Changes in sodium-lithium countertransport correlate with changes in triglyceride levels and body mass index over 2 1/2 years of follow-up in Utah.

We have previously reported from a cross-sectional study that plasma total cholesterol, triglycerides, and HDL-C were significantly and independently correlated with Na(+)-Li+ countertransport. These original participants were rescreened 2 1/2 years later (range of 20-58 months), with lipid, blood pressure, and Na(+)-Li+ countertransport measurements from both visits on 906 normotensive adults. The correlation found between age- and sex-adjusted triglyceride levels and Na(+)-Li+ countertransport at visit 1 (r = 0.34, p less than 0.0001) was reconfirmed at visit 2 (r = 0.32, p less than 0.0001). The Na(+)-Li+ countertransport correlations with HDL-C (r = -0.11, p less than 0.01) and body mass index (r = 0.24, p less than 0.0001) also remained at visit 2. After 30 months, there were significant increases of triglyceride, body mass index, blood pressure, and Na(+)-Li+ countertransport levels, and significant decreases of HDL-C and total cholesterol levels, after adjusting the changes in these variables between visit 2 and visit 1 for age, sex, time between the two visits, and the visit 1 level of the variable. Increases in triglycerides, cholesterol, and body mass index were significantly correlated with increases in Na(+)-Li+ countertransport (r = 0.23, r = 0.19, and r = 0.21, respectively). The correlations of the lipid and lipoprotein changes with Na(+)-Li+ countertransport changes were independent of body mass index and blood pressure changes. We conclude that increasing plasma triglyceride levels and body mass index are associated with increasing Na(+)-Li+ countertransport levels in both cross-sectional and longitudinal data.