ALTERATIONS OF THIAMINE METABOLISM AND INCERASED CABOXYMETHYLLYSINE LEVELS IN WOMEN WITH GESTATIONAL DIABETES MELLITUS
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| Year of publication | 2014 |
| Type | Appeared in Conference without Proceedings |
| Citation | |
| Description | Thiamine (vitamin B1) - as a cofactor of several enzymes incl. transketolase (TKT) - participates in the regulation of glucose metabolism. Experimental evidence has shown thiamine disturbances in diabetes are potentially involved in the development and progression of diabetic microvascular complications since non-oxidative branch of pentose phosphate pathway (PPP) with TKT as a key enzyme supposedly plays a protective role. Data are lacking whether similar abnormalities may also play a role in the development of gestational diabetes mellitus (GDM). One of the consequences of thiamine deficiency might be accelerated formation of Advanced Glycation End products (AGEs). AGEs are traditionally considered as a result of long-term dysregulation of glucose homeostasis, however detailed kinetic studies indicate a prompt reflexion of glucose metabolism, therefore GDM should be an ideal phenotype to study acute changes. We aimed to determine plasma thiamine levels, erythrocyte thiamine diphosphate (TDP) levels (both by HPLC) transketolase activity (using kinetic method) and thiamine effect in pregnant women with and without GDM. Furthermore carboxymethyllysine (CML), the dominant form of AGEs in plasma, was determined by ELISA to find out a possible correlation with glucose metabolism and thiamine parameters. A total of 182 pregnant women (105 had GDM, 77 had physiologic pregnancy) were included in the study. Samples of peripheral blood were taken from each participant between 24th and 30th week of pregnancy and from 6 weeks to 12 months postpartum. Significant differences in plasma thiamine levels, erythrocyte TDP and TKT activity between GDM and physiologic pregnancy group were found in the 2nd trimester of pregnancy (P=0.01, P<0.001 and P=0.02, respectively, Mann-Whitney test) while no significant differences were found postpartum (all three P?0.05, Mann-Whitney test). Plasma CML levels were significantly higher in GDM compared to normal pregnancy in 2nd trimester (P=0.02 resp., Mann-Whitney test). Plasma thiamine as well as CML levels in 2nd trimester significantly inversely correlated with pre-gestational BMI (P<0.05, Spearman) but not with age or glycaemias during oGTT test. In conclusion, we found statistically significant increase of plasma CML levels in pregnant women with GDM in the 2nd trimester of gravidity without concomitant alteration of parameters of thiamine metabolism. Therefore activity of PPP does not seem to play a protective role against the formation of AGEs. The relevance of their increased levels for both mother and child warrants further investigation. Supported by IGA MZ ČR grant, no. NT11405 |
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