[Leptin concentration and insulin sensitivity in type 1 diabetic children and adolescents].
OBJECTIVE
was to estimate the relationship between serum leptin levels and insulin sensitivity and components of metabolic syndrome in type 1 diabetic children and adolescents.


METHODS
158 patients with type 1 diabetes mellitus (70 girls and 88 boys) aged from 8.2 to 18.4 years (mean: 14.1+/-3.1 years) were included into the study. The diabetes duration ranged from 1.6 to 14.7 years (mean: 3.8+/-2.5 years). The height, weight, waist circumference (WC), skin folds and blood pressure were measured. Body mass index (BMI-SDS), body fat (BF) according to Slaughter formula, and daily dose of insulin were calculated. HbA1c (HPLC method) and serum lipids (enzymatic method) concentrations were examined. Serum leptin concentration was measured by ELISA method. Euglycemic-hyperinsulinemic clamp was performed to estimate insulin resistance. Glucose disposal rate (M index) determined during the last 30 min of the test was calculated as a surrogate of insulin resistance.


RESULTS
Serum leptin levels ranged from 1.47 to 57.39 ng/ml (median [quartiles]: 4.60 [3.18-10.2]). M index was 2.10-15.19 mg/kg/min. (median [quartiles]: 7.04 [5.57-8.69]. Leptin was positively correlated with BMI-SDS, WC, skin folds and BF. During puberty leptin levels increased in girls, but in boys the highest levels were observed at Tanner stage 3. Leptin concentrations, normalized for BMI-SDS or BF, were significantly higher in females than in males at Tanner stages 4 (pc=0.047) and 5 (pc<0.001). Leptin was negatively correlated with M index (r=-0.26; p=0.001 adjusted for sex and puberty), but after adjusting for BF or BMI-SDS there were no significant correlations. Leptin was not significantly associated with HDL-cholesterol, SBP and DBP. Using the multivariate linear regression models, we found that plasma leptin remained significantly associated with TG.


CONCLUSIONS
It is likely that the observed relationship between leptin concentration and insulin resistance in young patients with type 1 diabetes is due to body fat composition rather than represents an independent association in this group.
Klinika Chorób Dzieci I Katedry Pediatrii, ul. Sporna 36/50, Łodz. agnieszka.szadkowska@wp.pl
Agnieszka
A
Szadkowska
Krystyna
K
Wyka
Wojciech
W
Młynarski
Iwona
I
Pietrzak
Beata
B
Mianowska
Jerzy
J
Bodalski
D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood*; D008297:Male; D012737:Sex Factors
D020738:Leptin