Lipoprotein(a) and diet: consuming sugar-sweetened beverages lowers lipoprotein(a) levels in obese and overweight adults

Abstract

Lipoprotein(a) [Lp(a)] contributes to cardiovascular disease risk. A genetically determined size polymorphism in apolipoprotein(a) [apo(a)], determined by the number of Kringle (K) repeats, inversely regulates Lp(a) levels. Nongenetic factors including dietary saturated fat influence Lp(a) levels. However, less is known about the effects of carbohydrates including dietary sugars. In this double-blind, parallel arm study among 32 overweight/obese adults, we investigated the effect of consuming glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 weeks on Lp(a) level and assessed the role of the apo(a) size polymorphism. The mean (±SD) age of participants was 54 ± 8 years, 50% were women, and 75% were of European descent. Following the 10-week intervention, Lp(a) level was reduced by an average (±SEM) of -13.2% ± 4.3% in all participants (P = 0.005); -15.3% ± 7.8% in the 15 participants who consumed glucose (P = 0.07); and -11.3% ± 4.5% in the 17 participants who consumed fructose (P = 0.02), without any significant difference in the effect between the two sugar groups. Relative changes in Lp(a) levels were similar across subgroups of lower versus higher baseline Lp(a) level or carrier versus noncarrier of an atherogenic small (≤22K) apo(a) size. In contrast, LDL-C increased. In conclusion, in older, overweight/obese adults, consuming sugar-sweetened beverages reduced Lp(a) levels by ∼13% independently of apo(a) size variability and the type of sugar consumed. The Lp(a) response was opposite to that of LDL-C and triglyceride concentrations. These findings suggest that metabolic pathways might impact Lp(a) levels.

Trial registration: ClinicalTrials.gov NCT01165853.

Keywords: Lp(a) metabolism; apolipoprotein; fructose; glucose; nutrition.

Fig. 1

Opposite effects of consuming sugar-sweetened beverages on directly measured fasting LDL-C versus Lp(a) concentrations in all participants and by sugar types. Data are shown as mean (SEM) percent change in Lp(a) and directly measured LDL-C concentrations from baseline to week 10. Graphs are based on data from 32 participants for all, 15 participants for the glucose, and 17 participants for the fructose groups. a: P < 0.05; b: P < 0.01. Lp(a), lipoprotein(a).

Fig. 2

Individual responses of Lp(a) and directly measured LDL-C concentrations to sugar-sweetened beverages consumption in all participants and by sugar types. Data are shown as percent change in Lp(a) and directly measured LDL-C concentrations from baseline to week 10. Graphs are based on data from 32 participants for all (top panel), 15 participants for the glucose (bottom left panel), and 17 participants for the fructose (bottom right panel) groups. Lp(a), lipoprotein(a).