Gestational Diabetes Mellitus and Future Cardiovascular Risk: An Update

The prevalence of gestational diabetes mellitus is increasing in parallel with the rising prevalence of type 2 diabetes and obesity around the world. Current evidence strongly suggests that women who have had gestational diabetes mellitus are at greater risk of cardiovascular disease later in life. Given the growing prevalence of gestational diabetes mellitus, it is important to identify appropriate reliable markers of cardiovascular disease and specific treatment strategies capable of containing obesity, diabetes, and metabolic syndrome in order to reduce the burden of cardiovascular disease in the women affected.

Glucose Fluctuations during Gestation: An Additional Tool for Monitoring Pregnancy Complicated by Diabetes

Continuous glucose monitoring (CGM) gives a unique insight into magnitude and duration of daily glucose fluctuations. Limited data are available on glucose variability (GV) in pregnancy. We aimed to assess GV in healthy pregnant women and cases of type 1 diabetes mellitus or gestational diabetes (GDM) and its possible association with HbA1c. CGM was performed in 50 pregnant women (20 type 1, 20 GDM, and 10 healthy controls) in all three trimesters of pregnancy. We calculated mean amplitude of glycemic excursions (MAGE), standard deviation (SD), interquartile range (IQR), and continuous overlapping net glycemic action (CONGA), as parameters of GV. The high blood glycemic index (HBGI) and low blood glycemic index (LBGI) were also measured as indicators of hyperhypoglycemic risk. Women with type 1 diabetes showed higher GV, with a 2-fold higher risk of hyperglycemic spikes during the day, than healthy pregnant women or GDM ones. GDM women had only slightly higher GV parameters than healthy controls. HbA1c did not correlate with GV indicators in type 1 diabetes or GDM pregnancies. We provided new evidence of the importance of certain GV indicators in pregnant women with GDM or type 1 diabetes and recommended the use of CGM specifically in these populations.

AGEs, rather than hyperglycemia, are responsible for microvascular complications in diabetes: a "glycoxidation-centric" point of view

AIMS

Advanced glycation end products (AGE) excess is one of the most important mechanisms involved in the pathophysiology of chronic diabetic complications. This review first summarizes the role of these compounds in microvascular pathogenesis, particularly in the light of recently proposed biochemical mechanisms for diabetic retinopathy, nephropathy and neuropathy. Then we focus on the relationship between AGE and metabolic memory, trying to clarify the former's role in the missing link between micro- and macrovascular complications.

DATA SYNTHESIS

An excessive AGE formation has been demonstrated in the newly disclosed biochemical pathways involved in the microvascular pathobiology of type 2 diabetes, confirming the central role of AGE in the progression of diabetic neuropathy, retinopathy and nephropathy. As shown by recent studies, AGE seem to be not "actors", but "directors" of processes conducting to these complications, for at least two main reasons: first, AGE have several intra- and extracellular targets, so they can be seen as a "bridge" between intracellular and extracellular damage; secondly, whatever the level of hyperglycemia, AGE-related intracellular glycation of the mitochondrial respiratory chain proteins has been found to produce more reactive oxygen species, triggering a vicious cycle that amplifies AGE formation. This may help to explain the clinical link between micro- and macrovascular disease in diabetes, contributing to clarify the mechanisms behind metabolic memory.

CONCLUSIONS

The pathophysiological cascades triggered by AGE have a dominant, hyperglycemia-independent role in the onset of the microvascular complications of diabetes. An effective approach to prevention and treatment must therefore focus not only on early glycemic control, but also on reducing factors related to oxidative stress, and the dietary intake of exogenous AGE in particular.