Association between age at diagnosis and all-cause mortality in type 2 diabetes: the Renal Insufficiency and Cardiovascular Events (RIACE) Italian Multicenter Study

AIMS

It is unclear whether type 2 diabetes diagnosed in young adulthood is associated with increased severity than that occurring later in life beyond longer lifetime exposure to hyperglycemia. This study aimed at assessing the independent association of age at type 2 diabetes diagnosis with all-cause mortality.

METHODS

This prospective cohort study enrolled 15,773 Caucasian patients with type 2 diabetes in 19 Italian centers in 2006-2008. Cardiometabolic risk profile and presence of complications and comorbidities were assessed at baseline and participants were stratified by quartiles of age at diabetes diagnosis. All-cause mortality was verified on 31 October 2015.

RESULTS

Valid information on vital status was retrieved for 15,656 participants (99.3%). Patients in the lowest quartile had the longest diabetes duration, the worst glycemic control and the highest prevalence of insulin treatment, obesity, atherogenic dyslipidemia, and smoking habits. All complications were inversely associated with age at diabetes diagnosis after adjustment for age and sex, but not after further adjustment for diabetes duration. Percentages of death, Kaplan-Meier estimates, and unadjusted hazard ratios and mortality rates increased from the lowest to the highest quartile. In contrast, when adjusting for age and sex, participants falling in the lowest quartile, showed the highest mortality risk [hazard ratio 1.321 (95% confidence interval 1.196-1.460), P < 0.0001]. However, differences among quartiles disappeared after adjustment for diabetes duration, complications/comorbidities, or other cardiovascular risk factors.

CONCLUSIONS

Type 2 diabetes onset in young adulthood is associated with increased mortality that is mainly driven by longer diabetes duration favoring the development of complications.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481, retrospectively registered 15 July, 2008.

Independent association of history of diabetic foot with all-cause mortality in patients with type 2 diabetes: the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study

BACKGROUND

Foot ulcers and/or infections are common long-term complications of diabetes and are associated with increased mortality, especially from cardiovascular disease, though only a few studies have investigated the independent contribution of these events to risk of death. This study aimed at assessing the association of history of diabetic foot with all-cause mortality in individuals with type 2 diabetes, independent of cardiovascular risk factors, other complications, and comorbidities.

METHODS

This prospective cohort study enrolled 15,773 Caucasian patients in 19 Italian centers in the years 2006-2008. Prior lower extremity, coronary, and cerebrovascular events and major comorbidities were ascertained by medical records, diabetic retinopathy by fundoscopy, diabetic kidney disease by albuminuria and estimated glomerular filtration rate, cardiovascular risk factors by standard methods. All-cause mortality was retrieved for 15,656 patients on 31 October 2015.

RESULTS

At baseline, 892 patients (5.7%) had a history of diabetic foot, including ulcer/gangrene and/or amputation (n = 565; 3.58%), with (n = 126; 0.80%) or without (n = 439; 2.78%) lower limb revascularization, and revascularization alone (n = 330; 2.09%). History of diabetic foot was associated with all-cause death over a 7.42-year follow-up (adjusted hazard ratio, 1.502 [95% confidence interval, 1.346-1.676], p < 0.0001), independent of confounders, among which age, male sex, smoking, hemoglobin A1c, current treatments, other complications, comorbidities and, inversely, physical activity level and total and HDL cholesterol were correlated independently with mortality. Both ulcer/gangrene and amputation alone were independently associated with death, with a higher strength of association for amputation than for ulcer/gangrene (1.874 [1.144-3.070], p = 0.013 vs. 1.567 [1.353-1.814], p < 0.0001). Both ulcer/gangrene/amputation and lower limb revascularization alone were independently associated with death; mortality risk was much higher for ulcer/gangrene/amputation than for revascularization (1.641 [1.420-1.895], p < 0.0001 vs. 1.229 [1.024-1.475], p = 0.018) and further increased only slightly for combined ulcer/gangrene/amputation and revascularization (1.733 [1.368-2.196], p < 0.0001).

CONCLUSIONS

In patients with type 2 diabetes, an history of diabetic foot event, including ulcer/gangrene, amputation, and lower limb revascularization, was associated with a ~ 50% increased risk of subsequent death, independent of cardiovascular risk factors, other complications and severe comorbidities, which were also significantly associated with mortality. The association with mortality was greatest for amputation, whereas that for revascularization alone was relatively modest.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481, retrospectively registered 15 July, 2008.

Independent association of estimated pulse-wave velocity with all-cause mortality in individuals with type 2 diabetes

BACKGROUND

Estimated pulse wave velocity (ePWV), a surrogate measure of arterial stiffness, was shown to independently predict morbidity and mortality from cardiovascular disease and other causes in both the general population and high-risk individuals. However, in people with type 2 diabetes, it is unknown whether ePWV adds prognostic information beyond the parameters used for calculating it.

AIMS

To assess the independent association of ePWV with all-cause mortality in individuals with type 2 diabetes.

DESIGN

Prospective cohort study that enrolled 15,773 patients in 19 Italian centres in 2006-2008.

METHODS

ePWV was calculated from a regression equation using age and mean blood pressure (BP). All-cause mortality was retrieved for 15,656 patients in 2015.

RESULTS

Percentage and rate of deaths, Kaplan-Meier estimates, and unadjusted hazard ratios increased from quartile I to quartile IV of ePWV. After adjustment for age, sex, BP levels and anti-hypertensive treatment, the strength of association decreased but mortality risk remained significantly higher for quartiles II (+34%), III (+82%), and IV (+181%) versus quartile I and was virtually unchanged when further adjusting for other cardiovascular risk factors and complications/comorbidities. Each m·s - 1 increase in ePWV was associated with an increased adjusted risk of death in the whole cohort (+53%) and in participants with (+52%) and without (+65%) cardiorenal complications. Moreover, ePWV significantly improved prediction of mortality risk over cardiovascular risk factors and complications/comorbidities, though the net increase was modest.

CONCLUSIONS

These findings suggest that ePWV may represent a simple and inexpensive tool for providing prognostic information beyond traditional cardiovascular risk factors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481, https://clinicaltrials.gov/ct2/show/NCT00715481.

Retinopathy as an independent predictor of all-cause mortality in individuals with type 2 diabetes

AIMS

To assess whether the presence and grade of diabetic retinopathy (DR) predict all-cause mortality, independent of risk factors for cardiovascular disease (CVD) and other complications, including diabetes-related kidney disease (DKD) and CVD, in individuals with type 2 diabetes mellitus.

METHODS

Prospective cohort study that enroled 15,773 patients in 19 Italian centers in 2006-2008. DR ascertained by fundoscopy, DKD by albuminuria and estimated glomerular filtration rate, and prior CVD by hospital discharge records. All-cause mortality retrieved for 15,656 patients on 31 October 2015.

