Certain Apolipoproteins Are Associated With Risk for Metabolic Syndrome

Apolipoprotein levels are associated with the presence of metabolic syndrome, according to findings published in Lipids in Health and Disease.

Metabolic syndrome (MetS) is associated with an increased risk of various pathologies, with a 1.5 higher risk of all-cause mortality. Additionally, the prevalence of MetS in the United States has increased from 28.23% in 1999 to 37.09% in 2018. Apolipoproteins have been associated with MetS, however sufficient data has been lacking. Researchers investigated the association of MetS with various apolipoproteins, notably ApoA1, ApoB, ApoB/A1 ratio and lipoprotein(a) [Lp(a)].

A systematic review and meta-analysis was conducted using cohort/case-control/cross-sectional studies that evaluated the association of apolipoproteins of interest and metabolic syndrome in adult patients aged older than 18 years. Databases utilized included PubMed, Scopus, Embase, Ovid/Medline, and Web of Science. Systematic reviews, narrative reviews, and conference abstracts were excluded from the study.

The researchers identified 2,262 studies in the search, that of which 50 were eligible for inclusion in the meta-analysis. The total cohort consisted of 150,519 participants, of which 62,083 were women and 77,958 were men.

Twenty-nine studies assessed the association of ApoB and the presence of MetS; increased values were associated with a higher risk for MetS (OR, 2.8; 95% CI: 2.44-3.22; P <.01, I²=99%). Subgroup analysis found high heterogeneity across all subgroups, indicating that the association persisted through all various subgroups. Similarly, reduced ApoA1 values were associated with a lower risk for MetS (OR, 0.42, 95% CI: 0.38-0.47, P <.01, I²=99%), as evidenced from 28 studies.

With regards to the ApoB/ApoA1 ratio levels, increased values were associated with MetS (OR, 4.97; 95% CI: 3.83-6.44; P <.01, I²=97%). Of note, a decrease in Lp(a) values was associated with a decreased risk for MetS (OR, 0.89; 95% CI: 0.82-0.96; P <.01, I²=92%).

Limitations of the study include variability among studies (clinical/methodological), which the study authors did not take into account for, as evidenced by the high heterogeneity after subgroup analysis. As most studies that were included in the meta-analysis were cross-sectional, there is a risk of reverse causality as well.

“These findings suggest that these lipid markers may serve as potential indicators for identifying subjects at risk of developing MetS,” the study authors wrote. “However, additional studies are warranted to gain a deeper understanding of the underlying mechanisms driving these associations.”