High Plasmatic Levels of Advanced Glycation End Products are Associated with Metabolic Alterations and Insulin Resistance in Preeclamptic Women

Increased calcium intake from skimmed milk in energy-restricted diets reduces glycation markers in adults with type 2 diabetes and overweight: A secondary analysis of a randomized clinical trial

The effect of calcium (Ca) on glycation markers is unknown. We hypothesized that increased Ca intake from skimmed milk associated with an energy-restricted diet intake will reduce glycation markers. This reduction will be associated with a greater improvement in markers of metabolic control in adults with type 2 diabetes, overweight, and low habitual Ca intake (<600 mg/d). In this secondary data analysis based on a crossover clinical trial, 14 adults were allocated into 2 groups: high calcium (shake containing 700 mg Ca/day) or low calcium (shake with 6.4 mg Ca/day), for 12 consecutive weeks per session. Energy-restricted diets were also prescribed (-500 kcal/d, 800 mg of dietary Ca/d) to all participants. Advanced glycation end products (AGEs), soluble receptor for AGEs (sRAGE), glycemic control, and lipid profile were assessed at baseline and after 12 weeks. High-calcium serum AGE concentrations and AGE/sRAGE ratio were lower at the end of the study. ΔAGE and ΔAGE/sRAGE ratio were both positively associated with Δtriglycerides, Δtotal cholesterol, Δtriglyceride-glucose index and variations, and Δvisceral adiposity index. ΔAGE/sRAGE was positively associated with Δfructosamine and Δhigh-density lipoprotein-cholesterol, and negatively associated with male sex. Consumption of approximately 1200 mg/day of calcium (3 servings of skim milk) reduced serum AGEs concentrations and the AGE/sRAGE ratio in individuals with diabetes. In general, positive changes in glycation markers are associated with lipid profile, insulin resistance, and adiposity markers worsening. ΔAGEs/ΔsRAGE ratio seems to be a better marker of metabolic status than ΔAGEs and ΔsRAGE alone. Registered in ClinicalTrials.gov (NCT02377076).

Can grape polyphenols affect glycation markers? A systematic review

Advanced glycation end-products (AGEs) favor inflammation and oxidative stress, playing a role in chronic diseases pathogenesis. Grape polyphenols exert antiglycative and antioxidant effects which may contribute to prevent chronic diseases. However, clinical evidence of grape polyphenols on chronic disease prevention and treatment by glycation markers modulation are limited. Therefore, we aimed to critically analyze studies about that topic to investigate the antiglycative power of dietary grape polyphenol, and to explore the molecular mechanism involved. This systematic review was conducted and reported according to PRISMA guidelines. The following search terms were used: "grape", "extract", "grape seed extract", "grape skin extract", "polyphenol extract", "grape polyphenol(s)", "grape juice", "resveratrol", "quercetin", "catechin", "epicatechin", "procyanidin(s)", and "anthocyanin(s)". Seven studies were included. Glycated hemoglobin was not affected. The interventions duration may not have been enough to detect changes. Grape polyphenols reduced fructosamine and methylglyoxal (MGO) concentrations, and increased endogenous secretory RAGE (esRAGE) gene expression but did not affect the serum concentration. Resveratrol antiglycative effects are mainly due its ability to trap MGO and downregulate RAGE. In conclusion, grape polyphenols may have a positive impact on early glycation products, AGEs and esRAGE. Future studies are needed to explore how they modulate AGEs and receptors in chronic diseases.

Association of pre-pregnancy subclinical insulin resistance with cardiac dysfunction in healthy nulliparous women

OBJECTIVES

To investigate the association between pre-pregnancy subclinical insulin resistance and cardiovascular dysfunction in healthy nulliparous women, and with hypertension in subsequent pregnancy.

STUDY DESIGN

Secondary analysis of a single center prospective observational study conducted November 2011-June 2014. Healthy nulliparous women underwent detailed cardiovascular and metabolic assessment. Insulin resistance was determined by homeostasis model assessment (HOMA-IR). Associations of HOMA-IR with metabolic and cardiovascular measurements were assessed with Spearman correlations. Charts were reviewed in women who conceived singleton pregnancies.

MAIN OUTCOME MEASURES

Metabolic measurements included serum glucose, insulin, creatinine, CRP, and lipids. HOMA-IR was calculated using fasting serum insulin and glucose. Indices of cardiovascular stiffness were determined from pulse wave velocity and response to volume challenge. Pregnancy outcomes included delivery mode and gestational age, birthweight, and hypertension.

RESULTS

HOMA-IR was positively associated with BMI (r = 0.462, p < 0.001), body fat percentile (r = 0.463, p < 0.001), CRP (r = 0.364, p = 0.003), and negatively associated with serum HDL (r = -0.38, p = 0.002) and creatinine (r = -0.242, p = 0.049). HOMA-IR was positively associated with blood pressure (r = 0.347, p = 0.004), resting heart rate (r = 0.433, p = <0.001), response to volume challenge (r = 0.325, p < 0.01). Increased HOMA-IR was associated with a faster cardiac ejection time in response to volume challenge (r = -0.415, p < 0.001), which is a marker of decreased cardiac compliance to volume increase, or cardiac stiffness.

CONCLUSION

HOMA-IR is associated with pre-pregnancy cardiac stiffness. Cholesterol was not associated with cardiovascular dysfunction. A non-significant trend was observed between HOMA-IR and hypertension in subsequent pregnancy.