RESULTS

The adjusted risk of death was increased in patients with any DR (hazard ratio, 1.136 [95% confidence interval, 1.054;1.224] P < 0.0001), advanced DR, including severe non-proliferative and proliferative DR and diabetic macula edema (1.213 [1.097;1.340] P < 0.0001), and especially proliferative DR alone (1.381 [1.207;1.580] P < 0.0001), compared with those without DR. The impact of DR was more evident in patients without than in those with DKD or CVD. Mortality risk was increased in participants with DR alone, though much less than in those with DKD or CVD alone and particularly in those with both DR and DKD or CVD. DR grade was related to mortality in individuals without DKD or CVD, whereas it conferred no additional risk to those with albuminuric or nonalbuminuric DKD or established CVD.

CONCLUSIONS

In patients with type 2 diabetes mellitus, the excess mortality risk conferred by DR is relatively small and higher in those without DKD and CVD, suggesting that it may be mediated by the concurrent presence of these complications, even at a subclinical level.

Body mass index versus surrogate measures of central adiposity as independent predictors of mortality in type 2 diabetes

BACKGROUND

An "obesity paradox" for mortality has been shown in chronic disorders such as diabetes, and attributed to methodological bias, including the use of body mass index (BMI) for obesity definition. This analysis investigated the independent association of BMI versus surrogate measures of central adiposity with all-cause mortality in individuals with type 2 diabetes.

METHODS

The Renal Insufficiency And Cardiovascular Events Italian Multicentre Study is a prospective cohort study that enrolled 15,773 patients in 19 Italian centres in 2006-2008. Exposures were BMI and the surrogate measures of central adiposity waist circumference (WC), waist-to-height ratio (WHtR), and A Body Shape Index (ABSI). Vital status was retrieved on 31 October 2015 for 15,656 patients (99.3%), RESULTS: Age- and sex-adjusted hazard ratios and 95% confidence intervals were significantly higher in BMI-based underweight (1.729 [1.193-2.505), P = 0.004), moderately obese (1.214 [1.058-1.392), P = 0.006) and severely obese (1.703 [1.402-2.068), P < 0.0001), lower in overweight (0.842 [0.775-0.915), P < 0.0001) and similar in mildly obese (0.950 [0.864-1.045), P = 0.292), compared to normal-weight individuals. When further adjusting for smoking, physical activity (PA), and comorbidities, risk was lower also in mildly obese versus normal-weight patients. The BMI-mortality relationship did not change after sequentially excluding ever smokers, individuals with comorbidities, and those died within two years from enrollment and when analyzing separately participants below and above the median age. Conversely, a paradox relationship was observed among inactive/moderately inactive, but not moderately/highly active patients. Mortality risk adjusted for age, gender, smoking, PA and comorbidities was significantly higher in the highest tertile of WC (1.279 [1.089-1.501], P = 0.003), WHtR (1.372 [1.165-1.615], P < 0.0001), and ABSI (1.263 [1.067-1.495], P = 0.007) versus the lowest tertile. However, risk was lower in the intermediate versus lowest tertile for WC (0.823 [0.693-0.979], P = 0.028), similar for WHtR, and higher, though not significantly, for ABSI.

CONCLUSIONS

An "overweight paradox" remained after controlling for age, smoking, and comorbidities, arguing against a collider bias or reverse causation. However, it could be partly explained by confounding from PA level, possibly through its impact on lean mass and cardiorespiratory fitness. No obesity paradox was observed with WHtR and especially ABSI, which predicted mortality risk associated with central adiposity better than WC. Trial registration ClinicalTrials.gov, NCT00715481, 15 July, 2008.

Risk of all-cause mortality according to the European Society of Cardiology risk categories in individuals with type 2 diabetes: the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study

AIMS

The 2019 and 2021 European Society of Cardiology (ESC) classifications stratified patients with type 2 diabetes into three categories according to the 10-year risk of death from atherosclerotic cardiovascular disease (ASCVD). The very high-risk category included individuals with established ASCVD, target organ damage (TOD), and/or, in the 2019 classification only, ≥ 3 additional ASCVD risk factors. We assessed risk of all-cause mortality according to the two ESC classifications in the Renal Insufficiency And Cardiovascular Events cohort.

METHODS

Participants (n = 15,773) were stratified based on the presence of ASCVD, TOD, and ASCVD risk factors at baseline (2006-2008). Vital status was retrieved in 2015.

RESULTS

Less than 1% of participants fell in the moderate-risk category. According to the 2019 classification, ~ 1/3 fell in the high-risk and ~ 2/3 in the very high-risk category, whereas the opposite occurred with the 2021 classification. Mortality risk increased across categories according to both classifications. Among very high-risk patients, mortality was much lower in those with ≥ 3 additional ASCVD risk factors and almost equal in those with TOD and ASCVD ± TOD, using the 2019 classification, whereas it was much higher in those with ASCVD + TOD and, to a lesser extent, TOD only than in those with ASCVD only, using the 2021 classification.

CONCLUSIONS

The negligible number of moderate-risk patients suggests that these classifications might overestimate risk of ASCVD death. Downgrading patients with ≥ 3 additional ASCVD risk factors to the high-risk category is consistent with mortality data. Risk of death is very high in the presence of TOD irrespective of established ASCVD.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481.

Insulin resistance, diabetic kidney disease, and all-cause mortality in individuals with type 2 diabetes: a prospective cohort study

BACKGROUND

It is unclear whether insulin resistance (IR) contributes to excess mortality in patients with type 2 diabetes independent of diabetic kidney disease (DKD), which is strongly associated with IR and is a major risk factor for cardiovascular disease (CVD), the main cause of death in these individuals. We tested this hypothesis in patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events Italian Multicentre Study.

METHODS

This observational, prospective, cohort study enrolled 15,773 patients with type 2 diabetes attending 19 Italian Diabetes Clinics in 2006-2008. Insulin sensitivity was assessed as estimated glucose disposal rate (eGDR), which was validated against the euglycaemic-hyperinsulinemic clamp technique. Vital status on October 31, 2015, was retrieved for 15,656 patients (99.3%). Participants were stratified by eGDR tertiles from T1 (≥ 5.35 mg/kg/min) to T3 (≤ 4.14 mg/kg/min, highest IR).

RESULTS

CVD risk profile was worse in T2 and T3 vs T1. eGDR tertiles were independently associated with micro- and macroalbuminuria and the albuminuric DKD phenotypes (albuminuria with preserved or reduced estimated glomerular filtration rate [eGFR]) as well as with eGFR categories or the nonalbuminuric DKD phenotype. Over a 7.4-year follow-up, unadjusted death rates and mortality risks increased progressively across eGDR tertiles, but remained significantly elevated after adjustment only in T3 vs T1 (age- and gender- adjusted death rate, 22.35 vs 16.74 per 1000 person-years, p < 0.0001, and hazard ratio [HR] adjusted for multiple confounders including DKD, 1.140 [95% confidence interval [CI], 1.049-1.238], p = 0.002). However, eGDR was independently associated with mortality in participants with no DKD (adjusted HR, 1.214 [95% CI, 1.072-1.375], p = 0.002) and in those with nonalbuminuric DKD (1.276 [1.034-1.575], p = 0.023), but not in those with the albuminuric DKD phenotypes. Moreover, the association was stronger in males and in younger individuals and was observed in those without but not with prior CVD, though interaction was significant only for age.

