老年人不同甲状腺功能状态下脂代谢特征与氧化应激的关系

摘要

Objective To investigate the relationship between oxidative stress and lipid metabolism characteristics in elderly patients under different status of thyroid function. Methods Eighty-six newly-diagnosed elderly patients with thyroid diseases,83 non-elderly patients with thyroid diseases and 20 normal subjects as control were selected.and 47 hyperthyroidism and 39hypothyroidism in elderly,43 hyperthyroidism and 40 hypothyroidism in non-elderly were diagnosed according to diagnostic criteria of the thyroid disease.The levels of fasting plasma malondialdehyde(MDA),superoxide(SOD)and oxidized low density lipoprotein(OX-LDL)were measured by thiobarhiturates,colorimetric method and enzyme linked immunosorbent assay(ELISA).Meanwhile,lipid profile and thyroid function were also measured,SOD/MDA ratio was calculated. Results Lipid profiles in the elderly hyperthyroidism group were significantly higher than those in the non-elderly group(P＜O.05 or P＜0.01)but were significantly lower than those of normal control group(P＜0.05 or P＜0.01).The plasma MDA[(10.23±6.29)μmol/L vs.(3.66±2.53)μmol/L vs.(7.37±4.58)μmol/L],free fatty acids(FFA)[(0.86±0.58)mmol/L us.(0.45±0.12)mmol/L vs.(0.61±O.46)mmol/L]and SOD levels were significantly higher in elderly patients with hyperthyroidism than in normal control and non-elderly hyperthyroidism groups(P＜0.05 or P＜O.01).In the patients with hypothyroidism,the plasma MDA[(9.03±5.98)μmol/L vs.(6.59±3.18)μmol/L vs.(3.66±2.53)μmol/L],OX-LDL[(387.36±71.04)μg/L vs.(355.22±45.01)μg/L vs.(324.53±56.19)μg/L],TC,LDL-C,non-HDL-C,LP(a) and Apo-B100 levels were significantly higher in the elderly group than in the non-elderly and normal control groups(P＜0.05 orP＜0.01).The SOD/MDA ratio was significantly lower in the elderly patient groups with hyperthyroidism or hypothyroidism than in normal control and non-elderly groups(all P＜0.01).In a multiple step-wise regression analysis.FT4 and FFA were independent factors related tO MDA in hyperthyroidism group,and non-HDL-C and LDL-C were independent factors related to MDA inhypothyroidism group. Conclusions Serious lipid metabolic disorder exists in newly-diagnosed and untreated elderly patients with hyperthyroidism and hypothyroidism.It is suggested that oxidative stress is obviously strengthened in elderly patients with thyroid function disorder and that the degree of oxidative stress is correlated with lipid metabolic disorder.%目的 探讨老年人不同甲状腺功能状态下脂代谢特征与氧化应激的关系.方法 初诊老年甲状腺疾病患者86例[甲状腺功能亢进(甲亢)47例,甲状腺功能减退(甲减)39例]、非老年甲状腺疾病患者83例(甲亢43例,甲减40例)和老年健康对照组20例.检测空腹血浆丙二醛(MDA)和超氧化物歧化酶(SOD),氧化型低密度脂蛋白(OX-LDL)水平,同时测定血脂指标及甲状腺功能,计算SOD/MDA比值.结果 老年甲亢组血脂各组分均高于非老年甲亢组、低于老年对照组(P＜0.05或P＜0.01);老年甲亢组与非老年甲亢组、老年对照组比较,丙二醛[分别为(10.23±6.29)、(7.37±4.58)μmol/L和(3.66±2.53)μmol/L]、游离脂肪酸(FFA)[分别为(0.86±0.58)、(0.61±0.46)mmol/L和(0.45士0.12)mmol/L]和SOD显著升高(P＜0.01或P＜0.05).老年甲减组与非老年甲减组和老年对照组比较,MDA[(9.03±5.98)、(6.59±3.18)μmol/L和(3.66±2.53)μmol/L]、OX-LDL[(387.36±71.04)、(355.22±45.01)μg/L和(324.53±56.19)μg/L]及部分血脂组分均显著增高(P＜0.05或P＜O.01).老年甲亢组、甲减组SOD/MDA比值均低于老年对照组和非老年组(均为P＜0.01).多元回归分析,甲亢组游离甲状腺素(FT4)和FFA是影响MDA的因素,甲减组非HDL-C和LDL-C与MDA独立相关.结论 初诊老年甲亢和甲减患者氧化应激增强,氧化损伤程度与脂代谢紊乱有关.