ATHEROGENIC LIPOPROTEINS IN SUBCLINICAL HYPOTHYROIDISM AND THEIR RELATIONSHIP WITH HEPATIC LIPASE ACTIVITY. RESPONSE TO REPLACEMENT TREATMENT WITH LEVOTHYROXINE.

BRENTA, GABRIELA; BERG, GABRIELA; MIKSZTOWICZ, VERONICA; LOPEZ, GRACIELA; LUCERO, DIEGO; FAINGOLD, CRISTINA; NAKAJIMA, K; SCHREIER , LAURA

LEIDEN

Congreso; EUROPEAN THYROID ASSOCIATION MEETING 2013; 2013

Objectives:Subclinical hypothyroidism (SH) is not expected to alter dramatically the plasma lipoprotein-lipidprofile. How ever some few reports on qualitative lipid changes, such as an increase in fastinglipoprotein remnants, have been previously made. Our hypothesis about their increase in subclinicalhypothyroidism is based on the decrease in hepatic lipase activity, the enzyme that is regulated bythyroid hormones and is involved in the degradation of triglyceride-rich remnants. Our aim w as toquantify remnant-like lipoprotein particles (RLP) and hepatic lipase (HL) activity in patients w ith SHand to evaluate response to levothyroxine.Methods:Women w ith 2 TSH determinations one month apart above 4.5 mU/L w ere included in the SH groupand compared to age and BMI matched euthyroid w omen (E). The SHpre group included patients thataccepted to participate in a 6 months period w ith levothyroxine upon w hich, all biochemicalparameters w ere reassessed (SHpost). RLP levels w ere quantified by immunoaffinitychromatography. HL activity in postheparin plasma samples w as measured. Student T test, Wilcoxontest, Mann Whitney U Test w ere used.Results:Patients w ere distributed into the follow ing groups: SH: n39, E: n29, SHpre-SHpost: n23.Demographic and biochemical parameters of E vs SH w ere (median(range) or mean±SD):Age(years):58(26-73) vs 61(31-79) p:0.521; BMI:26±3 vs 27±3 p:0.878; RLPChol(mg/dL): 10.2(2.7-36.3) vs 20.3(5.8-66), p:0.007; RLPTrig(mg/dL): 12.1(2.5-61.6) vs 24.9(3.2-123), p:0.05;HL(UmolFFA/mlPHP.h): 9.92±5.20 vs 9.63±4.23 p:0.841. SHpre vs SHpost: RLPChol: 20.3(5.8-66.8)vs 14.5(4.1-45.6) p:0.017; HL: 9.75±4.04 vs 11.86 ± 4.58 p:0.013.Conclusions:SH w omen have higher RLP levels w hen compared to euthyroid w omen. These lipid alterationsreturn to values similar to the euthyroid group after 6 months of levothyroxine replacement treatment.Furthermore, HL activity also increases after treatment and this rise can be interpreted as onepossible explanation to the decrease of RLP.