CONCLUSIONS

The proxy of insulin sensitivity eGDR predicts all-cause mortality in type 2 diabetes, independent of confounders including DKD. However, the impact of IR in individuals with albuminuric DKD may be mediated by its relationship with albuminuria.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT00715481, retrospectively registered 15 July 2008.

Renal hyperfiltration is independently associated with increased all-cause mortality in individuals with type 2 diabetes: a prospective cohort study

INTRODUCTION

In addition to favoring renal disease progression, renal 'hyperfiltration' has been associated with an increased risk of death, though it is unclear whether and how excess mortality is related to increased renal function. We investigated whether renal hyperfiltration is an independent predictor of death in patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events Italian multicenter study.

RESEARCH DESIGN AND METHODS

This observational, prospective cohort study enrolled 15 773 patients with type 2 diabetes consecutively attending 19 Italian diabetes clinics in 2006-2008. Serum creatinine, albuminuria, cardiovascular risk factors, and complications/comorbidities were assessed at baseline. Vital status on 31 October 2015 was retrieved for 15 656 patients (99.26%). Patients were stratified (A) by absolute estimated glomerular filtration rate (eGFR) values in eGFR deciles or Kidney Disease: Improving Global Outcomes (KDIGO) categories and (B) based on age-corrected thresholds or age and gender-specific 95th and 5th percentiles in hyperfiltration, hypofiltration, and normofiltration groups.

RESULTS

The highest eGFR decile/category and the hyperfiltration group included (partly) different individuals with similar clinical features. Age and gender-adjusted death rates were significantly higher in deciles 1, 9, and 10 (≥103.9, 50.9-62.7, and <50.9 mL/min/1.73 m², respectively) versus the reference decile 3 (92.9-97.5 mL/min/1.73 m²). Mortality risk, adjusted for multiple confounders, was also increased in deciles 1 (HR 1.461 (95% CI 1.175 to 1.818), p=0.001), 9 (1.312 (95% CI 1.107 to 1.555), p=0.002), and 10 (1.976 (95% CI 1.673 to 2.333), p<0.0001) versus decile 3. Similar results were obtained by stratifying patients by KDIGO categories. Death rates and adjusted mortality risks were significantly higher in hyperfiltering and particularly hypofiltering versus normofiltering individuals.

CONCLUSIONS

In type 2 diabetes, both high-normal eGFR and hyperfiltration are associated with an increased risk of death from any cause, independent of confounders that may directly impact on mortality and/or affect GFR estimation. Further studies are required to clarify the nature of this relationship.

TRIAL REGISTRATION NUMBER

NCT00715481.

Is resistant hypertension an independent predictor of all-cause mortality in individuals with type 2 diabetes? A prospective cohort study

BACKGROUND

Resistant hypertension is independently associated with an increased risk of death in the general hypertensive population. We assessed whether resistant hypertension is an independent predictor of all-cause mortality in individuals with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study.

METHODS

On 31 October 2015, vital status information was retrieved for 15,656 of the 15,773 participants enrolled in 2006-2008. Based on baseline blood pressure (BP) values and treatment, participants were categorized as normotensive, untreated hypertensive, controlled hypertensive (i.e., on-target with < 3 drugs), uncontrolled hypertensive (i.e., not on-target with 1-2 drugs), or resistant hypertensive (i.e., uncontrolled with > 3 drugs or controlled with > 4 drugs). Kaplan-Meier and Cox proportional hazards regression analyses were used to assess the association with all-cause mortality.

RESULTS

Using the 130/80 mmHg targets for categorization, crude mortality rates and Kaplan-Meier estimates were highest among resistant hypertension participants, especially those with controlled resistant hypertension. As compared with resistant hypertension, risk for all-cause mortality was significantly lower for all the other groups, including individuals with controlled hypertension (hazard ratio 0.81 [95% confidence interval 0.74-0.89], P < 0.0001), but became progressively similar between resistant and controlled hypertension after adjustment for cardiovascular risk factors and complications/comorbidities. Also when compared with controlled resistant hypertension, mortality risk was significantly lower for all the other groups, including controlled hypertension, even after adjusting for cardiovascular risk factors (0.77 [0.63-0.95], P = 0.012), but not for complications/comorbidities (0.88 [0.72-1.08], P = 0.216). BP was well below target in the controlled hypertensive groups (resistant and non-resistant) and values < 120/70 mmHg were associated with an increased mortality risk. Results changed only partly when using the 140/90 mmHg targets for categorization.

CONCLUSIONS

In the RIACE cohort, at variance with the general hypertensive population, resistant hypertension did not predict death beyond target organ damage. Our findings may be explained by the high mortality risk conferred by type 2 diabetes and the low BP values observed in controlled hypertensive patients, which may mask risk associated with resistant hypertension. Less stringent BP goals may be preferable in high-risk patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481 , retrospectively registered 15 July, 2008.

Acute on chronic limb ischemia: From surgical embolectomy and thrombolysis to endovascular options

After the invention of the balloon catheter by Fogarty in 1963, surgical thromboembolectomy was considered the gold standard treatment for many years in patients with acute lower limb ischemia (ALLI). ALLI is a dramatic event, carrying a high risk of amputation and perioperative morbidity and mortality. The evolution of endovascular technologies has resulted in a variety of therapeutic options to establish arterial patency. In the 1970s, Dotter first introduced the idea of clot lysis in the treatment of ALLI, which was modified to catheter-directed thrombolysis, and now clot aspiration techniques. Currently, the majority of ALLI (about 70%) is arterial thrombosis, which generally occurs in the setting of preexisting vascular lesion. This condition is very common in patients with diabetes. Clinical presentation in case of thrombosis on atherosclerotic stenosis (so called "acute on chronic ischemia") may be less severe, but treatment is generally more challenging than ALLI due to embolism, considering the complexity in device trackability through the diseased vessels, potential vessel injury, incomplete revascularization, and need of correction of underlying vascular lesions. Although surgery is still a treatment option, especially for ALLI, endovascular interventions have assumed a prominent role in restoring limb perfusion. In this review, the treatment options for ALLI are detailed from surgical thromboembolectomy to thrombolysis and current endovascular techniques, including mechanical fragmentation, rheolytic thrombectomy, and aspiration thrombectomy. The evolution to endovascular therapies has resulted in improved clinical outcomes and lower rates of morbidity.

