无生长追赶小于胎龄儿胰岛素敏感性及垂体-甲状腺轴变化的研究

Altered insulin sensitivity and pituitary-thyroid axis in children born small for gestational age without catch-up growth

目的探讨无生长追赶小于胎龄儿(SGA)胰岛素敏感性及垂体-甲状腺轴的变化。方法选择近3年中山大学附属第一医院儿科内分泌专科门诊的青春前期生长迟缓儿童,按性别、年龄、体块指数(BMI)匹配分为两组,即无生长追赶SGA组和矮小适于胎龄儿组(AGA),各24例进行病例对照研究。两组均检测空腹血糖、血清胰岛素及血清TSH、T3、T4,并计算血糖/胰岛素比值(G/I比值)、胰岛素抵抗指数(HOMA-IR)和胰岛β细胞功能(HOMA%)。结果SGA组空腹血糖与AGA组比较无显著性差异,但空腹胰岛素、HOMA-IR、HOMA%均显著高于AGA组(8.0±6.2vs4.4±2.8mU/L,1.8±1.4vs1.0±0.7和183.0±145.9vs70.8±43.6,P均<0.05);SGA组HOMA-IR>3人数显著高于AGA组(7/24vs1/24,P<0.05);G/I比值显著低于AGA组(17.8±15.1vs33.2±28.9,P<0.05)。SGA组血清TSH显著高于AGA组(2.9±0.8vs1.9±0.9mU/L,P<0.01),而血清T3、T4两组比较差异无统计学意义。SGA血清胰岛素、HOMA-IR与出生体重SDS呈负相关(r=-0.547和-0.482,P均<0.05);SGA血清TSH与出生身长SDS呈负相关(r=-0.571,P<0.01)。结论无生长追赶SGA存在胰岛素抵抗和垂体-甲状腺轴的改变,无生长追赶SGA需要长期随访和早期干预,以预防或延缓代谢综合征发生。

Objective To study the change of insulin sensitivity and pituitary-thyroid axis in children born small for gestational age （SGA） without catch-up growth. Methods Twenty-four prepubertal SGA children without catch-up growth and 24 short children horn appropriate for gestational age （ AGA ）, matched for sex, age, body mass index （ BMI ）, were enrolled in this case-control study. All children were from our pediatric endocrine clinic during the recent three years. Blood glucose, serum insulin ,TSH ,T3 and T4 were measured in the fasting state in both groups. The ratio of fasting glucose/insulin （ G/I ratio ）, homeostasis assessment model for insulin resistance （HOMA-IR） and islet 13 cell function （ HOMA% ） were calculated. Results There was no significant difference in the fasting blood glucose between SGA and AGA group. However, fasting insulin, HOMA-IR and HOMA% in SGA group were significantly higher than those in AGA group （8.0±6.2 vs 4.4±2.8 mU/L,1.8 ±1.4 vs 1.0±0.7 and 183.0±145.9 vs 70. 8 ±43.6,all P 〈0.05）;The number of patients with HOMA-IR 〉 3 in SGA was significantly more than that of the AGA group （ 7/24 vs 1/24, P 〈 0. 05 ） ; G/I ratio was significantly lower than that of the AGA group （ 17.8 ± 15.1 vs 33.2 ± 28. 9, P 〈 0. 05 ）. The levels of serum TSH were significantly higher in the SGA than those in the AGA group （ 2. 9 ± 0. 8 vs 1.9 ± 0. 9 mU/L P 〈 0. 01 ） ,whereas serum T3 and T4 were similar in both groups. There was a negative correlation between fasting insulin or HOMA-IR and birth weight SDS in SGA children （ r = - 0. 547 and - 0. 482, all P 〈 0. 05 ） ; There was a negative cor-relation between serum TSH and birth length SDS in SGA children. （ r = - 0. 571, P 〈 0. 01 ）. Conclusion Insulin resistance and minor alteration of pituitary-thyroid axis occur in children born SGA without catch-up growth, suggesting the needs of long term follow-up and early intervention in preven-ting or delaying the development of metabolic syndrome.