Aims Low-density lipoprotein cholesterol (LDL-C) levels are often fairly normal in Type 2 diabetes mellitus (DM). We anticipated that a parabolic relation between plasma triglycerides and LDL-C, as previously demonstrated in familial combined hyperlipidaemia (FCHL), might account for this phenomenon.
Methods Our hypothesis was tested in 1343 subjects derived from the general population who were studied on two occasions 6 years apart (the Hoorn study). Three groups were constructed depending on plasma triglycerides: group A (individuals with both measurements below 1.5 mmol/l), group B (one measurement below and one above 1.5 mmol/l) and group C (both measurements above 1.5 mmol/l). Diabetes status was ascertained by an oral glucose tolerance test.
Results In a mixed linear model, a significant, positive relation between triglycerides and LDL-C was observed for males in group A (βa = 0.5, P < 0.001) and group B (βb = 0.2, P < 0.001), whereas a significant negative relation was found for males in group C (βc = −0.2, P = 0.003). The regression slopes did not differ between diabetic and non-diabetic subjects. Similar results were obtained for women, with the exception that the relation was not significantly negative in group C (βc = −0.1, P = 0.4).
Conclusion Plasma triglcyerides and LDL-C are related in a parabolic fashion, not only in FCHL, but also in the general population and Type 2 DM. These findings aid our interpretation of typical dyslipidaemia and the effects of treatment that are frequently observed in hypertriglyceridaemic states.