Serum Levels of miR-148a and miR-21-5p Are Increased in Type 1 Diabetic Patients and Correlated with Markers of Bone Strength and Metabolism

Type 1 diabetes (T1D) is characterized by bone loss and altered bone remodeling, resulting into reduction of bone mineral density (BMD) and increased risk of fractures. Identification of specific biomarkers and/or causative factors of diabetic bone fragility is of fundamental importance for an early detection of such alterations and to envisage appropriate therapeutic interventions. MicroRNAs (miRNAs) are small non-coding RNAs which negatively regulate genes expression. Of note, miRNAs can be secreted in biological fluids through their association with different cellular components and, in such context, they may represent both candidate biomarkers and/or mediators of bone metabolism alterations. Here, we aimed at identifying miRNAs differentially expressed in serum of T1D patients and potentially involved in bone loss in type 1 diabetes. We selected six miRNAs previously associated with T1D and bone metabolism: miR-21; miR-24; miR-27a; miR-148a; miR-214; and miR-375. Selected miRNAs were analyzed in sera of 15 T1D patients (age: 33.57 ± 8.17; BMI: 21.4 ± 1.65) and 14 non-diabetic subjects (age: 31.7 ± 8.2; BMI: 24.6 ± 4.34). Calcium, osteocalcin, parathormone (PTH), bone ALkaline Phoshatase (bALP), and Vitamin D (VitD) as well as main parameters of bone health were measured in each patient. We observed an increased expression of miR-148a (p = 0.012) and miR-21-5p (p = 0.034) in sera of T1D patients vs. non-diabetic subjects. The correlation analysis between miRNAs expression and the main parameters of bone metabolism, showed a correlation between miR-148a and Bone Mineral Density (BMD) total body (TB) values (p = 0.042) and PTH circulating levels (p = 0.033) and the association of miR-21-5p to Bone Mineral Content-Femur (BMC-FEM). Finally, miR-148a and miR-21-5p target genes prediction analysis revealed several factors involved in bone development and remodeling, such as MAFB, WNT1, TGFB2, STAT3, or PDCD4, and the co-modulation of common pathways involved in bone homeostasis thus potentially assigning a role to both miR-148a and miR-21-5p in bone metabolism alterations. In conclusion, these results lead us to hypothesize a potential role for miR-148a and miR-21-5p in bone remodeling, thus representing potential biomarkers of bone fragility in T1D.

Non-albuminuric renal impairment is a strong predictor of mortality in individuals with type 2 diabetes: the Renal Insufficiency And Cardiovascular Events (RIACE) Italian multicentre study

AIMS/HYPOTHESIS

Non-albuminuric renal impairment has become the prevailing diabetic kidney disease (DKD) phenotype in individuals with type 2 diabetes and an estimated GFR (eGFR) <60 ml min^-1 1.73 m^-2. In the present study, we compared the rate and determinants of all-cause death in individuals with this phenotype with those in individuals with albuminuric phenotypes.

METHODS

This observational prospective cohort study enrolled 15,773 individuals with type 2 diabetes in 2006-2008. Based on baseline albuminuria and eGFR, individuals were classified as having: no DKD (Alb^-/eGFR^-), albuminuria alone (Alb⁺/eGFR^-), reduced eGFR alone (Alb^-/eGFR⁺), or both albuminuria and reduced eGFR (Alb⁺/eGFR⁺). Vital status on 31 October 2015 was retrieved for 15,656 individuals (99.26%).

RESULTS

Mortality risk adjusted for confounders was lowest for Alb^-/eGFR^- (reference category) and highest for Alb⁺/eGFR⁺ (HR 2.08 [95% CI 1.88, 2.30]), with similar values for Alb⁺/eGFR^- (1.45 [1.33, 1.58]) and Alb^-/eGFR⁺ (1.58 [1.43, 1.75]). Similar results were obtained when individuals were stratified by sex, age (except in the lowest age category) and prior cardiovascular disease. In normoalbuminuric individuals with eGFR <45 ml min^-1 1.73 m^-2, especially with low albuminuria (10-29 mg/day), risk was higher than in microalbuminuric and similar to macroalbuminuric individuals with preserved eGFR. Using recursive partitioning and amalgamation analysis, prevalent cardiovascular disease and lower HDL-cholesterol were the most relevant correlates of mortality in all phenotypes. Higher albuminuria within the normoalbuminuric range was associated with death in non-albuminuric DKD, whereas the classic 'microvascular signatures', such as glycaemic exposure and retinopathy, were correlates of mortality only in individuals with albuminuric phenotypes.

CONCLUSIONS/INTERPRETATION

Non-albuminuric renal impairment is a strong predictor of mortality, thus supporting a major prognostic impact of renal dysfunction irrespective of albuminuria. Correlates of death partly differ from the albuminuric forms, indicating that non-albuminuric DKD is a distinct phenotype.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00715481.

Haemoglobin A1c variability is a strong, independent predictor of all-cause mortality in patients with type 2 diabetes

AIMS

To evaluate various measures of haemoglobin (Hb) A1c variability, compared with average HbA1c, as independent predictors of mortality.

MATERIALS AND METHODS

The Renal Insufficiency And Cardiovascular Events Italian multicentre study enroled 15 733 patients with type 2 diabetes from 19 diabetes clinics during 2006-2008. A total of 3 to 5 HbA1c measures, obtained during the 2-year period before enrolment, were available from 9 centres (8290 patients) and were used to calculate average HbA1c (HbA1c -MEAN) and HbA1c variability, measured as intra-individual standard deviation (HbA1c-SD), SD adjusted for the number of HbA1c assessments (HbA1c-AdjSD) and coefficient of variation (HbA1c-CV), that is, the HbA1c-SD to HbA1c-MEAN ratio. Vital status on October 31, 2015 was retrieved for 8252 patients (99.5%).

RESULTS

The measures of HbA1c variability increased according to quartiles of HbA1c-MEAN and vice versa. HbA1c-MEAN and measures of HbA1c variability were associated with all-cause mortality; however, the strength of association of HbA1c-MEAN was lower than that of HbA1c -SD, HbA1c-CV or HbA1c-AdjSD, and disappeared after adjusting for confounders and any of the measures of HbA1c variability. Mortality increased with quartiles of HbA1c-MEAN, HbA1c -SD, HbA1c-CV and HbA1c-AdjSD, but only the association with HbA1c variability measures remained after adjustment for confounders and/or each other measure. In the fully adjusted model, mortality risk was lower for HbA1c-SD below the median and higher for HbA1c-SD above the median, regardless of whether HbA1c-MEAN was below or above the median. Conclusions HbA1c variability is a strong, independent predictor of all-cause mortality in type 2 diabetes and appears to be even more powerful than average HbA1c in predicting mortality.

Defining the contribution of chronic kidney disease to all-cause mortality in patients with type 2 diabetes: the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study

AIMS

To define the contribution of chronic kidney disease (CKD) to excess mortality in patients with type 2 diabetes and identify the baseline variables associated with all-cause death in those with and without CKD using the RECursive Partitioning and Amalgamation (RECPAM) method.

METHODS

This observational, longitudinal, cohort study enrolled 15,773 consecutive non-dialytic patients with type 2 diabetes in 19 Diabetes Clinics throughout Italy in 2006-2008. Based on the presence of albuminuria ≥ 30 mg day^-1 and/or estimated glomerular filtration rate (eGFR) < 60 mL min^-1·1.73 m^-2 at baseline, patients were classified as having or not CKD. Vital status was verified on October 31, 2015 for 99.26% of patients.

