Glycaemic index and glycaemic load in relation to blood lipids - 6 years of follow-up in adult Danish men and women

BACKGROUND: Cross-sectional studies have suggested an association between glycaemic index (GI) or glycaemic load (GL) and serum lipids. However, no prospective studies have been performed.

OBJECTIVE: To examine whether GI or GL was associated with subsequent changes in serum lipids.

DESIGN: Prospective study with 6 years of follow-up. Overall dietary GI and GL of each participant were assessed from diet history interviews.

SETTING: Population-based study. Subjects Three hundred and thirty-five healthy men and women aged 35-65 years selected randomly from a larger sample of Danish adults.

RESULTS: In men GI was directly related to changes in total cholesterol (DeltaTC), regression coefficient (beta) = 0.0044 (95% confidence interval (CI): 0.0008-0.0081) and GL was positively related to changes in low-density lipoprotein cholesterol (DeltaLDL), beta = 0.1554 (95% CI: 0.0127-0.2982). Furthermore, the relationship between GL and DeltaTC was modified by age, being particularly strong for the younger men (P = 0.02). In women the relationship between GI and DeltaLDL was modified by age and was stronger for younger rather than older women (P = 0.01). A tendency for a similar interaction was seen for GI and DeltaTC (P = 0.09). Associations between GL and DeltaLDL and GL and DeltaTC were inverse for women with body mass index > or = 30 kg m(-2) (P = 0.03 and 0.04, respectively).

CONCLUSIONS: This is the first study to demonstrate that dietary GI and GL are related to 6-year changes in serum lipid levels. However, associations were weak and generally confined to subgroups.