Hypercholesterolaemia in anorexia nervosa: frequency and changes during refeeding.

Area of Science:

• Endocrinology and Metabolism
• Nutritional Psychiatry

Background:

• Elevated total cholesterol (TC) is frequently observed in patients with anorexia nervosa (AN), but the underlying mechanisms are not fully understood.
• Lipoprotein (LP) metabolism plays a crucial role in cholesterol transport and is potentially altered in malnutrition states like AN.

Purpose of the Study:

• To investigate the mechanisms behind high total cholesterol (TC) in anorexia nervosa (AN) by examining plasma lipoprotein (LP) profiles.
• To compare LP levels and related parameters in AN patients, malnourished non-AN patients, and healthy controls.

Main Methods:

• Prospective study involving 120 adult AN patients, 116 malnourished non-AN patients, and 119 healthy controls, matched for age and gender.
• Analysis of plasma lipoprotein (LP), haptoglobin, free T3 (fT3), free T4 (fT4), TSH, transthyretin, and albumin levels.
• Assessment of body mass index (BMI) and categorization of AN subtypes (restrictive vs. binge-purge).

Main Results:

• AN patients showed significantly higher TC, LDL-C, HDL-C, and HDL2 levels compared to non-AN patients.
• A biphasic LP profile was observed in AN patients: low levels at very low BMI (<13 kg/m²), normal levels at intermediate BMI, and high levels at the highest BMI, particularly with bulimic behaviors.
• Cholesterol ester transfer protein (CETP) activity was elevated in AN patients, suggesting increased cholesterol turnover.

Conclusions:

• Anorexia nervosa is associated with complex lipoprotein profiles, including both high and low levels, influenced by nutritional status and eating behaviors.
• Low T3 and reduced catabolism may help maintain LP levels, while increased CETP activity attempts to adapt to low cholesterol intake.
• Recovery from AN leads to the normalization of lipoprotein profiles, indicating the reversibility of these metabolic changes.