[A four-year prospective study on the influence of serum elevated lipoprotein (a) concentration on ischemic heart disease and cerebral infarction in elderly patients with type 2 diabetes].

To clarify the influence of elevated serum lipoprotein (a) (Lp(a)) concentration on ischemic heart disease (IHD) and the perforating artery occlusion type of cerebral infarction (CI) in elderly patients with type 2 diabetes, we measured the serum levels of Lp(a) of type 2 diabetic patients (n = 158, 81 men and 77 women). The group was followed up prospectively for 4 years and the incidence of IHD or CI was monitored. The diagnosis of CI was confirmed by computed tomography and that of IHD, which includes myocardial infarction and angina pectoris, was diagnosed by electrocardiogram and blood chemistry examination, Lp(a) concentrations of 20 mg/dl or more were identified as elevated Lp(a) levels and Lp(a) concentrations of less than 20 mg/dl were identified as normal Lp(a) levels. A Kaplan-Meier survival analysis (log-rank test) assessed the time to event rate stratified by an Lp(a) cutoff point of 20 mg/dl. The predictive value for CI or IHD events was assessed by multiple logistic regression analysis. The probability of IHD events was significantly higher in the elevated Lp(a) group than in the normal Lp(a) group without a history of IHD but was similar in the two groups for those patients with a history of IHD. There was no significant difference between the elevated Lp(a) group and the normal Lp(a) group with regard to CI events in patients without a history of CI and with a history of CI. On multiple logistic regression analysis, Lp(a), hyperlipidemia and a history of IHD were significant predictors of IHD and hypertension, hyperlipidemia and a history of CI were significant predictors of CI. These results show that elevated serum Lp(a) concentrations is an independent risk factor for IHD, but not for the perforating artery occlusion type of CI in type 2 elderly diabetic patients.