P1646Do Extracellular Vesicles repair chronic ischemic heart disease by replenishing the cardiomyocyte pool?

Introduction

Extracellular Vesicles (EV) seem to mediate the benefits of cell therapy for ischemic heart failure. Although their mechanism of action remains poorly understood, one hypothesis is that they might trigger the generation of new cardiomyocytes.

The doubly transgenic fate-mapping MerCreMer/ZEG mice model was thus used to distinguish whether these putative new cardiomyocytes originated from the division of preexisting ones (GFP+, Troponin T [TnT+], EdU+) or differentiated from endogenous progenitors, in which case they would stain positive for TnT+/EdU+ but negative for GFP.

Methods

Myocardial infarction was induced in 35 MerCreMer/ZEG mice by permanent occlusion of the left anterior descending coronary artery. Three weeks later, the surviving mice (n=18) with a left ventricular ejection fraction (LVEF) ≤45% received transcutaneous echo-guided injections in the peri-infarct myocardium of either EV (from 1.4 million human iPS-derived cardiovascular progenitor cells; 10 billion particles, n=9) or PBS (n=9); osmotic pumps were implanted to deliver EdU for 7 days in order to track the proliferation of new and native cardiomyocytes. Four-6 weeks after treatment all mice were evaluated by echocardiography (n=9 per group) and MRI (7 in each group), and then sacrificed for histological assessment, blindly.

Results

Based on echocardiography (MRI data pending), EV improved LVEF by 16% relative to baseline while a decrease of 4% was observed in the PBS group (p=0.46).

The number of new cardiomyocytes (TnT+/EdU+/GFP+) did not significantly differ between the EV-treated hearts and the controls, and averaged 0.54% of the total heart cell content in infarct, peri-infarct and remote areas. However, EV treatment better preserved preexisting GFP+/WGA+/TnT+ cardiomyocytes in the peri-infarct area as their number was greater by 5.15% compared to PBS (32 sections analyzed for each mouse). Compared to the PBS control group, EV delivery was also associated with a 2.5% decrease in fibrosis, a reduction of infarct size by 14.9%, and an increase in angiogenesis in the peri-infarct area (with a between-group absolute difference of 71 capillaries, on the basis of isolectin staining).

Conclusions

EV secreted by iPS-derived cardiovascular progenitors improve the function of chronically infarcted hearts. Preservation of the existing cardiomyocyte pool and limitation of adverse remodeling and scarred tissue, likely favored by increased neoangiogenesis, are the main mechanisms mediated by the EV, while fate mapping allowed to exclude the generation of new cardiomyocytes.

Diabetes-specific variables associated with quality of life changes in young diabetic people: the type 1 diabetes Registry of Turin (Italy)

BACKGROUND AND AIMS

Type 1 diabetes (T1DM) affects young people during the most active years of their life. Our aim was to assess quality of life (QoL) and associated variables in a large cohort of adults with childhood-onset and adult-onset T1DM.

METHODS

A cohort of adult patients (18 years and older) from the T1DM Registry of Turin, Italy, was recruited. Clinical characteristics and Diabetes QoL (DQOL) questionnaire were assessed by standardized procedures.

RESULTS

310 adults completed the questionnaire. Age and diabetes duration at assessment (mean ± SD) were 32.8 ± 7.3 years and 17.3 ± 6.3 years, respectively. DQOL and its subscores were in the lower quartiles of their distributions, indicating a good level of QoL. However, scores were significantly higher in females than in males, particularly for the subscale of diabetes-related worries. In multivariate analysis, lower QoL was independently associated with female sex (β = 1.07, 95% CI 1.03-1.11, p = 0.003), higher age at onset (β = 1.03, 1.00-1.05, p = 0.009), lower schooling (β = 1.05, 1.00-1.09, p = 0.02), higher fasting plasma glucose (β = 1.03, 1.01-1.05, p = 0.008), daily SMBG >4 (β = 1.06, 1.01-1.10, p = 0.01), severe hypoglycemia over the last year (β = 1.06, 1.01-1.11, p = 0.02), lower numbers of diabetologic visits (β = 1.07, 1.01-1.13, p = 0.02) and hypertension (β = 1.06, 1.02-1.10, p = 0.005). Autonomic neuropathy was associated with diabetes impact. Female sex (β = 4.36, 2.43-7.83) and daily SMBG >4 (β = 3.77, 1.72-8.30) were independently associated with worst level and CSII with better level (β = 0.22, 0.07-0.68) of diabetes-related worries.

