Cardiovascular risk profile of type 2 diabetic patients cared for by general practitioners or at a diabetes clinic: a population-based study

Population segmentation of type 2 diabetes mellitus patients and its clinical applications - a scoping review

Background

Population segmentation permits the division of a heterogeneous population into relatively homogenous subgroups. This scoping review aims to summarize the clinical applications of data driven and expert driven population segmentation among Type 2 diabetes mellitus (T2DM) patients.

Methods

The literature search was conducted in Medline®, Embase®, Scopus® and PsycInfo®. Articles which utilized expert-based or data-driven population segmentation methodologies for evaluation of outcomes among T2DM patients were included. Population segmentation variables were grouped into five domains (socio-demographic, diabetes related, non-diabetes medical related, psychiatric / psychological and health system related variables). A framework for PopulAtion Segmentation Study design for T2DM patients (PASS-T2DM) was proposed.

Results

Of 155,124 articles screened, 148 articles were included. Expert driven population segmentation approach was most commonly used, of which judgemental splitting was the main strategy employed (n = 111, 75.0%). Cluster based analyses (n = 37, 25.0%) was the main data driven population segmentation strategies utilized. Socio-demographic (n = 66, 44.6%), diabetes related (n = 54, 36.5%) and non-diabetes medical related (n = 18, 12.2%) were the most used domains. Specifically, patients’ race, age, Hba1c related parameters and depression / anxiety related variables were most frequently used. Health grouping/profiling (n = 71, 48%), assessment of diabetes related complications (n = 57, 38.5%) and non-diabetes metabolic derangements (n = 42, 28.4%) were the most frequent population segmentation objectives of the studies.

Conclusions

Population segmentation has a wide range of clinical applications for evaluating clinical outcomes among T2DM patients. More studies are required to identify the optimal set of population segmentation framework for T2DM patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01209-w.

Attending Diabetes Clinics is associated with a lower all-cause mortality. A meta-analysis of observational studies performed in Italy

OBJECTIVE

The epidemiological explosion of diabetes is a challenge for Health Systems and the identification of the most appropriate models of care are warranted. The inclusion of primary care physicians in the models is unquestioned whereas the role played by secondary and tertiary care (Diabetes Clinic) is often debated. However, studies focusing on hard endpoints and comparing Diabetes Clinic attendance vs. no attendance are scant.

RESEARCH DESIGN AND METHODS

A meta-analysis was performed including all observational cohort studies performed in Italy, reporting crude and/or adjusted estimates of all-cause mortality in patients with diabetes attending or not attending Diabetes Clinics. Attendance was defined by prescriptions and reimbursement of specialist visits by the National Health System.

RESULTS

Three studies enrolling 191,847 subjects with diabetes were included in the analysis, and about half of them had at least one visit in the Diabetes Clinic per year. During the follow-up, ranging 1-11 years, 9653 subjects died. Mortality was remarkably lower in subjects attending Diabetes Clinic (MH-OR 0.70, 95% CI 0.55-0.88, p = 0.002). Results were confirmed after adjusting for confounders (MH-OR 0.81, 95% CI 0.69-0.95, p = 0.009).

CONCLUSIONS

The results of the present study suggest that attending Diabetes Clinics is associated with a lower all-cause mortality. This finding might be instrumental to implement the best models of care for persons with diabetes.

The relative burden of diabetes complications on healthcare costs: The population-based CINECA-SID ARNO Diabetes Observatory

BACKGROUND AND AIMS

In the present population-based study, we aimed to describe the per patient annual healthcare cost of people with diabetes in 2007-2012, to assess the relative burden of diabetes complications and other potential determinants on healthcare costs in the 2012 cohort, and to describe and analyse the determinants of the cost of incident cases diagnosed in 2012.

