Relação entre a Síndrome Metabólica, teor de gordura intramiocelular e os níveis plasmáticos da Adiponectina: papel da Rosiglitazona / Relationship between the Metabolic Syndrome, intramyocellular fat and plasma Adiponectin: role of Rosiglitazone

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Insulin resistance (IR) is associated with intramyocellular lipid (IMCL) content and low serum adiponectin (ADP) levels. ADP is also involved in muscle fat oxidation but the relationship between them is still controversial. We aimed to further explore the relationship between ADP and IMCL content in non-diabetic adults and the role of rosiglitazone (RSG) in muscle fat compartment distribution in an adult population of obese nondiabetic metabolic syndrome patients. This study comprises two phases: a cross-sectional and a longitudinal, open-label, drug-interventional one. Laboratory for Clinical and Experimental Research on Vascular Biology (Biovasc) at the State University of Rio de Janeiro. During the cross-sectional phase, 24 obese, nondiabetic patients with metabolic syndrome (MS) and 9 lean healthy controls were studied. Proton nuclear magnetic resonance spectroscopy (1H-NMRS) was performed to quantify IMCL, as well as extramyocellular lipid (EMCL) content. The latter plus serum ADP, anthropometrics and biochemical parameters were evaluated and compared in these two groups. During the longitudinal phase, fifteen of the MS patients were studied by means of 1HNMRS before and after treatment with 8mg/day of RSG for 6 months. Anthropometrical and metabolic variables were assessed. Measurements and main results cross-sectional phase: MS patients had higher body mass index (BMI), waist, waist-to-hip ratio (WHR), glucose, insulin and triglycerides and lower HDL-c as compared to controls. HOMA-IR (3.25 [2.58-4.13] vs 1.02 [0.73-1.29]; p<0.0001) and IMCL content (266.1 [189.9-296.3] vs 72.85 [55.3-109.4) AU, p<0.0001] were higher, and QUICKI (0.32 [0.31-0.33] vs 0.38 [0.37-0.40]; p<0.0001) and ADP (8.6 [4.05-15.95] vs 21.1 [12.9-24.4] μg/ml; p=0.02) lower in MS compared to controls. IMCL content was directly associated with glucose, insulin, triglycerides and HOMAxiii IR and inversely to HDLc, QUICKI and, more importantly, with ADP (r = -0.41; p<0.05). Longitudinal phase: After RSG treatment, body weight and hip circumference increased [100.9 (91.12-138.7) vs 107,0 (79.6-142.8) kg and 118 (107-126) cm vs 122 (110-131) cm] respectively, while WHR decreased [0.93 (0.87-1.00) vs 0.89 (0.82-0.97); P<0.001 for all]. Additionally, fasting plasma glucose, insulin and HOMA-IR significantly decreased while adiponectin increased over 3 fold [9.7 (3.7-17.7) vs 38.0 (19.3-42.4) μg/ml]. Finally, IMCL did not change [267.54 (213.94-297.94) vs 305.75 (230.80-424.75) arbitrary units (AU)] while EMCL increased [275.53 (210.39-436.66) vs 411.39 (279.92-556.59) AU; P<0.01] therefore decreasing IMCL to EMCL ratio (IMCL/EMCL) [1.07 (0.78-1.23) vs. 0.71 (0.53-0.96); p<0.01]. ADP is inversely related to IMCL content in non-diabetic adults. This finding has possible implications for the role of ADP in muscle fat oxidation, IR and MS. RSG treatment increased body weight and hip circumference decreasing WHR and decreased IMCL/EMCL ratio by increasing EMCL without any significant change on IMCL, thus suggesting that this drug may prevent IMCL fat deposition by increasing EMCL and peripheral deposits.

ASSUNTO(S)

síndrome metabólica metabolic syndrome gordura intramiocelular rosiglitazona endocrinologia rosiglitazone adiponectina adiponectin intramyocellular fat

ACESSO AO ARTIGO

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