[Clinical study of maternal serum leptin levels as a predictor of gestational diabetes mellitus and gestational impaired glucose tolerance].

OBJECTIVE: To investigate whether maternal serum leptin level can be used as a predictor of gestational diabetes mellitus (GDM) and gestational impaired glucose tolerance (GIGT). METHODS: Five hundred and eighty-three pregnant women were screened for GDM by the 50g oral glucose challenge test. At the same time, serum leptin levels were determined by radioimmunoassay, then the relationship between maternal serum leptin level and the incidence of GIGT and GDM was analyzed. According to the screening result, all the pregnant women were divided into three groups, the normal glucose group (NGT group), the gestational impaired glucose tolerance group (GIGT group), and gestational diabetes mellitus group (GDM group). GIGT group and GDM group were named as glucose intolerant group as a whole. RESULTS: (1) The serum leptin concentration of normal pregnant women ascended gradually from (7.0 +/- 1.8) microg/L in 24 gestational week to (9.4 +/- 2.1) microg/L during 34 - 36 gestational week, and then declined slightly but still maintained high level till delivery. (2) The serum leptin concentration of the glucose intolerant pregnant women ranged from (11.3 +/- 3.1) microg/L to(14.5 +/- 4.3) microg/L, and showed no difference among different gestational weeks (P > 0.05). (3) Serum leptin level of glucose intolerant women was (12.5 +/- 3.5) microg/L on average, much higher than that of NGT group, (8.5 +/- 2.6) microg/L (P < 0.05), and this difference remained in any gestational week (P < 0.05). (4) Most of the GDM clustered in the higher leptin level groups and 66.7% GDM had a serum leptin level higher than 14.0 microg/L. Moreover, 64.7% of women whose serum leptin level was above 17.0 microg/L had different degree of glucose intolerance. Serum leptin level positively correlated with the incidence of GIGT and GDM. CONCLUSION: Serum leptin level is correlated with glucose tolerance during pregnancy. Its abnormal increase during pregnancy might have a predictive value for GDM and GIGT.