METHODS AND RESULTS

We analysed data from a retrospective cohort of residents in four Italian areas that were served by Local Health Units participating in the ARNO Observatory. Per patient annual healthcare costs (Euros) were estimated as the sum of all the resources supplied during that year (drugs, outpatient care, and hospitalisations). The mean per patient annual healthcare cost increased from €2752 in 2007 to €3191 in 2010, before decreasing to €2791 in 2012. The largest component of these costs was represented by hospitalisations (around €1550, on average; 51.7% of total cost), followed by outpatient care (€422; 14.6%) and drugs (€973; 33.7%). In 2012, the most relevant cost determinants were chronic diabetes complications, with an additional cost due to nephropathy/end stage renal disease (€4683), amputations (€5042), lower extremity revascularization (€4808), and cerebrovascular diseases (€3861). Costs associated with incidence cases were higher than those associated with prevalent.

CONCLUSION

The present study provides evidence on the excess of healthcare costs due to diabetes complications in both prevalent and incident cases.

High age predicts low referral of hyperthyroid patients to specialized hospital departments: evidence for referral bias

BACKGROUND

Hospital-based studies may be hampered by referral bias. We investigated how the phenomenon may influence studies of hyperthyroid patients.

METHODS

By means of a computer-based linkage to the laboratory database and subsequent detailed evaluation of subjects with abnormal test results, we prospectively identified all 1148 patients diagnosed with overt hyperthyroidism in a four-year period in and around Aalborg City, Denmark. Each patient was classified according to nosological type of hyperthyroidism. We studied the referral pattern of patients to local hospital units, and analyzed how referral depended on subtype of disease, sex, age, and degree of biochemical hyperthyroidism.

RESULTS

In a 4-year period, 1032 hyperthyroid patients were diagnosed at primary care offices, and 435 of these (42.2%) were referred to specialized units, 92 patients had hyperthyroidism diagnosed in other hospital departments (referral: 43, 46.7%), and 24 patients had hyperthyroidism diagnosed at the specialized unit after referral for other diseases. Patients suffering from Graves' disease (GD; n=474, median age=65.8 years) were referred more often (odds ratio=1.7 [95% confidence interval 1.3-2.2]) than those diagnosed with multinodular toxic goiter (MNTG; n=525, median age=74.6 years). Higher age was associated with less referral of patients suffering from MNTG (referred vs. nonreferred patients, 64.0 vs. 77.4 years, p<0.001) and GD (43.9 vs. 56.4 years, p<0.001), whereas GD patients referred to a hospital had more severe biochemical hyperthyroidism (serum total triiodothyronine, 4.86 vs. 3.79 nmol/L; serum total thyroxine, 204 vs. 180 nmol/L; both p<0.001). Findings were confirmed in multivariate models reporting age as a significant predictor for referral in both GD and MNTG patients (both p<0.001). Among referred hyperthyroid patients (all combined), those aged up to 40 years (referral rate, 66.8%) were represented 11.6 (6.6-20.6) times more often than those aged 80 years and above (referral rate, 14.8%).

CONCLUSIONS

Hyperthyroid patients referred to a specialized hospital unit were younger (GD+MNTG) and had more severe biochemical hyperthyroidism (GD) compared to nonreferred patients. Thus, referral bias may influence hospital-based studies of hyperthyroid patients, and may hamper external generalization of such studies. Whether the referral bias of hyperthyroid patients in Denmark can be generalized to other countries or cultures remains unknown.

Prediction of mortality and macrovascular complications in type 2 diabetes: validation of the UKPDS Outcomes Model in the Casale Monferrato Survey, Italy

AIMS/HYPOTHESIS

The United Kingdom Prospective Diabetes Study (UKPDS) Outcomes Model can be used to estimate the lifetime occurrence of major diabetes-related complications in order to calculate health economic outcomes. The aim of the study was to assess the performance of the model by comparing the predicted and observed mortality and the incidence of macrovascular complications in an Italian population-based cohort with type 2 diabetes.

METHODS

We used data from the Casale Monferrato Survey, a cohort enrolled in 1988 and surveyed in 1991 (n = 1,967) to assess the prevalence of cardiovascular risk factors. In 2000, a new survey included all the members of the original cohort who were still alive (n = 860), and in addition all individuals identified with a new diagnosis of type 2 diabetes since 1993 (n = 2,389). We compared the mortality predicted by the model for the 1991 survey over the subsequent 17-year period with the observed risk. The following outcomes were analysed in the 2000 survey: myocardial infarction (MI), other ischaemic heart disease, stroke, congestive heart failure (CHF) and amputation.

