Pathological lesions in senile diabetes: Possible pathogenetic interpretations

Summary istological alterations of the kidney and pancreas were studied in a group of elderly diabetics divided into “aged diabetics” (AD) (onset of diabetes before 60 years of age) and “senile diabetics” (SD) (onset of diabetes after 70 years of age). The control groups were formed by middle-aged non-insulin dependent diabetics (NIDDM) and non-diabetic elderly subjects. The non-diabetic elderly subjects showed no damage of pancreatic islets and the arterioles were also intact. The middle-aged NIDDM group having had diabetes for less than one year presented no alterations either. Middle-aged NIDDM patients affected by the disease for longer than 10 years, displayed the characteristic diabetic damage (hyalinization of the islets and arteriolar damage). In addition, AD presented pancreatic lesions characteristic of long-term NIDDM. SD were divided into two groups depending on the duration of disease: shorter than 6 and longer than 10 years. The former presented small islets with few fibrotic cells and arteriolar damage, while the latter presented a picture of transition between SD with duration of disease shorter than 6 years and AD. The kidney in AD and SD affected by diabetes longer than 10 years resembled the kidney of NIDDM patients. SD with duration of disease shorter than 6 years had aspecific age-related damage. These lesions seem to confirm that macroangiopathy represents the main pathogenesis of senile diabetes, being aggravated by the persisting hyperglycemia causing microangiopathy.