Tomás Meroño

Pro-inflammatory and atherogenic circulating factors in non-alcoholic fatty liver disease associated to metabolic syndrome

BACKGROUND It is not elucidated if liver fat deposits associated to metabolic syndrome (MS) aggravate the atherogenic state. We evaluated, in MS patients, if the presence of non-alcoholic hepatic steatosis (HS) determines differences in inflammatory markers and VLDL characteristics. METHODS Seventy-five patients with MS were divided into 2 groups depending on the presence or absence of HS, assessed by ultrasound. Lipid profile, free fatty acids (FFA), VLDL composition, adiponectin, tumor necrosis factor-alpha (TNF-α), high sensitivity C-reactive protein (hs-CRP), and soluble adhesion molecules (sVCAM-1 and sICAM-1) were measured. RESULTS HS patients presented increased triglycerides levels, HOMA-IR and FFA. Patients with HS showed a reduction in adiponectin (p = 0.04) and increase in hs-CRP (p = 0.02), independently of insulin-resistance (IR). FFA correlated positively with TNF-α (p = 0.04) and inversely with adiponectin (p = 0.01). hs-CRP correlated with all inflammatory markers, independently of IR: TNF-α (r = 0.34, p = 0.02), sVCAM-1 (r = 0.29 p = 0.03), sICAM-1 (r = 0.56, p = 0.01), adiponectin (r = -0.34, p = 0.04). HS patients presented higher VLDL mass and number of particles. Adiponectin correlated with VLDL cholesterol content (r = -0.47, p = 0.04), independently of IR. VLDL, once secreted, would suffer from changes, becoming more atherogenic. CONCLUSIONS Simple HS would play an important role increasing cardiovascular risk, independently of IR. hs-CRP may represent a useful biomarker of this condition.

Altered lipidome and antioxidative activity of small, dense HDL in normolipidemic rheumatoid arthritis: Relevance of inflammation

OBJECTIVE High-density lipoprotein (HDL) particles exert potent antiatherogenic activities, including antioxidative actions, which are relevant to attenuation of atherosclerosis progression. Such activities are enriched in small, dense HDL and can be compromised under conditions of chronic inflammation like rheumatoid arthritis (RA). However, structure-function relationships of HDL largely remain indeterminate. METHODS The relationships between HDL structure and function were evaluated in normolipidemic patients with active RA (DAS28 > 3.2; n = 12) and in normolipidemic age-matched controls (n = 10). Small, dense HDL3b and 3c particles were isolated from plasma or serum by density gradient ultracentrifugation and their physicochemical characteristics, lipidome (by LC/MS/MS) and antioxidative function (as protection of normolipidemic LDL from free radical-induced oxidation) were evaluated. RESULTS As expected, active RA patients featured significantly elevated plasma levels of high-sensitivity C-reactive protein (hsCRP; p < 0.001) and serum amyloid A (SAA; p < 0.01) relative to controls. Antioxidative activity and weight % chemical composition of small, dense HDL did not differ between RA patients and controls (p > 0.05), whereas HDL phosphosphingolipidome was significantly altered in RA. Subgroup analyses revealed that RA patients featuring high levels of inflammation (hsCRP>10 mg/l) possessed small, dense HDL with reduced antioxidative activities (p < 0.01). Furthermore, antioxidative activity of HDL was inversely correlated with plasma hsCRP (p < 0.01). CONCLUSIONS These data revealed that (i) despite normolipidemic state, the lipidome of small, dense HDL was altered in RA and (ii) high levels of inflammation can be responsible for the functional deficiency of small, dense HDL in RA.

High risk of cardiovascular disease in iron overload patients

Eur J Clin Invest 2011; 41 (5): 479–486

GH levels and insulin sensitivity are differently associated with biomarkers of cardiovascular disease in active acromegaly

Acromegaly is characterized by GH excess and insulin resistance. It is not known which of these disorders is responsible for the increased atherogenic risk in these patients.