RESULTS

For all-cause mortality, the predictions from the model at 5 and 10 years (23% and 47%, respectively) were identical to the observed risks. At 15 years, the risk of death was slightly overestimated (an estimate of 67% vs 64% observed, 95% CI 61%, 66%). The performance of the model was best for patients with a recent history of disease (duration <6 years). Among the complications, the predicted cumulative incidences of MI and CHF were very close to those observed.

CONCLUSIONS/INTERPRETATION

External validation is essential to assess the accuracy of simulation models. The UKPDS Outcomes Model satisfactorily predicted a set of actual incidences of mortality and complications in an Italian diabetes cohort up to a duration of approximately 12 years. The longer term performance of such models should be carefully evaluated.

The metabolic syndrome is related to albuminuria in Type 2 diabetes

AIMS

To determine the relationships between metabolic syndrome (MetS), diabetic nephropathy (DN) and renal function in Type 2 diabetes.

METHODS

In a clinic-based cohort of 1314 Type 2 diabetic patients (58% male; age 62 +/- 10 years), we analysed MetS, detected DN and estimated glomerular filtration rate (eGFR).

RESULTS

Prevalence of both microalbuminuria and macroalbuminuria were higher in subjects with MetS than in those without. Prevalence of DN (microalbuminuria and macroalbuminuria) increased with the number of MetS components. eGFR was lower in subjects with MetS than in those without (87 +/- 23 vs. 92 +/- 20 ml/min per 1.73 m2; P < 0.001). The lowest eGFR values were found in those with four or more components of the MetS. Prevalence of low eGFR increased with the stage of DN and was affected by MetS only in normoalbuminuric patients. MetS was independently associated with DN, also after adjustment for confounders [odds ratio (OR) 2.82, confidence interval (CI) 1.93, 4.11] and the presence of low eGFR in the model (OR 2.74, CI 1.87, 4.01). Similarly, MetS was a predictor of low eGFR (OR 1.93, CI 1.11, 3.36), but after adjustment for DN, the association was lost. Finally, MetS per se was independently associated with DN, but not with low eGFR after adjustment for all of the individual components of the MetS.

CONCLUSIONS

This study suggests a close and independent association between MetS and renal impairment. However, it is unclear whether and to what extent treating MetS by an intensive multifactorial therapeutic approach will prevent or delay progression to renal failure.

The clinical reality of guidelines for primary prevention of cardiovascular disease in type 2 diabetes in Italy

INTRODUCTION AND AIM

Guidelines for cardiovascular prevention in diabetes have been issued by the national and international scientific societies. No audit as ever been performed to evaluate the implementation of these documents in clinical practice in Italy. The study evaluates the prevalence, treatment, and control of major cardiovascular risk factors in type 2 diabetic patients, to assess the clinical practice of primary cardiovascular prevention in type 2 diabetes.

PATIENTS AND METHODS

Two thousand four hundred and sixty-five men and women with type 2 diabetes, aged 50-75 and free of cardiovascular events were recruited on a consecutive basis at 10 hospital based outpatients diabetes clinics. Clinical variables were measured by standard protocol. Biochemical parameters were evaluated at each centre. The laboratories were monitored by an external quality control assessment in order to reach and maintain a standard of quality and traceability among the participating centres.

RESULTS

A minority of patients (5%) met the recommended targets for LDL cholesterol, blood pressure, glycated haemoglobin and smoking habits, whereas the vast majority (66%) had unsatisfactory control of three or more of the above. Achievement of desirable control of risk factors differed according to gender and known diabetes duration. Lipid lowering and, to a lesser extent, antihypertensive medications were under-used and their titration insufficiently target-driven. Prophylactic use of antiplatelet agents was scarce, only one out of five patients was treated independent of absolute cardiovascular risk.

