Changes over time in the prevalence and quality of care of type 2 diabetes in Italy: the Casale Monferrato surveys, 1988 and 2000.

BACKGROUND AND AIMS: In this study we assessed the prevalence of diagnosed type 2 diabetes and the quality of care during the period 1988-2000 in an Italian population. METHODS AND RESULTS: Two population-based surveys, using similar methods and centralized measurements, were conducted in 1988 and 2000 in a representative Italian area to identify people with known diabetes. The adjusted prevalence (reference, 2001 Italian population) was computed. The age- and sex-adjusted prevalence rates of diabetes in the population of Casale Monferrato were 2.13% (2.05-2.22) in 1988 and 3.07% (2.97-3.17) in 2000. In comparison with diabetic persons recruited in 1988 and independently of age and sex, persons recruited in 2000 had a lower likelihood of having HbA1c > or = 7.0% (OR=0.48; 0.42-0.56), diastolic blood pressure > or = 80 mmHg (OR=0.61; 0.49-0.75), LDL cholesterol > or = 2.59 mmol/l (OR=0.77; 0.63-0.93) and AER > or = 20 microg/min (OR=0.53; 0.45-0.61; they had a higher likelihood of having BMI > or = 25 kg/m(2) (OR=1.49; 1.2-1.74). However, 45.4% of patients still had HbA1c > or = 7.0%, 80% blood pressure > or = 130/80 mmHg and 79% LDL-cholesterol values > or =2.59 mmol/l. CONCLUSION: More than two-thirds of Italians with diabetes are now aged 65 years and more. The quality of control of glycemia, lipids and blood pressure improved and the prevalence of diabetic nephropathy decreased over time, although complete adherence to international guidelines has not yet been achieved.

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.

Metabolic syndrome as a predictor of all-cause and cardiovascular mortality in type 2 diabetes: the Casale Monferrato Study.

OBJECTIVE: The aim of this study was to assess in an 11-year survival follow-up of a population-based cohort of type 2 diabetes the predictive role of World Health Organization-defined metabolic syndrome, independent of conventional cardiovascular risk factors. RESEARCH DESIGN AND METHODS: During the follow-up (1991-2001), 1,565 patients were regularly examined with centralized measurements of HbA(1c). The independent role of the metabolic syndrome as a predictor of all-cause and cardiovascular mortality was assessed with multivariate Cox proportional hazards modeling. RESULTS: At baseline, the prevalence of the metabolic syndrome was 75.6% (95% CI 73.6-77.9). Results are based on 685 deaths (520 with the metabolic syndrome and 165 without it) in 10,890.2 person-years of observations. With respect to subjects without the metabolic syndrome, those with the metabolic syndrome had a similar hazard ratio (HR) of cardiovascular mortality after adjustment for age, sex, smoking, total cholesterol level, and coronary heart disease. In contrast, relative to subjects with diabetes only, the HR of subjects with only one component of the syndrome was 2.92 (1.16-7.33), independent of other risk factors. CONCLUSIONS: We found that 1) the prevalence of the metabolic syndrome in a population-based cohort of type 2 diabetes is high (75.6%); 2) the metabolic syndrome is not a predictor of 11-year all-cause and cardiovascular mortality; and 3) more than twofold higher cardiovascular risk, independent of conventional risk factors, is evident in diabetic subjects with only one component of the syndrome compared with those with diabetes only. Categorizing type 2 diabetic subjects as having or not having the metabolic syndrome does not provide further prediction compared with the knowledge of its single components.

What is the clinical usefulness of the metabolic syndrome? The Casale Monferrato study.

OBJECTIVE: Data on the clinical usefulness of the metabolic syndrome with respect to cardiovascular risk are not conclusive. We have assessed this issue in a large population-based cohort of diabetic and nondiabetic people in Southern Europe. METHODS: An Italian population-based cohort of 3729 individuals (2211 without diabetes and 1518 with diabetes) was examined, with centralized measurements, including the Homeostasis Model Assessment (HOMA) index in nondiabetic people. The usefulness of the metabolic syndrome (ATP III criteria) as an indicator of cardiovascular disease (CVD), independently of classical and novel risk factor [C-reactive protein (CRP) and albumin excretion rate (AER)] was assessed by using unconditional logistic regression. RESULTS: One thousand, seven hundred and fifty-three individuals (47.0%) had neither diabetes nor the metabolic syndrome, 458 (12.3%) had the metabolic syndrome only, 442 (11.8%) had type 2 diabetes only and 1076 (28.9%) had both diabetes and the metabolic syndrome. The highest likelihood of having CVD was conferred by both diabetes and the metabolic syndrome [odds ratio (OR) = 4.37, 95% confidence interval (CI) 3.25-5.87], independently of age, sex, low-density lipoprotein-cholesterol, smoke, AER, and CRP values. After further adjustment for its individual components, the association between CVD and the metabolic syndrome was no more evident. Among people with CRP 3 mg/l or less, ORs were similar in nondiabetic people with the metabolic syndrome and in diabetic people without it, whereas among those with CRP greater than 3 mg/l OR was two-fold higher in the latter. Values in upper quartiles of the HOMA-IR conferred a significant two-fold increased OR of CVD, even after adjustment for individual components of the metabolic syndrome, CRP and AER. CONCLUSIONS: The additional information provided by the metabolic syndrome is limited, in both diabetic and nondiabetic people, whereas the HOMA index is a useful indicator of CVD, independently of individual components of the metabolic syndrome, classical and novel risk factors.

C-reactive protein and 5-year survival in type 2 diabetes: the Casale Monferrato Study.

OBJECTIVE: To determine to what extent plasma C-reactive protein (CRP) values influence 5-year all-cause and cardiovascular mortality in type 2 diabetic individuals, independently of albumin excretion rate (AER) and other cardiovascular risk factors, and its incremental usefulness for predicting individual risk of mortality. RESEARCH DESIGN AND METHODS: Measurements of CRP were performed in 2,381 of 3,249 (73.3%) subjects as part of the population-based Casale Monferrato Study. Its association with 5-year all-cause and cardiovascular mortality was assessed with multivariate Cox proportional hazards modeling. The C statistic and measures of calibration and global fit were also assessed. RESULTS: Results are based on 496 deaths in 11.717 person-years of observations (median follow-up 5.4 years). With respect to subjects with CRP < or =3 mg/l, those with higher values had an adjusted hazard ratio (HR) of 1.51 (95% CI 1.18-1.92) for all-cause mortality and 1.44 (0.99-2.08) for cardiovascular mortality. In normoalbuminuric subjects, respective HRs of CRP were 1.56 (1.13-2.15) and 1.65 (1.00-2.74), AER being neither a modifier nor a confounder of CRP association. In analysis limited to diabetic subjects without cardiovascular disease (CVD), adjusted HRs were 1.67 (1.24-2.24) for all-cause mortality and 1.36 (0.83-2.24) for cardiovascular mortality. The improvement in individual risk assessment was marginal when measured with various statistical measures of model discrimination, calibration, and global fit. CONCLUSIONS: CRP measurement is independently associated with short-term mortality risk in type 2 diabetic individuals, even in normoalbuminuric subjects and in those without a previous diagnosis of CVD. Its clinical usefulness in individual assessment of 5-year risk of mortality, however, is limited.