Incidence of new diabetic patients on dialysis in Piedmont,Italy: Major changes recorded over a 10-year period

Different incidence rates of new diabetic patients on dialysis are reported in various settings; although prevalence of this disease is often considered a marker of acceptance policy, rates are thought to be influenced also by genetic, epidemiological and other characteristics of a population (genetic composition, age distribution, lifestyle). Moreover, since features of a general population are often not stable (as in the setting analysed) changes at this level may have important reflections in the incidence of diabetics with end-stage renal disease (ESRD). In the region studied (Piedmont, northern Italy, about 4400 000 inhabitants, 20 dialysis centres, open acceptance since the mid-1970s, yearly information on 100% of patients, gathered by a Dialysis and Transplantation Registry) the incidence of diabetic patients with ESRD (389 cases recorded 1981–1990: 222 males, 167 females: mean age at start increasing from 55.5 years in 1981–1985 to 58.7 years in 1986–1990) differs according to age and sex. Incidence was higher in males, and rose from 6.23/year patients per million population (p.m.p.) in 1981–1982 to 12.88/year p.m.p. in 1989–1990, with a peak at age 60–69 (from 18.46/year p.m.p. in 1981–1982, to 46.12/year p.m.p. in 1989–1990). While relatively stable in the younger age groups from 1981 to 1990, incidence increased in the elderly (males age 70–79: 7.12/year p.m.p. in 1981–1982, 26.08/year p.m.p. in 1989–1990). As regards clinical and metabolic patterns, at the first update, in 1986–1990, 88.3% of diabetic patients were hypertensive or taking hypotensive drugs; albumin levels were below the normal range (<3.5 g/dl) in 30.3%; cholesterol levels were below the normal range (<150 mg/dl) in 16.15%. As regards entry criteria, creatinine clearances ranged from <1 to 14 ml/min (mean values at first update: 3.45±2.76 ml/min). In conclusion, presentation of diabetic patients with ESRD is changing. The stability of incidence in the younger age groups confirms the appropriateness of an open acceptance policy, at least for these ages. The increase in the elderly probably reflects the longer lifespan of diabetic patients in the overall population, while the influence of a hidden preselection must be further assessed. Since this cohort increasingly requires in-hospital high-tolerance treatment, future provision of dialysis needs must take into account the trend towards an increase in this high-risk elderly population.