CONCLUSION

In clinical practice there is poor adherence to national and international guidelines for primary cardiovascular prevention in type 2 diabetes in Italy. The study underlines the great potential for prevention, particularly in women and in high-risk patients.

Non-traditional cardiovascular risk factors contribute to peripheral arterial disease in patients with type 2 diabetes

OBJECTIVE

This study evaluated the prevalence of peripheral arterial disease (PAD) in type 2 diabetes and its association with traditional and non-traditional cardiovascular (CV) risk factors.

SUBJECTS AND METHODS

In 1610 type 2 diabetics PAD was defined as ankle-brachial pressure index (ABPI)<0.9.

RESULTS

PAD prevalence was 17%, increased with age, diabetes duration, HbA 1c levels, previous CV events. There were no significant differences in the prevalence of traditional CV risk factors between patients with and without PAD. PAD patients had higher levels of fibrinogen (10.88+/-2.32 versus 10.2+/-2.23micromol/L; p<0.0001), uric acid (327.1+/-89.2 versus 315.2+/-83.3micromol/L, p<0.01), pulse pressure (70+/-18 versus 60+/-16mm Hg, p<0.0001), higher rate of microalbuminuria (21.3% versus 13.7%; p<0.05) and lower glomerular filtration rate (GFR, 80.7+/-24 versus 89.9+/-22 ml/min/1.73 m2; p<0.001) than those without. In age-gender-adjusted analysis, smoking (OR 1.5; CI: 1.07-2.2), HbA 1c (OR 1.45; CI: 1.07-2.08), high pulse pressure (OR 2.81; CI: 1.63-4.82), reduced GFR (OR 2.16; CI: 1.4-3.3), microalbuminuria (OR 1.62; CI: 1.11-2.36), high fibrinogen levels (OR 2.03; CI: 1.34-3.07) were associated with PAD. In multivariate analysis age, male sex, smoking, high pulse pressure, low GFR, high fibrinogen levels, previous CV events were independent risk factors for PAD.

CONCLUSIONS

PAD prevalence is high in Type 2 diabetic patients. Non-traditional cardiovascular risk factors may be involved in the development of this complication.

Effect of age on the association of non-high-density-lipoprotein cholesterol and apolipoprotein B with cardiovascular mortality in a Mediterranean population with type 2 diabetes: the Casale Monferrato study

AIMS/HYPOTHESIS

Measurement of plasma apolipoprotein (Apo) B may improve prediction of cardiovascular risk, as it provides a measure of the total number of atherogenic particles. The aim of this population-based study was to compare the association of non-HDL-cholesterol, ApoB and the ApoB:ApoA-I ratio with cardiovascular mortality in people with type 2 diabetes.

SUBJECTS AND METHODS

We assessed the association of lipids, lipoprotein lipids and apolipoproteins with 11-year mortality from cardiovascular disease in the population-based cohort of the Casale Monferrato Study (1,565 people with diabetes; median age 68.9 years), and determined the effect of age (< or =70 and >70 years) on these relationships.

RESULTS

On the basis of 341 deaths from cardiovascular disease in 10,809 person-years of observation, there was a decreasing trend in risk adjusted for multiple factors across quartiles of total cholesterol, and LDL- and non-HDL-cholesterol in people aged >70 years, but no trend in those aged < or =70 years. Age did not affect the protective effect of HDL-cholesterol. ApoB and ApoB:ApoA-I were associated with outcome in people in both age groups independently of non-HDL-cholesterol. After adjustment for multiple factors, including non-HDL-cholesterol, the hazard ratios for ApoB:ApoA-I in the upper vs lower quartile were 2.98 (95% CI 1.15-7.75; p for trend=0.009) for people aged < or =70 years and 1.94 (95% CI 1.20-3.13; p for trend=0.003) for those aged >70 years.

CONCLUSIONS/INTERPRETATION

In this cohort of Mediterranean subjects with diabetes, ApoB and the ApoB:ApoA-I ratio were associated with cardiovascular disease mortality independently of non-HDL-cholesterol. Our findings support the recommendation that ApoB and ApoA-I should be measured routinely in all people with diabetes, particularly in the elderly.

