Atherogenic Index of Plasma and the Gamma Gap: Considerations by Physical Activity

Abstract Background Atherogenic index of plasma (AIP), calculated as log(triglycerides/high-density lipoprotein-cholesterol), is utilized to predict risk of cardiovascular disease. An elevated (≥ 3.1 g/dl) gamma gap (Total Protein (g/dl) – Albumin (g/dl)) is associated with cardiovascular disease. No previous studies have evaluated the association between AIP and the gamma gap. Consequentially, the purpose of this study was to explore this association, with considerations by moderate-to-vigorous physical activity (MVPA), which may plausibly be associated with both AIP and gamma gap. Methods Data from the 1999–2006 National Health and Nutrition Examination Survey were used (N = 6681 adults 20–85 yrs). AIP was assessed from a blood sample, physical activity was self-reported via a survey assessing leisure-time physical activity over the previous 30-days, and the gamma gap was evaluated by subtracting albumin from total protein using the Hitachi Model 704 multichannel analyzer. Results Participants with an elevated (> 0.24 vs. < 0.25 mmol/L) AIP had a 27% increased odds of having an elevated gamma gap (odds ratio [OR] = 1.27; 95% CI: 1.04–1.55; P = 0.01; N = 6681). AIP was significantly, positively associated with increased odds for an elevated gamma gap among those meeting MVPA guidelines (for a 1 mmol/L increase in AIP: OR = 2.57; 95% CI: 1.54–4.27; P < 0.001; N = 2688) and those not meeting MVPA guidelines (for a 1 mmol/L increase in AIP: OR = 1.70; 95% CI: 1.19–2.42; P = 0.004; N = 3993). Conclusion AIP and gamma gap are positively associated, however MVPA does not appear to influence this association.