Relationship between serum cholesterol and Graves' orbitopathy (GO): a confirmatory study.

BACKGROUND: It has been suggested that high cholesterol represents a risk factor for Graves' orbitopathy (GO). In a recent cross-sectional study, a correlation between cholesterol and the presence of GO was found in patients with a Graves' disease (GD) of recent onset. To confirm this observation, we conducted a retrospective investigation in consecutive patients with GD. The primary outcome was the relationship between the presence of GO and low-density lipoprotein (LDL)-cholesterol.

METHODS: The design entailed the inclusion of consecutive patients with a GD of recent onset, with or without GO, who came to our observation to receive radioiodine over a period of 6 months, and a stratification aimed at having two homogeneous group of patients in terms of thyroid function. A total of 86 patients fulfilled the inclusion and evaded the exclusion criteria. All patients underwent an ophthalmological assessment and serum lipids were measured.

RESULTS: Serum levels of LDL-cholesterol were significantly higher in patients with GO (135.3 ± 41.3 mg/dL) compared with those without GO (106.6 ± 23.9 mg/dL, P = 0.0007). In a similar manner, serum levels of total cholesterol were higher in patients with GO (211.6 ± 44.0 mg/dL) than in those without GO (176.0 ± 27.2 mg/dL, P = 0.0001). There was no relationship between GO severity and activity and cholesterol. There was no relationship between GO and high-density lipoprotein-cholesterol or triglycerides.

CONCLUSIONS: Our study confirms a relationship between the presence of GO and cholesterol in patients with GD of recent onset. Whether lowering of cholesterol ameliorates, GO remains to be established.