Background

Cuba's life expectancy at 79 is third highest in Latin America. Many attribute this to social investments in health and education, but comparative research is sparse, thus we compare Cuba with neighboring Dominican Republic, Costa Rica due to its strong social protections, and the U.S. Given high cardiovascular mortality, we focus on cardiovascular risk factor levels. To assess the role of health care, we distinguish medically amenable biomarkers from behavioral risk factors. To assess the role of Cuba's focus on equity, we compare education gradients in risk factors.

Methods

We analyze Cuban data from the 10/66 Dementia Research Group baseline survey of urban adults ages 65 plus. Comparison samples are drawn from the Dominican Republic 10/66 survey, the Costa Rican CRELES, and U.S. NHANES. We analyze cross-country levels and education gradients of medically amenable (hypertension, diabetes, hypercholesterolemia, access to health care) and behavioral (smoking, obesity) risk factors,-using sex-stratified weighted means comparisons and age-adjusted logistic regression.

Results

Neither medically amenable nor behavioral risk factors are uniformly better in Cuba than comparison countries. Obesity is lower in Cuba, but male smoking is higher. Hypertension, diabetes, and hypercholesterolemia levels are high in all countries, though Cuba's are lower than Costa Rica. Hypertension awareness in Cuba is similar to Costa Rica. Cuba has a higher proportion of hypertensives on treatment than Costa Rica, though lower than the U.S. Comparative gradients by education are similarly mixed. For behavioral factors, Cuba shows the strongest gradients (primarily for men) among the countries compared: smoking improves, but obesity worsens with education. Hypertension awareness also improves with education in Cuba, but Cuba shows no significant differences by education in hypertension treatment.

Conclusion

Smoking is comparatively high in Cuba, but obesity is low, and the resulting biomarkers show comparatively mixed patterns. Cuba's social protections have not eliminated strong educational gradients in behavioral risk factors, but the healthcare system appears to have eliminated disparities such as in hypertension treatment.

We undertook a prospective temporal study collecting blood samples from consenting pregnant women, to test the hypothesis that circulating extracellular vesicles (EVs) carrying specific non-coding microRNA signatures can underlie gestational diabetes mellitus (GDM). To test this hypothesis, miRNA cargo of isolated and characterized EVs revealed contributions from the placenta and differential expression at all three trimesters and at delivery between pregnant and non-pregnant states. Many miRNAs originate from the placental-specific chromosome 19 microRNA cluster (19MC) and chromosome 14 microRNA cluster (14MC). Further a positive correlation emerged between third trimester and at delivery EVs containing miRNAs and those expressed by the corresponding post-parturient placentas (R value = 0.63 to 0.69, p value = 2.2X10-16), in normal and GDM. In addition, distinct differences at all trimesters emerged between women who subsequently developed GDM. Analysis by logistic regression with leave-one-out-cross validation revealed the optimal combination of miRNAs using all the circulating miRNAs (miR-92a-3p, miR-192-5p, miR-451a, miR-122-5p), or using only the differentially expressed miRNAs (has-miR-92a-3p, hsa-miR-92b-3p, hsa-miR-100-5p and hsa-miR-125a-3p) in GDM during the first trimester. As an initial step, both sets of miRNAs demonstrated a predictive probability with an area under the curve of 0.95 to 0.96. These miRNAs targeted genes involved in cell metabolism, proliferation and immune tolerance. In particular genes of the P-I-3-Kinase, FOXO, insulin signaling and glucogenic pathways were targeted, suggestive of placental connectivity with various maternal organs/cells, altering physiology along with pathogenic mechanisms underlying the subsequent development of GDM. We conclude that circulating EVs originating from the placenta with their miRNA cargo communicate and regulate signaling pathways in maternal organs, thereby predetermining development of GDM.

Oxidative stress is a biological imbalance in reactive oxygen species and antioxidants. Increased oxidative stress during pregnancy has been associated with adverse birth outcomes. Omega-3 fatty acid (n-3 FA) supplementation may decrease oxidative stress; however, this relationship is seldom examined during pregnancy. This study assessed the association between n-3 FA supplement use during pregnancy and urinary oxidative stress biomarker concentrations. Data came from The Infant Development and the Environment Study (TIDES), a prospective cohort study that recruited pregnant women in 4 US cities between 2010-2012. Third trimester n-3 FA intake was self-reported. Third trimester urinary 8-iso-prostaglandin F2α (8-iso-PGF2α) was measured as an oxidative stress biomarker. Additionally, we measured the major metabolite of 8-iso-PGF2α and Prostaglandin F2α (PGF2α) and utilized the 8-iso-PGF2α to PGF2α ratio to calculate the change in 8-iso-PGF2α reflecting oxidative stress versus inflammation. Adjusted linear models were used to determine associations with control for confounding. Of 725 women, 165 reported n-3 FA supplement use in the third trimester. In adjusted linear models, n-3 FA use was associated with 10.2% lower levels of 8-iso-PGF2α (95% Confidence Interval [CI]: -19.6, 0.25) and 10.3% lower levels of the metabolite (95% CI: -17.1, -2.91). No associations were observed with PGF2α. The lower levels of 8-iso-PGF2α appeared to reflect a decrease in oxidative stress (percent change with supplement use: -18.7, 95% CI: -30.1, -5.32) rather than inflammation. Overall, third trimester n-3 FA intake was associated with lower concentrations of 8-iso-PGF2α and its metabolite, suggesting a decrease in maternal oxidative stress during pregnancy.