Effects of a 2-y dietary weight-loss intervention on cholesterol metabolism in moderately obese men.

Abstract

BACKGROUND:

Long-term dietary weight loss results in complex metabolic changes. However, its effect on cholesterol metabolism in obese subjects is still unclear.

OBJECTIVE:

We assessed the effects of 2 y of weight loss achieved with various diet regimens on phytosterols (markers of intestinal cholesterol absorption), lanosterol (marker of de novo cholesterol synthesis), and changes in apolipoprotein concentrations.

DESIGN:

We conducted the 2-y Dietary Intervention Randomized Controlled Trial (DIRECT-a study of low-fat, Mediterranean, and low-carbohydrate diets). We assessed circulating phytosterol and lanosterol concentrations and their ratios to cholesterol and apolipoproteins A-I and B-100 in 90 DIRECT participants at 0, 6, and 24 mo.

RESULTS:

We observed a significant upregulation of the markers of cholesterol absorption (campesterol: +16.8%, P < 0.001) and a downregulation of the markers of cholesterol synthesis (lanosterol: -16.5%, P = 0.008) during the active weight-loss phase (first 6 mo, weight loss of 5%, 6%, and 10% in the 3 diet groups, respectively), followed by a rebound (campesterol: -6.2%, P = 0.045; lanosterol: +43.7%, P < 0.001) during the next 18 mo (weight gain of 1%, 1%, and 2% in the 3 diet groups, respectively). HDL cholesterol continuously increased during the study (17.0%, P < 0.001), whereas LDL cholesterol remained constant. At the end of the 24-mo follow-up period, campesterol (P < 0.001) and lanosterol (P = 0.016) amounts were significantly higher than baseline values. The concentration of apolipoprotein B-100 correlated with cholesterol metabolism (ρ = 0.299 and P = 0.020 for lanosterol; ρ = -0.105 and NS for campesterol), and the homeostasis model assessment of insulin resistance correlated with lanosterol (ρ = 0.09, P = 0.001).

CONCLUSIONS:

Long-term weight loss is related to a characteristic response suggestive of altered cholesterol and apolipoprotein metabolism. Various diets have a similar effect on these effects. DIRECT is registered at clinicaltrials.gov as NCT00160108.

• Authors: Alexander B Leichtle, Christin Helmschrodt, Uta Ceglarek, Iris Shai, Yaakov Henkin, Dan Schwarzfuchs, Rachel Golan, Yftach Gepner, Meir J Stampfer, Matthias Blüher, Michael Stumvoll, Joachim Thiery, Georg M Fiedler
• Journal: The American journal of clinical nutrition (Am J Clin Nutr) Vol. 94 Issue 5 Pg. 1189-95 (Nov 2011) ISSN: 1938-3207 [Electronic] United States
• PMID: 21940598 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Apolipoprotein A-I
• Apolipoprotein B-100
• Phytosterols
• Lanosterol
• Cholesterol

Topics

• Adult
• Apolipoprotein A-I (blood)
• Apolipoprotein B-100 (blood)
• Body Weight (physiology)
• Cholesterol (metabolism)
• Diet, Reducing (methods, standards)
• Humans
• Lanosterol (blood)
• Male
• Middle Aged
• Obesity (blood, diet therapy, metabolism)
• Phytosterols (blood)
• Statistics, Nonparametric
• Weight Loss (physiology)