[Lipoprotein (a) and diabetes mellitus].

Lp(a) has atherogenic and thrombotic properties and is considered to be a major risk factor for the development of atherosclerotic disease. The risk of cardiovascular disease is increased in both insulin-dependent (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM), and Lp(a) has attracted attention as a potential risk factor in diabetic patients. Lp(a) levels are "probably" elevated in IDDM patients and related to altered metabolic control and increased urinary albumin excretion rate or renal insufficiency, although results are controversial. There appears to be a real difference between the Lp(a) of patients with proliferative diabetic retinopathy and those with or without background retinopathy. The plasma Lp(a) level may therefore be associated with microangiopathy in some IDDM patients. However, data relating Lp(a) to complications of diabetes are limited, and the literature is conflicting. The few available data suggest that Lp(a) is not elevated in NIDDM patients and that there is no strong link between blood glucose control and plasma Lp(a). There is no clear evidence as to whether Lp(a) is related to microalbuminuria in NIDDM patients. There is little evidence for a correlation between increased risk of cardiovascular disease and plasma Lp(a) among diabetic patients. However, some diabetic patients with coronary heart disease have elevated plasma Lp(a), which seems to be correlated with genetic factors (especially the isoforms of apolipoprotein a) rather than to diabetes per se. Lp(a) synthesis and catabolism could be influenced by insulin or by diabetes and its metabolic concomitants. The atherogenic and thrombogenic potential of Lp(a) could also be increased in diabetic patients. Plasma Lp(a) should be measured for both IDDM and NIDDM patients. If the Lp(a) level is elevated, it seems reasonable to check the other major vascular risk factors.