RESULTS

Mortality increased with increasing albuminuria and eGFR category. Excess risk versus the general population was maximal in patients aged < 55 years in the worse albuminuria or eGFR category. Conversely, in subjects aged ≥ 75 years with albuminuria < 10 mg day^-1 or eGFR ≥ 75 mL min^-1·1.73 m^-2, excess mortality was no longer detectable. At RECPAM analysis, the main correlates of death in the whole cohort were albuminuria > 44 mg day^-1, prevalent CVD, and eGFR < ~ 75 mL min^-1·1.73 m^-2; gender, prevalent CVD, and higher albuminuria in the normoalbuminuric range, in patients without CKD; and CVD, eGFR ~ < 50 mL min^-1·1.73 m^-2, and albuminuria > 53 mg day^-1, in those with CKD.

CONCLUSIONS

CKD is a major contributor to excess mortality in type 2 diabetes, conferring a very high risk in younger patients and fully accounting for excess risk in the older ones. Higher albuminuria and lower eGFR, even in the normal range, identify individuals with increased mortality risk. Trial registration ClinicalTrials.gov (NCT00715481; https://clinicaltrials.gov/ct2/show/NCT00715481 ).

Fighting diabetic foot ulcers-The diabetologist: A king maker of the fight

Diabetic foot ulcer is a costly and serious complication of diabetes mellitus and is the major cause of non-traumatic limb amputations worldwide. Its development is primarily the result of diabetic neuropathy and/or peripheral arterial disease with accompanied bone abnormalities and is complicated by invasive infection. The management of this clinical condition focuses on identification of the "at-risk" foot, treatment of the ulcerated foot, and prevention of further complications. As diabetic foot ulcer represents the sum of multiple etiologies, its treatment requires a multidisciplinary team, which can result in a significant reduction in the incidence of ulcers, infections and amputations. The team should include a diabetologist, a podiatrist, an orthoptist, an educator and a plaster technician, in close collaboration with a vascular surgeon, an orthopedic/podiatric surgeon and a dermatologist. It is recommended that a diabetologist be the multidisciplinary team leader, as diabetic foot ulcer is a complication of diabetes and chronic hyperglycemia represents the main cause for its development. The appropriate composition of professionals involved in the team is institution-dependent and may vary worldwide, depending on the diabetic population. The concept of establishing a diabetic foot care team is recommended by all National and International Diabetes Scientific Societies and Associations.

Independent correlates of urinary albumin excretion within the normoalbuminuric range in patients with type 2 diabetes: The Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study

AIMS

Within the normoalbuminuric range, low albuminuria (LA, 10-29 mg/24 h) is associated with higher adverse cardiovascular and renal outcomes than normal albuminuria (NA, <10 mg/24 h). This cross-sectional analysis of the cohort from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study was aimed at assessing the independent correlates of LA versus NA in patients with type 2 diabetes.

METHODS

This analysis involved 11,538 normoalbuminuric patients (73.2 % of the entire RIACE cohort): 6023 (52.2 %) with NA and 5515 (47.8 %) with LA. Binary logistic regression analysis with backward conditional variable selection was applied to assess the independent correlates of LA versus NA.

RESULTS

Compared with NA subjects, LA patients were more frequently males, older and with family history of hypertension, had longer diabetes duration, lower HDL cholesterol, and higher haemoglobin (Hb) A1c, triglycerides, and blood pressure (BP), use of anti-hyperglycaemic and anti-hypertensive drugs, and prevalence of metabolic syndrome, retinopathy, chronic kidney disease, any cardiovascular disease, myocardial infarction, and coronary and peripheral events. Men with LA were also more frequently current or former smokers and had higher body mass index, waist circumference, and non-HDL cholesterol. Independent correlates of LA were age (OR 1.018), family history of hypertension (OR 1.321), smoking status (former, OR 1.158; current, OR 1.237), HbA1c (OR 1.062), waist circumference (OR 1.050), triglycerides (OR 1.001), and diastolic BP (OR 1.014), together with use of anti-hyperglycaemic and anti-hypertensive agents.

CONCLUSIONS

Several risk factors are associated with increased albuminuria within the normoalbuminuric range. As most of these factors are potentially modifiable, treating them aggressively might reduce the excess risk associated with LA.

TRIAL REGISTRATION

NCT00715481; www.ClinicalTrials.gov .

Hypertriglyceridemia Is Independently Associated with Renal, but Not Retinal Complications in Subjects with Type 2 Diabetes: A Cross-Sectional Analysis of the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study

Objective

Atherogenic dyslipidemia seems to play a major role in microvascular complications and in residual microvascular risk after statin therapy, which reduces triglycerides up to 40%. We assessed whether raised TG levels are associated with an increased burden from microvascular complications in patients with type 2 diabetes.

Methods

Subjects from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study (n=15,773) were divided in 4 groups depending on whether they had plasma triglycerides below (NTG, 67.8%) or above (HTG, 32.2%) 1.7 mmol/L and were (42.4%) or not on (57.6%) statin therapy. Estimated GFR (eGFR) was calculated from serum creatinine, albuminuria was measured by immunonephelometry or immunoturbidimetry, and retinopathy was evaluated by fundus examination.

Results

HTG subjects, either with or without statin, had higher prevalence of albuminuria, reduced eGFR and chronic kidney disease (CKD), especially the albuminuric forms, but not of retinopathy, than NTG subjects. In contrast, cardiovascular disease and advanced DR were more prevalent in subjects on statin than in those not, independently of triglyceride levels. Logistic regression analysis confirmed that HTG, without or with statin, was independently associated with micro and macroalbuminuria, mildly to severely reduced eGFR, and all CKD phenotypes, but not with retinopathy. The adjusted odd ratios for CKD increased linearly for every 0.26 mmol/L increase (approximately one decile) in triglyceride levels. The increase was higher with increasing severity of albuminuria, eGFR loss and CKD phenotype as well as in subjects receiving than in those not receiving statin treatment.

Conclusions

Triglycerides are associated with CKD, but not retinopathy in subjects with type 2 diabetes, independently of statin treatment. These data point to a possible role of hypertriglyceridemia in the development of CKD, though it remains to be demonstrated that diabetic individuals might benefit from triglyceride reduction with statins and eventually with combination therapy with fibrates.

Trial Registration

www.ClinicalTrials.gov NCT00715481

Chronic kidney disease in type 2 diabetes: lessons from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study

The Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study is an ongoing observational survey that examines the role of estimated glomerular filtration rate (eGFR) as an independent predictor of cardiovascular and renal outcomes in 15,773 Italian subjects with type 2 diabetes. The analysis of data collected at the enrollment visit provided a picture of chronic kidney disease (CKD) and its association with other complications, risk factors for cardiovascular disease (CVD) and treatments in a large contemporary cohort. Main results of this analysis were that (a) non-albuminuric renal impairment is the predominant clinical phenotype in patients, particularly women, with reduced eGFR; (b) concordance between CKD and diabetic retinopathy is low, with only a minority of patients with renal dysfunction presenting with any or advanced retinal lesions; (c) the non-albuminuric form is associated with a significant prevalence of CVD, especially at the level of the coronary vascular bed; (d) CKD is associated with hemoglobin (Hb) A1c variability more than with average HbA1c, whereas retinopathy and CVD are not; (e) in elderly individuals with moderate-to-severe eGFR reduction, use of agents which are not recommended, such as sulphonylureas and metformin, is still frequent; and (f) though complications are generally more prevalent in men (except non-albuminuric renal impairment) women show a less favorable CVD risk profile and achieve therapeutic targets to a lesser extent than men, despite the fact that treatment intensity is not lower. These data update existing information on the natural history of CKD in patients with type 2 diabetes.

