OBJECTIVESMetabolic syndrome (MS) in adolescents was reported to be closely associated with cardiovascular diseases in adulthood. However, no unified treatment measure for MS in adolescents is currently available. The aim of this study was to measure the changes of serum adiponectin levels, insulin sensitivity and other biochemical markers after metformin therapy in adolescents with MS, which might provide some information for set up a unified therapeutic measure for MS in adolescents.

METHODSIn this study, 348 moderately or severely obese adolescents and 24 non-obese healthy adolescents matched in age and sex were enrolled. The obese group included 208 males and 140 females aged from 7 to 16 years (11.5 +/- 2.1 years). Oral glucose tolerance test and biochemical markers measurement were done to all these subjects. Whole body insulin sensitivity index (WBISI), homeostasis model assessment-insulin resistance (HOMA-IR) and fasting serum adiponectin were compared among 36 adolescents with MS (who had two or three abnormalities of hyperglycosemia, hypertension or dyslipidemia), 61 simple obese subjects without abnormality of biochemical markers and 24 healthy controls. Moreover, the changes of WBISI, HOMA-IR and adiponectin levels in 20 cases with MS after metformin therapy for 3 months were measured.

RESULTS(1) HOMA-IR in control group (1.3), simple obese group (2.3) and MS group (4.9) increased by turns (F = 54.08, P < 0.001). WBISI and serum adiponectin in control group, simple obese group and MS group decreased by turns with significant difference [89.6, 22.8 and 10.7, F = 30.06; (7.1 +/- 2.6), (5.9 +/- 1.9), (2.8 +/- 0.9) mg/L, F = 64.93; P < 0.01 for all]. (2) HOMA-IR after metformin therapy decreased [5.7 (1.9-12.4) vs. 2.9 (0.9-7.4), t = 5.05, P < 0.01]; while the serum adiponectin levels increased with significant differences [(3.0 +/- 0.9) mg/L vs. (6.1 +/- 1.9) mg/L, t = 6.19, P < 0.01]. Systolic blood pressure [(132.4 +/- 7.5) mm Hg vs. (116.6 +/- 9.1) mm Hg, t = 8.36, P < 0.01], 2-hour glucose [(8.2 +/- 2.9) mmol/L vs. (5.3 +/- 1.0) mmol/L, t = 3.96, P < 0.01], triglyceride [(2.8 +/- 1.2) mmol/L vs. (1.3 +/- 0.9) mmol/L, t = 4.22, P < 0.01], total cholesterol [(4.9 +/- 0.6) mmol/L vs. (4.0 +/- 0.6) mmol/L, t = 4.72, P < 0.01], alanine aminotransferase [80.5 (29.0-286.0) U/L vs. 56.0 (23.0-163.0) U/L, t = 3.80, P < 0.01].

CONCLUSIONInsulin sensitivity in adolescents with MS was lower than that of simple obese group. Metformin can improve or ameliorate adiponectin levels, insulin sensitivity and some clinical markers.