Association Between Lipoprotein(a) and Insulin-Like Growth Factor I During Puberty and the Relationship to Microalbuminuria in Children and Adolescents With IDDM
Association Between Lipoprotein(a) and Insulin-Like Growth Factor I During Puberty and the Relationship to Microalbuminuria in Children and Adolescents With IDDM
复制标题
青春期脂蛋白 (a) 和胰岛素样生长因子 I 之间的关联以及 IDDM 儿童和青少年微量白蛋白尿的关系
作者：
S. Rudberg;B. Persson
目的探讨青春期胰岛素依赖型糖尿病（IDDM）患者血清脂蛋白（a）[Lp（a）]和胰岛素样生长因子I（IGF-I）的变化及其与微量白蛋白尿的关系。研究设计和方法在一项横断面研究中，对79名年龄≥ 5岁的IDDM儿童和青少年（59名正常白蛋白尿，20名微量白蛋白尿）以及54名健康对照者进行了调查。空腹血清Lp（a）;分析载脂蛋白（apo）A-1和B;总胆固醇、低密度脂蛋白（LDL）和高密度脂蛋白胆固醇;甘油三酯和IGF-I，以及HbA 1c和过夜白蛋白排泄率（AER）。青春期发育通过坦纳分期进行评估。结果正常白蛋白尿的IDDM患者Lp（a）、apoB、甘油三酯、总胆固醇和低密度脂蛋白胆固醇均高于正常对照组（P < 0.001），apoA-1低于正常对照组（P = 0.03）。在青春期（2-4期），胰岛素依赖型糖尿病患者的Lp（a）升高，但在健康受试者中不升高，而IGF-I仅在健康对照受试者的青春期显著升高。在IDDM患者中，Lp（a）与胰岛素剂量、总胆固醇和LDL胆固醇相关，但与IGF-I、HbA 1c、收缩压和舒张压、糖尿病病程、年龄或性别无关。在以Lp（a）为因变量的多元回归分析中，青春期是唯一显著的回归贡献者（r2 = 0.33，P = 0.008）。微量白蛋白尿仅见于青春期4-5期。Lp（a）和apoB有增高的趋势（P = 0.06），而IGF-I则低于相同青春期白蛋白尿正常的患者（P < 0.001）。多因素分析中，以log AER为因变量，apoB/apoA-1、收缩压、年龄、IGF-1对回归有促进作用（r ~ 2 = 0.47，P < 0.0001），Lp（a）无影响。结论：正常白蛋白尿的IDDM患者青春期Lp（a）升高，与代谢控制和IGF-I无关。在微量白蛋白尿中，Lp（a）趋于进一步升高，但似乎不是log AER的决定因素，而低IGF-I则是。需要进行前瞻性研究以确定儿童和青少年IDDM患者Lp（a）升高与微量白蛋白尿之间的时间关系。
OBJECTIVE To study pubertal changes in serum lipoprotein(a) [Lp(a)] and insulin-like growth factor I (IGF-I) in insulin-dependent diabetes mellitus (IDDM) and the relationship to microalbuminuria. RESEARCH DESIGN AND METHODS Seventy-nine children and adolescents (59 with normoalbuminuria, 20 with microalbuminuria) with ≥ 5 years of IDDM were investigated together with 54 healthy control subjects in a cross-sectional study. Fasting serum Lp(a); apolipoprotein (apo) A-1 and B; total, low-density lipoprotein (LDL), and high-density lipoprotein cholesterol; triglycerides; and IGF-I were analyzed as were HbA1c and overnight albumin excretion rate (AER). Pubertal development was assessed by Tanner staging. RESULTS Lp(a), apoB, triglycerides, and total and LDL cholesterol were higher (P < 0.001) and apoA-1 was lower (P = 0.03) in normoalbuminuric IDDM patients than in healthy control subjects. Lp(a) was increased during puberty (stages 2–4) in IDDM patients but not in healthy subjects, whereas IGF-I was significantly increased during puberty in healthy control subjects only. In IDDM patients Lp(a) correlated to insulin dose, total cholesterol, and LDL cholesterol, but not to IGF-I, HbA1c, systolic and diastolic blood pressure, diabetes duration, age, or sex. In multiple regression analysis with Lp(a) as the dependent variable, puberty was the only significant contributor to the regression (r2 = 0.33, P = 0.008). Microalbuminuria was seen only in the pubertal stage 4–5. Lp(a) tended to be higher (P = 0.06) as did apoB, whereas IGF-I was lower (P < 0.001) in this group than in normoalbuminuric patients of the same pubertal stages. In multivariate analysis, with log AER as the dependent variable, apoB/apoA-1, systolic blood pressure, age, and IGF-I but not Lp(a) added to the regression (r2 = 0.47, P < 0.0001). CONCLUSIONS Lp(a) is elevated during puberty in normoalbuminuric subjects with IDDM, independent of metabolic control and IGF-I. Lp(a) tends to be further increased in microalbuminuria but does not seem to be a contributing determinant of log AER whereas low IGF-I does. Prospective studies are required to establish the temporal relationship between increased Lp(a) and microalbuminuria in children and adolescents with IDDM.