CONCLUSIONS

The impact of T1DM on QoL may depend on demographic, metabolic control-related variables, presence of complications and insulin delivery modality.

Uric acid is not an independent predictor of cardiovascular mortality in type 2 diabetes: a population-based study

OBJECTIVE

Although some studies have suggested that uric acid is a risk factor for mortality, this relationship is still uncertain in people with type 2 diabetes.

METHODS

The study base was the population-based cohort of 1540 diabetic subjects (median age 68.9 years) of the Casale Monferrato Study. The role of serum uric acid on 15-years all-cause, cardiovascular and non-cardiovascular mortality was assessed by multivariate Cox proportional hazards modeling.

RESULTS

Baseline levels of serum uric acid were negatively correlated with HbA1c, were higher in men and in the elderly and were independently associated with components of the metabolic syndrome. Out of 14,179 person-years, 1000 deaths (514 due to cardiovascular diseases) were observed. Compared to the lower quartile of uric acid, HRs (95% CI) in the upper quartile were 1.47 (1.22-1.76) for all-cause mortality; 1.40 (1.09-1.80) for cardiovascular mortality and 1.50 (1.15-1.96) for non-cardiovascular mortality. In multiple adjusted models, however, HRs were 1.30 (1.06-1.60) for all-cause mortality, 1.13 (0.85-1.50) for cardiovascular mortality and 1.50 (1.11-2.02) for non-cardiovascular mortality (men 1.87, 1.19-2.95; women 1.20, 0.80-1.80); the latter appeared to be due to neoplastic diseases (HR in all combined quartiles vs. lower quartile: both sexes 1.59, 1.05-2.40; men 1.54, 0.83-2.84, women 1.68, 0.95-2.92).

CONCLUSIONS

In diabetic people, uric acid is associated with components of the metabolic syndrome but it may not be accounted as an independent risk factor for cardiovascular mortality. The increased all-cause mortality risk with higher levels of uric acid might be due to increased neoplastic mortality and deserves future studies.

The incidence of type 1 diabetes is increasing in both children and young adults in Northern Italy: 1984-2004 temporal trends

AIMS/HYPOTHESIS

A shift towards younger age at onset of diabetes in susceptible people has been suggested as a possible explanation for the increasing temporal trend in incidence of type 1 diabetes. We aimed to test this hypothesis by assessing trends in incidence rates in the period 1984-2004 in children and young adults in Northern Italy.

METHODS

The study bases were: (1) children resident in the Province of Turin in the period 1984-2004 and in the remaining areas of the Piedmont Region in the period 1990-2004; and (2) young adults (15-29 years) resident in the Province of Turin in the period 1984-2003. Temporal trends in rates were analysed using Poisson regression models.

RESULTS

A total of 1,773 incident cases were identified. Overall incidence rates/100,000 person-years in the age groups 0-14 and 15-29 years were 11.3 (95% CI 10.7-12.0) and 7.1 (95% CI 6.6-7.7), respectively, with sex differences among young adults only (incidence rate ratio [IRR] in males vs females 1.41 [95% CI 1.20-1.64]). Average annual increases in incidence rates were similar in children and young adults at 3.3% (95% CI 2.5-4.1). Compared with the period 1984-89, in 2000-2004 a 60% higher risk was found in both age 0-14 years (IRR 1.60, 95% CI 1.31-1.95) and 15-29 years (IRR 1.57, 95% CI 1.26-1.96) groups. The Poisson modelling showed no interaction between calendar period and age at onset.