HOMA-IR and non-HDL-C as predictors of high cholesteryl ester transfer protein activity in patients at risk for type 2 diabetes

BACKGROUND AND AIMS Metabolic syndrome (MS) and type 2 diabetes are highly associated with an abnormal lipoprotein profile, which may be generated and accentuated by high cholesteryl ester transfer protein (CETP) activity. Given the difficulty in measuring CETP activity, the aim was to identify simple biochemical predictors of high CETP activity. DESIGN AND METHODS Eighty five subjects at risk for type 2 diabetes were classified according to the presence of MS. Lipoprotein profile, HOMA-IR and endogenous CETP activity were evaluated. RESULTS As expected, MS patients presented higher concentration of glucose, insulin, triglycerides and non-HDL-C and lower HDL-C levels. Moreover, MS patients exhibited increased HOMA-IR and CETP activity. Employing a ROC curve for MS, high CETP activity was defined as >250%ml⁻¹ h⁻¹. The predictive variables of high CETP were non-HDL-C≥160mg/dl (OR=11.1;95%IC=3.3-38.2;p<0.001) and HOMA-IR>2.1 (OR=4.4;95%IC=1.3-14.8;p<0.05). CONCLUSIONS High non-HDL-C and insulin resistance were predictors for increased CETP activity which measurement is not accessible for clinical laboratories.

HDL-associated enzymes and proteins in hemodialysis patients.

OBJECTIVES To evaluate HDL-associated proteins and enzymes and their relation with lipoprotein profile and inflammatory markers in chronic renal patients on hemodialysis. DESIGN AND METHODS We studied 53 patients under hemodialysis and 32 healthy subjects as controls. We compared plasma lipids, Apoprotein-AI and hs-CRP, as a marker of chronic inflammation. We evaluated proteins and enzymes associated to HDL, involved in several points of lipoprotein metabolism: CETP, paraoxonase and LpPLA2 activities. Hepatic lipase was measured in postheparin plasma. RESULTS Patients showed higher triglycerides and lower LDL-, HDL- and total-cholesterol than controls (p<0.05). Also, in comparison with controls, Apoprotein-AI, paraoxonase and hepatic lipase were lower, while CETP was higher (p<0.03). LpPLA2 did not show changes between groups. CONCLUSION Beyond plasma lipid-lipoprotein profile, other factors could contribute to induce a pro-oxidative and pro-inflammatory status. The protective role of HDL does not only depend on its concentration, but also on its functionality.

Increased oxidized low density lipoprotein associated with high ceruloplasmin activity in patients with active acromegaly

Objective  Active acromegaly is associated with increased mortality from cardiovascular causes. Several studies have shown increased atherogenic risk factors and biomarkers of inflammation and atherosclerosis in association with growth hormone excess. The aim of this study was to evaluate oxidized low density lipoprotein (oxLDL) levels and some modulators of LDL oxidative modification in patients with acromegaly.

High TSH and low T4 as prognostic markers in older patients

OBJECTIVETo examine the association between thyroid profile and morbidity/mortality (MM) in hospitalized older patients.DESIGNThis is a retrospective study of patients over the age of 60yr admitted to the Dr. Cesar Milstein Hospital between 2009 and 2010 and who had thyroid function tests (TFT). The patients were grouped as per their thyroid tests and their clinical characteristics and MM was associated with their TFT. High MM was defined as mortality, intensive care unit (ICU) requirement or prolonged hospital stay (>18 days, 75thpercentile), and mortality assessed during an 18-month follow-up period after their hospital discharge.RESULTSOut of 2599 older patients admitted to our hospital, 7% had TFT performed for various reasons. The patients who had TFT were mostly women and presented in a more serious clinical condition compared to the rest of the patients. The patients were grouped as per their thyroid values as follows: 61% of them had a non-thyroidal illness, 25% were euthyroid, 7% had overt hyperthyroidism, 5% overt hypothyroidism and 1% had subclinical hyper- or hypothyroidism. The hypothyroid patients had a worse clinical outcome compared to the others. Patients with increased MM exhibited higher TSH and lower TT4 (p<0.005). Short-term MM (OR=2.0,95%CI=1.1–3.6, p<0.01) was associated with the decrease of TT4 adjusted by age, sex, T3 and TSH, while for long-term MM the increase in TSH (OR=1.6,95%CI 1.1–2.3, p<0.05) was also significant.CONCLUSIONAmong hospitalized older patients who had TFT tests, low TT4 and high TSH were associated with a worse prognosis. We propose that TFT be used as an additional tool in assessing MM in elderly hospitalized patients.