Distribution of cardiovascular disease and retinopathy in patients with type 2 diabetes according to different classification systems for chronic kidney disease: a cross-sectional analysis of the renal insufficiency and cardiovascular events (RIACE) Italian multicenter study

Background

The National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative (NKF’s KDOQI) staging system for chronic kidney disease (CKD) is based primarily on estimated GFR (eGFR). This study aimed at assessing whether reclassification of subjects with type 2 diabetes using two recent classifications based on both eGFR and albuminuria, the Alberta Kidney Disease Network (AKDN) and the Kidney Disease: Improving Global Outcomes (KDIGO), provides a better definition of burden from cardiovascular disease (CVD) and diabetic retinopathy (DR) than the NKF’s KDOQI classification.

Methods

This is a cross-sectional analysis of patients with type 2 diabetes (n = 15,773) from the Renal Insufficiency And Cardiovascular Events Italian Multicenter Study, consecutively visiting 19 Diabetes Clinics throughout Italy in years 2007-2008. Exclusion criteria were dialysis or renal transplantation. CKD was defined based on eGFR, as calculated from serum creatinine by the simplified Modification of Diet in Renal Disease Study equation, and albuminuria, as measured by immunonephelometry or immunoturbidimetry. DR was assessed by dilated fundoscopy. Prevalent CVD, total and by vascular bed, was assessed from medical history by recording previous documented major acute events.

Results

Though prevalence of complications increased with increasing CKD severity with all three classifications, it differed significantly between NKF’s KDOQI stages and AKDN or KDIGO risk categories. The AKDN and KDIGO systems resulted in appropriate reclassification of uncomplicated patients in the lowest risk categories and a more graded independent association with CVD and DR than the NKF’s KDOQI classification. However, CVD, but not DR prevalence was higher in the lowest risk categories of the new classifications than in the lowest stages of the NKF’s KDOQI, due to the inclusion of subjects with reduced eGFR without albuminuria. CVD prevalence differed also among eGFR and albuminuria categories grouped into AKDN and KDIGO risk category 1 and moderate, respectively, and to a lesser extent into higher risk categories.

Conclusions

Though the new systems perform better than the NKF’s KDOQI in grading complications and identifying diabetic subjects without complications, they might underestimate CVD burden in patients assigned to lower risk categories and should be tested in large prospective studies.

Trial registration

ClinicalTrials.gov; NCT00715481

Gender differences in cardiovascular disease risk factors, treatments and complications in patients with type 2 diabetes: the RIACE Italian multicentre study

OBJECTIVES

Poorer control of risk factors for cardiovascular disease (CVD) has been reported in diabetic women, as compared with diabetic men. It has been proposed that this finding is due to gender disparities in treatment intensity. We investigated this hypothesis in a large contemporary cohort of subjects with type 2 diabetes.

DESIGN

Observational, cross-sectional study.

SUBJECTS AND SETTING

Consecutive patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian multicentre study (n = 15 773), attending 19 hospital-based diabetes clinics in 2007-2008.

MAIN OUTCOME MEASURES

Traditional CVD risk factors, macro- and microvascular complications and current glucose-, lipid- and blood pressure (BP)-lowering treatments were assessed.

RESULTS

Although CVD was more prevalent in men, women showed a less favourable CVD risk profile and worse performance in achieving treatment targets for haemoglobin A1c , LDL, HDL and non-HDL cholesterol, systolic blood pressure (BP) and in particular obesity [body mass index (BMI) and waist circumference], but not for triglycerides and diastolic BP. However, women were more frequently receiving pharmacological treatment for hypertension and to a lesser extent hyperglycaemia and dyslipidaemia than men, and female gender remained an independent predictor of unmet therapeutic targets after adjustment for confounders such as treatments, BMI, duration of diabetes and, except for the systolic BP goal, age.

CONCLUSIONS

In women with type 2 diabetes from the RIACE cohort, a more adverse CVD risk profile and a higher likelihood of failing treatment targets, compared with men, were not associated with treatment differences. This suggests that factors other than gender disparities in treatment intensity are responsible.

HbA1c variability as an independent correlate of nephropathy, but not retinopathy, in patients with type 2 diabetes: the Renal Insufficiency And Cardiovascular Events (RIACE) Italian multicenter study

OBJECTIVE

To examine the association of hemoglobin (Hb) A1c variability with microvascular complications in the large cohort of subjects with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study.

RESEARCH DESIGN AND METHODS

Serial (3-5) HbA1c values collected in a 2-year period before enrollment were available from 8,260 subjects from 9 centers (of 15,773 patients from 19 centers). HbA1c variability was measured as the intraindividual SD of 4.52 ± 0.76 values. Diabetic retinopathy (DR) was assessed by dilated funduscopy. Chronic kidney disease (CKD) was defined based on albuminuria, as measured by immunonephelometry or immunoturbidimetry, and estimated glomerular filtration rate (eGFR) was calculated from serum creatinine.

RESULTS

Median and interquartile range of average HbA1c (HbA1c-MEAN) and HbA1c-SD were 7.57% (6.86-8.38) and 0.46% (0.29-0.74), respectively. The highest prevalence of microalbuminuria, macroalbuminuria, reduced eGFR, albuminuric CKD phenotypes, and advanced DR was observed when both HbA1c parameters were above the median and the lowest when both were below the median. Logistic regression analyses showed that HbA1c-SD adds to HbA1c-MEAN as an independent correlate of microalbuminuria and stages 1-2 CKD and is an independent predictor of macroalbuminuria, reduced eGFR, and stages 3-5 albuminuric CKD, whereas HbA1c-MEAN is not. The opposite was found for DR, whereas neither HbA1c-MEAN nor HbA1c-SD affected nonalbuminuric CKD.

CONCLUSIONS

In patients with type 2 diabetes, HbA1c variability affects (albuminuric) CKD more than average HbA1c, whereas only the latter parameter affects DR, thus suggesting a variable effect of these measures on microvascular complications.

Hemoglobin A1c variability as an independent correlate of cardiovascular disease in patients with type 2 diabetes: a cross-sectional analysis of the renal insufficiency and cardiovascular events (RIACE) Italian multicenter study

BACKGROUND

Previous reports have clearly indicated a significant relationship between hemoglobin (Hb) A1c change from one visit to the next and microvascular complications, especially nephropathy (albuminuria and albuminuric chronic kidney disease, CKD). In contrast, data on macrovascular disease are less clear. This study was aimed at examining the association of HbA1c variability with cardiovascular disease (CVD) in the large cohort of subjects with type 2 diabetes from the Renal Insufficiency and Cardiovascular Events (RIACE) Italian Multicenter Study.

