Prevalence and phenotypic distribution of dyslipidemia in type 1 diabetes mellitus: effect of glycemic control.

BACKGROUND: Data on the prevalence of dyslipidemia in type 1 diabetes mellitus are scarce and are based on total triglyceride and total cholesterol concentrations alone.

OBJECTIVE: To assess the effect of glycemic optimization on the prevalence of dyslipidemia and low-density lipoprotein cholesterol (LDL-C) concentrations requiring intervention in patients with type 1 diabetes.

PATIENTS: A total of 334 adults with type 1 diabetes and 803 nondiabetic control subjects.

METHODS: Levels of glycosylated hemoglobin, total cholesterol, total triglyceride, high-density lipoprotein cholesterol (HDL-C), and LDL-C were assessed at baseline and after 3 to 6 months of intensive therapy with multiple insulin doses.

RESULTS: Levels of LDL-C greater than 4.13 mmol/L (>160 mg/dL) and total triglyceride greater than 2.25 mmol/L (>200 mg/dL) and low HDL-C levels (<0.9 mmol/L [<35 mg/dL] in men or <1.1 mmol/L [<45 mg/dL] in women) were found in 16%, 5%, and 20% of patients and 13%, 6%, and 9% of controls, respectively (P<.001 for HDL-C). Diabetic women showed more hypercholesterolemia than nondiabetic women (15.6% vs 8.5%; P =.04). After glycemic optimization (mean +/- SD glycosylated hemoglobin decrease, 2.2 +/- 1.96 percentage points), the prevalence of LDL-C levels greater than 4.13 mmol/L (>160 mg/dL) became lower in diabetic men than in nondiabetic men (9.7% vs 17.5%; P =.04), but women showed frequencies of dyslipidemia similar to their nondiabetic counterparts. The proportion of patients with LDL-C concentrations requiring lifestyle (>2.6 mmol/L [>100 mg/dL]) or drug (>3.4 mmol/L [>130 mg/dL]) intervention decreased from 78% and 42% to 66% and 26%, respectively.

CONCLUSIONS: Low HDL-C is the most frequent dyslipidemic disorder in patients with poorly controlled insulin-treated type 1 diabetes, and a high proportion show LDL-C levels requiring intervention. Less favorable lipid profiles could explain the absence of sex protection in diabetic women. The improvement caused by glycemic optimization puts forward intensive therapy as the initial treatment of choice for dyslipidemia in poorly controlled type 1 diabetes.