Poor glycemic control in type 2 diabetes enhances functional and compositional alterations of small, dense HDL3c

High-density lipoprotein (HDL) possesses multiple biological activities; small, dense HDL3c particles displaying distinct lipidomic composition exert potent antiatherogenic activities which can be compromised in dyslipidemic, hyperglycemic insulin-resistant states. However, it remains indeterminate (i) whether such functional HDL deficiency is related to altered HDL composition, and (ii) whether it originates from atherogenic dyslipidemia, dysglycemia, or both. In the present work we analyzed compositional characteristics of HDL subpopulations and functional activity of small, dense HDL3c particles in treatment-naïve patients with well-controlled (n=10) and poorly-controlled (n=8) type 2 diabetes (T2D) and in normolipidemic age- and sex-matched controls (n=11). Our data reveal that patients with both well- and poorly-controlled T2D displayed dyslipidemia and low-grade inflammation associated with altered HDL composition. Such compositional alterations in small, dense HDL subfractions were specifically correlated with plasma HbA1c levels. Further analysis using a lipidomic approach revealed that small, dense HDL3c particles from T2D patients with poor glycemic control displayed additional modifications of their chemical composition. In parallel, antioxidative activity of HDL3c towards oxidation of low-density lipoprotein was diminished. These findings indicate that defective functionality of small, dense HDL particles in patients with T2D is not only affected by the presence of atherogenic dyslipidemia, but also by the level of glycemic control, reflecting compositional alterations of HDL.

Proatherogenic disturbances in lipoprotein profile, associated enzymes and transfer proteins in women with iron deficiency anaemia

OBJECTIVE To characterize the lipid-related atherogenic risk factors in iron deficiency anaemia (IDA) patients. DESIGN AND METHODS Twenty IDA women were compared to healthy age-matched controls. Lipoprotein profile, cholesteryl ester transfer protein (CETP), paraoxonase (PON) 1 and lipoprotein-associated phospholipase A(2) (LpPLA(2)) activities and plasma levels of oxidized-LDL were evaluated. RESULTS Triglycerides were higher (median [range]) (1.0 [0.5-1.9] vs. 0.7 [0.5-1.5] mmol/L, p<0.05) and HDL-C lower (mean + or - SD) (1.3 + or - 0.3 vs. 1.6 + or - 0.4 mmol/L, p<0.01) in the patients group. CETP (197 + or - 29% vs. 151 + or - 29% mL(-1) h(-1), p<0.001), PON 1 (122 + or - 17 vs. 140 + or - 33 micromol mL(-1) min(-1), p<0.05) and LpPLA(2) (9.6 + or - 2.0 vs. 8.1 + or - 1.7 micromol mL(-1) h(-1), p<0.05) activities were different in IDA women. No difference was observed in oxidized-LDL. Haemoglobin correlated negatively with triglycerides (r=-0.35, p<0.05), CETP (r=-0.62, p<0.001) and LpPLA(2) (r=-0.34, p<0.05), while ferritin was positively associated with HDL-C (r=0.39, p<0.05) and inversely with CETP (r=-0.49, p<0.005). CONCLUSION The alterations in lipoprotein profile, CETP, PON 1 and LpPLA(2) activities described in the present study indicate that non-treated IDA might represent a proatherogenic state.