METHODS

Serial (3-5) HbA1c values obtained during the 2-year period preceding recruitment, including that obtained at the enrolment, were available from 8,290 subjects from 9 centers (out of 15,773 patients from 19 centers). Average HbA1c and HbA1c variability were calculated as the intra-individual mean (HbA1c-MEAN) and standard deviation (HbA1c-SD), respectively, of 4.52 ± 0.76 values. Prevalent CVD, total and by vascular bed, was assessed from medical history by recording previous documented major acute events. Diabetic retinopathy (DR) was assessed by dilated fundoscopy. CKD was defined based on albuminuria, as measured by immunonephelometry or immunoturbidimetry, and estimated glomerular filtration rate, as calculated from serum creatinine.

RESULTS

HbA1c-MEAN, but not HbA1c-SD, was significantly higher (P<0.0001) in subjects with history of any CVD (n. 2,133, 25.7%) than in those without CVD (n. 6,157, 74.3%). Median and interquartile range were 7.78 (7.04-8.56) and 7.49 (6.81-8.31), respectively, for HbA1c-MEAN, and 0.47 (0.29-0.75) and 0.46 (0.28-0.73), respectively, for HbA1c-SD. Logistic regression analyses showed that HbA1c-MEAN, but not HbA1c-SD (and independent of it), was a significant correlate of any CVD. Similar findings were observed in subjects with versus those without any coronary or cerebrovascular event or myocardial infarction. Conversely, none of these measures were associated with stroke, whereas both correlated with any lower limb vascular event and HbA1c-SD alone with ulceration/gangrene. All these associations were independent of known CVD risk factors and microvascular complications (DR and CKD).

CONCLUSIONS

In patients with type 2 diabetes, HbA1c variability has not a major impact on macrovascular complications, at variance with average HbA1c, an opposite finding as compared with microvascular disease, and particularly nephropathy.

TRIAL REGISTRATION

ClinicalTrials.Gov NCT00715481.

High prevalence of advanced retinopathy in patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study

AIMS

The natural history of diabetic complications, including diabetic retinopathy (DR), is changing due to improved care. This study aimed at assessing prevalence of advanced DR and its correlation with risk factors and complications in subjects with type 2 diabetes from the Renal Insufficiency and Cardiovascular Events (RIACE) Italian Multicenter Study.

METHODS

This study enrolled 15,773 patients visiting consecutively 19 Diabetes Clinics in years 2007-2008. DR was assessed by dilated fundoscopy and classified according to the Global Diabetic Retinopathy Project Group.

RESULTS

Advanced DR was observed in 9.8% of patients (4.2% pre-proliferative, 4.2% proliferative, 1.3% maculopathy, 0.1% blindness). Advanced DR was independently associated with hemoglobin (Hb) A(1c), diabetes duration and treatment, particularly with insulin, hypertension, previous cardiovascular disease (CVD), albuminuria and, inversely, age, age at diabetes diagnosis, smoking and estimated glomerular filtration rate. Maculopathy alone was associated with female gender, but not HbA(1c), hypertension and age.

CONCLUSIONS

We found an alarming high prevalence of advanced DR in subjects with type 2 diabetes from the RIACE cohort, suggesting that the expected favorable effect of improved diabetes management has not emerged yet. Independent correlates of advanced DR were indexes of glycemic exposure, hypertension, CVD, albuminuria and, inversely, age at diagnosis and smoking.

Diverging association of reduced glomerular filtration rate and albuminuria with coronary and noncoronary events in patients with type 2 diabetes: the renal insufficiency and cardiovascular events (RIACE) Italian multicenter study

OBJECTIVE

Although a reduced estimated glomerular filtration rate (eGFR) was shown to be a powerful independent predictor of cardiovascular disease (CVD), other studies suggested that it confers a much lower risk than albuminuria alone, whereas the combination of the two abnormalities is associated with multiplicative risk. This study aimed at assessing the independent association of previous CVD events, either total or by vascular bed, with eGFR and albuminuria and chronic kidney disease (CKD) phenotypes.

RESEARCH DESIGN AND METHODS

This cross-sectional study evaluated 15,773 patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study in 19 outpatient diabetes clinics in years 2007-2008. Albuminuria was assessed by immunonephelometry or immunoturbidimetry. GFR was estimated by the simplified Modification of Diet in Renal Disease Study and the Chronic Kidney Disease-Epidemiology Collaboration equation. CKD was defined as an eGFR <60 mL/min/1.73 m(2) or micro- or macroalbuminuria. Major acute CVD events were adjudicated based on hospital discharge records or specialist visits.

RESULTS

CVD risk increased linearly with eGFR decline and albuminuria and became significant for values <78 mL/min/1.73 m(2) and ≥10.5 mg/24 h, respectively. Beyond traditional CVD risk factors, total CVD showed an independent association with albuminuria alone (odds ratio 1.20 [95% CI 1.08-1.33]), reduced eGFR alone (1.52 [1.34-1.73]), and both abnormalities (1.90 [1.66-2.19]). However, coronary events were associated predominantly with reduced eGFR alone, whereas cerebrovascular and peripheral events showed a stronger correlation with the albuminuric CKD phenotypes.

CONCLUSIONS

These data, although cross-sectional, show that reduced eGFR, irrespective of albuminuria, is associated with significant CVD, particularly in the coronary district.

Clinical significance of nonalbuminuric renal impairment in type 2 diabetes

OBJECTIVE

In type 2 diabetes, prevalence of nonalbuminuric renal impairment is increasing worldwide, though its clinical significance remains unclear. This large-cohort study aimed at evaluating the association of this phenotype with cardiovascular risk factors and other complications.

METHODS

Type 2 diabetic patients from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study (n = 15,773), visiting consecutively 19 hospital-based Diabetes Clinics in years 2007-2008, were examined. Serum creatinine was assessed by the Jaffe method; albuminuria was measured by immunonephelometry or immunoturbidimetry.

RESULTS

Of patients with renal impairment, as identified by an estimated glomerular filtration rate (eGFR) less than 60 ml/min per 1.73 m², 56.6% were normoalbuminuric, 30.8% were microalbuminuric, and 12.6% were macroalbuminuric. Percentages were similar when GFR was estimated using the more accurate Chronic Kidney Disease Epidemiology Collaboration equation instead of the simplified Modification of Diet in Renal Disease formula, and were independent of age, thus indicating that the increasing prevalence of this phenotype does not reflects misclassification of elderly patients. Nonalbuminuric renal impairment was not associated with HbA(1c) and correlated less strongly with retinopathy and hypertension than albuminuria, either alone or associated with reduced eGFR. It was associated with a higher prevalence of cardiovascular disease (CVD) than albuminuria alone, but lower than albuminuric renal impairment. Female sex correlated with nonalbuminuric renal impairment and male sex with the albuminuric forms.

CONCLUSIONS

These data show that type 2 diabetic patients with nonalbuminuric renal impairment exhibit distinct clinical features, suggesting predominance of macroangiopathy as underlying renal pathology, and that this phenotype is associated with significant CVD burden.

