Laboratory Assessment of Lipoproteins in Type 2 Diabetes

Clinical management of lipoprotein abnormalities associated with any form of diabetes mellitus requires effective laboratory assessment. Diabetes may result in quantitative and/or qualitative changes in lipoproteins. High-throughput automated analytical techniques quantify total cholesterol, fasting triglyceride, and high-density lipoprotein cholesterol, from which more precise assessment of the risk of macrovascular disease may be made using derived parameters such as calculated low-density lipoprotein cholesterol and non-HDL cholesterol. The measurement of individual apolipoproteins such as apolipoprotein B and lipoprotein(a) may further enhance risk assessment. The recognition of the latter as an independent risk factor is an example of genetic techniques such as Mendelian randomization which have led to the development of novel forms of therapy. Laboratory analysis is required for the comprehensive diagnosis, assessment, and long-term monitoring of diabetic dyslipidemia. It requires consideration of other laboratory markers such as those that reflect severity of hepatic steatosis, renal impairment, thyroid dysfunction, and pancreatitis. Some qualitative lipoprotein changes in diabetes remain a matter for research, but much of the impact on macrovascular disease is reflected by the number of LDL particles which can be measured via apolipoprotein B level. Nuclear magnetic resonance spectroscopy, which provides quantitative measurement of a range of lipoprotein subclasses, and vertical ultra-centrifugation, provide alternative methods for detailed compositional analysis of lipoproteins. Lipidomic analysis allows the measurement of numerous lipid species in whole plasma. Medical decisions depend on the clinical context of the individual patient, particularly in terms of the absolute risk of clinical events, which is weighed against evidence-based public health guidelines and quantitative targets. Laboratory assessment of lipoproteins provides the basis for this process which tends to favor active management of underlying lipoprotein abnormalities in most patients with diabetes mellitus.