摘要目的 探讨短期极低热量限食对代谢综合征患者甲状腺功能的影响.方法 入选59例代谢综合征患者,其中男性23例,女性36例,平均年龄(38.17±9.61)岁,住院行9d极低热量限食治疗(300～600 kcal/d).采用化学发光法检测限食前后血清游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、TSH水平,放射免疫法检测其中31例患者限食前后血清反-三碘甲状腺原氨酸(rT3)水平,同时测量限食前后体重、体重指数、腰围、血压;检测空腹血糖、胰岛素、血脂等指标,并以稳态模型评估的胰岛素抵抗指数(HOMA-IR)评估胰岛素敏感性.结果 短期极低热量限食后患者平均体重由(76.30±19.61) kg降至(71.97±18.58) kg(P＜0.01),腰围减少6.98 cm(P＜0.01).患者收缩压、舒张压、总胆固醇、三酰甘油、低密度脂蛋白胆固醇、空腹血糖、空腹胰岛素、HOMA-IR均明显下降(均P＜0.01).限食后,患者血FT3水平较前显著降低[(5.09±0.58对4.52±0.58)pmoL/L,P＜0.01].FT4、TSH、rT3水平较前无明显变化.相关性分析显示,患者基线FT3水平与基线体重、体重指数、腰围呈正相关(r分别为0.335、0.297、0.262,均P＜0.05),与HbAIC、空腹血糖呈负相关(r分别为-0.293、-0.268,均P＜0.05);基线FT4与空腹胰岛素、HOMA-IR呈负相关(r分别为-0.284、-0.330,均P＜0.05);基线TSH则与空腹胰岛素、HOMA-IR呈正相关(r分别为0.381、0.281,均P＜0.05).基线体重与腰围、空腹胰岛素、HOMA-IR呈正相关(r分别为0.899、0.382、0.305,均P＜0.05),与高密度脂蛋白胆固醇呈负相关(r=-0.333,P＜0.05).进一步分析发现,限食后FT3变化与基线体重、腰围、空腹血糖无明显相关性.而体重的变化与基线体重、腰围、胰岛素、HOMA-IR以及FT3呈正相关(r=0.564、0.494、0.307、0.245、0.384,均P＜0.05).结论 短期极低热量限食可降低代谢综合征患者血FT3水平,并改善患者体重、腰围、血糖、血脂、胰岛素抵抗等代谢指标.代谢综合征患者血清FT3水平与体重呈正相关,与HbAIC、空腹血糖呈负相关;FT4与HOMA-IR呈负相关;而TSH则与HOMA-IR呈正相关.基线体重越大、FT3水平越高以及胰岛素抵抗越显著者,限食后体重下降越明显.

abstractsObjective To investigate the effect of short-term very low calorie diet on the thyroid function in patients with metabolic syndrome.Method Fifty-nine patients [(23 males and 36 females,average age (38.17 ± 9.61) years] with metabolic syndrome were received very low calorie diet for 9 days in our hospital.Anthropometric and biochemical parameters were determined before and after very low calorie diet.The level of serum FT3,FT4,TSH was measured by chemiluminescent assay,and the level of serum reverse triiodothyronine (rT3) was measured by radioimmunoassay in 31 cases.Homeostasis model assessment for insulin resistance (HOMA-IR) was employed to evaluate the severity of insulin sensitivity.Results After short-term very low calorie diet,the average body weight decreased from (76.30± 19.61)kg to (71.97 ± 18.58)kg (P＜0.01);waist circumference reduced by 6.98 cm (P＜ 0.01).The blood pressure,total cholesterol,triglycerides,low density lipoprotein-cholesterol,fasting blood glucose,fasting insulin,and HOMA-IR were all reduced significantly after very low calorie diet.The serum FT3 level decreased from (5.09 ± 0.58) pmol/L to (4.52 ± 0.58) pmol/L (P＜0.01).The changes of FT4,TSH,and rT3 were without difference.The basal FT3 levels were positively correlated with basal body weight,body mass index,waist circumference (r =0.335,0.297,and 0.262 respectively,all P＜ 0.05),and negatively correlated with HbAIC,fasting blood glucose (r=-0.293,-0.268,both P＜0.05).The basal FT4 level was negatively correlated with basal fasting insulin,HOMA-IR (r =-0.284,-0.330,both P＜0.05),while the basal TSH level was positively correlated with fasting insulin and HOMA-IR (r=0.381,0.281,both P＜0.05).The basal body weight was positively correlated with waist circumference,fasting insulin,HOMA-IR,while negatively correlated with high density lipoproteincholesterol (HDL-C;r =0.899,0.382,0.305,-0.333,all P＜0.05).After very low calorie diet,there were no more significant correlations between FT3 changes and baseline body weights,waist circumferences,and fasting blood glucose levels.The variation amplitude of body weight was positively correlated with baseline weight,waist circumference,fasting insulin,HOMA-IR,and FT3 levels (r =0.564,0.494,0.307,0.245,0.384,all P＜ 0.05).Conclusions Short-term very low calorie diet decreases the serum FT3 level and improves metabolic markers in patients with metabolic syndrome.The serum FT3 level of patients with metabolic syndrome was positively associated with body weight,whereas negatively associated with HbAIC and fasting blood glucose.Moreover,FT4 level had negative correlation with HOMA-IR,but TSH level had positive correlation with HOMA-IR.Those who had higher body weights,FT3 and HOMA-IR levels,may have more profound decrease of body weight after very low calorie diet.