CONCLUSIONS/INTERPRETATION

Incidence of type 1 diabetes in Northern Italy is increasing over time in both children and young adults, not supporting the hypothesis of a shift towards younger age as the main explanation for the increasing temporal trend in children.

Estimated glomerular filtration rate, albuminuria and mortality in type 2 diabetes: the Casale Monferrato study

AIMS/HYPOTHESIS

Estimated glomerular filtration rate (eGFR) predicts mortality in non-diabetic populations, but its role in people with type 2 diabetes is unknown. We assessed to what extent a reduction in eGFR in people with type 2 diabetes predicts 11-year all-cause and cardiovascular mortality, independently of AER and other cardiovascular risk factors.

MATERIALS AND METHODS

The study population was the population-based cohort (n = 1,538; median age 68.9 years) of the Casale Monferrato Study. GFR was estimated by the abbreviated Modification of Diet in Renal Disease Study equation.

RESULTS

At baseline, the prevalence of chronic kidney disease (eGFR <60 ml min(-1) 1.73 m(-2)) was 34.3% (95% CI 33.0-36.8). There were 670 deaths in 10,708 person-years of observation. Hazard ratios of 1.23 (95% CI 1.03-1.47) for all-cause mortality and 1.18 (95% CI 0.92-1.52) for cardiovascular mortality were observed after adjusting for cardiovascular risk factors and AER. When five levels of eGFR were analysed we found that most risk was conferred by eGFR 15-29 ml min(-1) 1.73 m(-2), whereas no increased risk was evident in people with eGFR values between 30 and 59 ml min(-1) 1.73 m(-2). In an analysis stratified by AER categories, a significant increasing trend in risk with decreasing eGFR was evident only in people with macroalbuminuria.

CONCLUSIONS/INTERPRETATION

Our study suggests that in type 2 diabetes macroalbuminuria is the main predictor of mortality, independently of both eGFR and cardiovascular risk factors, whereas eGFR provides no further information in normoalbuminuric people.

Estimated glomerular filtration rate, albuminuria and mortality in type 2 diabetes: the Casale Monferrato study

AIMS/HYPOTHESIS

Estimated glomerular filtration rate (eGFR) predicts mortality in non-diabetic populations, but its role in people with type 2 diabetes is unknown. We assessed to what extent a reduction in eGFR in people with type 2 diabetes predicts 11-year all-cause and cardiovascular mortality, independently of AER and other cardiovascular risk factors.

MATERIALS AND METHODS

The study population was the population-based cohort (n = 1,538; median age 68.9 years) of the Casale Monferrato Study. GFR was estimated by the abbreviated Modification of Diet in Renal Disease Study equation.

RESULTS

At baseline, the prevalence of chronic kidney disease (eGFR <60 ml min(-1) 1.73 m(-2)) was 34.3% (95% CI 33.0-36.8). There were 670 deaths in 10,708 person-years of observation. Hazard ratios of 1.23 (95% CI 1.03-1.47) for all-cause mortality and 1.18 (95% CI 0.92-1.52) for cardiovascular mortality were observed after adjusting for cardiovascular risk factors and AER. When five levels of eGFR were analysed we found that most risk was conferred by eGFR 15-29 ml min(-1) 1.73 m(-2), whereas no increased risk was evident in people with eGFR values between 30 and 59 ml min(-1) 1.73 m(-2). In an analysis stratified by AER categories, a significant increasing trend in risk with decreasing eGFR was evident only in people with macroalbuminuria.

CONCLUSIONS/INTERPRETATION

Our study suggests that in type 2 diabetes macroalbuminuria is the main predictor of mortality, independently of both eGFR and cardiovascular risk factors, whereas eGFR provides no further information in normoalbuminuric people.