Can NK cells be a therapeutic target in human type 1 diabetes?

Type 1 diabetes is caused by the autoimmune destruction of insulin-producing cells with consequent hyperglycemia and serious chronic complications. Both innate and adaptive immune responses participate in disease pathogenesis. Studies in animal models and in man have shown that NK cells are involved both in disease progression and in disease protection, thus suggesting that NK cells can represent a potential therapeutic target in type 1 diabetes, once the contribution of these cells to islet autoimmunity has been fully elucidated.

Generalised reduction of putative endothelial progenitors and CXCR4-positive peripheral blood cells in type 2 diabetes

AIMS/HYPOTHESIS

In patients with type 2 diabetes, reduced levels of circulating endothelial progenitor cells have been reported and these have been correlated with disease severity. In this study, we examined a panel of markers widely used to identify progenitor and/or stem cells, and determined their association with disease severity in diabetic patients. Since expression of chemokine (C-X-C motif) receptor 4 (CXCR4) has been associated with mobilisation and recruitment of progenitor cells, CXCR4 expression was also analysed.

METHODS

Peripheral blood mononuclear cells (PBMCs) from 98 patients with type 2 diabetes and 39 control individuals were analysed by flow cytometry for surface marker expression.

RESULTS

Cells expressing different combinations of progenitor and/or stem cell markers were severely reduced in PBMCs of diabetic patients compared with those of control participants. Moreover, a number of these putative progenitor cell populations were negatively associated with disease severity. Reduced expression of CXCR4 and CD34/CXCR4-positive cells was also observed in diabetic patients. PBMCs expressing CXCR4 positively correlated with levels of progenitor cells in control participants but not in diabetic patients. Levels of putative progenitor and CXCR4-positive cells were further decreased in patients with diabetic complications, including cardiovascular and microvascular diseases.

CONCLUSIONS/INTERPRETATION

A generalised decrease in a range of progenitor cell populations was observed in type 2 diabetic patients. This reduction was also negatively associated with disease severity.

[Effect of naloxone and naltrexone on the postprandial energy expenditure and endocrine pancreas response to a mixed meal in essential obesity]

It has been recently shown that the opioid antagonists naloxone and naltrexone are able to reduce appetite and to raise energy expenditure in animal models. The results of studies in humans are inconclusive. In 10 female obese patients we have evaluated the effects of naloxone infusion (2 mg/2 h) on energy expenditure, measured by indirect calorimetry (Deltatrac) and on plasmatic levels of glucose, insulin, glucagon and somatostatin, fasting and after the assumption of a standard 567 kcal meal (C = 20%, P = 20%, L = 60%). We have repeated the tests after a dietary period of 1 month, associated with naltrexone assumption. Acute administration of naloxone caused similar effects at the beginning and at the end of the study; we have observed a raise of caloric expenditure, a decrease of hyperinsulinemia and a high response of somatostatin to metabolic stimulus. After therapy, even with a weight reduction of 6%, we haven't observed either variations of energy expenditure or hormonal level changes. We conclude that in obese women opioid hypertone plays a role in thermic effect of meals and in the impaired response to the nutrients of the gastroenteropancreatic axis. The absence of any effects of naltrexone on the variables that we have studied is perhaps due to the difference in the dose, way of administration and of the different action on the target receptor by the two opioid antagonists.

Prevalence of glomerular hyperfiltration and nephromegaly in normo- and microalbuminuric type 2 diabetic patients

Glomerular hyperfiltration, correlated with nephromegaly, is a frequent finding in type 1 (insulin-dependent) diabetes. In type 2 (non-insulin-dependent) diabetes, very few studies have been performed, and the results have been inconclusive. Glomerular filtration rate (GFR) and kidney volume, using 99mTc-DTPA scintigraphy and ultrasonography, respectively, were evaluated in 58 control subjects and 163 type 2 diabetic patients; 79 of whom were normoalbuminuric and 84 microalbuminuric. In the two groups of patients, these parameters did not differ significantly from those of controls, even when hypertensive subjects were excluded. Glomerular hyperfiltration was observed in 10 cases; all were normotensive (9.8%), of whom 7 were normoalbuminuric and 3 microalbuminuric. Nephromegaly was observed in 3 other normotensive microalbuminuric diabetic patients. Hypertensive subjects showed a lower GFR than normotensive patients and control subjects. Multivariate analysis showed a negative correlation between glomerular filtrate and systolic blood pressure (BP) in the overall population of patients and in normo- and microalbuminuric patients taken separately. It is concluded that the relationship between these variables forms a continuum in our type 2 diabetic patients; it may also be important in determining the low prevalence of hyperfiltration and nephromegaly found in our patients, who had BP levels higher than those of controls.

[Glomerular filtration and renal volume in type II diabetes (non-insulin-dependent): study in normal and microalbuminuria patients]

In type 2 diabetes elevated glomerular filtration rate (GFR) and increased renal volume (RV), often accompanied to normo or microalbuminuria, were demonstrated. This condition is considered a pathogenetic factor for clinical nephropathy. As this topic is little studied in type 2 diabetes, we have investigated 73 type 2 diabetic patients (34 normo and 39 microalbuminuric), looking for a correlation between GFR, RV, hypertension, duration of diabetes and indexes of metabolic control. GFR was measured by a scintigraphy, after infusion of 99Tc-DTPA. Renal volume was determined by ultrasound scanning. Between the groups GFR and RV weren't different; elevated GFR was demonstrated in 3 patients; increased RV in 1 patient. In the hypertensive group GFR was lower than in normotensive group and in controls. Multivariate analysis in stepwise demonstrated that GFR presents a negative correlation to systolic blood pressure as in normo as in microalbuminuric patients. In the normotensive group GFR didn't correlate to the other variables. The present data suggest that in type 2 diabetes there is a little prevalence of glomerular hyperfiltration and increased renal volume and that hypertension plays a role on GFR of hypertensive diabetic patients.

[Validity of the first morning urine collection for screening for microalbuminuria in the diabetic]

With the aim of evaluating the reliability of morning urine collection, compared to the overnight period, in the assessment of microalbuminuria, we measured albumin and creatinine concentration in overnight and morning urine of 125 diabetic outpatients. The overnight albumin excretion rate resulted in relation to morning albumin concentration and morning albumin/creatinine ratio. The sensitivity of this method of urine collection, compared to the overnight sample, was 55.5%, the specificity 96.6% and the predictive value 43% using, as a measure, the albumin concentration. These values improved by correcting albumin for creatinine concentration. Concerning high risk albuminuria (overnight excretion rate greater than 30 micrograms/min), we found a sensitivity and predictive value of the first morning collection highly improved by the albumin/creatinine ratio. It is concluded that the first morning urine collection can be used in the diagnosis of microalbuminuria in diabetic patients, especially when we calculate the albumin/creatinine ratio. This simple and reliable method allows the identification of microalbuminuric subjects and of the patients at risk to develop clinical nephropathy with a good sensitivity.