Fibrinogen and AER are major independent predictors of 11-year cardiovascular mortality in type 2 diabetes: the Casale Monferrato Study

AIMS/HYPOTHESIS

Fibrinogen and elevated AER increase cardiovascular mortality, but few data are available in the type 2 diabetic population. We have conducted an 11-year follow-up study of the Casale Monferrato cohort to assess: (1) the long-term predictive role of AER independently of conventional risk factors; (2) the shape of its relationship with cardiovascular mortality; and (3) whether fibrinogen has a predictive effect independent of the increased cardiovascular risk associated with nephropathy.

METHODS

During the follow-up period (1991-2001) a population-based cohort of 1,565 patients was regularly examined, and measurements of HbA1c were centralised. Multivariate Cox proportional hazards modelling was employed to assess the role of fibrinogen and AER as predictors of all-cause and cardiovascular mortality, independently of baseline variables and individual cumulative average values of HbA1c during follow-up.

RESULTS

In 10,890.2 person-years of observations, 685 deaths were identified, giving an all-cause mortality rate of 63.4 per 1,000 person-years (95% CI 58.8-68.3). In Cox regression analyses, the strongest predictor of cardiovascular mortality was macroalbuminuria (relative risk 2.18, 95% CI 1.62-2.94), which was mainly associated with a high risk of short-term mortality. No increased risk was evident until the upper microalbuminuric range of AER values. Plasma fibrinogen was also a major independent predictor, and its role was not modified by AER, or by the exclusion of subjects developing chronic renal failure or diabetic nephropathy during follow-up.

CONCLUSIONS/INTERPRETATION

The results indicate that: (1) AER is the main independent predictor of 11-year cardiovascular mortality; (2) this effect is mainly evident in the upper range of microalbuminuria and in macroalbuminuria; and (3) fibrinogen has an independent effect on cardiovascular mortality, but no synergistic effect with AER, suggesting that both endothelial dysfunction and chronic inflammation are involved in the excess cardiovascular mortality of type 2 diabetic patients.

Low incidence of end-stage renal disease and chronic renal failure in type 2 diabetes: a 10-year prospective study

OBJECTIVE

Data on the incidence of end-stage renal disease (ESRD) and chronic renal failure from population-based studies in Caucasian type 2 diabetic patients are lacking. To provide such data, a population-based cohort of type 2 diabetic patients was identified in Casale Monferrato, Italy, and prospectively examined from 1991 to 2001.

RESEARCH DESIGN AND METHODS

During the follow-up period, patients were regularly examined with centralized measurements of plasma creatinine and HbA(1c). Independent predictors of progression to renal events were identified with multivariate Cox proportional hazards modeling, with sex, age, and individual follow-up time as confounders.

RESULTS

We followed 1,408 of 1,540 (91.4%) patients (average follow-up time 6.7 years, range 0.011-11.1); 10 new cases of ESRD and 72 of chronic renal failure (plasma values of creatinine >or=2.0 mg/dl) were identified, giving incidence rates/1,000 person-years of 1.04 (95% CI 0.56-1.94) and 7.63 (6.06-9.61), respectively. Cumulative risks for chronic renal failure adjusted for competing mortality were 6.1 and 9.3% after 20 and 30 years from diagnosis of diabetes, respectively. Incidence rates and cumulative risks of chronic renal failure defined by plasma creatinine values >1.5 mg/dl increased to 13.1/1,000 person-years, 8.6 and 14.8%, respectively. In Cox regression analysis, predictors of progression (after adjustment for confounders) were hypertension (P = 0.078), diastolic blood pressure (P = 0.034), BMI (P = 0.03), and albumin excretion rate (AER) (P < 0.0001).

CONCLUSIONS

We provide evidence that the individual risk of ESRD and chronic renal failure is low. AER and diastolic blood pressure are independent predictors of progression. These findings underline the relevance of primary prevention to reduce the number of diabetic patients with ESRD.

