with metabolic syndrome (HD-MS); 48 had neither T2DM nor metabolic syndrome (HD-C). Lipoprotein profile, including atherogenic remnant lipoproteins (RLP), and inflammation markers--high sensitivity C-reactive protein (hsCRP), adiponectin, and interleukin-6 (IL-6)--were measured. RESULTS: In all HD patients, triglycerides, free fatty acids, and RLP showed no differences between HD groups, whereas high-density lipoprotein cholesterol (HDL-C) was decreased, particularly in HD-T2DM and HD-MS, with respect to HD-C (P<0.01). Regarding inflammatory parameters, both IL-6 and hsCRP were found to be similar between HD groups. Adiponectin paradoxically shows higher values in relation to those expected for insulin resistance situations showing no differences between HD groups. CONCLUSIONS: The presence of T2DM or metabolic syndrome did not worsen atherogenic lipoprotein levels, but did reduce HDL-C. Neither was the proinflammatory profile further altered in HD patients in the presence of insulin resistance conditions.
Assuntos
Diabetes Mellitus Tipo 2/sangue , Inflamação/sangue , Resistência à Insulina , Falência Renal Crônica/sangue , Lipídeos/sangue , Diálise Renal/métodos , Adiponectina/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Aterosclerose/sangue , Aterosclerose/imunologia , Proteína C-Reativa/metabolismo , HDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/imunologia , Ácidos Graxos não Esterificados/sangue , Feminino , Humanos , Interleucina-6/sangue , Falência Renal Crônica/imunologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Triglicerídeos/sangueRESUMO
OBJECTIVE: To study size heterogeneity of triglyceride rich lipoproteins (TRL) in metabolic syndrome (MS). DESIGN AND METHODS: Thirty MS patients and 14 healthy subjects were included. In fasting serum we measured: lipid profile, free fatty acids (FFA) and adiponectin; TRL were isolated (d<1.006 g/mL) and analysis by size exclusion HPLC followed by UV detection was performed; each subfraction was expressed as percentage of total TRL. RESULTS: MS patients, even those with normal triglycerides, presented higher proportion of very large VLDL (90 nm diameter) and large VLDL (60 nm) and slightly lower of typical VLDL (37 nm) (p<0.04); increased FFA (p=0.04) and lower adiponectin (p=0.001). FFA correlated with large VLDL% (r=0.58; p=0.003), independently of insulin-resistance and waist. Furthermore, the lower the adiponectin, the greater the predominance of large VLDL (r=-0.40; p=0.04). CONCLUSION: MS was associated with large VLDL, described as more atherogenic beyond triglyceride levels. Size exclusion HPLC would represent a useful tool for assessing subfractions' lipoprotein profile.
Assuntos
Lipoproteínas VLDL/sangue , Síndrome Metabólica/sangue , Adiponectina/sangue , Adulto , Argentina/epidemiologia , Aterosclerose/epidemiologia , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Ácidos Graxos não Esterificados/sangue , Feminino , Humanos , Lipoproteínas VLDL/química , Lipoproteínas VLDL/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Tamanho da Partícula , Risco , Triglicerídeos/sangue , UltracentrifugaçãoRESUMO
BACKGROUND: Dietary salt restriction has been reported to adversely modify the plasma lipoprotein profile in hypertensive and in normotensive subjects. We investigated the effects of the low sodium intake (LSI) on the plasma lipoprotein profile and on inflammation and thrombosis biomarkers during the fasting and postprandial periods. METHODS: Non-obese, non-treated hypertensive adults (n=41) were fed strictly controlled diets. An initial week on a control diet (CD, Na=160 mmol/day) was followed by 3 weeks on LSI (Na=60 mmol/day). At admission and on the last day of each period, the 24-h ambulatory blood pressure was monitored and blood was drawn after an overnight fasting period and after a fat-rich test meal. RESULTS: The dietary adherence was confirmed by 24-h urinary sodium excretion. Fasting triglyceride (TG), chylomicron-cholesterol, hsC-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) concentrations, renin activity, aldosterone, insulin, and homeostasis model assessment insulin resistance (HOMA-IR) values were higher, but non-esterified fatty acids (NEFA) were lower on LSI than on CD. For LSI, areas under the curve (AUC) of TG, chylomicron-cholesterol, apoB and the cholesterol/apoB ratio were increased, whereas AUC-NEFA was lowered. LSI did not modify body weight, hematocrit, fasting plasma cholesterol, glucose, adiponectin, leptin, fibrinogen and factor VII (FVII), and AUC of lipoprotein lipase and of lipoprotein remnants. CONCLUSION: LSI induced alterations in the plasma lipoproteins and in inflammatory markers that are common features of the metabolic syndrome.