Progression to overt nephropathy in type 2 diabetes: the Casale Monferrato Study

OBJECTIVE

The first sign of diabetic nephropathy is microalbuminuria, but its predictive role of progression to overt nephropathy in type 2 diabetes has not yet been clarified. The aims of this study were to assess during 7 years of follow-up the incidence rate of overt nephropathy and the predictive role of microalbuminuria and other baseline variables (blood pressure, lipids, fibrinogen, uric acid, smoking, and HbA(1c) cumulative average during follow-up).

RESEARCH DESIGN AND METHODS

A prospective population-based study was performed in Casale Monferrato, Italy, including 1,253 type 2 diabetic patients recruited at baseline (1991-1992), 765 with normoalbuminuria (albumin excretion rate [AER] <20 microg/min) and 488 with microalbuminuria (AER 20-200 microg/min). All measurements were centralized. A nested case-control study within the cohort was performed, selecting four control subjects, frequency matched for age and attained individual time of follow-up with each case. Conditional regression analysis was performed to assess variables independently associated with risk of progression to overt nephropathy.

RESULTS

Of 1,253 total patients, 1,103 (88.0%) were included in the follow-up examination (median 5.33 years); their age and duration of disease at baseline were 68.4 +/- 10.5 years and 10.4 +/- 6.6 years, respectively. Cases of overt nephropathy were 202, giving an incidence rate of 37.0/1,000 person-years (95% CI 32.3-42.6). In conditional logistic regression analyses, microalbuminuria provided a 42% increased risk with respect to normoalbuminuria (95% CI 0.98-2.06), independently of duration of diabetes, hypertension, and systolic blood pressure. Other variables independently associated with progression to overt nephropathy were HbA(1c) cumulative average (P = 0.002), apolipoprotein B (P = 0.013), fibrinogen (P = 0.02), and HDL cholesterol (P = 0.03).

CONCLUSIONS

Of type 2 diabetic patients, 3.7% progress every year to overt nephropathy. Microalbuminuria is associated with a 42% increased risk of progression to overt nephropathy. Other independent predictors are HbA(1c), HDL cholesterol, apolipoprotein B, and fibrinogen.

Prevalence of increased QT interval duration and dispersion in type 2 diabetic patients and its relationship with coronary heart disease: a population-based cohort

OBJECTIVE

To evaluate the prevalence of prolonged QT interval and dispersion in a population-based cohort of type 2 diabetic patients and their relationship with clinical and metabolic variables.

DESIGN

Cross-sectional population-based cohort.

SETTING

Diabetes clinics and general practitioners in Casale Monferrato (Northern Italy).

SUBJECTS

A total of 1357 patients with known type 2 diabetes (70% of the cohort).

MAIN OUTCOMES MEASURES

Albumin excretion rate and coronary heart disease (CHD); a standard supine 12-lead electrocardiogram (ECG) was recorded and coded according to the Minnesota code criteria. QT interval corrected for heart rate (QTc) > 0.44 s and QTc dispersion > 0.080 s were considered abnormally prolonged.

RESULTS

Prevalence of increased QTc duration and QTc dispersion were 25.8% (95% CI 23.5-28.3) and 33.1% (95% CI 30.6-35.7), with no sex differences. No metabolic differences were found, apart from fibrinogen and creatinine levels, which were higher in patients with increased QTc dispersion. Patients with CHD had higher mean adjusted values of QTc and QTc dispersion, whereas no association was found with albumin excretion rate (AER) and diabetes treatment. QTc duration and QTc dispersion were significantly correlated (0.17, P < 0.001). In multiple regression analysis, only CHD was independently associated with QTc, after adjustment for age and sex (beta=0.010, P < 0.001, R2=2.5%); as regards QTc dispersion, a similar association with CHD was found (beta=0.20, P < 0.001, R2=4.8%).

CONCLUSIONS

This population-based study shows a considerably high prevalence of increased QTc and QTc dispersion in type 2 diabetic patients and their association with CHD. These findings have both epidemiological and clinical relevance, as they might be implicated in the excess mortality risk of type 2 diabetic patients.